add mid-roll filler expression (#2138)

CHANGELOG.md

@@ -63,6 +63,15 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
         - `random % 4 + 1` will play between 1 and 4 items
         - `2` (similar to before this change) will play exactly two items
 - Show health check warning and error badges in nav menu
+- Add `Expression` for mid-roll filler to allow custom logic for using or skipping chapter markers
+  - The following parameters can be used:
+    - `total_points`: total number of potential mid-roll points
+    - `total_duration`: total duration of the content, in seconds
+    - `total_progress`: normalized position from 0 to 1
+    - `last_mid_filler`: seconds since last mid-roll filler
+    - `remaining_duration`: duration of the content after this mid-roll point, in seconds
+    - `point`: the position of the mid-roll point, in seconds
+    - `num`: the mid-roll point number, starting with 1
 
 ### Changed
 - Allow `Other Video` libraries and `Image` libraries to use the same folders

ErsatzTV.Application/Filler/Commands/CreateFillerPreset.cs

@@ -16,5 +16,6 @@ public record CreateFillerPreset(
     int? CollectionId,
     int? MediaItemId,
     int? MultiCollectionId,
-    int? SmartCollectionId
+    int? SmartCollectionId,
+    string Expression
 ) : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/Filler/Commands/CreateFillerPresetHandler.cs

@@ -36,7 +36,8 @@ public class CreateFillerPresetHandler : IRequestHandler<CreateFillerPreset, Eit
                 CollectionId = request.CollectionId,
                 MediaItemId = request.MediaItemId,
                 MultiCollectionId = request.MultiCollectionId,
-                SmartCollectionId = request.SmartCollectionId
+                SmartCollectionId = request.SmartCollectionId,
+                Expression = request.FillerKind is FillerKind.MidRoll ? request.Expression : null
             };
 
             await dbContext.FillerPresets.AddAsync(fillerPreset, cancellationToken);

ErsatzTV.Application/Filler/Commands/UpdateFillerPreset.cs

@@ -17,5 +17,6 @@ public record UpdateFillerPreset(
     int? CollectionId,
     int? MediaItemId,
     int? MultiCollectionId,
-    int? SmartCollectionId
+    int? SmartCollectionId,
+    string Expression
 ) : IRequest<Either<BaseError, Unit>>;

ErsatzTV.Application/Filler/Commands/UpdateFillerPresetHandler.cs

@@ -37,6 +37,7 @@ public class UpdateFillerPresetHandler : IRequestHandler<UpdateFillerPreset, Eit
         existing.MediaItemId = request.MediaItemId;
         existing.MultiCollectionId = request.MultiCollectionId;
         existing.SmartCollectionId = request.SmartCollectionId;
+        existing.Expression = request.FillerKind is FillerKind.MidRoll ? request.Expression : null;
 
         await dbContext.SaveChangesAsync();
 

ErsatzTV.Application/Filler/FillerPresetViewModel.cs

@@ -16,4 +16,5 @@ public record FillerPresetViewModel(
     int? CollectionId,
     int? MediaItemId,
     int? MultiCollectionId,
-    int? SmartCollectionId);
+    int? SmartCollectionId,
+    string Expression);

ErsatzTV.Application/Filler/Mapper.cs

@@ -18,5 +18,6 @@ internal static class Mapper
             fillerPreset.CollectionId,
             fillerPreset.MediaItemId,
             fillerPreset.MultiCollectionId,
-            fillerPreset.SmartCollectionId);
+            fillerPreset.SmartCollectionId,
+            fillerPreset.Expression);
 }

ErsatzTV.Core.Tests/Scheduling/PlayoutModeSchedulerBaseTests.cs

@@ -296,6 +296,227 @@ public class PlayoutModeSchedulerBaseTests : SchedulerTestBase
             playoutItems[4].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(55));
         }
 
