update changelog for release v0.4.2-alpha [no ci]

* fix videotoolbox acceleration with new transcoder

* cleanup

CHANGELOG.md

@@ -5,6 +5,24 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 
 ## [Unreleased]
 
+## [0.4.2-alpha] - 2022-02-26
+### Fixed
+- Add improved but experimental transcoder logic, which can be toggled on and off in `Settings`
+- Fix `HLS Segmenter` bug when source video packet contains no duration (`N/A`)
+- Fix green line at the bottom of some content scaled using QSV acceleration
+
+### Added
+- Add configurable channel group (M3U) and categories (XMLTV)
+- Add `Shuffle Schedule Items` option to schedule configuration
+  - When this is enabled, schedule items will be shuffled rather than looped in order
+  - **To support this, all playouts will be rebuilt (one time) after upgrading to this version**
+
+### Changed
+- Disable framerate normalization by default and on all ffmpeg profiles
+  - If framerate normalization is desired (not typically needed), it can be re-enabled manually
+- Show watermarks over songs
+- Hide unused local libraries
+
 ## [0.4.1-alpha] - 2022-02-10
 ### Fixed
 - Normalize smart quotes in search queries as they are unsupported by the search library
@@ -967,7 +985,8 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Initial release to facilitate testing outside of Docker.
 
 
-[Unreleased]: https://github.com/jasongdove/ErsatzTV/compare/v0.4.1-alpha...HEAD
+[Unreleased]: https://github.com/jasongdove/ErsatzTV/compare/v0.4.2-alpha...HEAD
+[0.4.2-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.4.1-alpha...v0.4.2-alpha
 [0.4.1-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.4.0-alpha...v0.4.1-alpha
 [0.4.0-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.3.8-alpha...v0.4.0-alpha
 [0.3.8-alpha]: https://github.com/jasongdove/ErsatzTV/compare/v0.3.7-alpha...v0.3.8-alpha

ErsatzTV.Application/Channels/ChannelViewModel.cs

@@ -6,6 +6,8 @@ namespace ErsatzTV.Application.Channels
         int Id,
         string Number,
         string Name,
+        string Group,
+        string Categories,
         int FFmpegProfileId,
         string Logo,
         string PreferredLanguageCode,

ErsatzTV.Application/Channels/Commands/CreateChannel.cs

@@ -9,6 +9,8 @@ namespace ErsatzTV.Application.Channels.Commands
     (
         string Name,
         string Number,
+        string Group,
+        string Categories,
         int FFmpegProfileId,
         string Logo,
         string PreferredLanguageCode,

ErsatzTV.Application/Channels/Commands/CreateChannelHandler.cs

@@ -27,7 +27,7 @@ namespace ErsatzTV.Application.Channels.Commands
             CreateChannel request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
             Validation<BaseError, Channel> validation = await Validate(dbContext, request);
             return await validation.Apply(c => PersistChannel(dbContext, c));
         }
@@ -65,6 +65,8 @@ namespace ErsatzTV.Application.Channels.Commands
                     {
                         Name = name,
                         Number = number,
+                        Group = request.Group,
+                        Categories = request.Categories,
                         FFmpegProfileId = ffmpegProfileId,
                         StreamingMode = request.StreamingMode,
                         Artwork = artwork,

ErsatzTV.Application/Channels/Commands/UpdateChannel.cs

@@ -10,6 +10,8 @@ namespace ErsatzTV.Application.Channels.Commands
         int ChannelId,
         string Name,
         string Number,
+        string Group,
+        string Categories,
         int FFmpegProfileId,
         string Logo,
         string PreferredLanguageCode,

ErsatzTV.Application/Channels/Commands/UpdateChannelHandler.cs

@@ -28,7 +28,7 @@ namespace ErsatzTV.Application.Channels.Commands
             UpdateChannel request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
             Validation<BaseError, Channel> validation = await Validate(dbContext, request);
             return await validation.Apply(c => ApplyUpdateRequest(dbContext, c, request));
         }
@@ -37,6 +37,8 @@ namespace ErsatzTV.Application.Channels.Commands
         {
             c.Name = update.Name;
             c.Number = update.Number;
+            c.Group = update.Group;
+            c.Categories = update.Categories;
             c.FFmpegProfileId = update.FFmpegProfileId;
             c.PreferredLanguageCode = update.PreferredLanguageCode;
             c.Artwork ??= new List<Artwork>();

ErsatzTV.Application/Channels/Mapper.cs

@@ -11,6 +11,8 @@ namespace ErsatzTV.Application.Channels
                 channel.Id,
                 channel.Number,
                 channel.Name,
+                channel.Group,
+                channel.Categories,
                 channel.FFmpegProfileId,
                 GetLogo(channel),
                 channel.PreferredLanguageCode,

ErsatzTV.Application/FFmpegProfiles/Commands/UpdateFFmpegSettingsHandler.cs

@@ -85,6 +85,10 @@ namespace ErsatzTV.Application.FFmpegProfiles.Commands
                 Directory.CreateDirectory(FileSystemLayout.FFmpegReportsFolder);
             }
 
+            await _configElementRepository.Upsert(
+                ConfigElementKey.FFmpegUseExperimentalTranscoder,
+                request.Settings.UseExperimentalTranscoder.ToString());
+
             await _configElementRepository.Upsert(
                 ConfigElementKey.FFmpegPreferredLanguageCode,
                 request.Settings.PreferredLanguageCode);

ErsatzTV.Application/FFmpegProfiles/FFmpegSettingsViewModel.cs

@@ -12,5 +12,6 @@
         public int HlsSegmenterIdleTimeout { get; set; }
         public int WorkAheadSegmenterLimit { get; set; }
         public int InitialSegmentCount { get; set; }
+        public bool UseExperimentalTranscoder { get; set; }
     }
 }

ErsatzTV.Application/FFmpegProfiles/Queries/GetFFmpegSettingsHandler.cs

@@ -36,6 +36,8 @@ namespace ErsatzTV.Application.FFmpegProfiles.Queries
                 await _configElementRepository.GetValue<int>(ConfigElementKey.FFmpegWorkAheadSegmenters);
             Option<int> initialSegmentCount =
                 await _configElementRepository.GetValue<int>(ConfigElementKey.FFmpegInitialSegmentCount);
+            Option<bool> useExperimentalTranscoder =
+                await _configElementRepository.GetValue<bool>(ConfigElementKey.FFmpegUseExperimentalTranscoder);
 
             var result = new FFmpegSettingsViewModel
             {
@@ -46,7 +48,8 @@ namespace ErsatzTV.Application.FFmpegProfiles.Queries
                 PreferredLanguageCode = await preferredLanguageCode.IfNoneAsync("eng"),
                 HlsSegmenterIdleTimeout = await hlsSegmenterIdleTimeout.IfNoneAsync(60),
                 WorkAheadSegmenterLimit = await workAheadSegmenterLimit.IfNoneAsync(1),
-                InitialSegmentCount = await initialSegmentCount.IfNoneAsync(1)
+                InitialSegmentCount = await initialSegmentCount.IfNoneAsync(1),
+                UseExperimentalTranscoder = await useExperimentalTranscoder.IfNoneAsync(false)
             };
 
             foreach (int watermarkId in watermark)

ErsatzTV.Application/Libraries/Queries/GetConfiguredLibraries.cs

@@ -3,5 +3,5 @@ using MediatR;
 
 namespace ErsatzTV.Application.Libraries.Queries
 {
-    public record GetAllLibraries : IRequest<List<LibraryViewModel>>;
+    public record GetConfiguredLibraries : IRequest<List<LibraryViewModel>>;
 }

ErsatzTV.Application/Libraries/Queries/GetConfiguredLibrariesHandler.cs

@@ -10,13 +10,16 @@ using static ErsatzTV.Application.Libraries.Mapper;
 
 namespace ErsatzTV.Application.Libraries.Queries
 {
-    public class GetAllLibrariesHandler : IRequestHandler<GetAllLibraries, List<LibraryViewModel>>
+    public class GetConfiguredLibrariesHandler : IRequestHandler<GetConfiguredLibraries, List<LibraryViewModel>>
     {
         private readonly ILibraryRepository _libraryRepository;
 
-        public GetAllLibrariesHandler(ILibraryRepository libraryRepository) => _libraryRepository = libraryRepository;
+        public GetConfiguredLibrariesHandler(ILibraryRepository libraryRepository) =>
+            _libraryRepository = libraryRepository;
 
-        public Task<List<LibraryViewModel>> Handle(GetAllLibraries request, CancellationToken cancellationToken) =>
+        public Task<List<LibraryViewModel>> Handle(
+            GetConfiguredLibraries request,
+            CancellationToken cancellationToken) =>
             _libraryRepository.GetAll()
                 .Map(
                     list => list.Filter(ShouldIncludeLibrary)
@@ -28,7 +31,7 @@ namespace ErsatzTV.Application.Libraries.Queries
         private static bool ShouldIncludeLibrary(Library library) =>
             library switch
             {
-                LocalLibrary => true,
+                LocalLibrary => library.Paths.Count > 0,
                 PlexLibrary plex => plex.ShouldSyncItems,
                 JellyfinLibrary jellyfin => jellyfin.ShouldSyncItems,
                 EmbyLibrary emby => emby.ShouldSyncItems,

ErsatzTV.Application/ProgramSchedules/Commands/CreateProgramSchedule.cs

@@ -8,5 +8,6 @@ namespace ErsatzTV.Application.ProgramSchedules.Commands
     public record CreateProgramSchedule(
         string Name,
         bool KeepMultiPartEpisodesTogether,
-        bool TreatCollectionsAsShows) : IRequest<Either<BaseError, CreateProgramScheduleResult>>;
+        bool TreatCollectionsAsShows,
+        bool ShuffleScheduleItems) : IRequest<Either<BaseError, CreateProgramScheduleResult>>;
 }

ErsatzTV.Application/ProgramSchedules/Commands/CreateProgramScheduleHandler.cs

@@ -50,7 +50,8 @@ namespace ErsatzTV.Application.ProgramSchedules.Commands
                     {
                         Name = name,
                         KeepMultiPartEpisodesTogether = keepMultiPartEpisodesTogether,
-                        TreatCollectionsAsShows = keepMultiPartEpisodesTogether && request.TreatCollectionsAsShows
+                        TreatCollectionsAsShows = keepMultiPartEpisodesTogether && request.TreatCollectionsAsShows,
+                        ShuffleScheduleItems = request.ShuffleScheduleItems
                     };
                 });
 

ErsatzTV.Application/ProgramSchedules/Commands/UpdateProgramSchedule.cs

@@ -10,5 +10,6 @@ namespace ErsatzTV.Application.ProgramSchedules.Commands
         int ProgramScheduleId,
         string Name,
         bool KeepMultiPartEpisodesTogether,
-        bool TreatCollectionsAsShows) : IRequest<Either<BaseError, UpdateProgramScheduleResult>>;
+        bool TreatCollectionsAsShows,
+        bool ShuffleScheduleItems) : IRequest<Either<BaseError, UpdateProgramScheduleResult>>;
 }

ErsatzTV.Application/ProgramSchedules/Commands/UpdateProgramScheduleHandler.cs

@@ -31,7 +31,7 @@ namespace ErsatzTV.Application.ProgramSchedules.Commands
             UpdateProgramSchedule request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
 
             Validation<BaseError, ProgramSchedule> validation = await Validate(dbContext, request);
             return await validation.Apply(ps => ApplyUpdateRequest(dbContext, ps, request));
@@ -45,12 +45,14 @@ namespace ErsatzTV.Application.ProgramSchedules.Commands
             // we need to rebuild playouts if the playback order or keep multi-episodes has been modified
             bool needToRebuildPlayout =
                 programSchedule.KeepMultiPartEpisodesTogether != request.KeepMultiPartEpisodesTogether ||
-                programSchedule.TreatCollectionsAsShows != request.TreatCollectionsAsShows;
+                programSchedule.TreatCollectionsAsShows != request.TreatCollectionsAsShows ||
+                programSchedule.ShuffleScheduleItems != request.ShuffleScheduleItems;
 
             programSchedule.Name = request.Name;
             programSchedule.KeepMultiPartEpisodesTogether = request.KeepMultiPartEpisodesTogether;
             programSchedule.TreatCollectionsAsShows = programSchedule.KeepMultiPartEpisodesTogether &&
                                                       request.TreatCollectionsAsShows;
+            programSchedule.ShuffleScheduleItems = request.ShuffleScheduleItems;
 
             await dbContext.SaveChangesAsync();
 

ErsatzTV.Application/ProgramSchedules/Mapper.cs

@@ -10,7 +10,8 @@ namespace ErsatzTV.Application.ProgramSchedules
                 programSchedule.Id,
                 programSchedule.Name,
                 programSchedule.KeepMultiPartEpisodesTogether,
-                programSchedule.TreatCollectionsAsShows);
+                programSchedule.TreatCollectionsAsShows,
+                programSchedule.ShuffleScheduleItems);
 
         internal static ProgramScheduleItemViewModel ProjectToViewModel(ProgramScheduleItem programScheduleItem) =>
             programScheduleItem switch

ErsatzTV.Application/ProgramSchedules/ProgramScheduleViewModel.cs

@@ -4,5 +4,6 @@
         int Id,
         string Name,
         bool KeepMultiPartEpisodesTogether,
-        bool TreatCollectionsAsShows);
+        bool TreatCollectionsAsShows,
+        bool ShuffleScheduleItems);
 }

ErsatzTV.Application/ProgramSchedules/Queries/GetAllProgramSchedulesHandler.cs

@@ -25,7 +25,8 @@ namespace ErsatzTV.Application.ProgramSchedules.Queries
                         ps.Id,
                         ps.Name,
                         ps.KeepMultiPartEpisodesTogether,
-                        ps.TreatCollectionsAsShows))
+                        ps.TreatCollectionsAsShows,
+                        ps.ShuffleScheduleItems))
                 .ToListAsync(cancellationToken);
         }
     }

ErsatzTV.Application/ProgramSchedules/Queries/GetProgramScheduleByIdHandler.cs

@@ -21,7 +21,7 @@ namespace ErsatzTV.Application.ProgramSchedules.Queries
             GetProgramScheduleById request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
             return await dbContext.ProgramSchedules
                 .SelectOneAsync(ps => ps.Id, ps => ps.Id == request.Id)
                 .MapT(ProjectToViewModel);

ErsatzTV.Application/ProgramSchedules/Queries/GetProgramScheduleItemsHandler.cs

@@ -4,6 +4,7 @@ using System.Threading;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Infrastructure.Data;
+using ErsatzTV.Infrastructure.Extensions;
 using LanguageExt;
 using MediatR;
 using Microsoft.EntityFrameworkCore;
@@ -23,7 +24,11 @@ namespace ErsatzTV.Application.ProgramSchedules.Queries
             GetProgramScheduleItems request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+            Option<ProgramSchedule> maybeProgramSchedule =
+                await dbContext.ProgramSchedules.SelectOneAsync(ps => ps.Id, ps => ps.Id == request.Id);
+
             return await dbContext.ProgramScheduleItems
                 .Filter(psi => psi.ProgramScheduleId == request.Id)
                 .Include(i => i.Collection)
@@ -51,7 +56,29 @@ namespace ErsatzTV.Application.ProgramSchedules.Queries
                 .Include(i => i.TailFiller)
                 .Include(i => i.FallbackFiller)
                 .ToListAsync(cancellationToken)
-                .Map(programScheduleItems => programScheduleItems.Map(ProjectToViewModel).ToList());
+                .Map(
+                    programScheduleItems => programScheduleItems.Map(ProjectToViewModel)
+                        .Map(psi => EnforceProperties(maybeProgramSchedule, psi)).ToList());
+        }
+
+        // shuffled schedule items supports a limited set of properly values
+        private ProgramScheduleItemViewModel EnforceProperties(
+            Option<ProgramSchedule> maybeProgramSchedule,
+            ProgramScheduleItemViewModel item)
+        {
+            foreach (ProgramSchedule programSchedule in maybeProgramSchedule)
+            {
+                if (programSchedule.ShuffleScheduleItems)
+                {
+                    item = item with { StartType = StartType.Dynamic };
+                    if (item.PlayoutMode == PlayoutMode.Flood)
+                    {
+                        item = item with { PlayoutMode = PlayoutMode.One };
+                    }
+                }
+            }
+
+            return item;
         }
     }
 }

ErsatzTV.Application/Streaming/Commands/StartFFmpegSessionHandler.cs

@@ -22,6 +22,7 @@ namespace ErsatzTV.Application.Streaming.Commands
         private readonly IServiceScopeFactory _serviceScopeFactory;
         private readonly IFFmpegSegmenterService _ffmpegSegmenterService;
         private readonly IConfigElementRepository _configElementRepository;
+        private readonly IHlsPlaylistFilter _hlsPlaylistFilter;
         private readonly ILocalFileSystem _localFileSystem;
 
         public StartFFmpegSessionHandler(
@@ -29,13 +30,15 @@ namespace ErsatzTV.Application.Streaming.Commands
             ILogger<StartFFmpegSessionHandler> logger,
             IServiceScopeFactory serviceScopeFactory,
             IFFmpegSegmenterService ffmpegSegmenterService,
-            IConfigElementRepository configElementRepository)
+            IConfigElementRepository configElementRepository,
+            IHlsPlaylistFilter hlsPlaylistFilter)
         {
             _localFileSystem = localFileSystem;
             _logger = logger;
             _serviceScopeFactory = serviceScopeFactory;
             _ffmpegSegmenterService = ffmpegSegmenterService;
             _configElementRepository = configElementRepository;
+            _hlsPlaylistFilter = hlsPlaylistFilter;
         }
 
         public Task<Either<BaseError, Unit>> Handle(StartFFmpegSession request, CancellationToken cancellationToken) =>
@@ -78,7 +81,7 @@ namespace ErsatzTV.Application.Streaming.Commands
             return Unit.Default;
         }
 
-        private static async Task WaitForPlaylistSegments(string playlistFileName, int initialSegmentCount, IHlsSessionWorker worker)
+        private async Task WaitForPlaylistSegments(string playlistFileName, int initialSegmentCount, IHlsSessionWorker worker)
         {
             while (!File.Exists(playlistFileName))
             {
@@ -92,7 +95,7 @@ namespace ErsatzTV.Application.Streaming.Commands
                 
                 DateTimeOffset now = DateTimeOffset.Now.AddSeconds(-30);
                 string[] input = await File.ReadAllLinesAsync(playlistFileName);
-                TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(worker.PlaylistStart, now, input);
+                TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(worker.PlaylistStart, now, input);
                 segmentCount = result.SegmentCount;
             }
         }

ErsatzTV.Application/Streaming/HlsSessionWorker.cs

@@ -24,6 +24,7 @@ namespace ErsatzTV.Application.Streaming
     public class HlsSessionWorker : IHlsSessionWorker
     {
         private static int _workAheadCount;
+        private readonly IHlsPlaylistFilter _hlsPlaylistFilter;
         private readonly IServiceScopeFactory _serviceScopeFactory;
         private readonly ILogger<HlsSessionWorker> _logger;
         private DateTimeOffset _lastAccess;
@@ -33,8 +34,9 @@ namespace ErsatzTV.Application.Streaming
         private DateTimeOffset _playlistStart;
         private Option<int> _targetFramerate;
 
-        public HlsSessionWorker(IServiceScopeFactory serviceScopeFactory, ILogger<HlsSessionWorker> logger)
+        public HlsSessionWorker(IHlsPlaylistFilter hlsPlaylistFilter, IServiceScopeFactory serviceScopeFactory, ILogger<HlsSessionWorker> logger)
         {
+            _hlsPlaylistFilter = hlsPlaylistFilter;
             _serviceScopeFactory = serviceScopeFactory;
             _logger = logger;
         }
@@ -123,7 +125,11 @@ namespace ErsatzTV.Application.Streaming
             }
         }
 
