From 2a689f268bc88ee7ab7e25121a6d43f71c1f8a5f Mon Sep 17 00:00:00 2001 From: Piotr Niełacny Date: Sat, 21 Mar 2026 21:57:58 +0100 Subject: Embed external subtitles into MKV when transcoding Allow external subtitle files (SRT, ASS, PGS, etc.) to be muxed into MKV output containers when the device profile requests Embed delivery. Previously, the IsExternal guard in GetSubtitleProfile excluded external subtitles from Embed consideration entirely, forcing them to be served as separate sidecar files even when the output container supports embedding. Changes: - Extract CanConsiderEmbedSubtitle in StreamBuilder to allow external subs through when transcoding to MKV - Add external subtitle file as FFmpeg input (-i) for Embed delivery - Map external embedded subs from the correct FFmpeg input index - Fix external audio map index to account for the new subtitle input - Extract NeedsExternalSubtitleMuxing in EncodingHelper to deduplicate the external subtitle input check Fixes #16403 --- .../MediaEncoding/EncodingHelper.cs | 58 ++++++++++++++-------- MediaBrowser.Model/Dlna/StreamBuilder.cs | 15 +++++- .../Dlna/StreamBuilderTests.cs | 54 ++++++++++++++++++++ 3 files changed, 104 insertions(+), 23 deletions(-) diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs index 65f6b79656..1fdb5fd4bd 100644 --- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs +++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs @@ -1267,22 +1267,23 @@ namespace MediaBrowser.Controller.MediaEncoding .Append(_mediaEncoder.GetInputPathArgument(state)); } - // sub2video for external graphical subtitles - if (state.SubtitleStream is not null - && ShouldEncodeSubtitle(state) - && !state.SubtitleStream.IsTextSubtitleStream - && state.SubtitleStream.IsExternal) + if (NeedsExternalSubtitleMuxing(state)) { var subtitlePath = state.SubtitleStream.Path; - var subtitleExtension = Path.GetExtension(subtitlePath.AsSpan()); + var isGraphicalBurnIn = ShouldEncodeSubtitle(state) && !state.SubtitleStream.IsTextSubtitleStream; - // dvdsub/vobsub graphical subtitles use .sub+.idx pairs - if (subtitleExtension.Equals(".sub", StringComparison.OrdinalIgnoreCase)) + if (isGraphicalBurnIn) { - var idxFile = Path.ChangeExtension(subtitlePath, ".idx"); - if (File.Exists(idxFile)) + var subtitleExtension = Path.GetExtension(subtitlePath.AsSpan()); + + // dvdsub/vobsub graphical subtitles use .sub+.idx pairs + if (subtitleExtension.Equals(".sub", StringComparison.OrdinalIgnoreCase)) { - subtitlePath = idxFile; + var idxFile = Path.ChangeExtension(subtitlePath, ".idx"); + if (File.Exists(idxFile)) + { + subtitlePath = idxFile; + } } } @@ -1307,7 +1308,7 @@ namespace MediaBrowser.Controller.MediaEncoding arg.Append(' ').Append(seekSubParam); } - if (!string.IsNullOrEmpty(canvasArgs)) + if (isGraphicalBurnIn && !string.IsNullOrEmpty(canvasArgs)) { arg.Append(canvasArgs); } @@ -3072,11 +3073,8 @@ namespace MediaBrowser.Controller.MediaEncoding int audioStreamIndex = FindIndex(state.MediaSource.MediaStreams, state.AudioStream); if (state.AudioStream.IsExternal) { - bool hasExternalGraphicsSubs = state.SubtitleStream is not null - && ShouldEncodeSubtitle(state) - && state.SubtitleStream.IsExternal - && !state.SubtitleStream.IsTextSubtitleStream; - int externalAudioMapIndex = hasExternalGraphicsSubs ? 2 : 1; + bool hasExternalSubAsInput = NeedsExternalSubtitleMuxing(state); + int externalAudioMapIndex = hasExternalSubAsInput ? 2 : 1; args += string.Format( CultureInfo.InvariantCulture, @@ -3104,12 +3102,20 @@ namespace MediaBrowser.Controller.MediaEncoding } else if (subtitleMethod == SubtitleDeliveryMethod.Embed) { - int subtitleStreamIndex = FindIndex(state.MediaSource.MediaStreams, state.SubtitleStream); + if (state.SubtitleStream.IsExternal) + { + // External subtitle file is added as second FFmpeg input + args += " -map 1:0"; + } + else + { + int subtitleStreamIndex = FindIndex(state.MediaSource.MediaStreams, state.SubtitleStream); - args += string.Format( - CultureInfo.InvariantCulture, - " -map 0:{0}", - subtitleStreamIndex); + args += string.Format( + CultureInfo.InvariantCulture, + " -map 0:{0}", + subtitleStreamIndex); + } } else if (state.SubtitleStream.IsExternal && !state.SubtitleStream.IsTextSubtitleStream) { @@ -7886,6 +7892,14 @@ namespace MediaBrowser.Controller.MediaEncoding || (state.BaseRequest.AlwaysBurnInSubtitleWhenTranscoding && !IsCopyCodec(state.OutputVideoCodec)); } + private static bool NeedsExternalSubtitleMuxing(EncodingJobInfo state) + { + return