+        [Test]
+        public void Should_Schedule_Post_Roll_After_Padded_Mid_Roll_With_Expression()
+        {
+            // content 45 min, mid roll pad to 60, post roll 5 min
+            // content + post = 50 min, mid roll will add two 5 min items
+            // content + mid + post = 60 min
+
+            Collection collectionOne = TwoItemCollection(1, 2, TimeSpan.FromMinutes(45));
+            Collection collectionTwo = TwoItemCollection(3, 4, TimeSpan.FromMinutes(5));
+            Collection collectionThree = TwoItemCollection(5, 6, TimeSpan.FromMinutes(5));
+
+            var scheduleItem = new ProgramScheduleItemOne
+            {
+                Id = 1,
+                Index = 1,
+                Collection = collectionOne,
+                CollectionId = collectionOne.Id,
+                StartTime = null,
+                PlaybackOrder = PlaybackOrder.Chronological,
+                TailFiller = null,
+                FallbackFiller = null,
+                MidRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.MidRoll,
+                    FillerMode = FillerMode.Pad,
+                    PadToNearestMinute = 60,
+                    CollectionId = 2,
+                    Collection = collectionTwo,
+                    Expression = "point > (5 * 60) and total_progress < 0.5"
+                },
+                PostRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.PostRoll,
+                    FillerMode = FillerMode.Count,
+                    Count = 1,
+                    CollectionId = 3,
+                    Collection = collectionThree
+                }
+            };
+
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
+
+            var enumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionOne.MediaItems,
+                new CollectionEnumeratorState());
+
+            var midRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionTwo.MediaItems,
+                new CollectionEnumeratorState());
+
+            var postRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionThree.MediaItems,
+                new CollectionEnumeratorState());
+
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            Dictionary<CollectionKey, IMediaCollectionEnumerator> enumerators = CollectionEnumerators(
+                scheduleItem,
+                enumerator);
+
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.MidRollFiller), midRollFillerEnumerator);
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.PostRollFiller), postRollFillerEnumerator);
+
+            List<PlayoutItem> playoutItems = _scheduler
+                .AddFiller(
+                    startState,
+                    enumerators,
+                    scheduleItem,
+                    new PlayoutItem
+                    {
+                        MediaItemId = 1,
+                        Start = startState.CurrentTime.UtcDateTime,
+                        Finish = startState.CurrentTime.AddHours(1).UtcDateTime
+                    },
+                    [
+                        new MediaChapter { StartTime = TimeSpan.Zero, EndTime = TimeSpan.FromMinutes(3) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(3), EndTime = TimeSpan.FromMinutes(6) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(6), EndTime = TimeSpan.FromMinutes(30) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(30), EndTime = TimeSpan.FromMinutes(45) }
+                    ],
+                    true,
+                    _cancellationToken);
+
+            playoutItems.Count.ShouldBe(5);
+
+            // content chapter 1
+            playoutItems[0].MediaItemId.ShouldBe(1);
+            playoutItems[0].StartOffset.ShouldBe(startState.CurrentTime);
+
+            // mid-roll 1
+            playoutItems[1].MediaItemId.ShouldBe(3);
+            playoutItems[1].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(6));
+
+            // mid-roll 2
+            playoutItems[2].MediaItemId.ShouldBe(4);
+            playoutItems[2].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(11));
+
+            // content chapter 2
+            playoutItems[3].MediaItemId.ShouldBe(1);
+            playoutItems[3].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(16));
+
+            // post-roll
+            playoutItems[4].MediaItemId.ShouldBe(5);
+            playoutItems[4].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(55));
+        }
+
+        [Test]
+        public void Should_Schedule_Post_Roll_After_Padded_Mid_Roll_With_Expression_Split()
+        {
+            // content 45 min, mid roll pad to 60, post roll 5 min
+            // content + post = 50 min, mid roll will add two 5 min items
+            // content + mid + post = 60 min
