Live multi-period playback crashes

Created by: TobbeMobiTV

There is a live multiperiod option of the DASH-IF live source simulator. Content-wise, it is very simple. It uses one content, but chops it up in periods with different startTimes and different startNumbers and new periodIds. It keeps a number of old periods corresponding to what is needed to seek back to the start of the time-shift-buffer. As the MPD is updated, there will regularly be new periods added and old ones removed.

I've tested with latest dev version of dash.js a94adb5c and the test URL:

http://vm2.dashif.org/livesim/periods_60/tsbd_60/testpic_2s/Manifest.mpd

which gives a new period every minute and uses a timeshiftbufferdepth of 60s. There are typically 4 periods in the MPD, and the minimumUpdatePerido of 25s (a little less than half the period duration).

In Chrome 45, this typically starts and the first period change is handled correctly (although visible). However, it then crashes at line 40 in DashAdapter.js due to an exception:

 <exception>: TypeError: Cannot read property '0' of undefined at getAdaptationForMediaInfo 

Chrome 43, works similarly, but seems to often stop earlier.

I think it has to do with removal of old periods not being handled properly.