Use source audio bitrate if requested codec is lossless

Jellyfin.Api/Controllers/DynamicHlsController.cs

@@ -13,6 +13,7 @@ using Jellyfin.Api.Constants;
 using Jellyfin.Api.Helpers;
 using Jellyfin.Api.Models.PlaybackDtos;
 using Jellyfin.Api.Models.StreamingDtos;
+using Jellyfin.Extensions;
 using Jellyfin.MediaEncoding.Hls.Playlist;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Controller.Configuration;
@@ -1694,7 +1695,7 @@ namespace Jellyfin.Api.Controllers
 
                 audioTranscodeParams += "-acodec " + audioCodec;
 
-                if (state.OutputAudioBitrate.HasValue)
+                if (state.OutputAudioBitrate.HasValue && !EncodingHelper.LosslessAudioCodecs.Contains(state.ActualOutputAudioCodec, StringComparison.OrdinalIgnoreCase))
                 {
                     audioTranscodeParams += " -ab " + state.OutputAudioBitrate.Value.ToString(CultureInfo.InvariantCulture);
                 }
@@ -1715,11 +1716,11 @@ namespace Jellyfin.Api.Controllers
 
             // dts, flac, opus and truehd are experimental in mp4 muxer
             var strictArgs = string.Empty;
-
-            if (string.Equals(state.ActualOutputAudioCodec, "flac", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(state.ActualOutputAudioCodec, "opus", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(state.ActualOutputAudioCodec, "dts", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(state.ActualOutputAudioCodec, "truehd", StringComparison.OrdinalIgnoreCase))
+            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";
             }
@@ -1748,8 +1749,7 @@ namespace Jellyfin.Api.Controllers
             }
 
             var bitrate = state.OutputAudioBitrate;
-
-            if (bitrate.HasValue)
+            if (bitrate.HasValue && !EncodingHelper.LosslessAudioCodecs.Contains(actualOutputAudioCodec, StringComparison.OrdinalIgnoreCase))
             {
                 args += " -ab " + bitrate.Value.ToString(CultureInfo.InvariantCulture);
             }

Jellyfin.Api/Helpers/DynamicHlsHelper.cs

@@ -8,6 +8,7 @@ using System.Text;
 using System.Threading;
 using System.Threading.Tasks;
 using Jellyfin.Api.Models.StreamingDtos;
+using Jellyfin.Extensions;
 using MediaBrowser.Common.Configuration;
 using MediaBrowser.Common.Extensions;
 using MediaBrowser.Common.Net;
@@ -220,11 +221,26 @@ namespace Jellyfin.Api.Helpers
                         var sdrVideoUrl = ReplaceProfile(playlistUrl, "hevc", string.Join(',', requestedVideoProfiles), "main");
                         sdrVideoUrl += "&AllowVideoStreamCopy=false";
 
-                        var sdrOutputVideoBitrate = _encodingHelper.GetVideoBitrateParamValue(state.VideoRequest, state.VideoStream, state.OutputVideoCodec);
-                        var sdrOutputAudioBitrate = _encodingHelper.GetAudioBitrateParam(state.VideoRequest, state.AudioStream, state.OutputAudioChannels) ?? 0;
-                        var sdrTotalBitrate = sdrOutputAudioBitrate + sdrOutputVideoBitrate;
+                    var sdrOutputVideoBitrate = _encodingHelper.GetVideoBitrateParamValue(state.VideoRequest, state.VideoStream, state.OutputVideoCodec);
+                    var sdrOutputAudioBitrate = 0;
+                    if (EncodingHelper.LosslessAudioCodecs.Contains(state.VideoRequest.AudioCodec, StringComparison.OrdinalIgnoreCase))
+                    {
+                        sdrOutputAudioBitrate = state.AudioStream.BitRate ?? 0;
+                    }
+                    else
+                    {
+                        sdrOutputAudioBitrate = _encodingHelper.GetAudioBitrateParam(state.VideoRequest, state.AudioStream, state.OutputAudioChannels) ?? 0;
+                    }
 
-                        AppendPlaylist(builder, state, sdrVideoUrl, sdrTotalBitrate, subtitleGroup);
+                    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);
+                    }
 
                         // Restore the video codec
                         state.OutputVideoCodec = "copy";

Jellyfin.Api/Helpers/StreamingHelpers.cs

@@ -182,12 +182,18 @@ namespace Jellyfin.Api.Helpers
                     : GetOutputFileExtension(state, mediaSource);
             }
 