+
+            Collection collectionOne = TwoItemCollection(1, 2, TimeSpan.FromMinutes(45));
+            Collection collectionTwo = TwoItemCollection(3, 4, TimeSpan.FromMinutes(5));
+            Collection collectionThree = TwoItemCollection(5, 6, TimeSpan.FromMinutes(5));
+
+            var scheduleItem = new ProgramScheduleItemOne
+            {
+                Id = 1,
+                Index = 1,
+                Collection = collectionOne,
+                CollectionId = collectionOne.Id,
+                StartTime = null,
+                PlaybackOrder = PlaybackOrder.Chronological,
+                TailFiller = null,
+                FallbackFiller = null,
+                MidRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.MidRoll,
+                    FillerMode = FillerMode.Pad,
+                    PadToNearestMinute = 60,
+                    CollectionId = 2,
+                    Collection = collectionTwo,
+                    Expression = "chapter_num % 2 == 0"
+                },
+                PostRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.PostRoll,
+                    FillerMode = FillerMode.Count,
+                    Count = 1,
+                    CollectionId = 3,
+                    Collection = collectionThree
+                }
+            };
+
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
+
+            var enumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionOne.MediaItems,
+                new CollectionEnumeratorState());
+
+            var midRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionTwo.MediaItems,
+                new CollectionEnumeratorState());
+
+            var postRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionThree.MediaItems,
+                new CollectionEnumeratorState());
+
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            Dictionary<CollectionKey, IMediaCollectionEnumerator> enumerators = CollectionEnumerators(
+                scheduleItem,
+                enumerator);
+
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.MidRollFiller), midRollFillerEnumerator);
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.PostRollFiller), postRollFillerEnumerator);
+
+            List<PlayoutItem> playoutItems = _scheduler
+                .AddFiller(
+                    startState,
+                    enumerators,
+                    scheduleItem,
+                    new PlayoutItem
+                    {
+                        MediaItemId = 1,
+                        Start = startState.CurrentTime.UtcDateTime,
+                        Finish = startState.CurrentTime.AddHours(1).UtcDateTime
+                    },
+                    [
+                        new MediaChapter { StartTime = TimeSpan.Zero, EndTime = TimeSpan.FromMinutes(3) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(3), EndTime = TimeSpan.FromMinutes(6) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(6), EndTime = TimeSpan.FromMinutes(20) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(20), EndTime = TimeSpan.FromMinutes(30) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(30), EndTime = TimeSpan.FromMinutes(45) }
+                    ],
+                    true,
+                    _cancellationToken);
+
+            playoutItems.Count.ShouldBe(6);
+
+            // content chapter 1
+            playoutItems[0].MediaItemId.ShouldBe(1);
+            playoutItems[0].StartOffset.ShouldBe(startState.CurrentTime);
+
+            // mid-roll 1
+            playoutItems[1].MediaItemId.ShouldBe(3);
+            playoutItems[1].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(6));
+
+            // content chapter 2
+            playoutItems[2].MediaItemId.ShouldBe(1);
+            playoutItems[2].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(11));
+
+            // mid-roll 2
+            playoutItems[3].MediaItemId.ShouldBe(4);
+            playoutItems[3].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(35));
+
+            // content chapter 3
+            playoutItems[4].MediaItemId.ShouldBe(1);
+            playoutItems[4].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(40));
+
+            // post-roll
+            playoutItems[5].MediaItemId.ShouldBe(5);
+            playoutItems[5].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(55));
+        }
+
         [Test]
         public void Should_Schedule_Padded_Post_Roll_After_Mid_Roll_Count()
         {
@@ -401,6 +622,114 @@ public class PlayoutModeSchedulerBaseTests : SchedulerTestBase
             playoutItems[4].MediaItemId.ShouldBe(6);
             playoutItems[4].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(55));
         }
+
+        [Test]
