Limit audio channels to 6 in video transcoding profile #4037
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| @@ -86,6 +86,7 @@ class ExoPlayerProfile( | |||
| protocol = "hls" | |||
| copyTimestamps = false | |||
| enableSubtitlesInManifest = true | |||
| maxAudioChannels = "6" | |||
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I don't think this is a proper fix. This will limit all transcodes to 6 channels, even when it's just the video codec that is not supported or subtitles need to be burned. While with direct play it will still go to up to 8 channels according to the downMixAudio preference.
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It may be worth noting that, with the nature of this bug, Direct Play of both video+audio actually plays the 8-channel audio without error.
Media where only the video is being transcoded is uniquely affected.
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The sever already limits transcodes to 6 channels. This is saying if the video for 8 channel media is being transcoded, then the audio should also be transcoded. There is no issue with direct play so that is the desired effect. I haven't considered brunt subtitles, will test that out.
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Burnt in subtitles had the same effect as lowering the bitrate, the video playback was unwatchable due to low framerates on 8 channel EAC3 media and playback failure on 8 channel AAC media.
For TrueHD and DTS (HD/MA/X) 7.1 the server automatically transcodes the audio when the video is transcoded by either lowering the bitrate or by burning in subs.
Stream #0:1(eng): Audio: truehd (Dolby TrueHD + Dolby Atmos), 48000 Hz, 7.1, s32 (24 bit)
Stream mapping:
Stream #0:0 (hevc) -> setparams:default (graph 0)
format:default (graph 0) -> Stream #0:0 (hevc_amf)
Stream #0:1 -> #0:1 (truehd (native) -> aac (libfdk_aac))
Stream #0:0: Video: hevc (hvc1 / 0x31637668), d3d11(tv, bt709, progressive)...
Stream #0:1: Audio: aac, 48000 Hz, 5.1, s16, 640 kb/s
Stream #0:1(eng): Audio: dts (DTS-HD MA + DTS:X IMAX), 48000 Hz, 7.1, s32p (24 bit) (default)
Stream mapping:
Stream #0:0 (hevc) -> setparams:default (graph 0)
format:default (graph 0) -> Stream #0:0 (hevc_amf)
Stream #0:1 -> #0:1 (dts (dca) -> aac (libfdk_aac))
Stream #0:0: Video: hevc (hvc1 / 0x31637668), d3d11(tv, bt709, progressive)...
Stream #0:1: Audio: aac, 48000 Hz, 5.1, s16, 640 kb/s (default)
So this PR would only change the behavior for transcoded AAC and EAC3 8 channel media and it would align with what the server is already doing to TrueHD and DTS (HD/MA/X) media.
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Concur with @MichaelRUSF on embedded subs. (Just came to report my testing, but he beat me to it)
I just tested a AAC 7.1 + VOBSUB file. It could only be played when transcoding both video & audio. Direct Play of video+audio fails due to sub burn-in.
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I checked JMP, and it also has maxAudioChannels set to 6 in their transcoding profile. So this would align with JMP's settings. |
Changes
Added
maxAudioChannels: Set to "6" in the TS video profile for improved audio handling when transcoding.Issues
Fixes #4038