IOAudioDMAEngineMixer.cpp [plain text]
#include <IOKit/audio/IOAudioDMAEngine.h>
#include <IOKit/audio/IOAudioStream.h>
#include <IOKit/audio/IOAudioTypes.h>
#include <IOKit/audio/IOAudioDebug.h>
IOReturn IOAudioDMAEngine::mixAndClip(const void *sourceBuf, void *mixBuf, void *sampleBuf, UInt32 firstSampleFrame, UInt32 numSampleFrames, const IOAudioStreamFormat *streamFormat, IOAudioStream *audioStream)
{
IOReturn result = kIOReturnSuccess;
#ifdef DEBUG_OUTPUT_CALLS
IOLog("IOAudioDMAEngine[0x%x]::mixAndClip(0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x, 0x%x)\n", this, sourceBuf, mixBuf, sampleBuf, firstSampleFrame, numSampleFrames, streamFormat, audioStream);
#endif
if (!sourceBuf || !mixBuf || !sampleBuf || !streamFormat || !audioStream) {
return kIOReturnBadArgument;
}
if ((firstSampleFrame + numSampleFrames) > numSampleFramesPerBuffer) {
result = mixAndClip(sourceBuf, mixBuf, sampleBuf, firstSampleFrame, numSampleFramesPerBuffer - firstSampleFrame, streamFormat, audioStream);
if (result == kIOReturnSuccess) {
result = mixAndClip(&((float *)sourceBuf)[(numSampleFramesPerBuffer - firstSampleFrame) * streamFormat->fNumChannels], mixBuf, sampleBuf, 0, numSampleFrames - (numSampleFramesPerBuffer - firstSampleFrame), streamFormat, audioStream);
}
} else {
float *floatSourceBuf, *floatMixBuf;
UInt32 numSamplesLeft;
floatSourceBuf = (float *)sourceBuf;
floatMixBuf = &(((float *)mixBuf)[firstSampleFrame * streamFormat->fNumChannels]);
numSamplesLeft = numSampleFrames * audioStream->format.fNumChannels;
while (numSamplesLeft > 0) {
*floatMixBuf += *floatSourceBuf;
floatMixBuf++;
floatSourceBuf++;
numSamplesLeft--;
}
result = clipToOutputStream(mixBuf, sampleBuf, firstSampleFrame, numSampleFrames, streamFormat, audioStream);
}
return result;
}