+        public void Should_Schedule_Padded_Post_Roll_After_Mid_Roll_Count_With_Expression()
+        {
+            // content 45 min, mid roll 5 min, post roll pad to 60
+            // content + mid = 50 min, post roll will add two 5 min items
+            // content + mid + post = 60 min
+
+            Collection collectionOne = TwoItemCollection(1, 2, TimeSpan.FromMinutes(45));
+            Collection collectionTwo = TwoItemCollection(3, 4, TimeSpan.FromMinutes(5));
+            Collection collectionThree = TwoItemCollection(5, 6, TimeSpan.FromMinutes(5));
+
+            var scheduleItem = new ProgramScheduleItemOne
+            {
+                Id = 1,
+                Index = 1,
+                Collection = collectionOne,
+                CollectionId = collectionOne.Id,
+                StartTime = null,
+                PlaybackOrder = PlaybackOrder.Chronological,
+                TailFiller = null,
+                FallbackFiller = null,
+                MidRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.MidRoll,
+                    FillerMode = FillerMode.Count,
+                    Count = 1,
+                    CollectionId = 2,
+                    Collection = collectionTwo,
+                    Expression = "point > (5 * 60) and total_progress < 0.5"
+                },
+                PostRollFiller = new FillerPreset
+                {
+                    FillerKind = FillerKind.PostRoll,
+                    FillerMode = FillerMode.Pad,
+                    PadToNearestMinute = 60,
+                    CollectionId = 3,
+                    Collection = collectionThree
+                }
+            };
+
+            var scheduleItemsEnumerator = new OrderedScheduleItemsEnumerator(
+                new List<ProgramScheduleItem> { scheduleItem },
+                new CollectionEnumeratorState());
+
+            var enumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionOne.MediaItems,
+                new CollectionEnumeratorState());
+
+            var midRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionTwo.MediaItems,
+                new CollectionEnumeratorState());
+
+            var postRollFillerEnumerator = new ChronologicalMediaCollectionEnumerator(
+                collectionThree.MediaItems,
+                new CollectionEnumeratorState());
+
+            PlayoutBuilderState startState = StartState(scheduleItemsEnumerator);
+
+            Dictionary<CollectionKey, IMediaCollectionEnumerator> enumerators = CollectionEnumerators(
+                scheduleItem,
+                enumerator);
+
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.MidRollFiller), midRollFillerEnumerator);
+            enumerators.Add(CollectionKey.ForFillerPreset(scheduleItem.PostRollFiller), postRollFillerEnumerator);
+
+            List<PlayoutItem> playoutItems = _scheduler
+                .AddFiller(
+                    startState,
+                    enumerators,
+                    scheduleItem,
+                    new PlayoutItem
+                    {
+                        MediaItemId = 1,
+                        Start = startState.CurrentTime.UtcDateTime,
+                        Finish = startState.CurrentTime.AddHours(1).UtcDateTime
+                    },
+                    [
+                        new MediaChapter { StartTime = TimeSpan.Zero, EndTime = TimeSpan.FromMinutes(3) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(3), EndTime = TimeSpan.FromMinutes(6) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(6), EndTime = TimeSpan.FromMinutes(30) },
+                        new MediaChapter { StartTime = TimeSpan.FromMinutes(30), EndTime = TimeSpan.FromMinutes(45) }
+                    ],
+                    true,
+                    _cancellationToken);
+
+            playoutItems.Count.ShouldBe(5);
+
+            // content chapter 1
+            playoutItems[0].MediaItemId.ShouldBe(1);
+            playoutItems[0].StartOffset.ShouldBe(startState.CurrentTime);
+
+            // mid-roll 1
+            playoutItems[1].MediaItemId.ShouldBe(3);
+            playoutItems[1].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(6));
+
+            // content chapter 2
+            playoutItems[2].MediaItemId.ShouldBe(1);
+            playoutItems[2].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(11));
+
+            // post-roll 1
+            playoutItems[3].MediaItemId.ShouldBe(5);
+            playoutItems[3].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(50));
+
+            // post-roll 2
+            playoutItems[4].MediaItemId.ShouldBe(6);
+            playoutItems[4].StartOffset.ShouldBe(startState.CurrentTime + TimeSpan.FromMinutes(55));
+        }
     }
 
