Alternative audio level buffers inconsistence after changing audio tracks

[sergiojm]

Environment

• The stream has correct Access-Control-Allow-Origin headers (CORS)
• There are no network errors such as 404s in the browser console when trying to play the stream
• The issue observed is not already reported by searching on Github under https://github.com/dailymotion/hls.js/issues
• The issue occurs in the latest reference client on http://dailymotion.github.io/hls.js/demo and not just on my page
• Link to playable M3U8 file:
• Hls.js version:
• Browser name/version: All
• OS name/version: All

When changing alternative track, bitrate selector becomes inconsistence(even worst when main has audio).

1. choose a bit rate
2. change audio track
3. load a level

It will take "huge" amount of time to change.
On demo page we can see the impact on the quality controls.

[sergiojm]

When changing audio track it gets a BUFFER_FLUSHING and on onBufferFlushed

if appending always the newRange.push(range) and not only on
if (BufferHelper.isBuffered(this.media,(range.start + range.end) / 2))

then becomes stable and switch as normal.

Debugging why...

[sergiojm]

When buffer reset on audio track switch(onBufferFlushed) its also reseting video element leaving level quality to "init"...

@mangui, Don't know if I understood the perfectly the logic but submitting a patch.

Leaving a suggestion...

One thing I would consider for future is to handle the audio of the main as an alternative track and work the logic of stream-control and audio-control as a key pair(main video + selected audio).

When main pushing to demuxer should only push video and the current selected audioTrack(main, track 1,track 2,etc). Instead of keeping track of values of the PTS/DTS...

Currently if we switch from alternative to main audio, it re downloads the entire main track, when shouldn't cause its "heavy" and we have it already.

Most of the production teams(live that then becomes vod) send main with audio so something to consider I would say...

[sergiojm]

#768

[mangui]

Hi @sergiojm well spotted, should be fixed

[sergiojm]

Tested and works for me :)

Thanks for fixing it. For alternative audio(VOD and LIVE) was crucial!

[mangui]

great, closing as fixed