-        private async Task<bool> Transcode(string channelNumber, bool firstProcess, bool realtime, CancellationToken cancellationToken)
+        private async Task<bool> Transcode(
+            string channelNumber,
+            bool firstProcess,
+            bool realtime,
+            CancellationToken cancellationToken)
         {
             try
             {
@@ -212,7 +218,7 @@ namespace ErsatzTV.Application.Streaming
 
             return true;
         }
-        
+
         private async Task TrimAndDelete(string channelNumber, CancellationToken cancellationToken)
         {
             string playlistFileName = Path.Combine(
@@ -224,7 +230,7 @@ namespace ErsatzTV.Application.Streaming
             {
                 // trim playlist and insert discontinuity before appending with new ffmpeg process
                 string[] lines = await File.ReadAllLinesAsync(playlistFileName, cancellationToken);
-                TrimPlaylistResult trimResult = HlsPlaylistFilter.TrimPlaylistWithDiscontinuity(
+                TrimPlaylistResult trimResult = _hlsPlaylistFilter.TrimPlaylistWithDiscontinuity(
                     _playlistStart,
                     DateTimeOffset.Now.AddMinutes(-1),
                     lines);
@@ -246,13 +252,13 @@ namespace ErsatzTV.Application.Streaming
                 var toDelete = allSegments.Filter(s => s.SequenceNumber < trimResult.Sequence).ToList();
                 // if (toDelete.Count > 0)
                 // {
-                    // _logger.LogInformation(
-                    //     "Deleting HLS segments {Min} to {Max} (less than {StartSequence})",
-                    //     toDelete.Map(s => s.SequenceNumber).Min(),
-                    //     toDelete.Map(s => s.SequenceNumber).Max(),
-                    //     trimResult.Sequence);
+                // _logger.LogInformation(
+                //     "Deleting HLS segments {Min} to {Max} (less than {StartSequence})",
+                //     toDelete.Map(s => s.SequenceNumber).Min(),
+                //     toDelete.Map(s => s.SequenceNumber).Max(),
+                //     trimResult.Sequence);
                 // }
-                    
+
                 foreach (Segment segment in toDelete)
                 {
                     File.Delete(segment.File);
@@ -261,7 +267,7 @@ namespace ErsatzTV.Application.Streaming
                 _playlistStart = trimResult.PlaylistStart;
             }
         }
-        
+
         private async Task<long> GetPtsOffset(IMediator mediator, string channelNumber, CancellationToken cancellationToken)
         {
             var directory = new DirectoryInfo(Path.Combine(FileSystemLayout.TranscodeFolder, channelNumber));

ErsatzTV.Application/Streaming/PtsAndDuration.cs

@@ -6,7 +6,11 @@ public record PtsAndDuration(long Pts, long Duration)
     {
         string[] split = ffprobeLine.Split("|");
         var left = long.Parse(split[0]);
-        var right = long.Parse(split[1]);
+        if (!long.TryParse(split[1], out long right))
+        {
+            // some durations are N/A, so we have to guess at something
+            right = 10_000;
+        }
         return new PtsAndDuration(left, right);
     }
 }

ErsatzTV.Application/Streaming/Queries/GetConcatProcessByChannelNumberHandler.cs

@@ -3,6 +3,7 @@ using System.Diagnostics;
 using System.Threading.Tasks;
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
@@ -13,14 +14,14 @@ namespace ErsatzTV.Application.Streaming.Queries
 {
     public class GetConcatProcessByChannelNumberHandler : FFmpegProcessHandler<GetConcatProcessByChannelNumber>
     {
-        private readonly IFFmpegProcessService _ffmpegProcessService;
+        private readonly IFFmpegProcessServiceFactory _ffmpegProcessServiceFactory;
 
         public GetConcatProcessByChannelNumberHandler(
             IDbContextFactory<TvContext> dbContextFactory,
-            IFFmpegProcessService ffmpegProcessService)
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory)
             : base(dbContextFactory)
         {
-            _ffmpegProcessService = ffmpegProcessService;
+            _ffmpegProcessServiceFactory = ffmpegProcessServiceFactory;
         }
 
         protected override async Task<Either<BaseError, PlayoutItemProcessModel>> GetProcess(
@@ -33,7 +34,8 @@ namespace ErsatzTV.Application.Streaming.Queries
                 .GetValue<bool>(ConfigElementKey.FFmpegSaveReports)
                 .Map(result => result.IfNone(false));
 
-            Process process = _ffmpegProcessService.ConcatChannel(
+            IFFmpegProcessService ffmpegProcessService = await _ffmpegProcessServiceFactory.GetService();
+            Process process = ffmpegProcessService.ConcatChannel(
                 ffmpegPath,
                 saveReports,
                 channel,

ErsatzTV.Application/Streaming/Queries/GetPlayoutItemProcessByChannelNumberHandler.cs

@@ -8,6 +8,7 @@ using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Domain.Filler;
 using ErsatzTV.Core.Errors;
 using ErsatzTV.Core.Extensions;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.Emby;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Jellyfin;
@@ -30,15 +31,15 @@ namespace ErsatzTV.Application.Streaming.Queries
         private readonly IMediaCollectionRepository _mediaCollectionRepository;
         private readonly ITelevisionRepository _televisionRepository;
         private readonly IArtistRepository _artistRepository;
-        private readonly IFFmpegProcessService _ffmpegProcessService;
         private readonly IJellyfinPathReplacementService _jellyfinPathReplacementService;
+        private readonly IFFmpegProcessServiceFactory _ffmpegProcessServiceFactory;
         private readonly ILocalFileSystem _localFileSystem;
         private readonly IPlexPathReplacementService _plexPathReplacementService;
         private readonly ISongVideoGenerator _songVideoGenerator;
 
         public GetPlayoutItemProcessByChannelNumberHandler(
             IDbContextFactory<TvContext> dbContextFactory,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ILocalFileSystem localFileSystem,
             IPlexPathReplacementService plexPathReplacementService,
             IJellyfinPathReplacementService jellyfinPathReplacementService,
@@ -49,7 +50,7 @@ namespace ErsatzTV.Application.Streaming.Queries
             ISongVideoGenerator songVideoGenerator)
             : base(dbContextFactory)
         {
-            _ffmpegProcessService = ffmpegProcessService;
+            _ffmpegProcessServiceFactory = ffmpegProcessServiceFactory;
             _localFileSystem = localFileSystem;
             _plexPathReplacementService = plexPathReplacementService;
             _jellyfinPathReplacementService = jellyfinPathReplacementService;
@@ -111,6 +112,8 @@ namespace ErsatzTV.Application.Streaming.Queries
                 maybePlayoutItem = await CheckForFallbackFiller(dbContext, channel, now);
             }
 
+            IFFmpegProcessService ffmpegProcessService = await _ffmpegProcessServiceFactory.GetService();
+
             return await maybePlayoutItem.Match(
                 async playoutItemWithPath =>
                 {
@@ -141,7 +144,7 @@ namespace ErsatzTV.Application.Streaming.Queries
                         .GetValue<bool>(ConfigElementKey.FFmpegSaveReports)
                         .Map(result => result.IfNone(false));
 
-                    Process process = await _ffmpegProcessService.ForPlayoutItem(
+                    Process process = await ffmpegProcessService.ForPlayoutItem(
                         ffmpegPath,
                         saveReports,
                         channel,
@@ -190,7 +193,7 @@ namespace ErsatzTV.Application.Streaming.Queries
                         case UnableToLocatePlayoutItem:
                             if (channel.FFmpegProfile.Transcode)
                             {
-                                Process errorProcess = await _ffmpegProcessService.ForError(
+                                Process errorProcess = await ffmpegProcessService.ForError(
                                     ffmpegPath,
                                     channel,
                                     maybeDuration,
@@ -210,7 +213,7 @@ namespace ErsatzTV.Application.Streaming.Queries
                         case PlayoutItemDoesNotExistOnDisk:
                             if (channel.FFmpegProfile.Transcode)
                             {
-                                Process errorProcess = await _ffmpegProcessService.ForError(
+                                Process errorProcess = await ffmpegProcessService.ForError(
                                     ffmpegPath,
                                     channel,
                                     maybeDuration,
@@ -230,7 +233,7 @@ namespace ErsatzTV.Application.Streaming.Queries
                         default:
                             if (channel.FFmpegProfile.Transcode)
                             {
-                                Process errorProcess = await _ffmpegProcessService.ForError(
+                                Process errorProcess = await ffmpegProcessService.ForError(
                                     ffmpegPath,
                                     channel,
                                     maybeDuration,

ErsatzTV.Application/Streaming/Queries/GetWrappedProcessByChannelNumberHandler.cs

@@ -3,6 +3,7 @@ using System.Diagnostics;
 using System.Threading.Tasks;
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Infrastructure.Data;
 using ErsatzTV.Infrastructure.Extensions;
@@ -13,14 +14,14 @@ namespace ErsatzTV.Application.Streaming.Queries
 {
     public class GetWrappedProcessByChannelNumberHandler : FFmpegProcessHandler<GetWrappedProcessByChannelNumber>
     {
-        private readonly IFFmpegProcessService _ffmpegProcessService;
+        private readonly IFFmpegProcessServiceFactory _ffmpegProcessServiceFactory;
 
         public GetWrappedProcessByChannelNumberHandler(
             IDbContextFactory<TvContext> dbContextFactory,
-            IFFmpegProcessService ffmpegProcessService)
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory)
             : base(dbContextFactory)
         {
-            _ffmpegProcessService = ffmpegProcessService;
+            _ffmpegProcessServiceFactory = ffmpegProcessServiceFactory;
         }
 
         protected override async Task<Either<BaseError, PlayoutItemProcessModel>> GetProcess(
@@ -33,7 +34,8 @@ namespace ErsatzTV.Application.Streaming.Queries
                 .GetValue<bool>(ConfigElementKey.FFmpegSaveReports)
                 .Map(result => result.IfNone(false));
 
-            Process process = _ffmpegProcessService.WrapSegmenter(
+            IFFmpegProcessService ffmpegProcessService = await _ffmpegProcessServiceFactory.GetService();
+            Process process = ffmpegProcessService.WrapSegmenter(
                 ffmpegPath,
                 saveReports,
                 channel,

ErsatzTV.Application/Watermarks/Commands/CreateWatermark.cs

@@ -1,5 +1,6 @@
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 using MediatR;
 
@@ -10,8 +11,8 @@ namespace ErsatzTV.Application.Watermarks.Commands
         string Image,
         ChannelWatermarkMode Mode,
         ChannelWatermarkImageSource ImageSource,
-        ChannelWatermarkLocation Location,
-        ChannelWatermarkSize Size,
+        WatermarkLocation Location,
+        WatermarkSize Size,
         int Width,
         int HorizontalMargin,
         int VerticalMargin,

ErsatzTV.Application/Watermarks/Commands/UpdateWatermark.cs

@@ -1,5 +1,6 @@
 using ErsatzTV.Core;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 using MediatR;
 
@@ -11,8 +12,8 @@ namespace ErsatzTV.Application.Watermarks.Commands
         string Image,
         ChannelWatermarkMode Mode,
         ChannelWatermarkImageSource ImageSource,
-        ChannelWatermarkLocation Location,
-        ChannelWatermarkSize Size,
+        WatermarkLocation Location,
+        WatermarkSize Size,
         int Width,
         int HorizontalMargin,
         int VerticalMargin,

ErsatzTV.Application/Watermarks/Commands/UpdateWatermarkHandler.cs

@@ -21,7 +21,7 @@ namespace ErsatzTV.Application.Watermarks.Commands
             UpdateWatermark request,
             CancellationToken cancellationToken)
         {
-            await using TvContext dbContext = _dbContextFactory.CreateDbContext();
+            await using TvContext dbContext = await _dbContextFactory.CreateDbContextAsync(cancellationToken);
             Validation<BaseError, ChannelWatermark> validation = await Validate(dbContext, request);
             return await validation.Apply(p => ApplyUpdateRequest(dbContext, p, request));
         }

ErsatzTV.Application/Watermarks/WatermarkViewModel.cs

@@ -1,4 +1,5 @@
 using ErsatzTV.Core.Domain;
+using ErsatzTV.FFmpeg.State;
 
 namespace ErsatzTV.Application.Watermarks
 {
@@ -8,8 +9,8 @@ namespace ErsatzTV.Application.Watermarks
         string Name,
         ChannelWatermarkMode Mode,
         ChannelWatermarkImageSource ImageSource,
-        ChannelWatermarkLocation Location,
-        ChannelWatermarkSize Size,
+        WatermarkLocation Location,
+        WatermarkSize Size,
         int Width,
         int HorizontalMargin,
         int VerticalMargin,

ErsatzTV.Core.Tests/ErsatzTV.Core.Tests.csproj

@@ -6,9 +6,12 @@
     </PropertyGroup>
 
     <ItemGroup>
-      <PackageReference Include="FluentAssertions" Version="6.4.0" />
+      <PackageReference Include="FluentAssertions" Version="6.5.1" />
       <PackageReference Include="LanguageExt.Core" Version="4.0.3" />
       <PackageReference Include="Microsoft.Extensions.DependencyInjection" Version="6.0.0" />
+      <PackageReference Include="Microsoft.Extensions.Logging" Version="6.0.0" />
+      <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="6.0.0" />
+      <PackageReference Include="Microsoft.Extensions.Logging.Debug" Version="6.0.0" />
       <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
       <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" Version="17.0.64">
         <PrivateAssets>all</PrivateAssets>

ErsatzTV.Core.Tests/FFmpeg/FFmpegComplexFilterBuilderTests.cs

@@ -2,6 +2,7 @@
 using System.Collections.Generic;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.FFmpeg;
+using ErsatzTV.FFmpeg.State;
 using FluentAssertions;
 using LanguageExt;
 using NUnit.Framework;
@@ -141,7 +142,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.BottomLeft,
+                WatermarkLocation.BottomLeft,
                 false,
                 100,
                 "[0:0][1:v]overlay=x=134:y=H-h-54[v]",
@@ -151,7 +152,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.BottomRight,
+                WatermarkLocation.BottomRight,
                 false,
                 100,
                 "[0:0][1:v]overlay=x=W-w-134:y=H-h-54[v]",
@@ -161,7 +162,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:0][1:v]overlay=x=134:y=54[v]",
@@ -171,7 +172,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopRight,
+                WatermarkLocation.TopRight,
                 false,
                 100,
                 "[0:0][1:v]overlay=x=W-w-134:y=54[v]",
@@ -181,7 +182,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 true,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[1:v]format=yuva420p|yuva444p|yuva422p|rgba|abgr|bgra|gbrap|ya8,fade=in:st=300:d=1:alpha=1:enable='between(t,0,314)',fade=out:st=315:d=1:alpha=1:enable='between(t,301,899)',fade=in:st=900:d=1:alpha=1:enable='between(t,316,914)',fade=out:st=915:d=1:alpha=1:enable='between(t,901,1499)',fade=in:st=1500:d=1:alpha=1:enable='between(t,916,1514)',fade=out:st=1515:d=1:alpha=1:enable='between(t,1501,2099)',fade=in:st=2100:d=1:alpha=1:enable='between(t,1516,2114)',fade=out:st=2115:d=1:alpha=1:enable='between(t,2101,2699)',fade=in:st=2700:d=1:alpha=1:enable='between(t,2116,2714)',fade=out:st=2715:d=1:alpha=1:enable='between(t,2701,3300)'[wmp];[0:0][wmp]overlay=x=134:y=54,format=nv12[v]",
@@ -191,7 +192,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 true,
                 100,
                 "[1:v]scale=384:-1[wmp];[0:0][wmp]overlay=x=134:y=54[v]",
@@ -201,7 +202,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 90,
                 "[1:v]format=yuva420p|yuva444p|yuva422p|rgba|abgr|bgra|gbrap|ya8,colorchannelmixer=aa=0.90[wmp];[0:0][wmp]overlay=x=134:y=54[v]",
@@ -211,7 +212,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 true,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:0]yadif=1[vt];[vt][1:v]overlay=x=134:y=54[v]",
@@ -221,7 +222,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 true,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 true,
                 100,
                 "[0:0]yadif=1[vt];[1:v]scale=384:-1[wmp];[vt][wmp]overlay=x=134:y=54[v]",
@@ -231,7 +232,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 true,
                 true,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:1]apad=whole_dur=3300000ms[a];[0:0]yadif=1[vt];[vt][1:v]overlay=x=134:y=54[v]",
@@ -241,7 +242,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 true,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:1]apad=whole_dur=3300000ms[a];[0:0][1:v]overlay=x=134:y=54[v]",
@@ -251,7 +252,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 bool alignAudio,
                 bool deinterlace,
                 bool intermittent,
-                ChannelWatermarkLocation location,
+                WatermarkLocation location,
                 bool scaled,
                 int opacity,
                 string expectedVideoFilter,
@@ -266,7 +267,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                     DurationSeconds = intermittent ? 15 : 0,
                     FrequencyMinutes = intermittent ? 10 : 0,
                     Location = location,
-                    Size = scaled ? ChannelWatermarkSize.Scaled : ChannelWatermarkSize.ActualSize,
+                    Size = scaled ? WatermarkSize.Scaled : WatermarkSize.ActualSize,
                     WidthPercent = scaled ? 20 : 0,
                     Opacity = opacity,
                     HorizontalMarginPercent = 7,
@@ -310,7 +311,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.BottomLeft,
+                WatermarkLocation.BottomLeft,
                 false,
                 100,
                 "[0:0]scale_cuda=format=yuv420p[vt];[1:v]format=yuva420p,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=H-h-54[v]",
@@ -321,7 +322,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.BottomLeft,
+                WatermarkLocation.BottomLeft,
                 false,
                 100,
                 "[0:0]scale_cuda=1920:1080,setsar=1,hwdownload,format=nv12,format=yuv420p,hwupload_cuda[vt];[1:v]format=yuva420p,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=H-h-54,hwupload[v]",
@@ -332,7 +333,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 true,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:0]scale_cuda=format=yuv420p[vt];[1:v]format=yuva420p,fade=in:st=300:d=1:alpha=1:enable='between(t,0,314)',fade=out:st=315:d=1:alpha=1:enable='between(t,301,899)',fade=in:st=900:d=1:alpha=1:enable='between(t,316,914)',fade=out:st=915:d=1:alpha=1:enable='between(t,901,1499)',fade=in:st=1500:d=1:alpha=1:enable='between(t,916,1514)',fade=out:st=1515:d=1:alpha=1:enable='between(t,1501,2099)',fade=in:st=2100:d=1:alpha=1:enable='between(t,1516,2114)',fade=out:st=2115:d=1:alpha=1:enable='between(t,2101,2699)',fade=in:st=2700:d=1:alpha=1:enable='between(t,2116,2714)',fade=out:st=2715:d=1:alpha=1:enable='between(t,2701,3300)',hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54[v]",
@@ -343,7 +344,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 true,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:0]scale_cuda=1920:1080,setsar=1,hwdownload,format=nv12,format=yuv420p,hwupload_cuda[vt];[1:v]format=yuva420p,fade=in:st=300:d=1:alpha=1:enable='between(t,0,314)',fade=out:st=315:d=1:alpha=1:enable='between(t,301,899)',fade=in:st=900:d=1:alpha=1:enable='between(t,316,914)',fade=out:st=915:d=1:alpha=1:enable='between(t,901,1499)',fade=in:st=1500:d=1:alpha=1:enable='between(t,916,1514)',fade=out:st=1515:d=1:alpha=1:enable='between(t,1501,2099)',fade=in:st=2100:d=1:alpha=1:enable='between(t,1516,2114)',fade=out:st=2115:d=1:alpha=1:enable='between(t,2101,2699)',fade=in:st=2700:d=1:alpha=1:enable='between(t,2116,2714)',fade=out:st=2715:d=1:alpha=1:enable='between(t,2701,3300)',hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54,hwupload[v]",
@@ -354,7 +355,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 true,
                 100,
                 "[0:0]scale_cuda=format=yuv420p[vt];[1:v]format=yuva420p,scale=384:-1,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54[v]",
@@ -365,7 +366,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 true,
                 100,
                 "[0:0]scale_cuda=1920:1080,setsar=1,hwdownload,format=nv12,format=yuv420p,hwupload_cuda[vt];[1:v]format=yuva420p,scale=384:-1,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54,hwupload[v]",
@@ -376,7 +377,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 90,
                 "[0:0]scale_cuda=format=yuv420p[vt];[1:v]format=yuva420p,colorchannelmixer=aa=0.90,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54[v]",
@@ -387,7 +388,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 90,
                 "[0:0]scale_cuda=1920:1080,setsar=1,hwdownload,format=nv12,format=yuv420p,hwupload_cuda[vt];[1:v]format=yuva420p,colorchannelmixer=aa=0.90,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54,hwupload[v]",
@@ -399,7 +400,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             //     false,
             //     true,
             //     false,
-            //     ChannelWatermarkLocation.TopLeft,
+            //     WatermarkLocation.TopLeft,
             //     false,
             //     100,
             //     "[0:0]yadif=1[vt];[vt][1:v]overlay=x=134:y=54[v]",
@@ -409,7 +410,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             //     false,
             //     true,
             //     false,
-            //     ChannelWatermarkLocation.TopLeft,
+            //     WatermarkLocation.TopLeft,
             //     true,
             //     100,
             //     "[0:0]yadif=1[vt];[1:v]scale=384:-1[wmp];[vt][wmp]overlay=x=134:y=54[v]",
@@ -419,7 +420,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             //     true,
             //     true,
             //     false,
-            //     ChannelWatermarkLocation.TopLeft,
+            //     WatermarkLocation.TopLeft,
             //     false,
             //     100,
             //     "[0:1]apad=whole_dur=3300000ms[a];[0:0]yadif=1[vt];[vt][1:v]overlay=x=134:y=54[v]",
@@ -429,7 +430,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 true,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:1]apad=whole_dur=3300000ms[a];[0:0]scale_cuda=format=yuv420p[vt];[1:v]format=yuva420p,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54[v]",
@@ -440,7 +441,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 true,
                 false,
                 false,
-                ChannelWatermarkLocation.TopLeft,
+                WatermarkLocation.TopLeft,
                 false,
                 100,
                 "[0:1]apad=whole_dur=3300000ms[a];[0:0]scale_cuda=1920:1080,setsar=1,hwdownload,format=nv12,format=yuv420p,hwupload_cuda[vt];[1:v]format=yuva420p,hwupload_cuda[wmp];[vt][wmp]overlay_cuda=x=134:y=54,hwupload[v]",
@@ -451,7 +452,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 bool alignAudio,
                 bool deinterlace,
                 bool intermittent,
-                ChannelWatermarkLocation location,
+                WatermarkLocation location,
                 bool scaled,
                 int opacity,
                 string expectedVideoFilter,
@@ -467,7 +468,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                     DurationSeconds = intermittent ? 15 : 0,
                     FrequencyMinutes = intermittent ? 10 : 0,
                     Location = location,
-                    Size = scaled ? ChannelWatermarkSize.Scaled : ChannelWatermarkSize.ActualSize,
+                    Size = scaled ? WatermarkSize.Scaled : WatermarkSize.ActualSize,
                     WidthPercent = scaled ? 20 : 0,
                     Opacity = opacity,
                     HorizontalMarginPercent = 7,

