wang-bin/QtAV — pull request #100 by edufelipe (2013-10-25 19:38:44+00:00)
Title: Fix corrupt initial frames https://github.com/wang-bin/QtAV/issues/70

There is a race condition where AVDemuxThread starts queueing packets
before AVThread::resetState is called from VideoThread.
When AVThread::resetState gets called, all collected frames get dropped.

This patch waits on a conditional variable for AVThreads to start properly.