void ChannelMergerHandler::process(size_t framesToProcess) {
AudioNodeOutput& output = this->output(0);
DCHECK_EQ(framesToProcess, output.bus()->length());
unsigned numberOfOutputChannels = output.numberOfChannels();
DCHECK_EQ(numberOfInputs(), numberOfOutputChannels);
// Merge multiple inputs into one output.
for (unsigned i = 0; i < numberOfOutputChannels; ++i) {
AudioNodeInput& input = this->input(i);
DCHECK_EQ(input.numberOfChannels(), 1u);
AudioChannel* outputChannel = output.bus()->channel(i);
if (input.isConnected()) {
// The mixing rules will be applied so multiple channels are down-
// mixed to mono (when the mixing rule is defined). Note that only
// the first channel will be taken for the undefined input channel
// layout.
//
// See:
// http://webaudio.github.io/web-audio-api/#channel-up-mixing-and-down-mixing
AudioChannel* inputChannel = input.bus()->channel(0);
outputChannel->copyFrom(inputChannel);
} else {
// If input is unconnected, fill zeros in the channel.
outputChannel->zero();
}
}
}
void ChannelMergerNode::process(size_t framesToProcess)
{
AudioNodeOutput* output = this->output(0);
ASSERT(output);
ASSERT_UNUSED(framesToProcess, framesToProcess == output->bus()->length());
// Output bus not updated yet, so just output silence.
if (m_desiredNumberOfOutputChannels != output->numberOfChannels()) {
output->bus()->zero();
return;
}
// Merge all the channels from all the inputs into one output.
unsigned outputChannelIndex = 0;
for (unsigned i = 0; i < numberOfInputs(); ++i) {
AudioNodeInput* input = this->input(i);
if (input->isConnected()) {
unsigned numberOfInputChannels = input->bus()->numberOfChannels();
// Merge channels from this particular input.
for (unsigned j = 0; j < numberOfInputChannels; ++j) {
AudioChannel* inputChannel = input->bus()->channel(j);
AudioChannel* outputChannel = output->bus()->channel(outputChannelIndex);
outputChannel->copyFrom(inputChannel);
++outputChannelIndex;
}
}
}
ASSERT(outputChannelIndex == output->numberOfChannels());
}
void ChannelMergerNode::process(size_t framesToProcess)
{
AudioNodeOutput* output = this->output(0);
ASSERT(output);
ASSERT_UNUSED(framesToProcess, framesToProcess == output->bus()->length());
// Output bus not updated yet, so just output silence.
if (m_desiredNumberOfOutputChannels != output->numberOfChannels()) {
output->bus()->zero();
return;
}
// Merge all the channels from all the inputs into one output.
unsigned outputChannelIndex = 0;
unsigned maxAllowedOutputChannels = output->numberOfChannels();
for (unsigned i = 0; i < numberOfInputs(); ++i) {
AudioNodeInput* input = this->input(i);
if (input->isConnected()) {
unsigned numberOfInputChannels = input->bus()->numberOfChannels();
// Merge channels from this particular input, but be careful not to exceed the number of
// output channels. (This can happen if there are many inputs with each input
// containing many channels.)
for (unsigned j = 0; j < numberOfInputChannels; ++j) {
if (outputChannelIndex < maxAllowedOutputChannels) {
AudioChannel* inputChannel = input->bus()->channel(j);
AudioChannel* outputChannel = output->bus()->channel(outputChannelIndex);
outputChannel->copyFrom(inputChannel);
++outputChannelIndex;
}
}
}
if (outputChannelIndex >= maxAllowedOutputChannels)
break;
}
ASSERT(outputChannelIndex == output->numberOfChannels());
}
void ChannelMergerNode::process(ContextRenderLock& r, size_t framesToProcess)
{
auto output = this->output(0);
ASSERT_UNUSED(framesToProcess, framesToProcess == output->bus(r)->length());
// Output bus not updated yet, so just output silence. See Note * in checkNumberOfChannelsForInput
if (m_desiredNumberOfOutputChannels != output->numberOfChannels())
{
output->bus(r)->zero();
return;
}
// Merge all the channels from all the inputs into one output.
uint32_t outputChannelIndex = 0;
for (uint32_t i = 0; i < numberOfInputs(); ++i)
{
auto input = this->input(i);
if (input->isConnected())
{
uint32_t numberOfInputChannels = input->bus(r)->numberOfChannels();
// Merge channels from this particular input.
for (uint32_t j = 0; j < numberOfInputChannels; ++j)
{
AudioChannel* inputChannel = input->bus(r)->channel(j);
AudioChannel* outputChannel = output->bus(r)->channel(outputChannelIndex);
outputChannel->copyFrom(inputChannel);
++outputChannelIndex;
}
}
}
ASSERT(outputChannelIndex == output->numberOfChannels());
}