void
AudioCaptureStream::ProcessInput(GraphTime aFrom, GraphTime aTo,
uint32_t aFlags)
{
uint32_t inputCount = mInputs.Length();
StreamBuffer::Track* track = EnsureTrack(mTrackId);
// Notify the DOM everything is in order.
if (!mTrackCreated) {
for (uint32_t i = 0; i < mListeners.Length(); i++) {
MediaStreamListener* l = mListeners[i];
AudioSegment tmp;
l->NotifyQueuedTrackChanges(
Graph(), mTrackId, 0, MediaStreamListener::TRACK_EVENT_CREATED, tmp);
l->NotifyFinishedTrackCreation(Graph());
}
mTrackCreated = true;
}
// If the captured stream is connected back to a object on the page (be it an
// HTMLMediaElement with a stream as source, or an AudioContext), a cycle
// situation occur. This can work if it's an AudioContext with at least one
// DelayNode, but the MSG will mute the whole cycle otherwise.
if (mFinished || InMutedCycle() || inputCount == 0) {
track->Get<AudioSegment>()->AppendNullData(aTo - aFrom);
} else {
// We mix down all the tracks of all inputs, to a stereo track. Everything
// is {up,down}-mixed to stereo.
mMixer.StartMixing();
AudioSegment output;
for (uint32_t i = 0; i < inputCount; i++) {
MediaStream* s = mInputs[i]->GetSource();
StreamBuffer::TrackIter tracks(s->GetStreamBuffer(), MediaSegment::AUDIO);
while (!tracks.IsEnded()) {
AudioSegment* inputSegment = tracks->Get<AudioSegment>();
StreamTime inputStart = s->GraphTimeToStreamTimeWithBlocking(aFrom);
StreamTime inputEnd = s->GraphTimeToStreamTimeWithBlocking(aTo);
AudioSegment toMix;
toMix.AppendSlice(*inputSegment, inputStart, inputEnd);
// Care for streams blocked in the [aTo, aFrom] range.
if (inputEnd - inputStart < aTo - aFrom) {
toMix.AppendNullData((aTo - aFrom) - (inputEnd - inputStart));
}
toMix.Mix(mMixer, MONO, Graph()->GraphRate());
tracks.Next();
}
}
// This calls MixerCallback below
mMixer.FinishMixing();
}
// Regardless of the status of the input tracks, we go foward.
mBuffer.AdvanceKnownTracksTime(GraphTimeToStreamTimeWithBlocking((aTo)));
}
void
CameraPreviewMediaStream::OnPreviewStateChange(bool aActive)
{
if (aActive) {
MutexAutoLock lock(mMutex);
if (!mTrackCreated) {
mTrackCreated = true;
VideoSegment tmpSegment;
for (uint32_t j = 0; j < mListeners.Length(); ++j) {
MediaStreamListener* l = mListeners[j];
l->NotifyQueuedTrackChanges(mFakeMediaStreamGraph, TRACK_VIDEO, 0,
MediaStreamListener::TRACK_EVENT_CREATED,
tmpSegment);
l->NotifyFinishedTrackCreation(mFakeMediaStreamGraph);
}
}
}
}