AudioDestinationMac.cpp [plain text]
#include "config.h"
#include "AudioDestinationCocoa.h"
#if ENABLE(WEB_AUDIO) && PLATFORM(MAC)
#include "AudioBus.h"
#include "VectorMath.h"
#include <CoreAudio/AudioHardware.h>
namespace WebCore {
void AudioDestinationCocoa::configure()
{
AudioComponent comp;
AudioComponentDescription desc;
desc.componentType = kAudioUnitType_Output;
desc.componentSubType = kAudioUnitSubType_DefaultOutput;
desc.componentManufacturer = kAudioUnitManufacturer_Apple;
desc.componentFlags = 0;
desc.componentFlagsMask = 0;
comp = AudioComponentFindNext(0, &desc);
ASSERT(comp);
OSStatus result = AudioComponentInstanceNew(comp, &outputUnit());
ASSERT(!result);
result = AudioUnitInitialize(outputUnit());
ASSERT(!result);
AURenderCallbackStruct input;
input.inputProc = inputProc;
input.inputProcRefCon = this;
result = AudioUnitSetProperty(outputUnit(), kAudioUnitProperty_SetRenderCallback, kAudioUnitScope_Global, 0, &input, sizeof(input));
ASSERT(!result);
AudioStreamBasicDescription streamFormat;
setAudioStreamBasicDescription(streamFormat, sampleRate());
result = AudioUnitSetProperty(outputUnit(), kAudioUnitProperty_StreamFormat, kAudioUnitScope_Input, 0, (void*)&streamFormat, sizeof(AudioStreamBasicDescription));
ASSERT(!result);
}
void AudioDestinationCocoa::processBusAfterRender(AudioBus& bus, UInt32 numberOfFrames)
{
const float kLowThreshold = -1;
const float kHighThreshold = 1;
for (unsigned i = 0; i < bus.numberOfChannels(); ++i) {
auto* channel = bus.channel(i);
if (!channel->isSilent())
VectorMath::vclip(channel->data(), 1, &kLowThreshold, &kHighThreshold, channel->mutableData(), 1, numberOfFrames);
}
}
}
#endif // ENABLE(WEB_AUDIO) && PLATFORM(MAC)