For media resources whose streams are captured before the load has started, we shouldn't even start
an audio thread. This saves a lot of resources and ensures we don't see races between the audio thread
and the code that copies packets from the audio queue to the MediaStreams.
The first part just handles the case where nsAudioStream failed to allocate a stream. It won't be playing
anything, so instead of trying to get the audio position, just fall back to the media graph current time.
Otherwise GetPositionInFrames returns -1 and things go badly from there.
The second part simplifies the calculation of the next mCurrentTime to just make it based on real time.
We had some code to not let it advance past the end of a stream's buffer, but the next part will make that
unnecessary.
The third part is the real fix. When the new current time has advanced past mBlockingDecisionsMadeUntilTime,
that means the control loop didn't run in time to replenish the audio output buffers and keep up with its
other duties. Effectively all streams have been blocked between mBlockingDecisionsMadeUntilTime and
the new current time. Account for that by adding the difference as extra blocked time for every stream.
We only need to ensure that the stream is marked blocked from mBlockingDecisionsMadeUntilTime indefinitely
far into the future, and then update mBlockingDecisionsMadeUntilTime to the new current time, because the
code takes into account that only blocking decisions up to mBlockingDecisionsMadeUntilTime are valid.
Fix a crash loading opus files when the media.opus.enabled pref is
false. The buffering code still tries to call our Time() method,
but without having read the headers we cannot perform the
conversion.
This commit adds a guard on mActive like the other ::Time
methods use.
This is currently not fully functional. The MediaStream always ends when the underlying resource ends. You can't use these APIs on a media element
whose src is a MediaStream. Seeking or pausing the resource will cause problems. The media element does not play back in sync with the MediaStream.
Add a short Ogg Opus file to the content/media/test
directory and add it to the gSeekTests, gSmallTests,
and gPlayTests in manifest.js. This file is crafted
to end on a packet boundary, so trimming to duration
is not verified.
Set the media.opus.enabled pref to true in manifest.js
so the various tests using the opus file succeed.
Add a stanza to can_play_type_ogg.js to test the
behaviour of canPlayType with an opus-specific
media type for both values of the pref.
Add support for the .opus filename extension to
the mochitest http server.
Parse and decode Opus streams embedded in the Ogg
container. Based on the draft specification from
https://wiki.xiph.org/OggOpus
Support is conditional on the runtime preference
setting media.opus.enabled, which is false by
default until we're confident the spec is stable
and useful.
This patch doesn't support the gain header or
multichannel files.
The LEUint*() functions from the skeleton parser
are used to read the multi-byte header fields.
This requires moving them to earlier in the file.
Mappings for the .opus filename extension are also
added to facilitate testing with local files.
