feat: sync generated music video credits to next engine (#2917)

* add endpoint for generating music video credits

* feat: sync music video subtitles to next engine

CHANGELOG.md

@@ -16,6 +16,7 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/).
 - Fix HLS Direct playback when JWT auth is also used
 - Use configured ffmpeg path for motion and subtitle graphics elements
   - Previously, these elements required ffmpeg to be on PATH
+- Fix erroneous warning `Unable to locate MPEG-TS Script in folder Default` on installations with case-sensitive file systems
 
 ## [26.5.1] - 2026-05-08
 ### Fixed

ErsatzTV.Application/Playouts/Commands/SyncNextPlayoutHandler.cs

@@ -304,6 +304,7 @@ public partial class SyncNextPlayoutHandler(
                     var audioVersion = new MediaItemAudioVersion(playoutItem.MediaItem, headVersion);
                     await SelectTracks(
                         channel,
+                        playoutItem,
                         audioVersion,
                         nextPlayoutItem,
                         playoutItem.PreferredAudioLanguageCode ?? channel.PreferredAudioLanguageCode,
@@ -327,6 +328,7 @@ public partial class SyncNextPlayoutHandler(
 
     private async Task SelectTracks(
         Channel channel,
+        PlayoutItem playoutItem,
         MediaItemAudioVersion audioVersion,
         Core.Next.PlayoutItem nextPlayoutItem,
         string preferredAudioLanguage,
@@ -335,7 +337,7 @@ public partial class SyncNextPlayoutHandler(
         ChannelSubtitleMode subtitleMode,
         CancellationToken cancellationToken)
     {
-        List<Subtitle> allSubtitles = await GetSubtitles(audioVersion.MediaItem);
+        List<Subtitle> allSubtitles = await GetSubtitles(audioVersion.MediaItem, playoutItem.Id, playoutItem.InPoint);
 
         Option<MediaStream> maybeAudioStream = Option<MediaStream>.None;
         Option<Subtitle> maybeSubtitle = Option<Subtitle>.None;
@@ -407,6 +409,21 @@ public partial class SyncNextPlayoutHandler(
                     };
                 }
             }
+            else if (subtitle.Path.StartsWith("http://localhost", StringComparison.OrdinalIgnoreCase))
+            {
+                if (nextPlayoutItem.Tracks?.Subtitle?.Source is null)
+                {
+                    nextPlayoutItem.Tracks ??= new Core.Next.PlayoutItemTracks();
+                    nextPlayoutItem.Tracks.Subtitle ??= new Core.Next.TrackSelection();
+                    nextPlayoutItem.Tracks.Subtitle.Source = new Core.Next.Source
+                    {
+                        SourceType = Core.Next.SourceType.Http,
+                        Uri = subtitle.Path,
+                        KeepAlive = false,
+                        Reconnect = true
+                    };
+                }
+            }
         }
     }
 
@@ -672,7 +689,10 @@ public partial class SyncNextPlayoutHandler(
         }
     }
 
-    private static async Task<List<Subtitle>> GetSubtitles(MediaItem mediaItem)
+    private static async Task<List<Subtitle>> GetSubtitles(
+        MediaItem mediaItem,
+        int playoutItemId,
+        TimeSpan playoutItemInPoint)
     {
         List<Subtitle> allSubtitles = mediaItem switch
         {
@@ -682,7 +702,7 @@ public partial class SyncNextPlayoutHandler(
             Movie movie => await Optional(movie.MovieMetadata).Flatten().HeadOrNone()
                 .Map(mm => mm.Subtitles ?? [])
                 .IfNoneAsync([]),
-            //MusicVideo musicVideo => await GetMusicVideoSubtitles(musicVideo, channel, settings),
+            MusicVideo => GetMusicVideoSubtitles(playoutItemId, playoutItemInPoint),
             OtherVideo otherVideo => await Optional(otherVideo.OtherVideoMetadata).Flatten().HeadOrNone()
                 .Map(mm => mm.Subtitles ?? [])
                 .IfNoneAsync([]),
@@ -703,4 +723,25 @@ public partial class SyncNextPlayoutHandler(
 
         return allSubtitles;
     }
+
+    private static List<Subtitle> GetMusicVideoSubtitles(int playoutItemId, TimeSpan playoutItemInPoint)
+    {
+        string seekToMs = playoutItemInPoint > TimeSpan.Zero
+            ? $"?seekToMs={(long)playoutItemInPoint.TotalMilliseconds}"
+            : string.Empty;
+
+        return
+        [
+            new Subtitle
+            {
+                Codec = "ass",
+                Default = true,
+                Forced = true,
+                IsExtracted = false,
+                SubtitleKind = SubtitleKind.Generated,
+                Path = $"http://localhost:{Settings.StreamingPort}/ffmpeg/music-video-credits/{playoutItemId}{seekToMs}",
+                SDH = false
+            }
+        ];
+    }
 }