state.SubtitleStream is not null + && state.SubtitleStream.IsExternal + && (state.SubtitleDeliveryMethod == SubtitleDeliveryMethod.Embed + || (ShouldEncodeSubtitle(state) && !state.SubtitleStream.IsTextSubtitleStream)); + } + public static string GetVideoSyncOption(string videoSync, Version encoderVersion) { if (string.IsNullOrEmpty(videoSync)) diff --git a/MediaBrowser.Model/Dlna/StreamBuilder.cs b/MediaBrowser.Model/Dlna/StreamBuilder.cs index 44697837ca..2ccd2a6c28 100644 --- a/MediaBrowser.Model/Dlna/StreamBuilder.cs +++ b/MediaBrowser.Model/Dlna/StreamBuilder.cs @@ -1451,7 +1451,7 @@ namespace MediaBrowser.Model.Dlna string? outputContainer, MediaStreamProtocol? transcodingSubProtocol) { - if (!subtitleStream.IsExternal && (playMethod != PlayMethod.Transcode || transcodingSubProtocol != MediaStreamProtocol.hls)) + if (CanConsiderEmbedSubtitle(subtitleStream, playMethod, transcodingSubProtocol, outputContainer)) { // Look for supported embedded subs of the same format foreach (var profile in subtitleProfiles) @@ -1540,6 +1540,19 @@ namespace MediaBrowser.Model.Dlna return false; } + private static bool CanConsiderEmbedSubtitle(MediaStream subtitleStream, PlayMethod playMethod, MediaStreamProtocol? transcodingSubProtocol, string? outputContainer) + { + if (subtitleStream.IsExternal) + { + return playMethod == PlayMethod.Transcode + && transcodingSubProtocol != MediaStreamProtocol.hls + && IsSubtitleEmbedSupported(outputContainer); + } + + return playMethod != PlayMethod.Transcode + || transcodingSubProtocol != MediaStreamProtocol.hls; + } + private static SubtitleProfile? GetExternalSubtitleProfile(MediaSourceInfo mediaSource, MediaStream subtitleStream, SubtitleProfile[] subtitleProfiles, PlayMethod playMethod, ITranscoderSupport transcoderSupport, bool allowConversion) { foreach (var profile in subtitleProfiles) diff --git a/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs b/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs index 0b103debad..16c586bcda 100644 --- a/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs +++ b/tests/Jellyfin.Model.Tests/Dlna/StreamBuilderTests.cs @@ -675,5 +675,59 @@ namespace Jellyfin.Model.Tests Assert.Equal(expectedMethod, result.Method); } + + [Theory] + // External text subs embedded into MKV when transcoding (#16403) + [InlineData("srt", true, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + [InlineData("ass", true, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + // External graphical subs embedded into MKV when transcoding + [InlineData("pgssub", true, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + [InlineData("dvdsub", true, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + // External subs remain external when transcoding to non-MKV containers + [InlineData("srt", true, PlayMethod.Transcode, "mp4", MediaStreamProtocol.hls, SubtitleDeliveryMethod.External)] + [InlineData("srt", true, PlayMethod.Transcode, "ts", MediaStreamProtocol.hls, SubtitleDeliveryMethod.External)] + // External subs remain external during DirectPlay even with MKV + [InlineData("srt", true, PlayMethod.DirectPlay, "mkv", null, SubtitleDeliveryMethod.External)] + // Internal subs still embedded into MKV when transcoding (existing behavior) + [InlineData("srt", false, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + [InlineData("pgssub", false, PlayMethod.Transcode, "mkv", MediaStreamProtocol.http, SubtitleDeliveryMethod.Embed)] + public void GetSubtitleProfile_ReturnsExpectedDeliveryMethod( + string codec, + bool isExternal, + PlayMethod playMethod, + string outputContainer, + MediaStreamProtocol? transcodingSubProtocol, + SubtitleDeliveryMethod expectedMethod) + { + var mediaSource = new MediaSourceInfo(); + var subtitleStream = new MediaStream + { + Codec = codec, + Language = "eng", + IsExternal = isExternal, + Type = MediaStreamType.Subtitle, + SupportsExternalStream = true + }; + + var subtitleProfiles = new[] + { + new SubtitleProfile { Format = codec, Method = SubtitleDeliveryMethod.Embed }, + new SubtitleProfile { Format = codec, Method = SubtitleDeliveryMethod.External } + }; + + var transcoderSupport = new Mock(); + transcoderSupport.Setup(x => x.CanExtractSubtitles(It.IsAny())).Returns(true); + + var result = StreamBuilder.GetSubtitleProfile( + mediaSource, + subtitleStream, + subtitleProfiles, + playMethod, + transcoderSupport.Object, + outputContainer, + transcodingSubProtocol); + + Assert.Equal(expectedMethod, result.Method); + } } } -- cgit v1.2.3