fix intel vaapi pgs subtitle pixel format (#1455)

CHANGELOG.md

@@ -21,6 +21,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix NVIDIA subtitle scaling when `scale_npp` filter is unavailable
 - Remove ffmpeg and ffprobe as required dependencies for scanning media server libraries
   - Note that ffmpeg is still *always* required for playback to work
+- Fix PGS subtitle pixel format with Intel VAAPI
 
 ### Changed
 - Upgrade ffmpeg to 6.1, which is now *required* for all installs

ErsatzTV.FFmpeg/Filter/Vaapi/VaapiSubtitlePixelFormatFilter.cs

@@ -0,0 +1,8 @@
+namespace ErsatzTV.FFmpeg.Filter.Vaapi;
+
+public class VaapiSubtitlePixelFormatFilter : BaseFilter
+{
+    public override FrameState NextState(FrameState currentState) => currentState;
+
+    public override string Filter => "format=vaapi|yuva420p|yuva444p|yuva422p|rgba|abgr|bgra|gbrap|ya8";
+}

ErsatzTV.FFmpeg/Pipeline/VaapiPipelineBuilder.cs

@@ -436,7 +436,7 @@ public class VaapiPipelineBuilder : SoftwarePipelineBuilder
             }
             else if (context.HasSubtitleOverlay)
             {
-                var pixelFormatFilter = new PixelFormatFilter(new PixelFormatArgb());
+                var pixelFormatFilter = new VaapiSubtitlePixelFormatFilter();
                 subtitle.FilterSteps.Add(pixelFormatFilter);
 
                 if (forceSoftwareOverlay)