ErsatzTV.Core.Tests/FFmpeg/HlsPlaylistFilterTests.cs

@@ -1,6 +1,9 @@
 using System;
 using ErsatzTV.Core.FFmpeg;
+using ErsatzTV.Core.Interfaces.FFmpeg;
 using FluentAssertions;
+using Microsoft.Extensions.Logging;
+using Moq;
 using NUnit.Framework;
 
 namespace ErsatzTV.Core.Tests.FFmpeg
@@ -8,8 +11,19 @@ namespace ErsatzTV.Core.Tests.FFmpeg
     [TestFixture]
     public class HlsPlaylistFilterTests
     {
+        private HlsPlaylistFilter _hlsPlaylistFilter;
+        
+        [SetUp]
+        public void SetUp()
+        {
+            _hlsPlaylistFilter = new HlsPlaylistFilter(
+                new Mock<ITempFilePool>().Object,
+                new Mock<ILogger<HlsPlaylistFilter>>().Object
+            );
+        }
+
         [Test]
-        public void HlsPlaylistFilter_ShouldRewriteProgramDateTime()
+        public void _hlsPlaylistFilter_ShouldRewriteProgramDateTime()
         {
             var start = new DateTimeOffset(2021, 10, 9, 8, 0, 0, TimeSpan.FromHours(-5));
             string[] input = NormalizeLineEndings(@"#EXTM3U
@@ -28,7 +42,7 @@ live001138.ts
 #EXT-X-PROGRAM-DATE-TIME:2021-10-08T08:34:57.320-0500
 live001139.ts").Split(Environment.NewLine);
 
-            TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(-30), input);
+            TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(-30), input);
 
             result.PlaylistStart.Should().Be(start);
             result.Sequence.Should().Be(1137);
@@ -53,7 +67,7 @@ live001139.ts
         }
         
         [Test]
-        public void HlsPlaylistFilter_ShouldLimitSegments()
+        public void _hlsPlaylistFilter_ShouldLimitSegments()
         {
             var start = new DateTimeOffset(2021, 10, 9, 8, 0, 0, TimeSpan.FromHours(-5));
             string[] input = NormalizeLineEndings(@"#EXTM3U
@@ -72,7 +86,7 @@ live001138.ts
 #EXT-X-PROGRAM-DATE-TIME:2021-10-08T08:34:57.320-0500
 live001139.ts").Split(Environment.NewLine);
 
-            TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(-30), input, 2);
+            TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(-30), input, 2);
 
             result.PlaylistStart.Should().Be(start);
             result.Sequence.Should().Be(1137);
@@ -94,7 +108,7 @@ live001138.ts
         }
         
         [Test]
-        public void HlsPlaylistFilter_ShouldAddDiscontinuity()
+        public void _hlsPlaylistFilter_ShouldAddDiscontinuity()
         {
             var start = new DateTimeOffset(2021, 10, 9, 8, 0, 0, TimeSpan.FromHours(-5));
             string[] input = NormalizeLineEndings(@"#EXTM3U
@@ -113,7 +127,7 @@ live001138.ts
 #EXT-X-PROGRAM-DATE-TIME:2021-10-08T08:34:57.320-0500
 live001139.ts").Split(Environment.NewLine);
 
-            TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(
+            TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(
                 start,
                 start.AddSeconds(-30),
                 input,
@@ -144,7 +158,7 @@ live001139.ts
         }
 
         [Test]
-        public void HlsPlaylistFilter_ShouldFilterOldSegments()
+        public void _hlsPlaylistFilter_ShouldFilterOldSegments()
         {
             var start = new DateTimeOffset(2021, 10, 9, 8, 0, 0, TimeSpan.FromHours(-5));
             string[] input = NormalizeLineEndings(@"#EXTM3U
@@ -163,7 +177,7 @@ live001138.ts
 #EXT-X-PROGRAM-DATE-TIME:2021-10-08T08:34:57.320-0500
 live001139.ts").Split(Environment.NewLine);
 
-            TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(6), input);
+            TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(6), input);
 
             result.PlaylistStart.Should().Be(start.AddSeconds(8));
             result.Sequence.Should().Be(1139);
@@ -182,7 +196,7 @@ live001139.ts
         }
         
         [Test]
-        public void HlsPlaylistFilter_ShouldFilterOldDiscontinuity()
+        public void _hlsPlaylistFilter_ShouldFilterOldDiscontinuity()
         {
             var start = new DateTimeOffset(2021, 10, 9, 8, 0, 0, TimeSpan.FromHours(-5));
             string[] input = NormalizeLineEndings(@"#EXTM3U
@@ -202,7 +216,7 @@ live001138.ts
 #EXT-X-PROGRAM-DATE-TIME:2021-10-08T08:34:57.320-0500
 live001139.ts").Split(Environment.NewLine);
 
-            TrimPlaylistResult result = HlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(6), input);
+            TrimPlaylistResult result = _hlsPlaylistFilter.TrimPlaylist(start, start.AddSeconds(6), input);
 
             result.PlaylistStart.Should().Be(start.AddSeconds(8));
             result.Sequence.Should().Be(1139);

ErsatzTV.Core.Tests/FFmpeg/TranscodingTests.cs

@@ -4,6 +4,8 @@ using System.Diagnostics;
 using System.IO;
 using System.Linq;
 using System.Security.Cryptography;
+using System.Text;
+using System.Threading;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Domain.Filler;
@@ -37,6 +39,8 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             Assert.Pass();
         }
 
+        public record InputFormat(string Encoder, string PixelFormat);
+
         public enum Padding
         {
             NoPadding,
@@ -56,22 +60,32 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 VideoScanKind.Progressive,
                 VideoScanKind.Interlaced
             };
-            
-            public static string[] InputCodecs =
-            {
-                "h264",
-                "mpeg2video",
-                "hevc",
-                "mpeg4"
-            };
 
-            public static string[] InputPixelFormats =
+            public static InputFormat[] InputFormats =
             {
-                "yuv420p",
-                "yuv420p10le",
-                // "yuvj420p",
-                // "yuv444p",
-                // "yuv444p10le"
+                new("libx264", "yuv420p"),
+                new("libx264", "yuvj420p"),
+                new("libx264", "yuv420p10le"),
+                // new("libx264", "yuv444p10le"),
+
+                new("mpeg1video", "yuv420p"),
+
+                new("mpeg2video", "yuv420p"),
+
+                new("libx265", "yuv420p"),
+                new("libx265", "yuv420p10le"),
+
+                new("mpeg4", "yuv420p"),
+
+                new("libvpx-vp9", "yuv420p"),
+
+                // new("libaom-av1", "yuv420p")
+                // av1    yuv420p10le    51
+
+                new("msmpeg4v2", "yuv420p"),
+                new("msmpeg4v3", "yuv420p")
+
+                // wmv3    yuv420p    1
             };
             
             public static Resolution[] Resolutions =
@@ -123,14 +137,23 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             {
                 HardwareAccelerationKind.VideoToolbox
             };
+
+            public static string[] QsvCodecs =
+            {
+                "h264_qsv",
+                "hevc_qsv"
+            };
+
+            public static HardwareAccelerationKind[] QsvAcceleration =
+            {
+                HardwareAccelerationKind.Qsv
+            };
         }
 
         [Test, Combinatorial]
         public async Task Transcode(
-            [ValueSource(typeof(TestData), nameof(TestData.InputCodecs))]
-            string inputCodec,
-            [ValueSource(typeof(TestData), nameof(TestData.InputPixelFormats))]
-            string inputPixelFormat,
+            [ValueSource(typeof(TestData), nameof(TestData.InputFormats))]
+            InputFormat inputFormat,
             [ValueSource(typeof(TestData), nameof(TestData.Resolutions))]
             Resolution profileResolution,
             [ValueSource(typeof(TestData), nameof(TestData.Paddings))]
@@ -143,11 +166,22 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             [ValueSource(typeof(TestData), nameof(TestData.NvidiaAcceleration))] HardwareAccelerationKind profileAcceleration)
             // [ValueSource(typeof(TestData), nameof(TestData.VaapiCodecs))] string profileCodec,
             // [ValueSource(typeof(TestData), nameof(TestData.VaapiAcceleration))] HardwareAccelerationKind profileAcceleration)
+            // [ValueSource(typeof(TestData), nameof(TestData.QsvCodecs))] string profileCodec,
+            // [ValueSource(typeof(TestData), nameof(TestData.QsvAcceleration))] HardwareAccelerationKind profileAcceleration)
             // [ValueSource(typeof(TestData), nameof(TestData.VideoToolboxCodecs))] string profileCodec,
             // [ValueSource(typeof(TestData), nameof(TestData.VideoToolboxAcceleration))] HardwareAccelerationKind profileAcceleration)
         {
+            if (inputFormat.Encoder is "mpeg1video" or "msmpeg4v2" or "msmpeg4v3")
+            {
+                if (videoScanKind == VideoScanKind.Interlaced)
+                {
+                    Assert.Inconclusive($"{inputFormat.Encoder} does not support interlaced content");
+                    return;
+                }
+            }
+
             string name = GetStringSha256Hash(
-                $"{inputCodec}_{inputPixelFormat}_{videoScanKind}_{padding}_{profileResolution}_{profileCodec}_{profileAcceleration}");
+                $"{inputFormat.Encoder}_{inputFormat.PixelFormat}_{videoScanKind}_{padding}_{profileResolution}_{profileCodec}_{profileAcceleration}");
 
             string file = Path.Combine(TestContext.CurrentContext.TestDirectory, $"{name}.mkv");
             if (!File.Exists(file))
@@ -158,7 +192,7 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 string flags = videoScanKind == VideoScanKind.Interlaced ? "-flags +ildct+ilme" : string.Empty;
                 
                 string args =
-                    $"-y -f lavfi -i anoisesrc=color=brown -f lavfi -i testsrc=duration=1:size={resolution}:rate=30 {videoFilter} -c:a aac -c:v {inputCodec} -shortest -pix_fmt {inputPixelFormat} -strict -2 {flags} {file}";
+                    $"-y -f lavfi -i anoisesrc=color=brown -f lavfi -i testsrc=duration=1:size={resolution}:rate=30 {videoFilter} -c:a aac -c:v {inputFormat.Encoder} -shortest -pix_fmt {inputFormat.PixelFormat} -strict -2 {flags} {file}";
                 var p1 = new Process
                 {
                     StartInfo = new ProcessStartInfo
@@ -175,19 +209,35 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 p1.ExitCode.Should().Be(0);
             }
 
-            var service = new FFmpegProcessService(
+            var oldService = new FFmpegProcessService(
                 new FFmpegPlaybackSettingsCalculator(),
                 new FakeStreamSelector(),
                 new Mock<IImageCache>().Object,
                 new Mock<ITempFilePool>().Object,
                 new Mock<ILogger<FFmpegProcessService>>().Object);
 
-            MediaVersion v = new MediaVersion();
+            var service = new FFmpegLibraryProcessService(
+                oldService,
+                new FFmpegPlaybackSettingsCalculator(),
+                new FakeStreamSelector(),
+                new Mock<ILogger<FFmpegLibraryProcessService>>().Object);
+
+            var v = new MediaVersion
+            {
+                MediaFiles = new List<MediaFile>
+                {
+                    new() { Path = file }
+                }
+            };
 
             var metadataRepository = new Mock<IMetadataRepository>();
             metadataRepository
                 .Setup(r => r.UpdateLocalStatistics(It.IsAny<MediaItem>(), It.IsAny<MediaVersion>(), It.IsAny<bool>()))
-                .Callback<MediaItem, MediaVersion, bool>((_, version, _) => v = version);
+                .Callback<MediaItem, MediaVersion, bool>((_, version, _) =>
+                {
+                    version.MediaFiles = v.MediaFiles;
+                    v = version;
+                });
 
             var localStatisticsProvider = new LocalStatisticsProvider(
                 metadataRepository.Object,
@@ -217,10 +267,12 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 false,
                 new Channel(Guid.NewGuid())
                 {
+                    Number = "1",
                     FFmpegProfile = FFmpegProfile.New("test", profileResolution) with
                     {
                         HardwareAcceleration = profileAcceleration,
-                        VideoCodec = profileCodec
+                        VideoCodec = profileCodec,
+                        AudioCodec = "aac"
                     },
                     StreamingMode = StreamingMode.TransportStream
                 },
@@ -242,25 +294,51 @@ namespace ErsatzTV.Core.Tests.FFmpeg
                 None);
 
             process.StartInfo.RedirectStandardError = true;
+            process.EnableRaisingEvents = true;
             
             // Console.WriteLine($"ffmpeg arguments {string.Join(" ", process.StartInfo.ArgumentList)}");
 
             process.Start().Should().BeTrue();
 
-            process.BeginOutputReadLine();
-            string error = await process.StandardError.ReadToEndAsync();
-            await process.WaitForExitAsync();
-            // ReSharper disable once MethodHasAsyncOverload
-            process.WaitForExit();
-
             string[] unsupportedMessages =
             {
                 "No support for codec",
                 "No usable",
                 "Provided device doesn't support"
             };
+
+            var errorBuffer = new StringBuilder();
             
-            if (profileAcceleration != HardwareAccelerationKind.None && unsupportedMessages.Any(error.Contains))
+            process.ErrorDataReceived += (_, errorLine) =>
+            {
+                string data = errorLine.Data ?? string.Empty;
+                errorBuffer.AppendLine(data);
+            };
+
+            process.BeginOutputReadLine();
+            process.BeginErrorReadLine();
+            // string error = await process.StandardError.ReadToEndAsync();
+
+            var timeoutSignal = new CancellationTokenSource(TimeSpan.FromSeconds(30));
+            try
+            {
+                await process.WaitForExitAsync(timeoutSignal.Token);
+                // ReSharper disable once MethodHasAsyncOverload
+                process.WaitForExit();
+            }
+            catch (OperationCanceledException)
+            {
+                process.Kill();
+
+                IEnumerable<string> quotedArgs = process.StartInfo.ArgumentList.Map(a => $"\'{a}\'");
+                Assert.Fail($"Transcode failure (timeout): ffmpeg {string.Join(" ", quotedArgs)}");
+                return;
+            }
+
+            var error = errorBuffer.ToString();
+            bool isUnsupported = unsupportedMessages.Any(error.Contains); 
+
+            if (profileAcceleration != HardwareAccelerationKind.None && isUnsupported)
             {
                 var quotedArgs = process.StartInfo.ArgumentList.Map(a => $"\'{a}\'").ToList();
                 process.ExitCode.Should().Be(1, $"Error message with successful exit code? {string.Join(" ", quotedArgs)}");
@@ -273,8 +351,12 @@ namespace ErsatzTV.Core.Tests.FFmpeg
             }
             else
             {
-                IEnumerable<string> quotedArgs = process.StartInfo.ArgumentList.Map(a => $"\'{a}\'");
-                process.ExitCode.Should().Be(0, error + Environment.NewLine + string.Join(" ", quotedArgs));
+                var quotedArgs = process.StartInfo.ArgumentList.Map(a => $"\'{a}\'").ToList();
+                process.ExitCode.Should().Be(0, errorBuffer + Environment.NewLine + string.Join(" ", quotedArgs));
+                if (process.ExitCode == 0)
+                {
+                    Console.WriteLine(string.Join(" ", quotedArgs));
+                }
             }
         }
         

ErsatzTV.Core.Tests/Scheduling/PlayoutBuilderTests.cs

@@ -624,8 +624,11 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 Anchor = new PlayoutAnchor
                 {
                     NextStart = HoursAfterMidnight(9).UtcDateTime,
-                    NextScheduleItem = items[0],
-                    NextScheduleItemId = 1,
+                    ScheduleItemsEnumeratorState = new CollectionEnumeratorState
+                    {
+                        Index = 0,
+                        Seed = 1
+                    },
                     InFlood = true
                 }
             };
@@ -918,8 +921,11 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 Anchor = new PlayoutAnchor
                 {
                     NextStart = HoursAfterMidnight(1).UtcDateTime,
-                    NextScheduleItem = items[0],
-                    NextScheduleItemId = 1,
+                    ScheduleItemsEnumeratorState = new CollectionEnumeratorState
+                    {
+                        Index = 0,
+                        Seed = 1
+                    },
                     MultipleRemaining = 2
                 }
             };
@@ -951,7 +957,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             result.Items[3].StartOffset.TimeOfDay.Should().Be(TimeSpan.FromHours(4));
             result.Items[3].MediaItemId.Should().Be(2);
 
-            result.Anchor.NextScheduleItem.Should().Be(items[1]);
+            result.Anchor.ScheduleItemsEnumeratorState.Index.Should().Be(1);
             result.Anchor.MultipleRemaining.Should().Be(1);
         }
 
@@ -1048,7 +1054,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             result.Items[4].StartOffset.TimeOfDay.Should().Be(TimeSpan.FromHours(4));
             result.Items[4].MediaItemId.Should().Be(5);
 
-            result.Anchor.NextScheduleItem.Should().Be(items[0]);
+            result.Anchor.ScheduleItemsEnumeratorState.Index.Should().Be(0);
             result.Anchor.MultipleRemaining.Should().BeNull();
         }
 
@@ -1116,8 +1122,11 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 Anchor = new PlayoutAnchor
                 {
                     NextStart = HoursAfterMidnight(1).UtcDateTime,
-                    NextScheduleItem = items[0],
-                    NextScheduleItemId = 1,
+                    ScheduleItemsEnumeratorState = new CollectionEnumeratorState
+                    {
+                        Index = 0,
+                        Seed = 1
+                    },
                     DurationFinish = HoursAfterMidnight(3).UtcDateTime
                 }
             };
@@ -1149,7 +1158,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             result.Items[3].StartOffset.TimeOfDay.Should().Be(TimeSpan.FromHours(4));
             result.Items[3].MediaItemId.Should().Be(2);
 
-            result.Anchor.NextScheduleItem.Should().Be(items[1]);
+            result.Anchor.ScheduleItemsEnumeratorState.Index.Should().Be(1);
             result.Anchor.DurationFinish.Should().Be(HoursAfterMidnight(6).UtcDateTime);
         }
         
@@ -1284,7 +1293,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             result.Items[11].StartOffset.TimeOfDay.Should().Be(new TimeSpan(5, 55, 0));
             result.Items[11].MediaItemId.Should().Be(3);
             
-            result.Anchor.NextScheduleItem.Should().Be(items[0]);
+            result.Anchor.ScheduleItemsEnumeratorState.Index.Should().Be(0);
             result.Anchor.DurationFinish.Should().BeNull();
         }
         
@@ -1361,7 +1370,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             result.Items[5].StartOffset.TimeOfDay.Should().Be(TimeSpan.FromHours(5));
             result.Items[5].MediaItemId.Should().Be(4);
 
-            result.Anchor.NextScheduleItem.Should().Be(items[0]);
+            result.Anchor.ScheduleItemsEnumeratorState.Index.Should().Be(0);
             result.Anchor.DurationFinish.Should().BeNull();
         }
 

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerDurationTests.cs

@@ -31,19 +31,25 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 PlaybackOrder = PlaybackOrder.Chronological
             };
 
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
+
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
                 new CollectionEnumeratorState());
+
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
             
