Separate audio and video streams in different files in HLS playlists

[Chocobozzz]

Allows:

• The HLS player to propose an "Audio only" resolution
• The live to output an "Audio only" resolution
• The live to ingest and output an "Audio only" stream

This feature is under a config for VOD videos and is enabled by default for lives

In the future we can imagine:

• To propose multiple audio streams for a specific video
• To ingest an audio only VOD and just output an audio only "video"
  (the player would play the audio file and PeerTube would not
  generate additional resolutions)

This commit introduce a new way to download videos:

• Add /download/videos/generate/:videoId endpoint where PeerTube can
  mux an audio only and a video only file to a mp4 container
• The download client modal introduces a new default panel where the
  user can choose resolutions it wants to download

[stevespaw]

@Chocobozzz This seems like great news. So am I understanding that we may have the ability to have Non-Muxed audio in the HLS? Roku: "Fragmented MP4, CMAF (muxing audio and video not supported for CMAF)"
https://developer.roku.com/docs/specs/media/streaming-specifications.md This would be huge. :-) Currently Roku plays the videos without any sound.

[Chocobozzz]

So am I understanding that we may have the ability to have Non-Muxed audio in the HLS? Roku: "Fragmented MP4, CMAF (muxing audio and video not supported for CMAF)"

I'm not sure because it's not written they support fragmented mp4 in HLS column. But if you can play the video currently I think they support it 🤔 When the PR is merged and deployed on our nightly instance, I'll provide a public URL so you can test.

[stevespaw]

@Chocobozzz Happy to test a new M3U8. Yes currently Peertube HLS play very nicely on ROKU but no audio. My next questions will be about captions, I will make another separate post with my questions on that 😄

[Chocobozzz]

My next questions will be about captions

I think you can create the issue to request captions to be included in the HLS playlist :)

[stevespaw]

Just want to add this reference here #5797

[stevespaw]

@Chocobozzz If you get a sample m3u8 I look forward to testing on ROKU !
Thank you so much for this work!

[Chocobozzz]

@stevespaw Please try the master playlist of https://peertube2.cpy.re/w/oBw6LwsMWWRkmXYfuYRpJd

[stevespaw]

Wow Roku with Audio !

[stevespaw]

@Chocobozzz
Do you have a VOD sample yet?

[Chocobozzz]

@stevespaw Yes: https://peertube2.cpy.re/w/85dip4jwa3hi5ugunw4SP7

[stevespaw]

This works well also on Roku!
Looking Good, @Chocobozzz
Are you envisioning a script that will convert, or where do you see this going from here?

[Chocobozzz]

Are you envisioning a script that will convert, or where do you see this going from here?

Admins can re-run HLS transcoding on existing videos with the "split audio and video" option enabled to convert them. We don't plan to convert all existing videos as it would consume too much CPU

[stevespaw]

And will there be a config setting to choose the "split" as default for new publishing?

[Chocobozzz]

And will there be a config setting to choose the "split" as default for new publishing?

Yes!