Splitting this off from bug 896884 because I've only implemented part of what that bug covers. The Dashif player example video doesn't decode a duration, and it just sets on using MediaSource.duration. I had to move the mDuration value from MediaSource into MediaSourceDecoder so that it can be protected by the monitor and accessed from multiple threads. This is because MediaSourceReader::ReadMetadata needs to update the duration value in MDSM immediately, but we're only supposed to use it if a value hasn't already been set using setDuration. Since this happens off the main-thread, we need to lock accesses to mDuration.

This fixes the dashif player use case, and *almost* passes the MediaSourceDuration test from the conformance test suite (with both mp4 and webm). I've filed bug 1097381 for the remaining work to get the test to pass.

Comment on attachment 8521039 [details] [diff] [review] Implement setDuration properly. Review of attachment 8521039 [details] [diff] [review]: ----------------------------------------------------------------- ::: dom/media/mediasource/MediaSourceDecoder.h @@ +77,5 @@ > dom::MediaSource* mMediaSource; > nsRefPtr<MediaSourceReader> mReader; > + > + // Protected by GetReentrantMonitor() > + double mDuration; This shadows |int64_t mDuration| on the base class. It could be confusing, maybe rename it if you can think of a good name?