Merge pull request #10067 from lonebyte/flac-hls-fixes

Jellyfin.Api/Controllers/DynamicHlsController.cs

@@ -45,6 +45,8 @@ public class DynamicHlsController : BaseJellyfinApiController
     private const string DefaultEventEncoderPreset = "superfast";
     private const TranscodingJobType TranscodingJobType = MediaBrowser.Controller.MediaEncoding.TranscodingJobType.Hls;
 
+    private readonly Version _minFFmpegFlacInMp4 = new Version(6, 0);
+
     private readonly ILibraryManager _libraryManager;
     private readonly IUserManager _userManager;
     private readonly IDlnaManager _dlnaManager;
@@ -1705,16 +1707,28 @@ public class DynamicHlsController : BaseJellyfinApiController
         var audioCodec = _encodingHelper.GetAudioEncoder(state);
         var bitStreamArgs = EncodingHelper.GetAudioBitStreamArguments(state, state.Request.SegmentContainer, state.MediaSource.Container);
 
+        // opus, dts, truehd and flac (in FFmpeg 5 and older) are experimental in mp4 muxer
+        var strictArgs = string.Empty;
+        var actualOutputAudioCodec = state.ActualOutputAudioCodec;
+        if (string.Equals(actualOutputAudioCodec, "opus", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(actualOutputAudioCodec, "dts", StringComparison.OrdinalIgnoreCase)
+            || string.Equals(actualOutputAudioCodec, "truehd", StringComparison.OrdinalIgnoreCase)
+            || (string.Equals(actualOutputAudioCodec, "flac", StringComparison.OrdinalIgnoreCase)
+                && _mediaEncoder.EncoderVersion < _minFFmpegFlacInMp4))
+        {
+            strictArgs = " -strict -2";
+        }
+
         if (!state.IsOutputVideo)
         {
             if (EncodingHelper.IsCopyCodec(audioCodec))
             {
-                return "-acodec copy -strict -2" + bitStreamArgs;
+                return "-acodec copy" + bitStreamArgs + strictArgs;
             }
 
             var audioTranscodeParams = string.Empty;
 
-            audioTranscodeParams += "-acodec " + audioCodec + bitStreamArgs;
+            audioTranscodeParams += "-acodec " + audioCodec + bitStreamArgs + strictArgs;
 
             var audioBitrate = state.OutputAudioBitrate;
             var audioChannels = state.OutputAudioChannels;
@@ -1746,17 +1760,6 @@ public class DynamicHlsController : BaseJellyfinApiController
             return audioTranscodeParams;
         }
 
-        // dts, flac, opus and truehd are experimental in mp4 muxer
-        var strictArgs = string.Empty;
-        var actualOutputAudioCodec = state.ActualOutputAudioCodec;
-        if (string.Equals(actualOutputAudioCodec, "flac", StringComparison.OrdinalIgnoreCase)
-            || string.Equals(actualOutputAudioCodec, "opus", StringComparison.OrdinalIgnoreCase)
-            || string.Equals(actualOutputAudioCodec, "dts", StringComparison.OrdinalIgnoreCase)
-            || string.Equals(actualOutputAudioCodec, "truehd", StringComparison.OrdinalIgnoreCase))
-        {
-            strictArgs = " -strict -2";
-        }
-
         if (EncodingHelper.IsCopyCodec(audioCodec))
         {
             var videoCodec = _encodingHelper.GetVideoEncoder(state, _encodingOptions);

Jellyfin.Api/Helpers/DynamicHlsHelper.cs

@@ -200,13 +200,6 @@ public class DynamicHlsHelper
 
         if (state.VideoStream is not null && state.VideoRequest is not null)
         {
-            // Provide a workaround for the case issue between flac and fLaC.
-            var flacWaPlaylist = ApplyFlacCaseWorkaround(state, basicPlaylist.ToString());
-            if (!string.IsNullOrEmpty(flacWaPlaylist))
-            {
-                builder.Append(flacWaPlaylist);
-            }
-
             var encodingOptions = _serverConfigurationManager.GetEncodingOptions();
 
             // Provide SDR HEVC entrance for backward compatibility.
@@ -236,14 +229,7 @@ public class DynamicHlsHelper
                     }
 
                     var sdrTotalBitrate = sdrOutputAudioBitrate + sdrOutputVideoBitrate;
-                    var sdrPlaylist = AppendPlaylist(builder, state, sdrVideoUrl, sdrTotalBitrate, subtitleGroup);
-
-                    // Provide a workaround for the case issue between flac and fLaC.
-                    flacWaPlaylist = ApplyFlacCaseWorkaround(state, sdrPlaylist.ToString());
-                    if (!string.IsNullOrEmpty(flacWaPlaylist))
-                    {
-                        builder.Append(flacWaPlaylist);
-                    }
+                    AppendPlaylist(builder, state, sdrVideoUrl, sdrTotalBitrate, subtitleGroup);
 
                     // Restore the video codec
                     state.OutputVideoCodec = "copy";
@@ -274,13 +260,6 @@ public class DynamicHlsHelper
                 state.VideoStream.Level = originalLevel;
                 var newPlaylist = ReplacePlaylistCodecsField(basicPlaylist, playlistCodecsField, newPlaylistCodecsField);
                 builder.Append(newPlaylist);
-
-                // Provide a workaround for the case issue between flac and fLaC.
-                flacWaPlaylist = ApplyFlacCaseWorkaround(state, newPlaylist);
-                if (!string.IsNullOrEmpty(flacWaPlaylist))
-                {
-                    builder.Append(flacWaPlaylist);
-                }
             }
         }
 
@@ -767,16 +746,4 @@ public class DynamicHlsHelper
             newValue.ToString(),
             StringComparison.Ordinal);
     }
-
-    private string ApplyFlacCaseWorkaround(StreamState state, string srcPlaylist)
-    {
-        if (!string.Equals(state.ActualOutputAudioCodec, "flac", StringComparison.OrdinalIgnoreCase))
-        {
-            return string.Empty;
-        }
-
-        var newPlaylist = srcPlaylist.Replace(",flac\"", ",fLaC\"", StringComparison.Ordinal);
-
-        return newPlaylist.Contains(",fLaC\"", StringComparison.Ordinal) ? newPlaylist : string.Empty;
-    }
 }

Jellyfin.Api/Helpers/HlsCodecStringHelpers.cs

@@ -5,7 +5,9 @@ using System.Text;
 namespace Jellyfin.Api.Helpers;
 
 /// <summary>
-/// Hls Codec string helpers.
+/// Helpers to generate HLS codec strings according to
+/// <a href="https://datatracker.ietf.org/doc/html/rfc6381#section-3.3">RFC 6381 section 3.3</a>
+/// and the <a href="https://mp4ra.org">MP4 Registration Authority</a>.
 /// </summary>
 public static class HlsCodecStringHelpers
 {
@@ -27,7 +29,7 @@ public static class HlsCodecStringHelpers
     /// <summary>
     /// Codec name for FLAC.
     /// </summary>
-    public const string FLAC = "flac";
+    public const string FLAC = "fLaC";
 
     /// <summary>
     /// Codec name for ALAC.
@@ -37,7 +39,7 @@ public static class HlsCodecStringHelpers
     /// <summary>
     /// Codec name for OPUS.
     /// </summary>
-    public const string OPUS = "opus";
+    public const string OPUS = "Opus";
 
     /// <summary>
     /// Gets a MP3 codec string.