     [TestFixture]

ErsatzTV.Core/Domain/Filler/FillerPreset.cs

@@ -19,4 +19,5 @@ public class FillerPreset
     public MultiCollection MultiCollection { get; set; }
     public int? SmartCollectionId { get; set; }
     public SmartCollection SmartCollection { get; set; }
+    public string Expression { get; set; }
 }

ErsatzTV.Core/Scheduling/FillerExpression.cs

@@ -0,0 +1,70 @@
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Domain.Filler;
+using NCalc;
+
+namespace ErsatzTV.Core.Scheduling;
+
+public static class FillerExpression
+{
+    public static List<MediaChapter> FilterChapters(FillerPreset fillerPreset, List<MediaChapter> effectiveChapters, PlayoutItem playoutItem)
+    {
+        if (effectiveChapters.Count == 0 || fillerPreset is null || string.IsNullOrWhiteSpace(fillerPreset.Expression))
+        {
+            return effectiveChapters;
+        }
+
+        var chapterPoints = effectiveChapters.Map(c => c.EndTime).SkipLast().ToList();
+
+        var newChapters = new List<MediaChapter>();
+
+        TimeSpan start = effectiveChapters.Select(c => c.StartTime).Min();
+        TimeSpan end = effectiveChapters.Select(c => c.EndTime).Max();
+
+        double lastFiller = start.TotalSeconds - 99999.0;
+        double contentDuration = (playoutItem.FinishOffset - playoutItem.StartOffset).TotalSeconds;
+
+        for (var index = 0; index < chapterPoints.Count; index++)
+        {
+            TimeSpan chapterPoint = chapterPoints[index];
+            var expression = new Expression(fillerPreset.Expression);
+            int chapterNum = index + 1;
+            double sinceLastFiller = chapterPoint.TotalSeconds - lastFiller;
+            expression.EvaluateParameter += (name, e) =>
+            {
+                e.Result = name switch
+                {
+                    "last_mid_filler" => sinceLastFiller,
+                    "total_points" => effectiveChapters.Count - 1,
+                    "total_duration" => contentDuration,
+                    "total_progress" => chapterPoint.TotalSeconds / end.TotalSeconds,
+                    "remaining_duration" => contentDuration - chapterPoint.TotalSeconds,
+                    "point" => chapterPoint.TotalSeconds,
+                    "num" => chapterNum,
+                    _ => e.Result
+                };
+            };
+
+            if (expression.Evaluate() as bool? == true)
+            {
+                lastFiller = chapterPoint.TotalSeconds;
+                newChapters.Add(effectiveChapters[index]);
+            }
+        }
+
+        if (newChapters.Count > 0)
+        {
+            newChapters[0].StartTime = start;
+
+            TimeSpan currentTime = start;
+            foreach (MediaChapter chapter in newChapters)
+            {
+                chapter.StartTime = currentTime;
+                currentTime = chapter.EndTime;
+            }
+
+            newChapters.Add(new MediaChapter { StartTime = currentTime, EndTime = end });
+        }
+
+        return newChapters;
+    }
+}

ErsatzTV.Core/Scheduling/PlayoutModeSchedulerBase.cs

@@ -248,7 +248,7 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
         if (allFiller.Count(f => f.FillerMode == FillerMode.Pad && f.PadToNearestMinute.HasValue) > 1)
         {
             Logger.LogError("Multiple pad-to-nearest-minute values are invalid; no filler will be used");
-            return new List<PlayoutItem> { playoutItem };
+            return [playoutItem];
         }
 
         // missing pad-to-nearest-minute value is invalid; use no filler
@@ -259,7 +259,7 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
             Logger.LogError(
                 "Pad filler ({Filler}) without pad-to-nearest-minute value is invalid; no filler will be used",
                 invalidPadFiller.Name);
-            return new List<PlayoutItem> { playoutItem };
+            return [playoutItem];
         }
 