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -51,26 +57,26 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
@@ -93,20 +99,26 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 PlaybackOrder = PlaybackOrder.Chronological,
                 CustomTitle = "Custom Title"
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -114,28 +126,28 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
             playoutItems[0].CustomTitle.Should().Be("Custom Title");
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
             playoutItems[1].CustomTitle.Should().Be("Custom Title");
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
@@ -158,20 +170,26 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 TailMode = TailMode.None,
                 PlaybackOrder = PlaybackOrder.Chronological
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -179,26 +197,26 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
@@ -220,48 +238,54 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 TailMode = TailMode.Offline,
                 PlaybackOrder = PlaybackOrder.Chronological
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
             // duration block should end after exact duration, with gap
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
-            playoutItems.Last().FinishOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
+            playoutItems.Last().FinishOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
             playoutBuilderState.DurationFinish.IsNone.Should().BeTrue();
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
@@ -290,6 +314,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionTwo.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -299,15 +327,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.FallbackFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -315,7 +345,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -323,25 +353,25 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
             
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Fallback);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
@@ -370,6 +400,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionTwo.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -379,15 +413,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -395,7 +431,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -403,37 +439,37 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
@@ -462,6 +498,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionTwo.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -471,23 +511,25 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
-            playoutItems.Last().FinishOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
+            playoutItems.Last().FinishOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
             playoutBuilderState.DurationFinish.IsNone.Should().BeTrue();
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -495,37 +537,37 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[4].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[5].GuideFinish.HasValue.Should().BeFalse();
@@ -561,6 +603,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionThree.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -574,9 +620,11 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerDuration(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -586,9 +634,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -596,7 +644,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
             
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -605,43 +653,43 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(7);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
             playoutItems[0].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             playoutItems[1].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             playoutItems[2].GuideFinish.HasValue.Should().BeTrue();
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[3].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[4].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
             playoutItems[5].GuideFinish.HasValue.Should().BeFalse();
 
             playoutItems[6].MediaItemId.Should().Be(5);
-            playoutItems[6].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutItems[6].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems[6].GuideGroup.Should().Be(3);
             playoutItems[6].FillerKind.Should().Be(FillerKind.Fallback);
             playoutItems[6].GuideFinish.HasValue.Should().BeFalse();

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerFloodTests.cs

@@ -40,16 +40,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -57,24 +63,24 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }
@@ -109,16 +115,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     StartTime = TimeSpan.FromHours(3),
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -126,24 +138,24 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }
@@ -188,15 +200,21 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 NextScheduleItem
             };
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.PostRollFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -204,7 +222,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -212,32 +230,32 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.PostRoll);
 
             playoutItems[2].MediaItemId.Should().Be(2);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[2].GuideGroup.Should().Be(2);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(4);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 55, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 55, 0)));
             playoutItems[3].GuideGroup.Should().Be(2);
             playoutItems[3].FillerKind.Should().Be(FillerKind.PostRoll);
 
             playoutItems[4].MediaItemId.Should().Be(1);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.PostRoll);
         }
@@ -268,16 +286,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -285,24 +309,24 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }
@@ -343,16 +367,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -360,7 +390,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -368,32 +398,32 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -434,16 +464,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.FallbackFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -451,7 +487,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -459,22 +495,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -515,16 +551,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -532,7 +574,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -540,32 +582,32 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -616,10 +658,16 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -629,9 +677,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -639,7 +687,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -648,37 +696,37 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(7);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[6].MediaItemId.Should().Be(5);
-            playoutItems[6].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutItems[6].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems[6].GuideGroup.Should().Be(3);
             playoutItems[6].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -729,10 +777,16 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 scheduleItem,
                 NextScheduleItem
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                sortedScheduleItems,
+                new CollectionEnumeratorState());
 
-            var scheduler = new PlayoutModeSchedulerFlood(sortedScheduleItems, new Mock<ILogger>().Object);
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            var scheduler = new PlayoutModeSchedulerFlood(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -742,9 +796,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -752,7 +806,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(1);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(0);
@@ -761,17 +815,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerMultipleTests.cs

@@ -33,6 +33,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 FallbackFiller = null,
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -42,16 +46,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
             {
                 { CollectionKey.ForScheduleItem(scheduleItem), collectionOne.MediaItems }
             }.ToMap();
-    
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -59,24 +65,24 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }
@@ -98,6 +104,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 FallbackFiller = null,
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -107,16 +117,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
             {
                 { CollectionKey.ForScheduleItem(scheduleItem), collectionOne.MediaItems }
             }.ToMap();
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -124,24 +136,24 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }
@@ -169,6 +181,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 FallbackFiller = null,
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -183,16 +199,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 { CollectionKey.ForScheduleItem(scheduleItem), collectionOne.MediaItems },
                 { CollectionKey.ForFillerPreset(scheduleItem.TailFiller), collectionTwo.MediaItems }
             }.ToMap();
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -200,7 +218,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -208,32 +226,32 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -261,6 +279,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 },
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -275,16 +297,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 { CollectionKey.ForScheduleItem(scheduleItem), collectionOne.MediaItems },
                 { CollectionKey.ForFillerPreset(scheduleItem.FallbackFiller), collectionTwo.MediaItems }
             }.ToMap();
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.FallbackFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -292,7 +316,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -300,22 +324,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -343,6 +367,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 FallbackFiller = null,
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -357,16 +385,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 { CollectionKey.ForScheduleItem(scheduleItem), collectionOne.MediaItems },
                 { CollectionKey.ForFillerPreset(scheduleItem.TailFiller), collectionTwo.MediaItems }
             }.ToMap();
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -374,7 +404,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -382,32 +412,32 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(6);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
             
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
         
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -441,6 +471,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 },
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -461,9 +495,11 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 { CollectionKey.ForFillerPreset(scheduleItem.FallbackFiller), collectionThree.MediaItems }
             }.ToMap();
 
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -473,9 +509,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -483,7 +519,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -492,37 +528,37 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(7);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddMinutes(55));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddMinutes(55));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
         
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(1, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
             
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[3].GuideGroup.Should().Be(3);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(4);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[4].GuideGroup.Should().Be(3);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Tail);
         
             playoutItems[5].MediaItemId.Should().Be(3);
-            playoutItems[5].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[5].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[5].GuideGroup.Should().Be(3);
             playoutItems[5].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[6].MediaItemId.Should().Be(5);
-            playoutItems[6].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutItems[6].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems[6].GuideGroup.Should().Be(3);
             playoutItems[6].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -556,6 +592,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 },
                 Count = 3
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -575,10 +615,12 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 { CollectionKey.ForFillerPreset(scheduleItem.TailFiller), collectionTwo.MediaItems },
                 { CollectionKey.ForFillerPreset(scheduleItem.FallbackFiller), collectionThree.MediaItems }
             }.ToMap();
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerMultiple(collectionMediaItems, new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -588,9 +630,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(4);
@@ -598,7 +640,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(0);
@@ -607,17 +649,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(3);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(2);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(2);
             playoutItems[1].FillerKind.Should().Be(FillerKind.None);
         
             playoutItems[2].MediaItemId.Should().Be(1);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.AddHours(2));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.AddHours(2));
             playoutItems[2].GuideGroup.Should().Be(3);
             playoutItems[2].FillerKind.Should().Be(FillerKind.None);
         }

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerOneTests.cs

@@ -30,20 +30,26 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 TailFiller = null,
                 FallbackFiller = null
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -51,14 +57,14 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator.State.Index.Should().Be(1);
 
             playoutItems.Count.Should().Be(1);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
         }
@@ -91,6 +97,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     Collection = collectionThree
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -104,15 +114,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
             
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2, scheduleItem.FallbackFiller, enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -120,7 +132,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(0);
@@ -129,7 +141,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(1);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
         }
@@ -156,6 +168,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 },
                 FallbackFiller = null
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -164,16 +180,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
             var enumerator2 = new ChronologicalMediaCollectionEnumerator(
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -181,7 +199,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -189,22 +207,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[2].MediaItemId.Should().Be(4);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.Tail);
         
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[3].GuideGroup.Should().Be(1);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -231,6 +249,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionTwo.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -239,16 +261,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
             var enumerator2 = new ChronologicalMediaCollectionEnumerator(
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.FallbackFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -256,7 +280,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -264,12 +288,12 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(2);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.AddHours(1));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.AddHours(1));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -296,6 +320,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 },
                 FallbackFiller = null
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -304,16 +332,18 @@ namespace ErsatzTV.Core.Tests.Scheduling
             var enumerator2 = new ChronologicalMediaCollectionEnumerator(
                 collectionTwo.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.TailFiller, enumerator2),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -321,7 +351,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -329,22 +359,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[2].MediaItemId.Should().Be(4);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.Tail);
         
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[3].GuideGroup.Should().Be(1);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
         }
@@ -377,6 +407,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionThree.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -389,10 +423,12 @@ namespace ErsatzTV.Core.Tests.Scheduling
             var enumerator3 = new ChronologicalMediaCollectionEnumerator(
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -402,9 +438,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -412,7 +448,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -421,27 +457,27 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(5);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[2].MediaItemId.Should().Be(4);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 49, 0)));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.Tail);
         
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 53, 0)));
             playoutItems[3].GuideGroup.Should().Be(1);
             playoutItems[3].FillerKind.Should().Be(FillerKind.Tail);
 
             playoutItems[4].MediaItemId.Should().Be(5);
-            playoutItems[4].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
+            playoutItems[4].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 57, 0)));
             playoutItems[4].GuideGroup.Should().Be(1);
             playoutItems[4].FillerKind.Should().Be(FillerKind.Fallback);
         }
@@ -474,6 +510,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionThree.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -486,10 +526,12 @@ namespace ErsatzTV.Core.Tests.Scheduling
             var enumerator3 = new ChronologicalMediaCollectionEnumerator(
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
+            
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
 
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(
                     scheduleItem,
                     enumerator1,
@@ -499,9 +541,9 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -509,7 +551,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(0);
@@ -518,7 +560,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(1);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
         }
@@ -553,6 +595,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionThree.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -566,15 +612,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
 
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.PostRollFiller, enumerator2, scheduleItem.FallbackFiller, enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -582,7 +630,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -590,22 +638,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.PostRoll);
 
             playoutItems[2].MediaItemId.Should().Be(4);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.PostRoll);
         
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[3].GuideGroup.Should().Be(1);
             playoutItems[3].FillerKind.Should().Be(FillerKind.PostRoll);
         }
@@ -640,6 +688,10 @@ namespace ErsatzTV.Core.Tests.Scheduling
                     CollectionId = collectionThree.Id
                 }
             };
+            
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
 
             var enumerator1 = new ChronologicalMediaCollectionEnumerator(
                 collectionOne.MediaItems,
@@ -653,15 +705,17 @@ namespace ErsatzTV.Core.Tests.Scheduling
                 collectionThree.MediaItems,
                 new CollectionEnumeratorState());
 
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
             var scheduler = new PlayoutModeSchedulerOne(new Mock<ILogger>().Object);
             (PlayoutBuilderState playoutBuilderState, List<PlayoutItem> playoutItems) = scheduler.Schedule(
-                StartState,
+                startState,
                 CollectionEnumerators(scheduleItem, enumerator1, scheduleItem.PostRollFiller, enumerator2, scheduleItem.FallbackFiller, enumerator3),
                 scheduleItem,
                 NextScheduleItem,
-                HardStop);
+                HardStop(scheduleItemsEnumerator));
 
-            playoutBuilderState.CurrentTime.Should().Be(StartState.CurrentTime.AddHours(3));
+            playoutBuilderState.CurrentTime.Should().Be(startState.CurrentTime.AddHours(3));
             playoutItems.Last().FinishOffset.Should().Be(playoutBuilderState.CurrentTime);
 
             playoutBuilderState.NextGuideGroup.Should().Be(2);
@@ -669,7 +723,7 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutBuilderState.InFlood.Should().BeFalse();
             playoutBuilderState.MultipleRemaining.IsNone.Should().BeTrue();
             playoutBuilderState.InDurationFiller.Should().BeFalse();
-            playoutBuilderState.ScheduleItemIndex.Should().Be(1);
+            playoutBuilderState.ScheduleItemsEnumerator.State.Index.Should().Be(0);
 
             enumerator1.State.Index.Should().Be(1);
             enumerator2.State.Index.Should().Be(1);
@@ -678,22 +732,22 @@ namespace ErsatzTV.Core.Tests.Scheduling
             playoutItems.Count.Should().Be(4);
 
             playoutItems[0].MediaItemId.Should().Be(1);
-            playoutItems[0].StartOffset.Should().Be(StartState.CurrentTime);
+            playoutItems[0].StartOffset.Should().Be(startState.CurrentTime);
             playoutItems[0].GuideGroup.Should().Be(1);
             playoutItems[0].FillerKind.Should().Be(FillerKind.None);
 
             playoutItems[1].MediaItemId.Should().Be(3);
-            playoutItems[1].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
+            playoutItems[1].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 45, 0)));
             playoutItems[1].GuideGroup.Should().Be(1);
             playoutItems[1].FillerKind.Should().Be(FillerKind.PostRoll);
 
             playoutItems[2].MediaItemId.Should().Be(4);
-            playoutItems[2].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
+            playoutItems[2].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 50, 0)));
             playoutItems[2].GuideGroup.Should().Be(1);
             playoutItems[2].FillerKind.Should().Be(FillerKind.PostRoll);
         
             playoutItems[3].MediaItemId.Should().Be(3);
-            playoutItems[3].StartOffset.Should().Be(StartState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
+            playoutItems[3].StartOffset.Should().Be(startState.CurrentTime.Add(new TimeSpan(2, 55, 0)));
             playoutItems[3].GuideGroup.Should().Be(1);
             playoutItems[3].FillerKind.Should().Be(FillerKind.PostRoll);
         }

ErsatzTV.Core.Tests/Scheduling/SchedulerTestBase.cs

@@ -10,8 +10,8 @@ namespace ErsatzTV.Core.Tests.Scheduling
 {
     public abstract class SchedulerTestBase
     {
-        protected static PlayoutBuilderState StartState => new(
-            0,
+        protected static PlayoutBuilderState StartState(IScheduleItemsEnumerator scheduleItemsEnumerator) => new(
+            scheduleItemsEnumerator,
             Prelude.None,
             Prelude.None,
             false,
@@ -24,7 +24,8 @@ namespace ErsatzTV.Core.Tests.Scheduling
             StartTime = null
         };
 
-        protected static DateTimeOffset HardStop => StartState.CurrentTime.AddHours(6);
+        protected static DateTimeOffset HardStop(IScheduleItemsEnumerator scheduleItemsEnumerator) =>
+            StartState(scheduleItemsEnumerator).CurrentTime.AddHours(6);
 
         protected static Dictionary<CollectionKey, IMediaCollectionEnumerator> CollectionEnumerators(
             ProgramScheduleItem scheduleItem, IMediaCollectionEnumerator enumerator) =>

ErsatzTV.Core/Domain/Channel.cs

@@ -13,6 +13,8 @@ namespace ErsatzTV.Core.Domain
         public Guid UniqueId { get; init; }
         public string Number { get; set; }
         public string Name { get; set; }
+        public string Group { get; set; }
+        public string Categories { get; set; }
         public int FFmpegProfileId { get; set; }
         public FFmpegProfile FFmpegProfile { get; set; }
         public int? WatermarkId { get; set; }

ErsatzTV.Core/Domain/ChannelWatermark.cs

@@ -1,4 +1,6 @@
-namespace ErsatzTV.Core.Domain
+using ErsatzTV.FFmpeg.State;
+
+namespace ErsatzTV.Core.Domain
 {
     public class ChannelWatermark
     {
@@ -7,8 +9,8 @@
         public ChannelWatermarkMode Mode { get; set; }
         public ChannelWatermarkImageSource ImageSource { get; set; }
         public string Image { get; set; }
-        public ChannelWatermarkLocation Location { get; set; }
-        public ChannelWatermarkSize Size { get; set; }
+        public WatermarkLocation Location { get; set; }
+        public WatermarkSize Size { get; set; }
         public int WidthPercent { get; set; }
         public int HorizontalMarginPercent { get; set; }
         public int VerticalMarginPercent { get; set; }
@@ -17,24 +19,6 @@
         public int Opacity { get; set; }
     }
 
-    public enum ChannelWatermarkLocation
-    {
-        BottomRight = 0,
-        BottomLeft = 1,
-        TopRight = 2,
-        TopLeft = 3,
-        TopMiddle = 4,
-        RightMiddle = 5,
-        BottomMiddle = 6,
-        LeftMiddle = 7
-    }
-
-    public enum ChannelWatermarkSize
-    {
-        Scaled = 0,
-        ActualSize = 1
-    }
-
     public enum ChannelWatermarkMode
     {
         None = 0,

ErsatzTV.Core/Domain/ConfigElementKey.cs

@@ -17,6 +17,7 @@
         public static ConfigElementKey FFmpegSegmenterTimeout => new("ffmpeg.segmenter.timeout_seconds");
         public static ConfigElementKey FFmpegWorkAheadSegmenters => new("ffmpeg.segmenter.work_ahead_limit");
         public static ConfigElementKey FFmpegInitialSegmentCount => new("ffmpeg.segmenter.initial_segment_count");
+        public static ConfigElementKey FFmpegUseExperimentalTranscoder => new("ffmpeg.use_experimental_transcoder");
         public static ConfigElementKey SearchIndexVersion => new("search_index.version");
         public static ConfigElementKey HDHRTunerCount => new("hdhr.tuner_count");
         public static ConfigElementKey ChannelsPageSize => new("pages.channels.page_size");

ErsatzTV.Core/Domain/PlayoutAnchor.cs

@@ -6,10 +6,7 @@ namespace ErsatzTV.Core.Domain
 {
     public class PlayoutAnchor
     {
-        public int NextScheduleItemId { get; set; }
-
-        public ProgramScheduleItem NextScheduleItem { get; set; }
-
+        public CollectionEnumeratorState ScheduleItemsEnumeratorState { get; set; }
         public DateTime NextStart { get; set; }
         public int? MultipleRemaining { get; set; }
         public DateTime? DurationFinish { get; set; }

ErsatzTV.Core/Domain/ProgramSchedule.cs

@@ -8,6 +8,7 @@ namespace ErsatzTV.Core.Domain
         public string Name { get; set; }
         public bool KeepMultiPartEpisodesTogether { get; set; }
         public bool TreatCollectionsAsShows { get; set; }
+        public bool ShuffleScheduleItems { get; set; }
         public List<ProgramScheduleItem> Items { get; set; }
         public List<Playout> Playouts { get; set; }
     }

ErsatzTV.Core/ErsatzTV.Core.csproj

@@ -9,6 +9,7 @@
       <PackageReference Include="Flurl" Version="3.0.4" />
       <PackageReference Include="LanguageExt.Core" Version="4.0.3" />
       <PackageReference Include="MediatR" Version="10.0.1" />
+      <PackageReference Include="Microsoft.Extensions.DependencyInjection.Abstractions" Version="6.0.0" />
       <PackageReference Include="Microsoft.Extensions.Http" Version="6.0.0" />
       <PackageReference Include="Microsoft.Extensions.Logging.Abstractions" Version="6.0.0" />
       <PackageReference Include="Microsoft.VisualStudio.Threading.Analyzers" Version="17.0.64">
@@ -25,5 +26,9 @@
             <_Parameter1>ErsatzTV.Core.Tests</_Parameter1>
         </AssemblyAttribute>
     </ItemGroup>
+    
+    <ItemGroup>
+      <ProjectReference Include="..\ErsatzTV.FFmpeg\ErsatzTV.FFmpeg.csproj" />
+    </ItemGroup>
 
 </Project>

ErsatzTV.Core/FFmpeg/ConcatPlaylist.cs

@@ -4,7 +4,7 @@
     {
         public override string ToString() =>
             $@"ffconcat version 1.0
-file http://localhost:{Settings.ListenPort}/ffmpeg/stream/{ChannelNumber}
-file http://localhost:{Settings.ListenPort}/ffmpeg/stream/{ChannelNumber}";
+file http://localhost:{Settings.ListenPort}/ffmpeg/stream/{ChannelNumber}?mode=ts-legacy
+file http://localhost:{Settings.ListenPort}/ffmpeg/stream/{ChannelNumber}?mode=ts-legacy";
     }
 }

ErsatzTV.Core/FFmpeg/FFmpegComplexFilterBuilder.cs

@@ -6,6 +6,7 @@ using System.Runtime.InteropServices;
 using System.Text;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 using static LanguageExt.Prelude;
 