-            state.OutputContainer = (containerInternal ?? string.Empty).TrimStart('.');
-
-            state.OutputAudioBitrate = encodingHelper.GetAudioBitrateParam(streamingRequest.AudioBitRate, streamingRequest.AudioCodec, state.AudioStream, state.OutputAudioChannels);
-
-            state.OutputAudioCodec = streamingRequest.AudioCodec;
+            var outputAudioCodec = streamingRequest.AudioCodec;
+            if (EncodingHelper.LosslessAudioCodecs.Contains(outputAudioCodec))
+            {
+                state.OutputAudioBitrate = state.AudioStream.BitRate ?? 0;
+            }
+            else
+            {
+                state.OutputAudioBitrate = encodingHelper.GetAudioBitrateParam(streamingRequest.AudioBitRate, streamingRequest.AudioCodec, state.AudioStream, state.OutputAudioChannels) ?? 0;
+            }
 
+            state.OutputAudioCodec = outputAudioCodec;
+            state.OutputContainer = (containerInternal ?? string.Empty).TrimStart('.');
             state.OutputAudioChannels = encodingHelper.GetNumAudioChannelsParam(state, state.AudioStream, state.OutputAudioCodec);
 
             if (state.VideoRequest != null)

MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs

@@ -62,6 +62,16 @@ namespace MediaBrowser.Controller.MediaEncoding
             "Main10"
         };
 
+        public static readonly string[] LosslessAudioCodecs = new string[]
+        {
+            "alac",
+            "ape",
+            "flac",
+            "mlp",
+            "truehd",
+            "wavpack"
+        };
+
         public EncodingHelper(
             IApplicationPaths appPaths,
             IMediaEncoder mediaEncoder,
@@ -2104,17 +2114,6 @@ namespace MediaBrowser.Controller.MediaEncoding
                 };
             }
 
-            if (string.Equals(audioCodec, "flac", StringComparison.OrdinalIgnoreCase)
-                || string.Equals(audioCodec, "alac", StringComparison.OrdinalIgnoreCase))
-            {
-                if (inputChannels >= 6)
-                {
-                    return Math.Min(3584000, bitrate);
-                }
-
-                return Math.Min(1536000, bitrate);
-            }
-
             if (string.Equals(audioCodec, "dts", StringComparison.OrdinalIgnoreCase)
                 || string.Equals(audioCodec, "dca", StringComparison.OrdinalIgnoreCase))
             {
@@ -2127,20 +2126,10 @@ namespace MediaBrowser.Controller.MediaEncoding
                 };
             }
 
-            if (string.Equals(audioCodec, "truehd", StringComparison.OrdinalIgnoreCase))
-            {
-                return (inputChannels, outputChannels) switch
-                {
-                    (> 0, > 0) => Math.Min(outputChannels * 768000, bitrate),
-                    (> 0, _) => Math.Min(inputChannels * 768000, bitrate),
-                    (_, _) => Math.Min(768000, bitrate)
-                };
-            }
-
             // Empty bitrate area is not allow on iOS
             // Default audio bitrate to 128K per channel if we don't have codec specific defaults
             // https://ffmpeg.org/ffmpeg-codecs.html#toc-Codec-Options
-            return 128000 * (outputAudioChannels ?? audioStream.Channels ?? 1);
+            return 128000 * (outputAudioChannels ?? audioStream.Channels ?? 2);
         }
 
         public string GetAudioFilterParam(EncodingJobInfo state, EncodingOptions encodingOptions)
@@ -5562,7 +5551,7 @@ namespace MediaBrowser.Controller.MediaEncoding
 
             var bitrate = state.OutputAudioBitrate;
 
-            if (bitrate.HasValue)
+            if (bitrate.HasValue && !LosslessAudioCodecs.Contains(codec, StringComparison.OrdinalIgnoreCase))
             {
                 args += " -ab " + bitrate.Value.ToString(CultureInfo.InvariantCulture);
             }
@@ -5582,8 +5571,10 @@ namespace MediaBrowser.Controller.MediaEncoding
             var audioTranscodeParams = new List<string>();
 
             var bitrate = state.OutputAudioBitrate;
+            var channels = state.OutputAudioChannels;
+            var outputCodec = state.OutputAudioCodec;
 
-            if (bitrate.HasValue)
+            if (bitrate.HasValue && !LosslessAudioCodecs.Contains(outputCodec, StringComparison.OrdinalIgnoreCase))
             {
                 audioTranscodeParams.Add("-ab " + bitrate.Value.ToString(CultureInfo.InvariantCulture));
             }
@@ -5593,7 +5584,12 @@ namespace MediaBrowser.Controller.MediaEncoding
                 audioTranscodeParams.Add("-ac " + state.OutputAudioChannels.Value.ToString(CultureInfo.InvariantCulture));
             }
 
-            if (!string.Equals(state.OutputAudioCodec, "opus", StringComparison.OrdinalIgnoreCase))
+            if (!string.IsNullOrEmpty(outputCodec))
+            {
+                audioTranscodeParams.Add("-acodec " + GetAudioEncoder(state));
+            }
+
+            if (!string.Equals(outputCodec, "opus", StringComparison.OrdinalIgnoreCase))
             {
                 // opus only supports specific sampling rates
                 var sampleRate = state.OutputAudioSampleRate;