void MediaElementAudioSourceHandler::process(size_t numberOfFrames)
{
AudioBus* outputBus = output(0).bus();
if (!mediaElement() || !m_sourceNumberOfChannels || !m_sourceSampleRate) {
outputBus->zero();
return;
}
// Use a tryLock() to avoid contention in the real-time audio thread.
// If we fail to acquire the lock then the HTMLMediaElement must be in the middle of
// reconfiguring its playback engine, so we output silence in this case.
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked()) {
if (AudioSourceProvider* provider = mediaElement()->audioSourceProvider()) {
// Grab data from the provider so that the element continues to make progress, even if
// we're going to output silence anyway.
if (m_multiChannelResampler.get()) {
ASSERT(m_sourceSampleRate != sampleRate());
m_multiChannelResampler->process(provider, outputBus, numberOfFrames);
} else {
// Bypass the resampler completely if the source is at the context's sample-rate.
ASSERT(m_sourceSampleRate == sampleRate());
provider->provideInput(outputBus, numberOfFrames);
}
// Output silence if we don't have access to the element.
if (!passesCORSAccessCheck()) {
if (m_maybePrintCORSMessage) {
// Print a CORS message, but just once for each change in the current media
// element source, and only if we have a document to print to.
m_maybePrintCORSMessage = false;
if (context()->executionContext()) {
context()->executionContext()->postTask(FROM_HERE,
createCrossThreadTask(&MediaElementAudioSourceHandler::printCORSMessage,
this,
m_currentSrcString));
}
}
outputBus->zero();
}
} else {
// Either this port doesn't yet support HTMLMediaElement audio stream access,
// or the stream is not yet available.
outputBus->zero();
}
} else {
// We failed to acquire the lock.
outputBus->zero();
}
}
void MediaElementAudioSourceHandler::process(size_t numberOfFrames) {
AudioBus* outputBus = output(0).bus();
// Use a tryLock() to avoid contention in the real-time audio thread.
// If we fail to acquire the lock then the HTMLMediaElement must be in the
// middle of reconfiguring its playback engine, so we output silence in this
// case.
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked()) {
if (!mediaElement() || !m_sourceNumberOfChannels || !m_sourceSampleRate) {
outputBus->zero();
return;
}
AudioSourceProvider& provider = mediaElement()->getAudioSourceProvider();
// Grab data from the provider so that the element continues to make
// progress, even if we're going to output silence anyway.
if (m_multiChannelResampler.get()) {
DCHECK_NE(m_sourceSampleRate, sampleRate());
m_multiChannelResampler->process(&provider, outputBus, numberOfFrames);
} else {
// Bypass the resampler completely if the source is at the context's
// sample-rate.
DCHECK_EQ(m_sourceSampleRate, sampleRate());
provider.provideInput(outputBus, numberOfFrames);
}
// Output silence if we don't have access to the element.
if (!passesCORSAccessCheck()) {
if (m_maybePrintCORSMessage) {
// Print a CORS message, but just once for each change in the current
// media element source, and only if we have a document to print to.
m_maybePrintCORSMessage = false;
if (context()->getExecutionContext()) {
context()->getExecutionContext()->postTask(
BLINK_FROM_HERE,
createCrossThreadTask(
&MediaElementAudioSourceHandler::printCORSMessage,
PassRefPtr<MediaElementAudioSourceHandler>(this),
m_currentSrcString));
}
}
outputBus->zero();
}
} else {
// We failed to acquire the lock.
outputBus->zero();
}
}
