start to use new ffmpeg library (#632)

* start to add ffmpeg library

* start to hook ffmpeg lib into main app

* improvements

* more progress

* make pipeline builder configurable

* more options

* move more logic down into ffmpeg lib

* ffmpeg lib desired state refactoring

* add software scaling and padding

* add loudness normalization and software deinterlace

* add metadata output options

* add setsar filter

* use built-in scaling logic

* fixes

* initial nvidia support

* nvidia improvements

* support hls mode

* print old arguments at debug level

* fix package reference

* start to add qsv support

* formatting

* fix tests

* add timeout to transcode tests

* show successful ffmpeg arguments

* add vaapi support

* add more software decoders

* add experimental transcoder option

* call existing ffmpeg process service for unimplemented features

* fix nvidia mpeg2video bug

* update changelog

* ignore some neglected unit tests

ErsatzTV.FFmpeg/Encoder/EncoderCopyVideo.cs

@@ -0,0 +1,8 @@
+namespace ErsatzTV.FFmpeg.Encoder;
+
+public class EncoderCopyVideo : EncoderBase
+{
+    public override FrameState NextState(FrameState currentState) => currentState;
+    public override string Name => "copy";
+    public override StreamKind Kind => StreamKind.Video;
+}