Enable Dolby AC-4 decoder (#11486)

Jellyfin.Api/Controllers/DynamicHlsController.cs

@@ -1735,6 +1735,13 @@ public class DynamicHlsController : BaseJellyfinApiController
             }
         }
 
+        if (state.AudioStream is not null && state.AudioStream.CodecTag.Equals("ac-4", StringComparison.Ordinal))
+        {
+            // ac-4 audio tends to hava a super weird sample rate that will fail most encoders
+            // force resample it to 48KHz
+            args += " -ar 48000";
+        }
+
         if (state.OutputAudioSampleRate.HasValue)
         {
             args += " -ar " + state.OutputAudioSampleRate.Value.ToString(CultureInfo.InvariantCulture);

MediaBrowser.MediaEncoding/Encoder/EncoderValidator.cs

@@ -27,6 +27,7 @@ namespace MediaBrowser.MediaEncoding.Encoder
             "msmpeg4",
             "dca",
             "ac3",
+            "ac4",
             "aac",
             "mp3",
             "flac",