ErsatzTV.Application/Streaming/Queries/GetMusicVideoCreditsByPlayoutItemId.cs

@@ -0,0 +1,3 @@
+namespace ErsatzTV.Application.Streaming;
+
+public record GetMusicVideoCreditsByPlayoutItemId(int PlayoutItemId, Option<long> SeekToMs) : IRequest<Option<string>>;

ErsatzTV.Application/Streaming/Queries/GetMusicVideoCreditsByPlayoutItemIdHandler.cs

@@ -0,0 +1,95 @@
+using ErsatzTV.Core;
+using ErsatzTV.Core.Domain;
+using ErsatzTV.Core.Interfaces.FFmpeg;
+using ErsatzTV.Infrastructure.Data;
+using Microsoft.EntityFrameworkCore;
+using Microsoft.Extensions.Logging;
+
+namespace ErsatzTV.Application.Streaming;
+
+public class GetMusicVideoCreditsByPlayoutItemIdHandler(
+    IDbContextFactory<TvContext> dbContextFactory,
+    IMusicVideoCreditsGenerator musicVideoCreditsGenerator,
+    ILogger<GetMusicVideoCreditsByPlayoutItemIdHandler> logger)
+    : IRequestHandler<GetMusicVideoCreditsByPlayoutItemId, Option<string>>
+{
+    public async Task<Option<string>> Handle(
+        GetMusicVideoCreditsByPlayoutItemId request,
+        CancellationToken cancellationToken)
+    {
+        await using TvContext dbContext = await dbContextFactory.CreateDbContextAsync(cancellationToken);
+
+        Option<PlayoutItem> maybePlayoutItem = await dbContext.PlayoutItems
+            .AsNoTracking()
+            .Include(pi => pi.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MusicVideoMetadata)
+            .ThenInclude(mvm => mvm.Subtitles)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MusicVideoMetadata)
+            .ThenInclude(mvm => mvm.Artists)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MusicVideoMetadata)
+            .ThenInclude(mvm => mvm.Studios)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MusicVideoMetadata)
+            .ThenInclude(mvm => mvm.Directors)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MediaVersions)
+            .ThenInclude(mv => mv.MediaFiles)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).MediaVersions)
+            .ThenInclude(mv => mv.Streams)
+            .Include(i => i.MediaItem)
+            .ThenInclude(mi => (mi as MusicVideo).Artist)
+            .ThenInclude(mv => mv.ArtistMetadata)
+            .Include(pi => pi.Playout)
+            .ThenInclude(p => p.Channel)
+            .ThenInclude(c => c.FFmpegProfile)
+            .ThenInclude(ff => ff.Resolution)
+            .SingleOrDefaultAsync(pi => pi.Id == request.PlayoutItemId, cancellationToken)
+            .Map(Optional);
+
+        var subtitles = new List<Subtitle>();
+        foreach (PlayoutItem playoutItem in maybePlayoutItem)
+        {
+            if (playoutItem.MediaItem is not MusicVideo musicVideo)
+            {
+                break;
+            }
+
+            switch (playoutItem.Playout.Channel.MusicVideoCreditsMode)
+            {
+                case ChannelMusicVideoCreditsMode.GenerateSubtitles:
+                    string templateName = playoutItem.Playout.Channel.MusicVideoCreditsTemplate;
+                    if (!string.IsNullOrWhiteSpace(templateName))
+                    {
+                        var fileWithExtension = $"{templateName}.sbntxt";
+                        subtitles.AddRange(
+                            await musicVideoCreditsGenerator.GenerateCreditsSubtitleFromTemplate(
+                                musicVideo,
+                                playoutItem.Playout.Channel.FFmpegProfile,
+                                request.SeekToMs.Map(TimeSpan.FromMilliseconds),
+                                Path.Combine(FileSystemLayout.MusicVideoCreditsTemplatesFolder, fileWithExtension)));
+                    }
+                    else
+                    {
+                        logger.LogWarning(
+                            "Music video credits template {Template} does not exist; falling back to built-in template",
+                            templateName);
+
+                        subtitles.AddRange(
+                            await musicVideoCreditsGenerator.GenerateCreditsSubtitle(
+                                musicVideo,
+                                playoutItem.Playout.Channel.FFmpegProfile));
+                    }
+
+                    break;
+                case ChannelMusicVideoCreditsMode.None:
+                default:
+                    break;
+            }
+        }
+
+        return subtitles.HeadOrNone().Map(s => s.Path);
+    }
+}