@@ -330,13 +331,13 @@ namespace ErsatzTV.Core.FFmpeg
 
                     string position = watermark.Location switch
                     {
-                        ChannelWatermarkLocation.BottomLeft => $"x={horizontalMargin}:y=H-h-{verticalMargin}",
-                        ChannelWatermarkLocation.TopLeft => $"x={horizontalMargin}:y={verticalMargin}",
-                        ChannelWatermarkLocation.TopRight => $"x=W-w-{horizontalMargin}:y={verticalMargin}",
-                        ChannelWatermarkLocation.TopMiddle => $"x=(W-w)/2:y={verticalMargin}",
-                        ChannelWatermarkLocation.RightMiddle => $"x=W-w-{horizontalMargin}:y=(H-h)/2",
-                        ChannelWatermarkLocation.BottomMiddle => $"x=(W-w)/2:y=H-h-{verticalMargin}",
-                        ChannelWatermarkLocation.LeftMiddle => $"x={horizontalMargin}:y=(H-h)/2",
+                        WatermarkLocation.BottomLeft => $"x={horizontalMargin}:y=H-h-{verticalMargin}",
+                        WatermarkLocation.TopLeft => $"x={horizontalMargin}:y={verticalMargin}",
+                        WatermarkLocation.TopRight => $"x=W-w-{horizontalMargin}:y={verticalMargin}",
+                        WatermarkLocation.TopMiddle => $"x=(W-w)/2:y={verticalMargin}",
+                        WatermarkLocation.RightMiddle => $"x=W-w-{horizontalMargin}:y=(H-h)/2",
+                        WatermarkLocation.BottomMiddle => $"x=(W-w)/2:y=H-h-{verticalMargin}",
+                        WatermarkLocation.LeftMiddle => $"x={horizontalMargin}:y=(H-h)/2",
                         _ => $"x=W-w-{horizontalMargin}:y=H-h-{verticalMargin}"
                     };
 
@@ -346,7 +347,7 @@ namespace ErsatzTV.Core.FFmpeg
                         watermarkPreprocess.Add($"colorchannelmixer=aa={opacity:F2}");
                     }
 
-                    if (watermark.Size == ChannelWatermarkSize.Scaled)
+                    if (watermark.Size == WatermarkSize.Scaled)
                     {
                         double width = Math.Round(watermark.WidthPercent / 100.0 * _resolution.Width);
                         watermarkPreprocess.Add($"scale={width}:-1");

ErsatzTV.Core/FFmpeg/FFmpegLibraryProcessService.cs

@@ -0,0 +1,410 @@
+using System;
+using System.Diagnostics;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using System.Text;
+using System.Threading.Tasks;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.FFmpeg;
+using ErsatzTV.FFmpeg.Environment;
+using ErsatzTV.FFmpeg.Format;
+using ErsatzTV.FFmpeg.OutputFormat;
+using ErsatzTV.FFmpeg.State;
+using LanguageExt;
+using Microsoft.Extensions.Logging;
+using static LanguageExt.Prelude;
+using FFmpegState = ErsatzTV.FFmpeg.FFmpegState;
+using MediaStream = ErsatzTV.Core.Domain.MediaStream;
+
+namespace ErsatzTV.Core.FFmpeg;
+
+public class FFmpegLibraryProcessService : IFFmpegProcessService
+{
+    private readonly FFmpegProcessService _ffmpegProcessService;
+    private readonly FFmpegPlaybackSettingsCalculator _playbackSettingsCalculator;
+    private readonly IFFmpegStreamSelector _ffmpegStreamSelector;
+    private readonly ILogger<FFmpegLibraryProcessService> _logger;
+
+    public FFmpegLibraryProcessService(
+        FFmpegProcessService ffmpegProcessService,
+        FFmpegPlaybackSettingsCalculator playbackSettingsCalculator,
+        IFFmpegStreamSelector ffmpegStreamSelector,
+        ILogger<FFmpegLibraryProcessService> logger)
+    {
+        _ffmpegProcessService = ffmpegProcessService;
+        _playbackSettingsCalculator = playbackSettingsCalculator;
+        _ffmpegStreamSelector = ffmpegStreamSelector;
+        _logger = logger;
+    }
+
+    public async Task<Process> ForPlayoutItem(
+        string ffmpegPath,
+        bool saveReports,
+        Channel channel,
+        MediaVersion videoVersion,
+        MediaVersion audioVersion,
+        string videoPath,
+        string audioPath,
+        DateTimeOffset start,
+        DateTimeOffset finish,
+        DateTimeOffset now,
+        Option<ChannelWatermark> globalWatermark,
+        VaapiDriver vaapiDriver,
+        string vaapiDevice,
+        bool hlsRealtime,
+        FillerKind fillerKind,
+        TimeSpan inPoint,
+        TimeSpan outPoint,
+        long ptsOffset,
+        Option<int> targetFramerate)
+    {
+        MediaStream videoStream = await _ffmpegStreamSelector.SelectVideoStream(channel, videoVersion);
+        Option<MediaStream> maybeAudioStream = await _ffmpegStreamSelector.SelectAudioStream(channel, audioVersion);
+
+        FFmpegPlaybackSettings playbackSettings = _playbackSettingsCalculator.CalculateSettings(
+            channel.StreamingMode,
+            channel.FFmpegProfile,
+            videoVersion,
+            videoStream,
+            maybeAudioStream,
+            start,
+            now,
+            inPoint,
+            outPoint,
+            hlsRealtime,
+            targetFramerate);
+
+        Option<WatermarkOptions> watermarkOptions =
+            await _ffmpegProcessService.GetWatermarkOptions(channel, globalWatermark, videoVersion, None, None);
+
+        Option<List<FadePoint>> maybeFadePoints = watermarkOptions
+            .Map(o => o.Watermark)
+            .Flatten()
+            .Where(wm => wm.Mode == ChannelWatermarkMode.Intermittent)
+            .Map(
+                wm =>
+                    WatermarkCalculator.CalculateFadePoints(
+                        start,
+                        inPoint,
+                        outPoint,
+                        playbackSettings.StreamSeek,
+                        wm.FrequencyMinutes,
+                        wm.DurationSeconds));
+        
+        var audioState = new AudioState(
+            playbackSettings.AudioCodec,
+            playbackSettings.AudioChannels,
+            playbackSettings.AudioBitrate,
+            playbackSettings.AudioBufferSize,
+            playbackSettings.AudioSampleRate,
+            videoPath == audioPath ? playbackSettings.AudioDuration : Option<TimeSpan>.None,
+            playbackSettings.NormalizeLoudness);
+
+        var ffmpegVideoStream = new VideoStream(
+            videoStream.Index,
+            videoStream.Codec,
+            AvailablePixelFormats.ForPixelFormat(videoStream.PixelFormat, _logger),
+            new FrameSize(videoVersion.Width, videoVersion.Height),
+            videoVersion.RFrameRate,
+            videoPath != audioPath); // still image when paths are different
+
+        var videoInputFile = new VideoInputFile(videoPath, new List<VideoStream> { ffmpegVideoStream });
+
+        Option<AudioInputFile> audioInputFile = maybeAudioStream.Map(
+            audioStream =>
+            {
+                var ffmpegAudioStream = new AudioStream(audioStream.Index, audioStream.Codec, audioStream.Channels);
+                return new AudioInputFile(audioPath, new List<AudioStream> { ffmpegAudioStream }, audioState);
+            });
+
+        var watermarkInputFile = GetWatermarkInputFile(watermarkOptions, maybeFadePoints);
+        
+        // TODO: need formats for these codecs
+        string videoFormat = playbackSettings.VideoCodec switch
+        {
+            "libx265" or "hevc_nvenc" or "hevc_qsv" or "hevc_vaapi" or "hevc_videotoolbox" => VideoFormat.Hevc,
+            "libx264" or "h264_nvenc" or "h264_qsv" or "h264_vaapi" or "h264_videotoolbox" => VideoFormat.H264,
+            "mpeg2video" => VideoFormat.Mpeg2Video,
+            "copy" => VideoFormat.Copy,
+            _ => throw new ArgumentOutOfRangeException($"unexpected video codec {playbackSettings.VideoCodec}")
+        };
+
+        HardwareAccelerationMode hwAccel = playbackSettings.HardwareAcceleration switch
+        {
+            HardwareAccelerationKind.Nvenc => HardwareAccelerationMode.Nvenc,
+            HardwareAccelerationKind.Qsv => HardwareAccelerationMode.Qsv,
+            HardwareAccelerationKind.Vaapi => HardwareAccelerationMode.Vaapi,
+            HardwareAccelerationKind.VideoToolbox => HardwareAccelerationMode.VideoToolbox,
+            _ => HardwareAccelerationMode.None
+        };
+
+        OutputFormatKind outputFormat = channel.StreamingMode == StreamingMode.HttpLiveStreamingSegmenter
+            ? OutputFormatKind.Hls
+            : OutputFormatKind.MpegTs;
+
+        Option<string> hlsPlaylistPath = outputFormat == OutputFormatKind.Hls
+            ? Path.Combine(FileSystemLayout.TranscodeFolder, channel.Number, "live.m3u8")
+            : Option<string>.None;
+
+        Option<string> hlsSegmentTemplate = outputFormat == OutputFormatKind.Hls
+            ? Path.Combine(FileSystemLayout.TranscodeFolder, channel.Number, "live%06d.ts")
+            : Option<string>.None;
+
+        // normalize songs to yuv420p
+        Option<IPixelFormat> desiredPixelFormat =
+            videoPath == audioPath ? ffmpegVideoStream.PixelFormat : new PixelFormatYuv420P();
+
+        var desiredState = new FrameState(
+            playbackSettings.RealtimeOutput,
+            false, // TODO: fallback filler needs to loop
+            videoFormat,
+            desiredPixelFormat,
+            await playbackSettings.ScaledSize.Map(ss => new FrameSize(ss.Width, ss.Height))
+                .IfNoneAsync(new FrameSize(videoVersion.Width, videoVersion.Height)),
+            new FrameSize(channel.FFmpegProfile.Resolution.Width, channel.FFmpegProfile.Resolution.Height),
+            playbackSettings.FrameRate,
+            playbackSettings.VideoBitrate,
+            playbackSettings.VideoBufferSize,
+            playbackSettings.VideoTrackTimeScale,
+            playbackSettings.Deinterlace);
+
+        var ffmpegState = new FFmpegState(
+            saveReports,
+            hwAccel,
+            VaapiDriverName(hwAccel, vaapiDriver),
+            VaapiDeviceName(hwAccel, vaapiDevice),
+            playbackSettings.StreamSeek,
+            finish - now,
+            channel.StreamingMode != StreamingMode.HttpLiveStreamingDirect,
+            "ErsatzTV",
+            channel.Name,
+            maybeAudioStream.Map(s => Optional(s.Language)).Flatten(),
+            outputFormat,
+            hlsPlaylistPath,
+            hlsSegmentTemplate,
+            ptsOffset);
+
+        _logger.LogDebug("FFmpeg desired state {FrameState}", desiredState);
+        
+        var pipelineBuilder = new PipelineBuilder(
+            videoInputFile,
+            audioInputFile,
+            watermarkInputFile,
+            FileSystemLayout.FFmpegReportsFolder,
+            _logger);
+
+        FFmpegPipeline pipeline = pipelineBuilder.Build(ffmpegState, desiredState);
+
+        return GetProcess(ffmpegPath, videoInputFile, audioInputFile, watermarkInputFile, None, pipeline);
+    }
+
+    private Option<WatermarkInputFile> GetWatermarkInputFile(
+        Option<WatermarkOptions> watermarkOptions,
+        Option<List<FadePoint>> maybeFadePoints)
+    {
+        foreach (WatermarkOptions options in watermarkOptions)
+        {
+            foreach (ChannelWatermark watermark in options.Watermark)
+            {
+                // skip watermark if intermittent and no fade points
+                if (watermark.Mode != ChannelWatermarkMode.None &&
+                    (watermark.Mode != ChannelWatermarkMode.Intermittent ||
+                     maybeFadePoints.Map(fp => fp.Count > 0).IfNone(false)))
+                {
+                    foreach (string path in options.ImagePath)
+                    {
+                        var watermarkInputFile = new WatermarkInputFile(
+                            path,
+                            new List<VideoStream>
+                            {
+                                new(
+                                    options.ImageStreamIndex.IfNone(0),
+                                    "unknown",
+                                    new PixelFormatUnknown(),
+                                    new FrameSize(1, 1),
+                                    Option<string>.None,
+                                    !options.IsAnimated)
+                            },
+                            new WatermarkState(
+                                maybeFadePoints.Map(
+                                    lst => lst.Map(
+                                        fp =>
+                                        {
+                                            return fp switch
+                                            {
+                                                FadeInPoint fip => (WatermarkFadePoint)new WatermarkFadeIn(
+                                                    fip.Time,
+                                                    fip.EnableStart,
+                                                    fip.EnableFinish),
+                                                FadeOutPoint fop => new WatermarkFadeOut(
+                                                    fop.Time,
+                                                    fop.EnableStart,
+                                                    fop.EnableFinish),
+                                                _ => throw new NotSupportedException() // this will never happen
+                                            };
+                                        }).ToList()),
+                                watermark.Location,
+                                watermark.Size,
+                                watermark.WidthPercent,
+                                watermark.HorizontalMarginPercent,
+                                watermark.VerticalMarginPercent,
+                                watermark.Opacity));
+
+                        return watermarkInputFile;
+                    }
+                }
+            }
+        }
+
+        return None;
+    }
+
+    public Task<Process> ForError(
+        string ffmpegPath,
+        Channel channel,
+        Option<TimeSpan> duration,
+        string errorMessage,
+        bool hlsRealtime,
+        long ptsOffset) =>
+        _ffmpegProcessService.ForError(ffmpegPath, channel, duration, errorMessage, hlsRealtime, ptsOffset);
+
+    public Process ConcatChannel(string ffmpegPath, bool saveReports, Channel channel, string scheme, string host)
+    {
+        var resolution = new FrameSize(channel.FFmpegProfile.Resolution.Width, channel.FFmpegProfile.Resolution.Height);
+
+        var concatInputFile = new ConcatInputFile(
+            $"http://localhost:{Settings.ListenPort}/ffmpeg/concat/{channel.Number}",
+            resolution);
+
+        var pipelineBuilder = new PipelineBuilder(None, None, None, FileSystemLayout.FFmpegReportsFolder, _logger);
+
+        FFmpegPipeline pipeline = pipelineBuilder.Concat(
+            concatInputFile,
+            FFmpegState.Concat(saveReports, channel.Name));
+
+        return GetProcess(ffmpegPath, None, None, None, concatInputFile, pipeline);
+    }
+
+    public Process WrapSegmenter(string ffmpegPath, bool saveReports, Channel channel, string scheme, string host) =>
+        _ffmpegProcessService.WrapSegmenter(ffmpegPath, saveReports, channel, scheme, host);
+
+    public Process ConvertToPng(string ffmpegPath, string inputFile, string outputFile) =>
+        _ffmpegProcessService.ConvertToPng(ffmpegPath, inputFile, outputFile);
+
+    public Process ExtractAttachedPicAsPng(string ffmpegPath, string inputFile, int streamIndex, string outputFile) =>
+        _ffmpegProcessService.ExtractAttachedPicAsPng(ffmpegPath, inputFile, streamIndex, outputFile);
+
+    public Task<Either<BaseError, string>> GenerateSongImage(
+        string ffmpegPath,
+        Option<string> subtitleFile,
+        Channel channel,
+        Option<ChannelWatermark> globalWatermark,
+        MediaVersion videoVersion,
+        string videoPath,
+        bool boxBlur,
+        Option<string> watermarkPath,
+        WatermarkLocation watermarkLocation,
+        int horizontalMarginPercent,
+        int verticalMarginPercent,
+        int watermarkWidthPercent) =>
+        _ffmpegProcessService.GenerateSongImage(
+            ffmpegPath,
+            subtitleFile,
+            channel,
+            globalWatermark,
+            videoVersion,
+            videoPath,
+            boxBlur,
+            watermarkPath,
+            watermarkLocation,
+            horizontalMarginPercent,
+            verticalMarginPercent,
+            watermarkWidthPercent);
+
+    private Process GetProcess(
+        string ffmpegPath,
+        Option<VideoInputFile> videoInputFile,
+        Option<AudioInputFile> audioInputFile,
+        Option<WatermarkInputFile> watermarkInputFile,
+        Option<ConcatInputFile> concatInputFile,
+        FFmpegPipeline pipeline)
+    {
+        IEnumerable<string> loggedSteps = pipeline.PipelineSteps.Map(ps => ps.GetType().Name);
+        IEnumerable<string> loggedVideoFilters =
+            videoInputFile.Map(f => f.FilterSteps.Map(vf => vf.GetType().Name)).Flatten();
+        IEnumerable<string> loggedAudioFilters =
+            audioInputFile.Map(f => f.FilterSteps.Map(af => af.GetType().Name)).Flatten();
+
+        _logger.LogDebug(
+            "FFmpeg pipeline {PipelineSteps}, {AudioFilters}, {VideoFilters}",
+            loggedSteps,
+            loggedAudioFilters,
+            loggedVideoFilters
+        );
+
+        IList<EnvironmentVariable> environmentVariables =
+            CommandGenerator.GenerateEnvironmentVariables(pipeline.PipelineSteps);
+        IList<string> arguments = CommandGenerator.GenerateArguments(
+            videoInputFile,
+            audioInputFile,
+            watermarkInputFile,
+            concatInputFile,
+            pipeline.PipelineSteps);
+
+        var startInfo = new ProcessStartInfo
+        {
+            FileName = ffmpegPath,
+            RedirectStandardOutput = true,
+            RedirectStandardError = false,
+            UseShellExecute = false,
+            CreateNoWindow = true,
+            StandardOutputEncoding = Encoding.UTF8
+        };
+
+        if (environmentVariables.Any())
+        {
+            _logger.LogDebug("FFmpeg environment variables {EnvVars}", environmentVariables);
+        }
+
+        foreach ((string key, string value) in environmentVariables)
+        {
+            startInfo.EnvironmentVariables[key] = value;
+        }
+
+        foreach (string argument in arguments)
+        {
+            startInfo.ArgumentList.Add(argument);
+        }
+
+        return new Process
+        {
+            StartInfo = startInfo
+        };
+    }
+
+    private static Option<string> VaapiDriverName(HardwareAccelerationMode accelerationMode, VaapiDriver driver)
+    {
+        if (accelerationMode == HardwareAccelerationMode.Vaapi)
+        {
+            switch (driver)
+            {
+                case VaapiDriver.i965:
+                    return "i965";
+                case VaapiDriver.iHD:
+                    return "iHD";
+                case VaapiDriver.RadeonSI:
+                    return "radeonsi";
+            }
+        }
+        
+        return Option<string>.None;
+    }
+
+    private static Option<string> VaapiDeviceName(HardwareAccelerationMode accelerationMode, string vaapiDevice)
+    {
+        return accelerationMode == HardwareAccelerationMode.Vaapi ? vaapiDevice : Option<string>.None;
+    }
+}

ErsatzTV.Core/FFmpeg/FFmpegProcessBuilder.cs

@@ -222,7 +222,7 @@ namespace ErsatzTV.Core.FFmpeg
                 _arguments.Add($"{fr}");
             
                 _arguments.Add("-vsync");
-                _arguments.Add("1");
+                _arguments.Add("cfr");
             }
 
             return this;

ErsatzTV.Core/FFmpeg/FFmpegProcessService.cs

@@ -7,9 +7,11 @@ using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Domain.Filler;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 using Microsoft.Extensions.Logging;
 using static LanguageExt.Prelude;
+using MediaStream = ErsatzTV.Core.Domain.MediaStream;
 
 namespace ErsatzTV.Core.FFmpeg
 {
@@ -182,23 +184,18 @@ namespace ErsatzTV.Core.FFmpeg
                 .WithMetadata(channel, maybeAudioStream)
                 .WithDuration(finish - now);
 
