All segments from time zero are reloaded when switching track

[davemevans]

#1242 seems to have caused a regression when switching tracks while fixing multiperiod.

This is because when a new StreamProcessor is created, its currentTime is no longer set which causes the scheduler to start from zero.

This was reported on another ticket - I've copied and pasted the detail below:

@esteban-dosztal wrote:

having an issue that seems related to this. I wrote an audio language selector, ad it works fine, but when I select a different language, I see in Chrome Dev Tools network panel that Dash.js starts to load all the previous audio fragments fragments, i.e., let's say I have to audio languages, english and spanish, and I have advanced in the reproduction, so my current english audio fragment is 250; then I select to change to spanish audio, and Dash starts to load spanish audio fragments from fragment 1. I'm calling this.mediaPlayer_.setTrackSwitchModeFor('audio', 'neverReplace'); before MediaPlayer.attachSource, but it didn't change anything. ¿Am I doing something wrong, or it is a bug in Dash.js? I'm using version 2.1.1.

[dsparacio]

@bbcrddave you happen to have a good multi-track test stream i am work this one out with?

[davemevans]

Give this one a go:http://rdmedia.bbc.co.uk/dash/ondemand/testcard/1/client_manifest-nosurround-ctv-multimainlang.mpd

[dsparacio]

Oh that is wonderful! OK I am able to reproduce this and will fix.

[dsparacio]

Easy to fix but need to make sure i do not break the original PR so it will take me some time to validate the fix. Thanks for catching this one guys.

[dsparacio]

OK I am pretty happy with fix so far and MP works just as well post change. Current time was already passed on track change to create stream processor but not set on index handler in the optional settings , with this line it picks up at the playhead not at id 1.

streamProcessor.getIndexHandler().setCurrentTime(optionalSettings.currentTime);

I want to make sure I am not fixing one thing and breaking something else so i need do a bit more digging on the change that took this line out which is different from the #1242 PR

[bwidtmann]

If I have understood this bug correctly, I think this is blocking us from deploying 2.1.1 as switching languages is a big issue for us and CDN costs as well.

[dsparacio]

You can fix with a one line change so do not let it block you. Ill push the change today in to dev branch. Sorry for the blocker guys.

[bwidtmann]

@AkamaiDASH thanks for pointing out.

[dsparacio]

@bwidtmann I have pushed it into dev (32f6982)