The complexity around not enabling the video renderer before it
has a valid surface is because MediaCodecTrackRenderer supports
a "discard" mode where it pulls through and discards samples
without a decoder. This mode means that if the demo app were to
enable the renderer before supplying the surface, the renderer
could discard the first few frames prior to getting the surface,
meaning video rendering wouldn't happen until the following sync
frame.
To get a handle on complexity, I think we're better off just removing
support for this mode, which nicely decouples how the demo app
handles surfaces v.s. how it handles enabling/disabling renderers.
Propagate elapsedRealtimeUs to the video renderer. This allows
the renderer to calculate and adjust for the elapsed time since
the start of the current rendering loop. Typically this is <2ms,
but there situations where it can go higher (normally when the
video renderer ends up processing more than 1 output buffer in
a single loop).
Also made variable naming more consistent throughout the package.
- Use native frame release timing in video renderer for
smoother video playback.
- Avoid unnecessary memory copy steps in audio renderer.
- Use non-blocking AudioTrack API.
- Bring back requirement for the first video frame to be rendered
before isReady returns true, *unless* we've deduced that the
upstream source is serving multiple renderers.
- Ditto for requiring that the audio track has some buffered data.
- Make MediaCodecTrackRenderer.isReady more permissive.
This largely fixes#21
- Bring WebmExtractor closer to FragmentedMp4Extractor.
The two will probably be placed under a common interface
fairly soon, which will allow significant code
deduplication.
AudioTrack time will go out of sync if the decodeOnly flag
is set of arbitrary samples (as opposed to just those following
a seek). It's a pretty obscure case and it would be weird for
anyone to do it, but we should be robust against it anyway.