-            switch (channel.StreamingMode)
+            return channel.StreamingMode switch
             {
                 // HLS needs to segment and generate playlist
-                case StreamingMode.HttpLiveStreamingSegmenter:
-                    return builder.WithHls(
-                            channel.Number,
-                            videoVersion,
-                            ptsOffset,
-                            playbackSettings.VideoTrackTimeScale,
-                            playbackSettings.FrameRate)
-                        .Build();
-                default:
-                    return builder.WithFormat("mpegts")
-                        .WithInitialDiscontinuity()
-                        .WithPipe()
-                        .Build();
-            }
+                StreamingMode.HttpLiveStreamingSegmenter => builder.WithHls(
+                        channel.Number,
+                        videoVersion,
+                        ptsOffset,
+                        playbackSettings.VideoTrackTimeScale,
+                        playbackSettings.FrameRate)
+                    .Build(),
+                _ => builder.WithFormat("mpegts").WithInitialDiscontinuity().WithPipe().Build()
+            };
         }
 
         public async Task<Process> ForError(
@@ -334,7 +331,7 @@ namespace ErsatzTV.Core.FFmpeg
             string videoPath,
             bool boxBlur,
             Option<string> watermarkPath,
-            ChannelWatermarkLocation watermarkLocation,
+            WatermarkLocation watermarkLocation,
             int horizontalMarginPercent,
             int verticalMarginPercent,
             int watermarkWidthPercent)
@@ -353,7 +350,7 @@ namespace ErsatzTV.Core.FFmpeg
                             HorizontalMarginPercent = horizontalMarginPercent,
                             VerticalMarginPercent = verticalMarginPercent,
                             Location = watermarkLocation,
-                            Size = ChannelWatermarkSize.Scaled,
+                            Size = WatermarkSize.Scaled,
                             WidthPercent = watermarkWidthPercent,
                             Opacity = 100
                         }
@@ -425,18 +422,13 @@ namespace ErsatzTV.Core.FFmpeg
         private bool NeedToPad(IDisplaySize target, IDisplaySize displaySize) =>
             displaySize.Width != target.Width || displaySize.Height != target.Height;
 
-        private async Task<WatermarkOptions> GetWatermarkOptions(
+        internal async Task<WatermarkOptions> GetWatermarkOptions(
             Channel channel,
             Option<ChannelWatermark> globalWatermark,
             MediaVersion videoVersion,
             Option<ChannelWatermark> watermarkOverride,
             Option<string> watermarkPath)
         {
-            if (videoVersion is BackgroundImageMediaVersion)
-            {
-                return new WatermarkOptions(None, None, None, false);
-            }
-
             if (channel.StreamingMode != StreamingMode.HttpLiveStreamingDirect && channel.FFmpegProfile.Transcode &&
                 channel.FFmpegProfile.NormalizeVideo)
             {

ErsatzTV.Core/FFmpeg/FFmpegProcessServiceFactory.cs

@@ -0,0 +1,31 @@
+using System;
+using System.Threading.Tasks;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.Core.Interfaces.Repositories;
+using LanguageExt;
+using Microsoft.Extensions.DependencyInjection;
+
+namespace ErsatzTV.Core.FFmpeg;
+
+public class FFmpegProcessServiceFactory : IFFmpegProcessServiceFactory
+{
+    private readonly IConfigElementRepository _configElementRepository;
+    private readonly IServiceProvider _serviceProvider;
+
+    public FFmpegProcessServiceFactory(IConfigElementRepository configElementRepository, IServiceProvider serviceProvider)
+    {
+        _configElementRepository = configElementRepository;
+        _serviceProvider = serviceProvider;
+    }
+
+    public async Task<IFFmpegProcessService> GetService()
+    {
+        Option<bool> useExperimentalTranscoder =
+            await _configElementRepository.GetValue<bool>(ConfigElementKey.FFmpegUseExperimentalTranscoder);
+
+        return await useExperimentalTranscoder.IfNoneAsync(false)
+            ? _serviceProvider.GetRequiredService<FFmpegLibraryProcessService>()
+            : _serviceProvider.GetRequiredService<FFmpegProcessService>();
+    }
+}

ErsatzTV.Core/FFmpeg/HlsPlaylistFilter.cs

@@ -1,110 +1,144 @@
 using System;
 using System.Globalization;
+using System.IO;
 using System.Text;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using Microsoft.Extensions.Logging;
 
 namespace ErsatzTV.Core.FFmpeg
 {
-    public class HlsPlaylistFilter
+    public class HlsPlaylistFilter : IHlsPlaylistFilter
     {
-        public static TrimPlaylistResult TrimPlaylist(
+        private readonly ITempFilePool _tempFilePool;
+        private readonly ILogger<HlsPlaylistFilter> _logger;
+
+        public HlsPlaylistFilter(ITempFilePool tempFilePool, ILogger<HlsPlaylistFilter> logger)
+        {
+            _tempFilePool = tempFilePool;
+            _logger = logger;
+        }
+
+        public TrimPlaylistResult TrimPlaylist(
             DateTimeOffset playlistStart,
             DateTimeOffset filterBefore,
             string[] lines,
             int maxSegments = 10,
             bool endWithDiscontinuity = false)
         {
-            DateTimeOffset currentTime = playlistStart;
-            DateTimeOffset nextPlaylistStart = DateTimeOffset.MaxValue;
-            
-            var discontinuitySequence = 0;
-            var startSequence = 0;
-            var output = new StringBuilder();
-            var started = false;
-            var i = 0;
-            var segments = 0;
-            while (!lines[i].StartsWith("#EXTINF:"))
+            try
             {
-                if (lines[i].StartsWith("#EXT-X-DISCONTINUITY-SEQUENCE"))
-                {
-                    discontinuitySequence = int.Parse(lines[i].Split(':')[1]);
-                }
+                DateTimeOffset currentTime = playlistStart;
+                DateTimeOffset nextPlaylistStart = DateTimeOffset.MaxValue;
 
-                i++;
-            }
-
-            while (i < lines.Length)
-            {
-                if (segments >= maxSegments)
+                var discontinuitySequence = 0;
+                var startSequence = 0;
+                var output = new StringBuilder();
+                var started = false;
+                var i = 0;
+                var segments = 0;
+                while (!lines[i].StartsWith("#EXTINF:"))
                 {
-                    break;
-                }
-
-                string line = lines[i];
-                // _logger.LogInformation("Line: {Line}", line);
-                if (line.StartsWith("#EXT-X-DISCONTINUITY"))
-                {
-                    if (started)
+                    if (lines[i].StartsWith("#EXT-X-DISCONTINUITY-SEQUENCE"))
                     {
-                        output.AppendLine("#EXT-X-DISCONTINUITY");
-                    }
-                    else
-                    {
-                        discontinuitySequence++;
+                        discontinuitySequence = int.Parse(lines[i].Split(':')[1]);
                     }
 
                     i++;
-                    continue;
                 }
 
-                var duration = TimeSpan.FromSeconds(
-                    double.Parse(
-                        lines[i].TrimEnd(',').Split(':')[1],
-                        NumberStyles.Number,
-                        CultureInfo.InvariantCulture));
-                if (currentTime < filterBefore)
+                while (i < lines.Length)
                 {
+                    if (segments >= maxSegments)
+                    {
+                        break;
+                    }
+
+                    string line = lines[i];
+                    // _logger.LogInformation("Line: {Line}", line);
+                    if (line.StartsWith("#EXT-X-DISCONTINUITY"))
+                    {
+                        if (started)
+                        {
+                            output.AppendLine("#EXT-X-DISCONTINUITY");
+                        }
+                        else
+                        {
+                            discontinuitySequence++;
+                        }
+
+                        i++;
+                        continue;
+                    }
+
+                    var duration = TimeSpan.FromSeconds(
+                        double.Parse(
+                            lines[i].TrimEnd(',').Split(':')[1],
+                            NumberStyles.Number,
+                            CultureInfo.InvariantCulture));
+                    if (currentTime < filterBefore)
+                    {
+                        currentTime += duration;
+                        i += 3;
+                        continue;
+                    }
+
+                    nextPlaylistStart = currentTime < nextPlaylistStart ? currentTime : nextPlaylistStart;
+
+                    if (!started)
+                    {
+                        startSequence = int.Parse(lines[i + 2].Replace("live", string.Empty).Split('.')[0]);
+
+                        output.AppendLine("#EXTM3U");
+                        output.AppendLine("#EXT-X-VERSION:6");
+                        output.AppendLine("#EXT-X-TARGETDURATION:4");
+                        output.AppendLine($"#EXT-X-MEDIA-SEQUENCE:{startSequence}");
+                        output.AppendLine($"#EXT-X-DISCONTINUITY-SEQUENCE:{discontinuitySequence}");
+                        output.AppendLine("#EXT-X-INDEPENDENT-SEGMENTS");
+                        output.AppendLine("#EXT-X-DISCONTINUITY");
+
+                        started = true;
+                    }
+
+                    output.AppendLine(lines[i]);
+                    string offset = currentTime.ToString("zzz").Replace(":", string.Empty);
+                    output.AppendLine($"#EXT-X-PROGRAM-DATE-TIME:{currentTime:yyyy-MM-ddTHH:mm:ss.fff}{offset}");
+                    output.AppendLine(lines[i + 2]);
+
                     currentTime += duration;
+                    segments++;
                     i += 3;
-                    continue;
                 }
-    
-                nextPlaylistStart = currentTime < nextPlaylistStart ? currentTime : nextPlaylistStart;
 
-                if (!started)
+                var playlist = output.ToString();
+                if (endWithDiscontinuity && !playlist.EndsWith($"#EXT-X-DISCONTINUITY{Environment.NewLine}"))
                 {
-                    startSequence = int.Parse(lines[i + 2].Replace("live", string.Empty).Split('.')[0]);
-
-                    output.AppendLine("#EXTM3U");
-                    output.AppendLine("#EXT-X-VERSION:6");
-                    output.AppendLine("#EXT-X-TARGETDURATION:4");
-                    output.AppendLine($"#EXT-X-MEDIA-SEQUENCE:{startSequence}");
-                    output.AppendLine($"#EXT-X-DISCONTINUITY-SEQUENCE:{discontinuitySequence}");
-                    output.AppendLine("#EXT-X-INDEPENDENT-SEGMENTS");
-                    output.AppendLine("#EXT-X-DISCONTINUITY");
-
-                    started = true;
+                    playlist += "#EXT-X-DISCONTINUITY" + Environment.NewLine;
                 }
 
-                output.AppendLine(lines[i]);
-                string offset = currentTime.ToString("zzz").Replace(":", string.Empty);
-                output.AppendLine($"#EXT-X-PROGRAM-DATE-TIME:{currentTime:yyyy-MM-ddTHH:mm:ss.fff}{offset}");
-                output.AppendLine(lines[i + 2]);
-
-                currentTime += duration;
-                segments++;
-                i += 3;
+                return new TrimPlaylistResult(nextPlaylistStart, startSequence, playlist, segments);
             }
-
-            var playlist = output.ToString();
-            if (endWithDiscontinuity && !playlist.EndsWith($"#EXT-X-DISCONTINUITY{Environment.NewLine}"))
+            catch (Exception ex)
             {
-                playlist += "#EXT-X-DISCONTINUITY" + Environment.NewLine;
-            }
+                try
+                {
+                    string file = _tempFilePool.GetNextTempFile(TempFileCategory.BadPlaylist);
+                    File.WriteAllLines(file, lines);
 
-            return new TrimPlaylistResult(nextPlaylistStart, startSequence, playlist, segments);
+                    _logger.LogError(ex, "Error filtering playlist. Bad playlist saved to {BadPlaylistFile}", file);
+                    
+                    // TODO: better error result?
+                    return new TrimPlaylistResult(playlistStart, 0, string.Empty, 0);
+                }
+                catch
+                {
+                    // do nothing
+                }
+
+                throw;
+            }
         }
 
-        public static TrimPlaylistResult TrimPlaylistWithDiscontinuity(
+        public TrimPlaylistResult TrimPlaylistWithDiscontinuity(
             DateTimeOffset playlistStart,
             DateTimeOffset filterBefore,
             string[] lines)

ErsatzTV.Core/FFmpeg/IFFmpegProcessServiceFactory.cs

@@ -0,0 +1,9 @@
+using System.Threading.Tasks;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+
+namespace ErsatzTV.Core.FFmpeg;
+
+public interface IFFmpegProcessServiceFactory
+{
+    Task<IFFmpegProcessService> GetService();
+}

ErsatzTV.Core/FFmpeg/IHlsPlaylistFilter.cs

@@ -0,0 +1,18 @@
+using System;
+
+namespace ErsatzTV.Core.FFmpeg;
+
+public interface IHlsPlaylistFilter
+{
+    TrimPlaylistResult TrimPlaylist(
+        DateTimeOffset playlistStart,
+        DateTimeOffset filterBefore,
+        string[] lines,
+        int maxSegments = 10,
+        bool endWithDiscontinuity = false);
+
+    TrimPlaylistResult TrimPlaylistWithDiscontinuity(
+        DateTimeOffset playlistStart,
+        DateTimeOffset filterBefore,
+        string[] lines);
+}

ErsatzTV.Core/FFmpeg/SongVideoGenerator.cs

@@ -7,6 +7,8 @@ using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
+using ErsatzTV.FFmpeg.Format;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 using static LanguageExt.Prelude;
 
@@ -19,16 +21,16 @@ namespace ErsatzTV.Core.FFmpeg
         
         private readonly ITempFilePool _tempFilePool;
         private readonly IImageCache _imageCache;
-        private readonly IFFmpegProcessService _ffmpegProcessService;
+        private readonly IFFmpegProcessServiceFactory _ffmpegProcessServiceFactory;
 
         public SongVideoGenerator(
             ITempFilePool tempFilePool,
             IImageCache imageCache,
-            IFFmpegProcessService ffmpegProcessService)
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory)
         {
             _tempFilePool = tempFilePool;
             _imageCache = imageCache;
-            _ffmpegProcessService = ffmpegProcessService;
+            _ffmpegProcessServiceFactory = ffmpegProcessServiceFactory;
         }
 
         public async Task<Tuple<string, MediaVersion>> GenerateSongVideo(
@@ -48,7 +50,7 @@ namespace ErsatzTV.Core.FFmpeg
                 SampleAspectRatio = "1:1",
                 Streams = new List<MediaStream>
                 {
-                    new() { MediaStreamKind = MediaStreamKind.Video, Index = 0 }
+                    new() { MediaStreamKind = MediaStreamKind.Video, Index = 0, PixelFormat = "yuv420p" }
                 }
             };
             
@@ -71,9 +73,9 @@ namespace ErsatzTV.Core.FFmpeg
             const int HORIZONTAL_MARGIN_PERCENT = 3;
             const int VERTICAL_MARGIN_PERCENT = 5;
             const int WATERMARK_WIDTH_PERCENT = 25;
-            ChannelWatermarkLocation watermarkLocation = NextRandom(2) == 0
-                ? ChannelWatermarkLocation.BottomLeft
-                : ChannelWatermarkLocation.BottomRight;
+            WatermarkLocation watermarkLocation = NextRandom(2) == 0
+                ? WatermarkLocation.BottomLeft
+                : WatermarkLocation.BottomRight;
             
             foreach (SongMetadata metadata in song.SongMetadata)
             {
@@ -120,10 +122,10 @@ namespace ErsatzTV.Core.FFmpeg
                 {
                     switch (watermarkLocation)
                     {
-                        case ChannelWatermarkLocation.BottomLeft:
+                        case WatermarkLocation.BottomLeft:
                             leftMarginPercent += WATERMARK_WIDTH_PERCENT + HORIZONTAL_MARGIN_PERCENT;
                             break;
-                        case ChannelWatermarkLocation.BottomRight:
+                        case WatermarkLocation.BottomRight:
                             leftMarginPercent = rightMarginPercent = HORIZONTAL_MARGIN_PERCENT;
                             rightMarginPercent += WATERMARK_WIDTH_PERCENT + HORIZONTAL_MARGIN_PERCENT;
                             break;
@@ -208,7 +210,8 @@ namespace ErsatzTV.Core.FFmpeg
                 new() { Path = videoPath }
             };
 
-            Either<BaseError, string> maybeSongImage = await _ffmpegProcessService.GenerateSongImage(
+            IFFmpegProcessService ffmpegProcessService = await _ffmpegProcessServiceFactory.GetService();
+            Either<BaseError, string> maybeSongImage = await ffmpegProcessService.GenerateSongImage(
                 ffmpegPath,
                 subtitleFile,
                 channel,
@@ -234,7 +237,13 @@ namespace ErsatzTV.Core.FFmpeg
                     SampleAspectRatio = "1:1",
                     Streams = new List<MediaStream>
                     {
-                        new() { MediaStreamKind = MediaStreamKind.Video, Index = 0 },
+                        new()
+                        {
+                            MediaStreamKind = MediaStreamKind.Video,
+                            Index = 0,
+                            Codec = VideoFormat.GeneratedImage,
+                            PixelFormat = new PixelFormatUnknown().Name // the resulting pixel format is unknown
+                        },
                     },
                     MediaFiles = new List<MediaFile>
                     {

ErsatzTV.Core/FFmpeg/TempFileCategory.cs

@@ -5,6 +5,8 @@
         Subtitle = 0,
         SongBackground = 1,
         CoverArt = 2,
-        CachedArtwork = 3
+        CachedArtwork = 3,
+
+        BadPlaylist = 99
     }
 }

ErsatzTV.Core/Interfaces/FFmpeg/IFFmpegProcessService.cs

@@ -4,6 +4,7 @@ using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Domain.Filler;
 using ErsatzTV.Core.FFmpeg;
+using ErsatzTV.FFmpeg.State;
 using LanguageExt;
 
 namespace ErsatzTV.Core.Interfaces.FFmpeg
@@ -56,7 +57,7 @@ namespace ErsatzTV.Core.Interfaces.FFmpeg
             string videoPath,
             bool boxBlur,
             Option<string> watermarkPath,
-            ChannelWatermarkLocation watermarkLocation,
+            WatermarkLocation watermarkLocation,
             int horizontalMarginPercent,
             int verticalMarginPercent,
             int watermarkWidthPercent);

ErsatzTV.Core/Interfaces/Scheduling/IScheduleItemsEnumerator.cs

@@ -0,0 +1,12 @@
+using ErsatzTV.Core.Domain;
+using LanguageExt;
+
+namespace ErsatzTV.Core.Interfaces.Scheduling;
+
+public interface IScheduleItemsEnumerator
+{
+    CollectionEnumeratorState State { get; }
+    ProgramScheduleItem Current { get; }
+    void MoveNext();
+    ProgramScheduleItem Peek(int offset);
+}

ErsatzTV.Core/Iptv/ChannelGuide.cs

@@ -53,6 +53,14 @@ namespace ErsatzTV.Core.Iptv
                     xml.WriteString(channel.Name);
                     xml.WriteEndElement(); // display-name
 
+                    foreach (string category in GetCategories(channel.Categories))
+                    {
+                        xml.WriteStartElement("category");
+                        xml.WriteAttributeString("lang", "en");
+                        xml.WriteString(category);
+                        xml.WriteEndElement(); // category
+                    }
+
                     xml.WriteStartElement("icon");
                     string logo = Optional(channel.Artwork).Flatten()
                         .Filter(a => a.ArtworkKind == ArtworkKind.Logo)
@@ -491,6 +499,13 @@ namespace ErsatzTV.Core.Iptv
                 }).Flatten();
         }
 
+        private static List<string> GetCategories(string categories) =>
+            (categories ?? string.Empty).Split(',')
+            .Map(s => s.Trim())
+            .Filter(s => !string.IsNullOrWhiteSpace(s))
+            .Distinct()
+            .ToList();
+
         private record ContentRating(Option<string> System, string Value);
     }
 }

ErsatzTV.Core/Iptv/ChannelPlaylist.cs

@@ -52,7 +52,7 @@ namespace ErsatzTV.Core.Iptv
                 string acodec = channel.FFmpegProfile.AudioCodec;
 
                 sb.AppendLine(
-                    $"#EXTINF:0 tvg-id=\"{channel.Number}.etv\" channel-id=\"{shortUniqueId}\" channel-number=\"{channel.Number}\" CUID=\"{shortUniqueId}\" tvg-chno=\"{channel.Number}\" tvg-name=\"{channel.Name}\" tvg-logo=\"{logo}\" group-title=\"ErsatzTV\" tvc-stream-vcodec=\"{vcodec}\" tvc-stream-acodec=\"{acodec}\", {channel.Name}");
+                    $"#EXTINF:0 tvg-id=\"{channel.Number}.etv\" channel-id=\"{shortUniqueId}\" channel-number=\"{channel.Number}\" CUID=\"{shortUniqueId}\" tvg-chno=\"{channel.Number}\" tvg-name=\"{channel.Name}\" tvg-logo=\"{logo}\" group-title=\"{channel.Group}\" tvc-stream-vcodec=\"{vcodec}\" tvc-stream-acodec=\"{acodec}\", {channel.Name}");
                 sb.AppendLine($"{_scheme}://{_host}/iptv/channel/{channel.Number}.{format}");
             }
 

