diff --git a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs index 6667c1c3b..efab87a38 100644 --- a/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs +++ b/MediaBrowser.Controller/MediaEncoding/EncodingHelper.cs @@ -1722,6 +1722,16 @@ namespace MediaBrowser.Controller.MediaEncoding : transcoderChannelLimit.Value; } + // Avoid transcoding to audio channels other than 1ch, 2ch, 6ch (5.1 layout) and 8ch (7.1 layout). + // https://developer.apple.com/documentation/http_live_streaming/hls_authoring_specification_for_apple_devices + if (isTranscodingAudio + && state.TranscodingType != TranscodingJobType.Progressive + && resultChannels.HasValue + && (resultChannels.Value > 2 && resultChannels.Value < 6 || resultChannels.Value == 7)) + { + resultChannels = 2; + } + return resultChannels; }