         List<MediaChapter> effectiveChapters = chapters;
@@ -353,14 +353,21 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
             foreach (FillerPreset filler in allFiller.Filter(f =>
                          f.FillerKind == FillerKind.MidRoll && f.FillerMode != FillerMode.Pad))
             {
+                List<MediaChapter> filteredChapters = FillerExpression.FilterChapters(filler, effectiveChapters, playoutItem);
+                if (filteredChapters.Count <= 1)
+                {
+                    result.Add(playoutItem);
+                    continue;
+                }
+
                 switch (filler.FillerMode)
                 {
                     case FillerMode.Duration when filler.Duration.HasValue:
                         IMediaCollectionEnumerator e1 = enumerators[CollectionKey.ForFillerPreset(filler)];
-                        for (var i = 0; i < effectiveChapters.Count; i++)
+                        for (var i = 0; i < filteredChapters.Count; i++)
                         {
-                            result.Add(playoutItem.ForChapter(effectiveChapters[i]));
-                            if (i < effectiveChapters.Count - 1)
+                            result.Add(playoutItem.ForChapter(filteredChapters[i]));
+                            if (i < filteredChapters.Count - 1)
                             {
                                 result.AddRange(
                                     AddDurationFiller(
@@ -379,10 +386,10 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
                         break;
                     case FillerMode.Count when filler.Count.HasValue:
                         IMediaCollectionEnumerator e2 = enumerators[CollectionKey.ForFillerPreset(filler)];
-                        for (var i = 0; i < effectiveChapters.Count; i++)
+                        for (var i = 0; i < filteredChapters.Count; i++)
                         {
-                            result.Add(playoutItem.ForChapter(effectiveChapters[i]));
-                            if (i < effectiveChapters.Count - 1)
+                            result.Add(playoutItem.ForChapter(filteredChapters[i]));
+                            if (i < filteredChapters.Count - 1)
                             {
                                 result.AddRange(
                                     AddCountFiller(
@@ -400,10 +407,10 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
                         break;
                     case FillerMode.RandomCount when filler.Count.HasValue:
                         IMediaCollectionEnumerator e3 = enumerators[CollectionKey.ForFillerPreset(filler)];
-                        for (var i = 0; i < effectiveChapters.Count; i++)
+                        for (var i = 0; i < filteredChapters.Count; i++)
                         {
-                            result.Add(playoutItem.ForChapter(effectiveChapters[i]));
-                            if (i < effectiveChapters.Count - 1)
+                            result.Add(playoutItem.ForChapter(filteredChapters[i]));
+                            if (i < filteredChapters.Count - 1)
                             {
                                 result.AddRange(
                                     AddRandomCountFiller(
@@ -471,10 +478,19 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
         {
             var totalDuration = TimeSpan.FromTicks(result.Sum(pi => (pi.Finish - pi.Start).Ticks));
 
+            List<MediaChapter> filteredChapters =
+                FillerExpression.FilterChapters(padFiller, effectiveChapters, playoutItem);
+
+            FillerKind fillerKind = padFiller.FillerKind;
+            if (filteredChapters.Count <= 1 && effectiveChapters.Count > 1)
+            {
+                fillerKind = FillerKind.PostRoll;
+            }
+
             // add primary content to totalDuration only if it hasn't already been added
             if (result.All(pi => pi.MediaItemId != playoutItem.MediaItemId))
             {
-                totalDuration += TimeSpan.FromTicks(effectiveChapters.Sum(c => (c.EndTime - c.StartTime).Ticks));
+                totalDuration += TimeSpan.FromTicks(filteredChapters.Sum(c => (c.EndTime - c.StartTime).Ticks));
             }
 
             int currentMinute = (playoutItem.StartOffset + totalDuration).Minute;
@@ -510,7 +526,7 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
             //     playoutItem.StartOffset,
             //     targetTime);
 
-            switch (padFiller.FillerKind)
+            switch (fillerKind)
             {
                 case FillerKind.PreRoll:
                     IMediaCollectionEnumerator pre1 = enumerators[CollectionKey.ForFillerPreset(padFiller)];
@@ -550,19 +566,19 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
                             padFiller.AllowWatermarks,
                             log,
                             cancellationToken));
-                    TimeSpan average = effectiveChapters.Count <= 1
+                    TimeSpan average = filteredChapters.Count <= 1
                         ? remainingToFill
-                        : remainingToFill / (effectiveChapters.Count - 1);
+                        : remainingToFill / (filteredChapters.Count - 1);
                     TimeSpan filled = TimeSpan.Zero;
 
