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33 #include "AudioChannelMerger.h"
35 #include "AudioContext.h"
36 #include "AudioNodeInput.h"
37 #include "AudioNodeOutput.h"
41 // This is considering that 5.1 (6 channels) is the largest we'll ever deal with.
42 // It can easily be increased to support more if the web audio specification is updated.
43 const unsigned NumberOfInputs = 6;
45 AudioChannelMerger::AudioChannelMerger(AudioContext* context, double sampleRate)
46 : AudioNode(context, sampleRate)
48 // Create a fixed number of inputs (able to handle the maximum number of channels we deal with).
49 for (unsigned i = 0; i < NumberOfInputs; ++i)
50 addInput(adoptPtr(new AudioNodeInput(this)));
52 addOutput(adoptPtr(new AudioNodeOutput(this, 1)));
54 setType(NodeTypeChannelMerger);
59 void AudioChannelMerger::process(size_t framesToProcess)
61 AudioNodeOutput* output = this->output(0);
63 ASSERT_UNUSED(framesToProcess, framesToProcess == output->bus()->length());
65 // Merge all the channels from all the inputs into one output.
66 unsigned outputChannelIndex = 0;
67 for (unsigned i = 0; i < numberOfInputs(); ++i) {
68 AudioNodeInput* input = this->input(i);
69 if (input->isConnected()) {
70 unsigned numberOfInputChannels = input->bus()->numberOfChannels();
72 // Merge channels from this particular input.
73 for (unsigned j = 0; j < numberOfInputChannels; ++j) {
74 AudioChannel* inputChannel = input->bus()->channel(j);
75 AudioChannel* outputChannel = output->bus()->channel(outputChannelIndex);
76 outputChannel->copyFrom(inputChannel);
83 ASSERT(outputChannelIndex == output->numberOfChannels());
86 void AudioChannelMerger::reset()
90 // Any time a connection or disconnection happens on any of our inputs, we potentially need to change the
91 // number of channels of our output.
92 void AudioChannelMerger::checkNumberOfChannelsForInput(AudioNodeInput* input)
94 ASSERT(context()->isAudioThread() && context()->isGraphOwner());
96 // Count how many channels we have all together from all of the inputs.
97 unsigned numberOfOutputChannels = 0;
98 for (unsigned i = 0; i < numberOfInputs(); ++i) {
99 AudioNodeInput* input = this->input(i);
100 if (input->isConnected())
101 numberOfOutputChannels += input->bus()->numberOfChannels();
104 // Set the correct number of channels on the output
105 AudioNodeOutput* output = this->output(0);
107 output->setNumberOfChannels(numberOfOutputChannels);
110 } // namespace WebCore
112 #endif // ENABLE(WEB_AUDIO)