1057201 - MP4Reader can get stuck in MP4Reader::Decode() somehow

Status: RESOLVED FIXED

(Core :: Audio/Video, defect)

Description

[Chris Pearce [:cpearce (Not reading bugmail)]]

I discovered that MP4Reader can get the decode thread stuck in the "prevNumFramesOutput == data.mNumSamplesOutput" wait at the bottom of Decode(). Not sure how to repro, but I think it has something to do with seeking when the network is slow.

Comment 1

[Chris Pearce [:cpearce (Not reading bugmail)]]

The problem is that MP4Reader::NotifyDataArrived() can dispatch an event to the audio/video task queues, and the MediaDataDecoders are assuming that only they dispatch to those task queues and they're using MediaTaskQueue.IsEmpty() to decide whether they've processed all their input. With the recent changes to GetBuffered(), that assumption is no longer valid.

Comment 2

[Chris Pearce [:cpearce (Not reading bugmail)]]

Attachment: Patch

Don't use the decoder's task queues to update index.

I'll try to figure out a way to not make these visible inside MP4Reader at all on Monday. For now, here's the fix.

Comment 3

[Chris Pearce [:cpearce (Not reading bugmail)]]

https://hg.mozilla.org/integration/mozilla-inbound/rev/e036df3c1caf

Comment 4

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/e036df3c1caf