ErsatzTV.Application/Streaming/Queries/GetPlayoutItemProcessByChannelNumberHandler.cs

@@ -654,7 +654,7 @@ public class GetPlayoutItemProcessByChannelNumberHandler : FFmpegProcessHandler<
                         await _musicVideoCreditsGenerator.GenerateCreditsSubtitleFromTemplate(
                             musicVideo,
                             channel.FFmpegProfile,
-                            settings,
+                            settings.StreamSeek,
                             Path.Combine(FileSystemLayout.MusicVideoCreditsTemplatesFolder, fileWithExtension)));
                 }
                 else

ErsatzTV.Core/Interfaces/FFmpeg/IMusicVideoCreditsGenerator.cs

@@ -10,6 +10,6 @@ public interface IMusicVideoCreditsGenerator
     Task<Option<Subtitle>> GenerateCreditsSubtitleFromTemplate(
         MusicVideo musicVideo,
         FFmpegProfile ffmpegProfile,
-        FFmpegPlaybackSettings settings,
+        Option<TimeSpan> streamSeek,
         string templateFileName);
 }

ErsatzTV.Infrastructure/FFmpeg/MusicVideoCreditsGenerator.cs

@@ -87,7 +87,7 @@ public class MusicVideoCreditsGenerator(ITempFilePool tempFilePool, ILogger<Musi
     public async Task<Option<Subtitle>> GenerateCreditsSubtitleFromTemplate(
         MusicVideo musicVideo,
         FFmpegProfile ffmpegProfile,
-        FFmpegPlaybackSettings settings,
+        Option<TimeSpan> streamSeek,
         string templateFileName)
     {
         try
@@ -111,12 +111,12 @@ public class MusicVideoCreditsGenerator(ITempFilePool tempFilePool, ILogger<Musi
                         metadata.Album,
                         metadata.Plot,
                         metadata.ReleaseDate,
-                        AllArtists = (metadata.Artists ?? new List<MusicVideoArtist>()).Map(a => a.Name),
+                        AllArtists = (metadata.Artists ?? []).Map(a => a.Name),
                         Artist = artist,
-                        Studios = (metadata.Studios ?? new List<Studio>()).Map(s => s.Name),
-                        Directors = (metadata.Directors ?? new List<Director>()).Map(s => s.Name),
+                        Studios = (metadata.Studios ?? []).Map(s => s.Name),
+                        Directors = (metadata.Directors ?? []).Map(s => s.Name),
                         musicVideo.GetHeadVersion().Duration,
-                        StreamSeek = await settings.StreamSeek.IfNoneAsync(TimeSpan.Zero)
+                        StreamSeek = await streamSeek.IfNoneAsync(TimeSpan.Zero)
                     });
 
                 string fileName = tempFilePool.GetNextTempFile(TempFileCategory.Subtitle);

ErsatzTV/Controllers/InternalController.cs

@@ -46,6 +46,23 @@ public class InternalController : StreamingControllerBase
     [HttpGet("ffmpeg/stream/{channelNumber}")]
     public Task<IActionResult> GetStream(string channelNumber) => GetTsLegacyStream(channelNumber);
 
+    [HttpGet("ffmpeg/music-video-credits/{playoutItemId:int}")]
+    public async Task<IActionResult> GetMusicVideoCredits(
+        int playoutItemId,
+        [FromQuery] long? seekToMs,
+        CancellationToken cancellationToken)
+    {
+        Option<string> maybeCreditsFile = await _mediator.Send(
+            new GetMusicVideoCreditsByPlayoutItemId(playoutItemId, Optional(seekToMs)),
+            cancellationToken);
+        foreach (string creditsFile in maybeCreditsFile)
+        {
+            return new PhysicalFileResult(creditsFile, "text/x-ssa");
+        }
+
+        return NotFound();
+    }
+
     [HttpGet("ffmpeg/remote-stream/{remoteStreamId}")]
     public async Task<IActionResult> GetRemoteStream(int remoteStreamId, CancellationToken cancellationToken)
     {