ErsatzTV.Core/Metadata/LocalFolderScanner.cs

@@ -50,7 +50,7 @@ namespace ErsatzTV.Core.Metadata
             .ToList();
 
         private readonly IImageCache _imageCache;
-        private readonly IFFmpegProcessService _ffmpegProcessService;
+        private readonly IFFmpegProcessServiceFactory _ffmpegProcessServiceFactory;
         private readonly ITempFilePool _tempFilePool;
 
         private readonly ILocalFileSystem _localFileSystem;
@@ -65,7 +65,7 @@ namespace ErsatzTV.Core.Metadata
             IMetadataRepository metadataRepository,
             IMediaItemRepository mediaItemRepository,
             IImageCache imageCache,
-            IFFmpegProcessService ffmpegProcessService, 
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory, 
             ITempFilePool tempFilePool,
             ILogger logger)
         {
@@ -74,7 +74,7 @@ namespace ErsatzTV.Core.Metadata
             _metadataRepository = metadataRepository;
             _mediaItemRepository = mediaItemRepository;
             _imageCache = imageCache;
-            _ffmpegProcessService = ffmpegProcessService;
+            _ffmpegProcessServiceFactory = ffmpegProcessServiceFactory;
             _tempFilePool = tempFilePool;
             _logger = logger;
         }
@@ -156,12 +156,14 @@ namespace ErsatzTV.Core.Metadata
                     // if ffmpeg path is passed, we need pre-processing
                     foreach (string path in ffmpegPath)
                     {
+                        IFFmpegProcessService ffmpegProcessService = await _ffmpegProcessServiceFactory.GetService();
+                        
                         artworkFile = await attachedPicIndex.Match(
                             async picIndex =>
                             {
                                 // extract attached pic (and convert to png)
                                 string tempName = _tempFilePool.GetNextTempFile(TempFileCategory.CoverArt);
-                                using Process process = _ffmpegProcessService.ExtractAttachedPicAsPng(
+                                using Process process = ffmpegProcessService.ExtractAttachedPicAsPng(
                                     path,
                                     artworkFile,
                                     picIndex,
@@ -175,7 +177,7 @@ namespace ErsatzTV.Core.Metadata
                             {
                                 // no attached pic index means convert to png
                                 string tempName = _tempFilePool.GetNextTempFile(TempFileCategory.CoverArt);
-                                using Process process = _ffmpegProcessService.ConvertToPng(path, artworkFile, tempName);
+                                using Process process = ffmpegProcessService.ConvertToPng(path, artworkFile, tempName);
                                 process.Start();
                                 await process.WaitForExitAsync();
 

ErsatzTV.Core/Metadata/MovieFolderScanner.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
 using ErsatzTV.Core.Interfaces.Metadata;
@@ -41,7 +42,7 @@ namespace ErsatzTV.Core.Metadata
             ILibraryRepository libraryRepository,
             IMediaItemRepository mediaItemRepository,
             IMediator mediator,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ITempFilePool tempFilePool,
             ILogger<MovieFolderScanner> logger)
             : base(
@@ -50,7 +51,7 @@ namespace ErsatzTV.Core.Metadata
                 metadataRepository,
                 mediaItemRepository,
                 imageCache,
-                ffmpegProcessService,
+                ffmpegProcessServiceFactory,
                 tempFilePool,
                 logger)
         {

ErsatzTV.Core/Metadata/MusicVideoFolderScanner.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
 using ErsatzTV.Core.Interfaces.Metadata;
@@ -42,7 +43,7 @@ namespace ErsatzTV.Core.Metadata
             ILibraryRepository libraryRepository,
             IMediaItemRepository mediaItemRepository,
             IMediator mediator,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ITempFilePool tempFilePool,
             ILogger<MusicVideoFolderScanner> logger) : base(
             localFileSystem,
@@ -50,7 +51,7 @@ namespace ErsatzTV.Core.Metadata
             metadataRepository,
             mediaItemRepository,
             imageCache,
-            ffmpegProcessService,
+            ffmpegProcessServiceFactory,
             tempFilePool,
             logger)
         {

ErsatzTV.Core/Metadata/OtherVideoFolderScanner.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
 using ErsatzTV.Core.Interfaces.Metadata;
@@ -40,7 +41,7 @@ namespace ErsatzTV.Core.Metadata
             IOtherVideoRepository otherVideoRepository,
             ILibraryRepository libraryRepository,
             IMediaItemRepository mediaItemRepository,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ITempFilePool tempFilePool,
             ILogger<OtherVideoFolderScanner> logger) : base(
             localFileSystem,
@@ -48,7 +49,7 @@ namespace ErsatzTV.Core.Metadata
             metadataRepository,
             mediaItemRepository,
             imageCache,
-            ffmpegProcessService,
+            ffmpegProcessServiceFactory,
             tempFilePool,
             logger)
         {

ErsatzTV.Core/Metadata/SongFolderScanner.cs

@@ -5,6 +5,7 @@ using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
 using ErsatzTV.Core.Extensions;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
 using ErsatzTV.Core.Interfaces.Metadata;
@@ -41,7 +42,7 @@ namespace ErsatzTV.Core.Metadata
             ISongRepository songRepository,
             ILibraryRepository libraryRepository,
             IMediaItemRepository mediaItemRepository,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ITempFilePool tempFilePool,
             ILogger<SongFolderScanner> logger) : base(
             localFileSystem,
@@ -49,7 +50,7 @@ namespace ErsatzTV.Core.Metadata
             metadataRepository,
             mediaItemRepository,
             imageCache,
-            ffmpegProcessService,
+            ffmpegProcessServiceFactory,
             tempFilePool,
             logger)
         {

ErsatzTV.Core/Metadata/TelevisionFolderScanner.cs

@@ -4,6 +4,7 @@ using System.IO;
 using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.FFmpeg;
 using ErsatzTV.Core.Interfaces.FFmpeg;
 using ErsatzTV.Core.Interfaces.Images;
 using ErsatzTV.Core.Interfaces.Metadata;
@@ -41,7 +42,7 @@ namespace ErsatzTV.Core.Metadata
             ILibraryRepository libraryRepository,
             IMediaItemRepository mediaItemRepository,
             IMediator mediator,
-            IFFmpegProcessService ffmpegProcessService,
+            IFFmpegProcessServiceFactory ffmpegProcessServiceFactory,
             ITempFilePool tempFilePool,
             ILogger<TelevisionFolderScanner> logger) : base(
             localFileSystem,
@@ -49,7 +50,7 @@ namespace ErsatzTV.Core.Metadata
             metadataRepository,
             mediaItemRepository,
             imageCache,
-            ffmpegProcessService,
+            ffmpegProcessServiceFactory,
             tempFilePool,
             logger)
         {

ErsatzTV.Core/Scheduling/OrderedScheduleItemsEnumerator.cs

@@ -0,0 +1,40 @@
+using System.Collections.Generic;
+using System.Linq;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Scheduling;
+
+namespace ErsatzTV.Core.Scheduling;
+
+public class OrderedScheduleItemsEnumerator : IScheduleItemsEnumerator
+{
+    private readonly IList<ProgramScheduleItem> _sortedScheduleItems;
+
+    public OrderedScheduleItemsEnumerator(
+        IEnumerable<ProgramScheduleItem> scheduleItems,
+        CollectionEnumeratorState state)
+    {
+        _sortedScheduleItems = scheduleItems.OrderBy(i => i.Index).ToList();
+
+        State = new CollectionEnumeratorState { Seed = state.Seed };
+
+        if (state.Index >= _sortedScheduleItems.Count)
+        {
+            state.Index = 0;
+            state.Seed = 0;
+        }
+
+        while (State.Index < state.Index)
+        {
+            MoveNext();
+        }
+    }
+
+    public CollectionEnumeratorState State { get; }
+
+    public ProgramScheduleItem Current => _sortedScheduleItems[State.Index];
+
+    public void MoveNext() => State.Index = (State.Index + 1) % _sortedScheduleItems.Count;
+
+    public ProgramScheduleItem Peek(int offset) =>
+        _sortedScheduleItems[(State.Index + offset) % _sortedScheduleItems.Count];
+}

ErsatzTV.Core/Scheduling/PlayoutBuilder.cs

@@ -3,7 +3,6 @@ using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using ErsatzTV.Core.Domain;
-using ErsatzTV.Core.Extensions;
 using ErsatzTV.Core.Interfaces.Repositories;
 using ErsatzTV.Core.Interfaces.Scheduling;
 using LanguageExt;
@@ -105,6 +104,12 @@ namespace ErsatzTV.Core.Scheduling
             }
 
             var sortedScheduleItems = playout.ProgramSchedule.Items.OrderBy(i => i.Index).ToList();
+            CollectionEnumeratorState scheduleItemsEnumeratorState =
+                playout.Anchor?.ScheduleItemsEnumeratorState ?? new CollectionEnumeratorState
+                    { Seed = Random.Next(), Index = 0 };
+            IScheduleItemsEnumerator scheduleItemsEnumerator = playout.ProgramSchedule.ShuffleScheduleItems
+                ? new ShuffledScheduleItemsEnumerator(playout.ProgramSchedule.Items, scheduleItemsEnumeratorState)
+                : new OrderedScheduleItemsEnumerator(playout.ProgramSchedule.Items, scheduleItemsEnumeratorState);
             var collectionEnumerators = new Dictionary<CollectionKey, IMediaCollectionEnumerator>();
             foreach ((CollectionKey collectionKey, List<MediaItem> mediaItems) in collectionMediaItems)
             {
@@ -119,7 +124,7 @@ namespace ErsatzTV.Core.Scheduling
             }
 
             // find start anchor
-            PlayoutAnchor startAnchor = FindStartAnchor(playout, playoutStart, sortedScheduleItems);
+            PlayoutAnchor startAnchor = FindStartAnchor(playout, playoutStart, scheduleItemsEnumerator);
 
             // start at the previously-decided time
             DateTimeOffset currentTime = startAnchor.NextStartOffset.ToLocalTime();
@@ -142,7 +147,7 @@ namespace ErsatzTV.Core.Scheduling
             // start with the previously-decided schedule item
             // start with the previous multiple/duration states
             var playoutBuilderState = new PlayoutBuilderState(
-                sortedScheduleItems.IndexOf(startAnchor.NextScheduleItem),
+                scheduleItemsEnumerator,
                 Optional(startAnchor.MultipleRemaining),
                 startAnchor.DurationFinishOffset,
                 startAnchor.InFlood,
@@ -153,17 +158,15 @@ namespace ErsatzTV.Core.Scheduling
             var schedulerOne = new PlayoutModeSchedulerOne(_logger);
             var schedulerMultiple = new PlayoutModeSchedulerMultiple(collectionMediaItems, _logger);
             var schedulerDuration = new PlayoutModeSchedulerDuration(_logger);
-            var schedulerFlood = new PlayoutModeSchedulerFlood(sortedScheduleItems, _logger);
+            var schedulerFlood = new PlayoutModeSchedulerFlood(_logger);
 
             // loop until we're done filling the desired amount of time
             while (playoutBuilderState.CurrentTime < playoutFinish)
             {
                 // get the schedule item out of the sorted list
-                ProgramScheduleItem scheduleItem =
-                    sortedScheduleItems[playoutBuilderState.ScheduleItemIndex % sortedScheduleItems.Count];
+                ProgramScheduleItem scheduleItem = playoutBuilderState.ScheduleItemsEnumerator.Current;
 
-                ProgramScheduleItem nextScheduleItem =
-                    sortedScheduleItems[(playoutBuilderState.ScheduleItemIndex + 1) % sortedScheduleItems.Count];
+                ProgramScheduleItem nextScheduleItem = playoutBuilderState.ScheduleItemsEnumerator.Peek(1);
 
                 Tuple<PlayoutBuilderState, List<PlayoutItem>> result = scheduleItem switch
                 {
@@ -205,8 +208,7 @@ namespace ErsatzTV.Core.Scheduling
             }
 
             // once more to get playout anchor
-            ProgramScheduleItem anchorScheduleItem =
-                sortedScheduleItems[playoutBuilderState.ScheduleItemIndex % sortedScheduleItems.Count];
+            ProgramScheduleItem anchorScheduleItem = playoutBuilderState.ScheduleItemsEnumerator.Current;
 
             // build program schedule anchors
             playout.ProgramScheduleAnchors = BuildProgramScheduleAnchors(playout, collectionEnumerators);
@@ -226,8 +228,7 @@ namespace ErsatzTV.Core.Scheduling
 
             playout.Anchor = new PlayoutAnchor
             {
-                NextScheduleItem = anchorScheduleItem,
-                NextScheduleItemId = anchorScheduleItem.Id,
+                ScheduleItemsEnumeratorState = playoutBuilderState.ScheduleItemsEnumerator.State,
                 NextStart = PlayoutModeSchedulerBase<ProgramScheduleItem>.GetStartTimeAfter(playoutBuilderState, anchorScheduleItem)
                     .UtcDateTime,
                 MultipleRemaining = playoutBuilderState.MultipleRemaining.IsSome
@@ -320,18 +321,17 @@ namespace ErsatzTV.Core.Scheduling
         private static PlayoutAnchor FindStartAnchor(
             Playout playout,
             DateTimeOffset start,
-            IReadOnlyCollection<ProgramScheduleItem> sortedScheduleItems) =>
+            IScheduleItemsEnumerator enumerator) =>
             Optional(playout.Anchor).IfNone(
                 () =>
                 {
-                    ProgramScheduleItem schedule = sortedScheduleItems.Head();
+                    ProgramScheduleItem schedule = enumerator.Current;
                     switch (schedule.StartType)
                     {
                         case StartType.Fixed:
                             return new PlayoutAnchor
                             {
-                                NextScheduleItem = schedule,
-                                NextScheduleItemId = schedule.Id,
+                                ScheduleItemsEnumeratorState = enumerator.State,
                                 NextStart = (start - start.TimeOfDay).UtcDateTime +
                                             schedule.StartTime.GetValueOrDefault()
                             };
@@ -339,8 +339,7 @@ namespace ErsatzTV.Core.Scheduling
                         default:
                             return new PlayoutAnchor
                             {
-                                NextScheduleItem = schedule,
-                                NextScheduleItemId = schedule.Id,
+                                ScheduleItemsEnumeratorState = enumerator.State,
                                 NextStart = (start - start.TimeOfDay).UtcDateTime
                             };
                     }

ErsatzTV.Core/Scheduling/PlayoutBuilderState.cs

@@ -1,10 +1,11 @@
 using System;
+using ErsatzTV.Core.Interfaces.Scheduling;
 using LanguageExt;
 
 namespace ErsatzTV.Core.Scheduling
 {
     public record PlayoutBuilderState(
-        int ScheduleItemIndex,
+        IScheduleItemsEnumerator ScheduleItemsEnumerator,
         Option<int> MultipleRemaining,
         Option<DateTimeOffset> DurationFinish,
         bool InFlood,

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerDuration.cs

@@ -122,9 +122,10 @@ namespace ErsatzTV.Core.Scheduling
 
                     nextState = nextState with
                     {
-                        DurationFinish = None,
-                        ScheduleItemIndex = nextState.ScheduleItemIndex + 1
+                        DurationFinish = None
                     };
+
+                    nextState.ScheduleItemsEnumerator.MoveNext();
                 }
             }
 
@@ -133,9 +134,10 @@ namespace ErsatzTV.Core.Scheduling
             {
                 nextState = nextState with
                 {
-                    DurationFinish = None,
-                    ScheduleItemIndex = nextState.ScheduleItemIndex + 1
+                    DurationFinish = None
                 };
+
+                nextState.ScheduleItemsEnumerator.MoveNext();
             }
 
             if (playoutItems.Select(pi => pi.GuideGroup).Distinct().Count() != 1)

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerFlood.cs

@@ -12,12 +12,9 @@ namespace ErsatzTV.Core.Scheduling
 {
     public class PlayoutModeSchedulerFlood : PlayoutModeSchedulerBase<ProgramScheduleItemFlood>
     {
-        private readonly List<ProgramScheduleItem> _sortedScheduleItems;
-
-        public PlayoutModeSchedulerFlood(List<ProgramScheduleItem> sortedScheduleItems, ILogger logger)
+        public PlayoutModeSchedulerFlood(ILogger logger)
             : base(logger)
         {
-            _sortedScheduleItems = sortedScheduleItems;
         }
 
         public override Tuple<PlayoutBuilderState, List<PlayoutItem>> Schedule(
@@ -35,8 +32,7 @@ namespace ErsatzTV.Core.Scheduling
             IMediaCollectionEnumerator contentEnumerator =
                 collectionEnumerators[CollectionKey.ForScheduleItem(scheduleItem)];
 
-            ProgramScheduleItem peekScheduleItem =
-                _sortedScheduleItems[(nextState.ScheduleItemIndex + 1) % _sortedScheduleItems.Count];
+            ProgramScheduleItem peekScheduleItem = nextScheduleItem;
 
             while (contentEnumerator.Current.IsSome && nextState.CurrentTime < hardStop && willFinishInTime)
             {
@@ -81,7 +77,7 @@ namespace ErsatzTV.Core.Scheduling
                 {
                     playoutItems.AddRange(
                         AddFiller(nextState, collectionEnumerators, scheduleItem, playoutItem, itemChapters));
-                    // LogScheduledItem(scheduleItem, mediaItem, itemStartTime);
+                    LogScheduledItem(scheduleItem, mediaItem, itemStartTime);
 
                     DateTimeOffset actualEndTime = playoutItems.Max(p => p.FinishOffset);
                     if (Math.Abs((itemEndTimeWithFiller - actualEndTime).TotalSeconds) > 1)
@@ -105,19 +101,19 @@ namespace ErsatzTV.Core.Scheduling
                 }
             }
 
-            // _logger.LogDebug(
-            //     "Advancing to next schedule item after playout mode {PlayoutMode}",
-            //     "Flood");
+            _logger.LogDebug(
+                "Advancing to next schedule item after playout mode {PlayoutMode}",
+                "Flood");
 
             nextState = nextState with
             {
-                ScheduleItemIndex = nextState.ScheduleItemIndex + 1,
                 InFlood = nextState.CurrentTime >= hardStop,
                 NextGuideGroup = nextState.DecrementGuideGroup
             };
-            
-            ProgramScheduleItem peekItem =
-                _sortedScheduleItems[nextState.ScheduleItemIndex % _sortedScheduleItems.Count];
+
+            nextState.ScheduleItemsEnumerator.MoveNext();
+
+            ProgramScheduleItem peekItem = nextScheduleItem;
             DateTimeOffset peekItemStart = GetStartTimeAfter(nextState, peekItem);
 
             if (scheduleItem.TailFiller != null)

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerMultiple.cs

@@ -97,10 +97,11 @@ namespace ErsatzTV.Core.Scheduling
 
                 nextState = nextState with
                 {
-                    ScheduleItemIndex = nextState.ScheduleItemIndex + 1,
                     MultipleRemaining = None,
                     NextGuideGroup = nextState.DecrementGuideGroup
                 };
+
+                nextState.ScheduleItemsEnumerator.MoveNext();
             }
             
             DateTimeOffset nextItemStart = GetStartTimeAfter(nextState, nextScheduleItem);

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerOne.cs

@@ -67,10 +67,10 @@ namespace ErsatzTV.Core.Scheduling
 
                 PlayoutBuilderState nextState = playoutBuilderState with
                 {
-                    CurrentTime = itemEndTimeWithFiller,
-                    ScheduleItemIndex = playoutBuilderState.ScheduleItemIndex + 1
+                    CurrentTime = itemEndTimeWithFiller
                 };
 
+                nextState.ScheduleItemsEnumerator.MoveNext();
                 contentEnumerator.MoveNext();
 
                 // LogScheduledItem(scheduleItem, mediaItem, itemStartTime);

