Switching audio track on LIVE stream stops the playback

Created by: devaublanc

(MacOSX#10.10.3, Chrome#50.0.2661 dash.js#2.1.1)

When I try to switch the audio track using (player.setCurrentTrack(MediaInfo)). The player stops downloading audio segments. The playback continues until the audio buffer starves, then the play enters rebuffering state, but still no audio segments are downloaded.

I did some investigations

1. I have checked inside NextFragmentRequestRule.execute() The variable time computed inside this method (let time = hasSeekTarget ? seekTarget : adapter.getIndexHandlerTime(streamProcessor)) equals 0 which causes segment lookup to be performed for time 0 instead of something close to video.currentTime

2. In the method getIndexForSegments() (DashHandler.js) The segments list we iterate over to find the next segment to download seems to be located at the beginning of the DVRWindow, instead of around video.currentTime.

I have tested some hacks

• Inside the getSegmentsFromTimeline() method. I tried to force the calculatedRange like this calculatedRange = {start:0, end: Infinity}, in order to iterate over the full list of segments and try to hack around 2)
• Then if I replace the variable time tovideo.currentTime instead of 0 to hack around 1) (using devTool by setting a break point in NextFragmentRequestRule.execute() once audio buffer is starved), audio segments are downloaded again and playback restarts, but the audio track is not changed (his seems to be a 3rd issue)
• If I reload my stream the player uses the audio set in the localStorage (during the former call to setCurrentTrack) and the playback start with the good audio track.

Recently I have test again after applying this fix 32f6982f. That works better but sometimes the audio don’t switch after calling player.setCurrentTrack.

@AkamaiDASH , @sebastien4 sent you a MPD url in a private message