void AudioBufferSourceNode::process(size_t framesToProcess)
{
AudioBus* outputBus = output(0)->bus();
if (!isInitialized()) {
outputBus->zero();
return;
}
// The audio thread can't block on this lock, so we call tryLock() instead.
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked()) {
if (!buffer()) {
outputBus->zero();
return;
}
// After calling setBuffer() with a buffer having a different number of channels, there can in rare cases be a slight delay
// before the output bus is updated to the new number of channels because of use of tryLocks() in the context's updating system.
// In this case, if the the buffer has just been changed and we're not quite ready yet, then just output silence.
if (numberOfChannels() != buffer()->numberOfChannels()) {
outputBus->zero();
return;
}
size_t quantumFrameOffset;
size_t bufferFramesToProcess;
updateSchedulingInfo(framesToProcess,
outputBus,
quantumFrameOffset,
bufferFramesToProcess);
if (!bufferFramesToProcess) {
outputBus->zero();
return;
}
for (unsigned i = 0; i < outputBus->numberOfChannels(); ++i)
m_destinationChannels[i] = outputBus->channel(i)->mutableData();
// Render by reading directly from the buffer.
if (!renderFromBuffer(outputBus, quantumFrameOffset, bufferFramesToProcess)) {
outputBus->zero();
return;
}
// Apply the gain (in-place) to the output bus.
float totalGain = gain()->value() * m_buffer->gain();
outputBus->copyWithGainFrom(*outputBus, &m_lastGain, totalGain);
outputBus->clearSilentFlag();
} else {
// Too bad - the tryLock() failed. We must be in the middle of changing buffers and were already outputting silence anyway.
outputBus->zero();
}
}
void AudioBufferSourceNode::process(size_t framesToProcess)
{
AudioBus* outputBus = output(0)->bus();
if (!isInitialized()) {
outputBus->zero();
return;
}
// The audio thread can't block on this lock, so we call tryLock() instead.
MutexTryLocker tryLocker(m_processLock);
if (tryLocker.locked()) {
if (!buffer()) {
outputBus->zero();
return;
}
size_t quantumFrameOffset;
size_t bufferFramesToProcess;
updateSchedulingInfo(framesToProcess,
outputBus,
quantumFrameOffset,
bufferFramesToProcess);
if (!bufferFramesToProcess) {
outputBus->zero();
return;
}
for (unsigned i = 0; i < outputBus->numberOfChannels(); ++i)
m_destinationChannels[i] = outputBus->channel(i)->mutableData();
// Render by reading directly from the buffer.
if (!renderFromBuffer(outputBus, quantumFrameOffset, bufferFramesToProcess)) {
outputBus->zero();
return;
}
// Apply the gain (in-place) to the output bus.
float totalGain = gain()->value() * m_buffer->gain();
outputBus->copyWithGainFrom(*outputBus, &m_lastGain, totalGain);
outputBus->clearSilentFlag();
} else {
// Too bad - the tryLock() failed. We must be in the middle of changing buffers and were already outputting silence anyway.
outputBus->zero();
}
}
void AudioBufferSourceNode::process(ContextRenderLock& r, size_t framesToProcess)
{
AudioBus* outputBus = output(0)->bus(r);
if (!buffer() || !isInitialized() || ! r.context()) {
outputBus->zero();
return;
}
// After calling setBuffer() with a buffer having a different number of channels, there can in rare cases be a slight delay
// before the output bus is updated to the new number of channels because of use of tryLocks() in the context's updating system.
// In this case, if the the buffer has just been changed and we're not quite ready yet, then just output silence.
if (numberOfChannels(r) != buffer()->numberOfChannels()) {
outputBus->zero();
return;
}
if (m_startRequested) {
// Do sanity checking of grain parameters versus buffer size.
double bufferDuration = buffer()->duration();
double grainOffset = std::max(0.0, m_requestGrainOffset);
m_grainOffset = std::min(bufferDuration, grainOffset);
m_grainOffset = grainOffset;
// Handle default/unspecified duration.
double maxDuration = bufferDuration - grainOffset;
double grainDuration = m_requestGrainDuration;
if (!grainDuration)
grainDuration = maxDuration;
grainDuration = std::max(0.0, grainDuration);
grainDuration = std::min(maxDuration, grainDuration);
m_grainDuration = grainDuration;
m_isGrain = true;
m_startTime = m_requestWhen;
// We call timeToSampleFrame here since at playbackRate == 1 we don't want to go through linear interpolation
// at a sub-sample position since it will degrade the quality.
// When aligned to the sample-frame the playback will be identical to the PCM data stored in the buffer.
// Since playbackRate == 1 is very common, it's worth considering quality.
m_virtualReadIndex = AudioUtilities::timeToSampleFrame(m_grainOffset, buffer()->sampleRate());
m_startRequested = false;
}
size_t quantumFrameOffset;
size_t bufferFramesToProcess;
updateSchedulingInfo(r, framesToProcess, outputBus, quantumFrameOffset, bufferFramesToProcess);
if (!bufferFramesToProcess)
{
outputBus->zero();
return;
}
for (unsigned i = 0; i < outputBus->numberOfChannels(); ++i)
{
m_destinationChannels[i] = outputBus->channel(i)->mutableData();
}
// Render by reading directly from the buffer.
if (!renderFromBuffer(r, outputBus, quantumFrameOffset, bufferFramesToProcess))
{
outputBus->zero();
return;
}
// Apply the gain (in-place) to the output bus.
float totalGain = gain()->value(r) * m_buffer->gain();
outputBus->copyWithGainFrom(*outputBus, &m_lastGain, totalGain);
outputBus->clearSilentFlag();
}