                     // remove post-roll to add after mid-roll/content
                     var postRoll = result.Where(i => i.FillerKind == FillerKind.PostRoll).ToList();
                     result.RemoveAll(i => i.FillerKind == FillerKind.PostRoll);
 
-                    for (var i = 0; i < effectiveChapters.Count; i++)
+                    for (var i = 0; i < filteredChapters.Count; i++)
                     {
-                        result.Add(playoutItem.ForChapter(effectiveChapters[i]));
-                        if (i < effectiveChapters.Count - 1)
+                        result.Add(playoutItem.ForChapter(filteredChapters[i]));
+                        if (i < filteredChapters.Count - 1)
                         {
                             TimeSpan current = TimeSpan.Zero;
                             while (current < average && filled < remainingToFill)
@@ -586,7 +602,7 @@ public abstract class PlayoutModeSchedulerBase<T> : IPlayoutModeScheduler<T> whe
                                         playoutBuilderState,
                                         enumerators,
                                         scheduleItem,
-                                        i < effectiveChapters.Count - 1 ? maxThisBreak : leftOverall,
+                                        i < filteredChapters.Count - 1 ? maxThisBreak : leftOverall,
                                         cancellationToken);
 
                                     foreach (PlayoutItem fallback in maybeFallback)

ErsatzTV.Infrastructure.MySql/Migrations/20250711215753_Add_FillerPresetExpression.cs

@@ -0,0 +1,29 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.MySql.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_FillerPresetExpression : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "Expression",
+                table: "FillerPreset",
+                type: "longtext",
+                nullable: true)
+                .Annotation("MySql:CharSet", "utf8mb4");
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "Expression",
+                table: "FillerPreset");
+        }
+    }
+}

ErsatzTV.Infrastructure.MySql/Migrations/TvContextModelSnapshot.cs

@@ -17,7 +17,7 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
         {
 #pragma warning disable 612, 618
             modelBuilder
-                .HasAnnotation("ProductVersion", "9.0.6")
+                .HasAnnotation("ProductVersion", "9.0.7")
                 .HasAnnotation("Relational:MaxIdentifierLength", 64);
 
             MySqlModelBuilderExtensions.AutoIncrementColumns(modelBuilder);
@@ -709,6 +709,9 @@ namespace ErsatzTV.Infrastructure.MySql.Migrations
                     b.Property<TimeSpan?>("Duration")
                         .HasColumnType("time(6)");
 
+                    b.Property<string>("Expression")
+                        .HasColumnType("longtext");
+
                     b.Property<int>("FillerKind")
                         .HasColumnType("int");
 

ErsatzTV.Infrastructure.Sqlite/Migrations/20250711215724_Add_FillerPresetExpression.cs

@@ -0,0 +1,28 @@
+using Microsoft.EntityFrameworkCore.Migrations;
+
+#nullable disable
+
+namespace ErsatzTV.Infrastructure.Sqlite.Migrations
+{
+    /// <inheritdoc />
+    public partial class Add_FillerPresetExpression : Migration
+    {
+        /// <inheritdoc />
+        protected override void Up(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.AddColumn<string>(
+                name: "Expression",
+                table: "FillerPreset",
+                type: "TEXT",
+                nullable: true);
+        }
+
+        /// <inheritdoc />
+        protected override void Down(MigrationBuilder migrationBuilder)
+        {
+            migrationBuilder.DropColumn(
+                name: "Expression",
+                table: "FillerPreset");
+        }
+    }
+}

ErsatzTV.Infrastructure.Sqlite/Migrations/TvContextModelSnapshot.cs

@@ -15,7 +15,7 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
         protected override void BuildModel(ModelBuilder modelBuilder)
         {
 #pragma warning disable 612, 618
-            modelBuilder.HasAnnotation("ProductVersion", "9.0.6");
+            modelBuilder.HasAnnotation("ProductVersion", "9.0.7");
 
             modelBuilder.Entity("ErsatzTV.Core.Domain.Actor", b =>
                 {
@@ -676,6 +676,9 @@ namespace ErsatzTV.Infrastructure.Sqlite.Migrations
                     b.Property<TimeSpan?>("Duration")
                         .HasColumnType("TEXT");
 