ErsatzTV.Core/Scheduling/ShuffledScheduleItemsEnumerator.cs

@@ -0,0 +1,107 @@
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.Scheduling;
+
+namespace ErsatzTV.Core.Scheduling;
+
+public class ShuffledScheduleItemsEnumerator : IScheduleItemsEnumerator
+{
+    private readonly int _scheduleItemsCount;
+    private readonly IList<ProgramScheduleItem> _scheduleItems;
+    private CloneableRandom _random;
+    private IList<ProgramScheduleItem> _shuffled;
+
+    public ShuffledScheduleItemsEnumerator(
+        IList<ProgramScheduleItem> scheduleItems,
+        CollectionEnumeratorState state)
+    {
+        _scheduleItemsCount = scheduleItems.Count;
+        _scheduleItems = scheduleItems;
+
+        if (state.Index >= _scheduleItems.Count)
+        {
+            state.Index = 0;
+            state.Seed = new Random(state.Seed).Next();
+        }
+
+        _random = new CloneableRandom(state.Seed);
+        _shuffled = Shuffle(_scheduleItems, _random);
+
+        State = new CollectionEnumeratorState { Seed = state.Seed };
+        while (State.Index < state.Index)
+        {
+            MoveNext();
+        }
+    }
+
+    public CollectionEnumeratorState State { get; }
+
+    public ProgramScheduleItem Current => _shuffled[State.Index % _scheduleItemsCount];
+
+    public void MoveNext()
+    {
+        if ((State.Index + 1) % _scheduleItemsCount == 0)
+        {
+            ProgramScheduleItem tail = Current;
+
+            State.Index = 0;
+            do
+            {
+                State.Seed = _random.Next();
+                _random = new CloneableRandom(State.Seed);
+                _shuffled = Shuffle(_scheduleItems, _random);
+            } while (_scheduleItems.Count > 1 && Current == tail);
+        }
+        else
+        {
+            State.Index++;
+        }
+
+        State.Index %= _scheduleItemsCount;
+    }
+
+    public ProgramScheduleItem Peek(int offset)
+    {
+        if (offset == 0)
+        {
+            return Current;
+        }
+
+        if ((State.Index + offset) % _scheduleItemsCount == 0)
+        {
+            IList<ProgramScheduleItem> shuffled;
+            ProgramScheduleItem tail = Current;
+
+            // clone the random
+            CloneableRandom randomCopy = _random.Clone();
+
+            do
+            {
+                int newSeed = randomCopy.Next();
+                randomCopy = new CloneableRandom(newSeed);
+                shuffled = Shuffle(_scheduleItems, randomCopy);
+            } while (_scheduleItems.Count > 1 && shuffled[0] == tail);
+
+            return shuffled[0];
+        }
+
+        return _shuffled[(State.Index + offset) % _scheduleItemsCount];
+    }
+
+    private IList<ProgramScheduleItem> Shuffle(IEnumerable<ProgramScheduleItem> list, CloneableRandom random)
+    {
+        ProgramScheduleItem[] copy = list.ToArray();
+
+        int n = copy.Length;
+        while (n > 1)
+        {
+            n--;
+            int k = random.Next(n + 1);
+            (copy[k], copy[n]) = (copy[n], copy[k]);
+        }
+
+        return copy;
+    }
+}

ErsatzTV.FFmpeg.Tests/ErsatzTV.FFmpeg.Tests.csproj

@@ -0,0 +1,32 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+    <PropertyGroup>
+        <TargetFramework>net6.0</TargetFramework>
+        <Nullable>enable</Nullable>
+
+        <IsPackable>false</IsPackable>
+    </PropertyGroup>
+
+    <ItemGroup>
+        <PackageReference Include="FluentAssertions" Version="6.5.1" />
+        <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+        <PackageReference Include="Moq" Version="4.16.1" />
+        <PackageReference Include="NUnit" Version="3.13.2" />
+        <PackageReference Include="NUnit3TestAdapter" Version="4.0.0" />
+        <PackageReference Include="coverlet.collector" Version="3.1.2">
+          <PrivateAssets>all</PrivateAssets>
+          <IncludeAssets>runtime; build; native; contentfiles; analyzers; buildtransitive</IncludeAssets>
+        </PackageReference>
+    </ItemGroup>
+
+    <ItemGroup>
+      <ProjectReference Include="..\ErsatzTV.FFmpeg\ErsatzTV.FFmpeg.csproj" />
+    </ItemGroup>
+
+    <ItemGroup>
+      <Reference Include="Microsoft.Extensions.Logging.Abstractions, Version=6.0.0.0, Culture=neutral, PublicKeyToken=adb9793829ddae60">
+        <HintPath>..\..\..\..\..\..\usr\share\dotnet\shared\Microsoft.AspNetCore.App\6.0.2\Microsoft.Extensions.Logging.Abstractions.dll</HintPath>
+      </Reference>
+    </ItemGroup>
+
+</Project>

ErsatzTV.FFmpeg.Tests/PipelineBuilderTests.cs

@@ -0,0 +1,116 @@
+using System;
+using System.Collections.Generic;
+using ErsatzTV.FFmpeg.Encoder;
+using ErsatzTV.FFmpeg.Format;
+using ErsatzTV.FFmpeg.OutputFormat;
+using ErsatzTV.FFmpeg.State;
+using NUnit.Framework;
+using FluentAssertions;
+using LanguageExt;
+using Microsoft.Extensions.Logging;
+using Moq;
+using static LanguageExt.Prelude;
+
+namespace ErsatzTV.FFmpeg.Tests;
+
+[TestFixture]
+public class PipelineGeneratorTests
+{
+    private readonly ILogger _logger = new Mock<ILogger>().Object;
+
+    [Test]
+    public void Incorrect_Video_Codec_Should_Use_Encoder()
+    {
+        var videoInputFile = new VideoInputFile(
+            "/tmp/whatever.mkv",
+            new List<VideoStream>
+                { new(0, VideoFormat.H264, new PixelFormatYuv420P(), new FrameSize(1920, 1080), "24", false) });
+
+        var audioInputFile = new AudioInputFile(
+            "/tmp/whatever.mkv",
+            new List<AudioStream> { new(1, AudioFormat.Aac, 2) },
+            new AudioState(
+                AudioFormat.Aac,
+                2,
+                320,
+                640,
+                48,
+                Option<TimeSpan>.None,
+                false));
+
+        var desiredState = new FrameState(
+            true,
+            false,
+            VideoFormat.Hevc,
+            new PixelFormatYuv420P(),
+            new FrameSize(1920, 1080),
+            new FrameSize(1920, 1080),
+            Option<int>.None,
+            2000,
+            4000,
+            90_000,
+            false);
+
+        var ffmpegState = new FFmpegState(
+            false,
+            HardwareAccelerationMode.None,
+            Option<string>.None,
+            Option<string>.None,
+            Option<TimeSpan>.None,
+            Option<TimeSpan>.None,
+            false,
+            Option<string>.None,
+            Option<string>.None,
+            Option<string>.None,
+            OutputFormatKind.MpegTs,
+            Option<string>.None,
+            Option<string>.None,
+            0);
+
+        var builder = new PipelineBuilder(videoInputFile, audioInputFile, None, "", _logger);
+        FFmpegPipeline result = builder.Build(ffmpegState, desiredState);
+
+        result.PipelineSteps.Should().HaveCountGreaterThan(0);
+        result.PipelineSteps.Should().Contain(ps => ps is EncoderLibx265);
+
+        PrintCommand(videoInputFile, audioInputFile, None, None, result);
+    }
+
+    [Test]
+    public void Concat_Test()
+    {
+        var resolution = new FrameSize(1920, 1080);
+        var concatInputFile = new ConcatInputFile("http://localhost:8080/ffmpeg/concat/1", resolution);
+
+        var builder = new PipelineBuilder(None, None, None, "", _logger);
+        FFmpegPipeline result = builder.Concat(concatInputFile, FFmpegState.Concat(false, "Some Channel"));
+
+        result.PipelineSteps.Should().HaveCountGreaterThan(0);
+
+        string command = PrintCommand(None, None, None, concatInputFile, result);
+        
+        command.Should().Be(
+            "-threads 1 -nostdin -hide_banner -nostats -loglevel error -fflags +genpts+discardcorrupt+igndts -f concat -safe 0 -protocol_whitelist file,http,tcp,https,tcp,tls -probesize 32 -re -stream_loop -1 -i http://localhost:8080/ffmpeg/concat/1 -muxdelay 0 -muxpreload 0 -movflags +faststart -flags cgop -sc_threshold 0 -c copy -map_metadata -1 -metadata service_provider=\"ErsatzTV\" -metadata service_name=\"Some Channel\" -f mpegts -mpegts_flags +initial_discontinuity pipe:1");
+    }
+
+    private static string PrintCommand(
+        Option<VideoInputFile> videoInputFile,
+        Option<AudioInputFile> audioInputFile,
+        Option<WatermarkInputFile> watermarkInputFile,
+        Option<ConcatInputFile> concatInputFile,
+        FFmpegPipeline pipeline)
+    {
+        IList<string> arguments = CommandGenerator.GenerateArguments(
+            videoInputFile,
+            audioInputFile,
+            watermarkInputFile,
+            concatInputFile,
+            pipeline.PipelineSteps);
+
+        var command = string.Join(" ", arguments);
+
+        Console.WriteLine($"Generated command: ffmpeg {string.Join(" ", arguments)}");
+
+        return command;
+    }
+}

ErsatzTV.FFmpeg/CommandGenerator.cs

@@ -0,0 +1,93 @@
+using ErsatzTV.FFmpeg.Environment;
+using ErsatzTV.FFmpeg.Option;
+using LanguageExt;
+
+namespace ErsatzTV.FFmpeg;
+
+public static class CommandGenerator
+{
+    public static IList<EnvironmentVariable> GenerateEnvironmentVariables(IEnumerable<IPipelineStep> pipelineSteps)
+    {
+        return pipelineSteps.SelectMany(ps => ps.EnvironmentVariables).ToList();
+    }
+
+    public static IList<string> GenerateArguments(
+        Option<VideoInputFile> maybeVideoInputFile,
+        Option<AudioInputFile> maybeAudioInputFile,
+        Option<WatermarkInputFile> maybeWatermarkInputFile,
+        Option<ConcatInputFile> maybeConcatInputFile,
+        IList<IPipelineStep> pipelineSteps)
+    {
+        var arguments = new List<string>();
+
+        foreach (IPipelineStep step in pipelineSteps)
+        {
+            arguments.AddRange(step.GlobalOptions);
+        }
+
+        var includedPaths = new System.Collections.Generic.HashSet<string>();
+        foreach (VideoInputFile videoInputFile in maybeVideoInputFile)
+        {
+            includedPaths.Add(videoInputFile.Path);
+            
+            foreach (IInputOption step in videoInputFile.InputOptions)
+            {
+                arguments.AddRange(step.InputOptions(videoInputFile));
+            }
+
+            arguments.AddRange(new[] { "-i", videoInputFile.Path });
+        }
+        
+        foreach (AudioInputFile audioInputFile in maybeAudioInputFile)
+        {
+            if (!includedPaths.Contains(audioInputFile.Path))
+            {
+                includedPaths.Add(audioInputFile.Path);
+                
+                foreach (IInputOption step in audioInputFile.InputOptions)
+                {
+                    arguments.AddRange(step.InputOptions(audioInputFile));
+                }
+
+                arguments.AddRange(new[] { "-i", audioInputFile.Path });
+            }
+        }
+
+        foreach (WatermarkInputFile watermarkInputFile in maybeWatermarkInputFile)
+        {
+            if (!includedPaths.Contains(watermarkInputFile.Path))
+            {
+                includedPaths.Add(watermarkInputFile.Path);
+
+                foreach (IInputOption step in watermarkInputFile.InputOptions)
+                {
+                    arguments.AddRange(step.InputOptions(watermarkInputFile));
+                }
+
+                arguments.AddRange(new[] { "-i", watermarkInputFile.Path });
+            }
+        }
+
+        foreach (ConcatInputFile concatInputFile in maybeConcatInputFile)
+        {
+            foreach (IInputOption step in concatInputFile.InputOptions)
+            {
+                arguments.AddRange(step.InputOptions(concatInputFile));
+            }
+
+            arguments.AddRange(new[] { "-i", concatInputFile.Path });
+        }
+
+        foreach (IPipelineStep step in pipelineSteps)
+        {
+            arguments.AddRange(step.FilterOptions);
+        }
+
+        foreach (IPipelineStep step in pipelineSteps)
+        {
+            arguments.AddRange(step.OutputOptions);
+        }
+
+        return arguments;
+    }
+}

ErsatzTV.FFmpeg/Decoder/AvailableDecoders.cs

@@ -0,0 +1,78 @@
+using ErsatzTV.FFmpeg.Decoder.Cuvid;
+using ErsatzTV.FFmpeg.Decoder.Qsv;
+using ErsatzTV.FFmpeg.Format;
+using LanguageExt;
+using Microsoft.Extensions.Logging;
+
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public static class AvailableDecoders
+{
+    public static Option<IDecoder> ForVideoFormat(FFmpegState ffmpegState, FrameState currentState, ILogger logger)
+    {
+        return (ffmpegState.HardwareAccelerationMode, currentState.VideoFormat,
+                currentState.PixelFormat.Match(pf => pf.Name, () => string.Empty)) switch
+            {
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Hevc, _) => new DecoderHevcCuvid(),
+
+                // nvenc doesn't support hardware decoding of 10-bit content
+                (HardwareAccelerationMode.Nvenc, VideoFormat.H264, PixelFormat.YUV420P10LE or PixelFormat.YUV444P10LE)
+                    => new DecoderH264(),
+
+                (HardwareAccelerationMode.Nvenc, VideoFormat.H264, _) => new DecoderH264Cuvid(),
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Mpeg2Video, _) => new DecoderMpeg2Cuvid(),
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Vc1, _) => new DecoderVc1Cuvid(),
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Vp9, _) => new DecoderVp9Cuvid(),
+                (HardwareAccelerationMode.Nvenc, VideoFormat.Mpeg4, _) => new DecoderMpeg4Cuvid(),
+
+                // hevc_qsv decoder sometimes causes green lines with 10-bit content
+                (HardwareAccelerationMode.Qsv, VideoFormat.Hevc, PixelFormat.YUV420P10LE) => new DecoderHevc(),
+
+                // h264_qsv does not support decoding 10-bit content
+                (HardwareAccelerationMode.Qsv, VideoFormat.H264, PixelFormat.YUV420P10LE or PixelFormat.YUV444P10LE) =>
+                    new DecoderH264(),
+
+                (HardwareAccelerationMode.Qsv, VideoFormat.Hevc, _) => new DecoderHevcQsv(),
+                (HardwareAccelerationMode.Qsv, VideoFormat.H264, _) => new DecoderH264Qsv(),
+                (HardwareAccelerationMode.Qsv, VideoFormat.Mpeg2Video, _) => new DecoderMpeg2Qsv(),
+                (HardwareAccelerationMode.Qsv, VideoFormat.Vc1, _) => new DecoderVc1Qsv(),
+                (HardwareAccelerationMode.Qsv, VideoFormat.Vp9, _) => new DecoderVp9Qsv(),
+
+                // vaapi should use implicit decoders
+                (HardwareAccelerationMode.Vaapi, _, _) => new DecoderVaapi(),
+
+                // videotoolbox should use implicit decoders
+                (HardwareAccelerationMode.VideoToolbox, _, _) => new DecoderVideoToolbox(),
+
+                (_, VideoFormat.Hevc, _) => new DecoderHevc(),
+                (_, VideoFormat.H264, _) => new DecoderH264(),
+                (_, VideoFormat.Mpeg1Video, _) => new DecoderMpeg1Video(),
+                (_, VideoFormat.Mpeg2Video, _) => new DecoderMpeg2Video(),
+                (_, VideoFormat.Vc1, _) => new DecoderVc1(),
+                (_, VideoFormat.MsMpeg4V2, _) => new DecoderMsMpeg4V2(),
+                (_, VideoFormat.MsMpeg4V3, _) => new DecoderMsMpeg4V3(),
+                (_, VideoFormat.Mpeg4, _) => new DecoderMpeg4(),
+                (_, VideoFormat.Vp9, _) => new DecoderVp9(),
+
+                (_, VideoFormat.Undetermined, _) => new DecoderImplicit(),
+                (_, VideoFormat.Copy, _) => new DecoderImplicit(),
+                (_, VideoFormat.GeneratedImage, _) => new DecoderImplicit(),
+
+                var (accel, videoFormat, pixelFormat) => LogUnknownDecoder(accel, videoFormat, pixelFormat, logger)
+            };
+    }
+
+    private static Option<IDecoder> LogUnknownDecoder(
+        HardwareAccelerationMode hardwareAccelerationMode,
+        string videoFormat,
+        string pixelFormat,
+        ILogger logger)
+    {
+        logger.LogWarning(
+            "Unable to determine decoder for {AccelMode} - {VideoFormat} - {PixelFormat}; may have playback issues",
+            hardwareAccelerationMode,
+            videoFormat,
+            pixelFormat);
+        return Option<IDecoder>.None;
+    }
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderH264Cuvid.cs

@@ -0,0 +1,18 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderH264Cuvid : DecoderBase
+{
+    public override string Name => "h264_cuvid";
+
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderHevcCuvid.cs

@@ -0,0 +1,17 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderHevcCuvid : DecoderBase
+{
+    public override string Name => "hevc_cuvid";
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderMpeg2Cuvid.cs

@@ -0,0 +1,17 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderMpeg2Cuvid : DecoderBase
+{
+    public override string Name => "mpeg2_cuvid";
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderMpeg4Cuvid.cs

@@ -0,0 +1,18 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderMpeg4Cuvid : DecoderBase
+{
+    public override string Name => "mpeg4_cuvid";
+
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderVc1Cuvid.cs

@@ -0,0 +1,17 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderVc1Cuvid : DecoderBase
+{
+    public override string Name => "vc1_cuvid";
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/Cuvid/DecoderVp9Cuvid.cs

@@ -0,0 +1,17 @@
+namespace ErsatzTV.FFmpeg.Decoder.Cuvid;
+
+public class DecoderVp9Cuvid : DecoderBase
+{
+    public override string Name => "vp9_cuvid";
+    public override IList<string> InputOptions(InputFile inputFile)
+    {
+        IList<string> result = base.InputOptions(inputFile);
+
+        result.Add("-hwaccel_output_format");
+        result.Add("cuda");
+
+        return result;
+    }
+
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Hardware;
+}

ErsatzTV.FFmpeg/Decoder/DecoderBase.cs

@@ -0,0 +1,21 @@
+using ErsatzTV.FFmpeg.Environment;
+
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public abstract class DecoderBase : IDecoder
+{
+    protected abstract FrameDataLocation OutputFrameDataLocation { get; }
+    public IList<EnvironmentVariable> EnvironmentVariables => Array.Empty<EnvironmentVariable>();
+    public IList<string> GlobalOptions => Array.Empty<string>();
+    public virtual IList<string> InputOptions(InputFile inputFile) => new List<string> { "-c:v", Name };
+    public IList<string> FilterOptions => Array.Empty<string>();
+    public IList<string> OutputOptions => Array.Empty<string>();
+    public virtual FrameState NextState(FrameState currentState) =>
+        currentState with { FrameDataLocation = OutputFrameDataLocation };
+    public abstract string Name { get; }
+    public bool AppliesTo(AudioInputFile audioInputFile) => false;
+
+    public bool AppliesTo(VideoInputFile videoInputFile) => true;
+
+    public bool AppliesTo(ConcatInputFile concatInputFile) => false;
+}

ErsatzTV.FFmpeg/Decoder/DecoderH264.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderH264 : DecoderBase
+{
+    public override string Name => "h264";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderHevc.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderHevc : DecoderBase
+{
+    public override string Name => "hevc";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderImplicit.cs

@@ -0,0 +1,8 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderImplicit : DecoderBase
+{
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+    public override string Name => string.Empty;
+    public override IList<string> InputOptions(InputFile inputFile) => Array.Empty<string>();
+}

ErsatzTV.FFmpeg/Decoder/DecoderMpeg1.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderMpeg1Video : DecoderBase
+{
+    public override string Name => "mpeg1video";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderMpeg2.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderMpeg2Video : DecoderBase
+{
+    public override string Name => "mpeg2video";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderMpeg4.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderMpeg4 : DecoderBase
+{
+    public override string Name => "mpeg4";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderMsMpeg4v2.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderMsMpeg4V2 : DecoderBase
+{
+    public override string Name => "msmpeg4v2";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderMsMpeg4v3.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderMsMpeg4V3 : DecoderBase
+{
+    public override string Name => "msmpeg4v3";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderVaapi.cs

@@ -0,0 +1,19 @@
+using ErsatzTV.FFmpeg.Format;
+
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderVaapi : DecoderBase
+{
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+    public override string Name => "implicit_vaapi";
+    public override IList<string> InputOptions(InputFile inputFile) => Array.Empty<string>();
+
+    public override FrameState NextState(FrameState currentState)
+    {
+        FrameState nextState = base.NextState(currentState);
+
+        return currentState.PixelFormat.Match(
+            pixelFormat => nextState with { PixelFormat = new PixelFormatNv12(pixelFormat.Name) },
+            () => nextState);
+    }
+}

ErsatzTV.FFmpeg/Decoder/DecoderVc1.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderVc1 : DecoderBase
+{
+    public override string Name => "vc1";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/DecoderVideoToolbox.cs

@@ -0,0 +1,8 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderVideoToolbox : DecoderBase
+{
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+    public override string Name => "implicit_videotoolbox";
+    public override IList<string> InputOptions(InputFile inputFile) => Array.Empty<string>();
+}

ErsatzTV.FFmpeg/Decoder/DecoderVp9.cs

@@ -0,0 +1,7 @@
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public class DecoderVp9 : DecoderBase
+{
+    public override string Name => "vp9";
+    protected override FrameDataLocation OutputFrameDataLocation => FrameDataLocation.Software;
+}

ErsatzTV.FFmpeg/Decoder/IDecoder.cs

@@ -0,0 +1,8 @@
+using ErsatzTV.FFmpeg.Option;
+
+namespace ErsatzTV.FFmpeg.Decoder;
+
+public interface IDecoder : IInputOption
+{
+    string Name { get; }
+}