+                    b.Property<string>("Expression")
+                        .HasColumnType("TEXT");
+
                     b.Property<int>("FillerKind")
                         .HasColumnType("INTEGER");
 

ErsatzTV/Pages/FillerPresetEditor.razor

@@ -178,6 +178,33 @@
                     </MudSelect>
                 </MudStack>
             }
+            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="form-field-stack gap-md-8 mb-5">
+                <div class="d-flex">
+                    <MudText>Expression</MudText>
+                </div>
+                <MudTextField @bind-Value="_model.Expression"
+                              For="@(() => _model.Expression)"
+                              Disabled="@(_model.FillerKind is not FillerKind.MidRoll)"
+                              HelperText="For mid-roll filler, only add filler when this expression evaluates to true for a given mid-roll point."/>
+            </MudStack>
+            <MudStack Row="true" Breakpoint="Breakpoint.SmAndDown" Class="gap-md-8 mb-5">
+                <div class="d-flex" style="width: 300px"></div>
+                <MudText Typo="Typo.body2">
+                    <span style="font-weight: bold;">total_points</span>: total number of potential mid-roll points
+                    <br />
+                    <span style="font-weight: bold;">total_duration</span>: total duration of the content, in seconds
+                    <br />
+                    <span style="font-weight: bold;">total_progress</span>: normalized position from 0 to 1
+                    <br />
+                    <span style="font-weight: bold;">last_mid_filler</span>: seconds since last mid-roll filler
+                    <br />
+                    <span style="font-weight: bold;">remaining_duration</span>: duration of the content after this mid-roll point, in seconds
+                    <br />
+                    <span style="font-weight: bold;">point</span>: the position of the mid-roll point, in seconds
+                    <br />
+                    <span style="font-weight: bold;">num</span>: the mid-roll point number, starting with 1
+                </MudText>
+            </MudStack>
         </MudContainer>
     </div>
 </MudForm>
@@ -246,6 +273,7 @@
                 _model.MediaItem = fillerPreset.MediaItemId.HasValue
                     ? _televisionShows.Append(_televisionSeasons).Append(_artists).ToList().Find(vm => vm.MediaItemId == fillerPreset.MediaItemId.Value)
                     : null;
+                _model.Expression = fillerPreset.Expression;
             });
         }
         else

ErsatzTV/ViewModels/FillerPresetEditViewModel.cs

@@ -30,6 +30,11 @@ public class FillerPresetEditViewModel
             {
                 FillerMode = FillerMode.None;
             }
+
+            if (_fillerKind is not FillerKind.MidRoll)
+            {
+                Expression = string.Empty;
+            }
         }
     }
 
@@ -81,6 +86,8 @@ public class FillerPresetEditViewModel
     public MultiCollectionViewModel MultiCollection { get; set; }
     public SmartCollectionViewModel SmartCollection { get; set; }
 
+    public string Expression { get; set; }
+
     public IRequest<Either<BaseError, Unit>> ToEdit() =>
         new UpdateFillerPreset(
             Id,
@@ -95,7 +102,8 @@ public class FillerPresetEditViewModel
             Collection?.Id,
             MediaItem?.MediaItemId,
             MultiCollection?.Id,
-            SmartCollection?.Id);
+            SmartCollection?.Id,
+            Expression);
 
     public IRequest<Either<BaseError, Unit>> ToUpdate() =>
         new CreateFillerPreset(
@@ -110,7 +118,8 @@ public class FillerPresetEditViewModel
             Collection?.Id,
             MediaItem?.MediaItemId,
             MultiCollection?.Id,
-            SmartCollection?.Id);
+            SmartCollection?.Id,
+            Expression);
 
     private static TimeSpan FixDuration(TimeSpan duration) =>
         duration > TimeSpan.FromDays(1) ? duration.Subtract(TimeSpan.FromDays(1)) : duration;