SINT SoundSourceMp3::readSampleFramesStereo(
SINT numberOfFrames, CSAMPLE* sampleBuffer,
SINT sampleBufferSize) {
return readSampleFrames(numberOfFrames,
sampleBuffer, sampleBufferSize,
true);
}
SINT AudioSource::readSampleFramesStereo(
SINT numberOfFrames,
CSAMPLE* sampleBuffer,
SINT sampleBufferSize) {
DEBUG_ASSERT(getSampleBufferSize(numberOfFrames, true) <= sampleBufferSize);
switch (getChannelCount()) {
case 1: // mono channel
{
const SINT readFrameCount = readSampleFrames(
numberOfFrames, sampleBuffer);
SampleUtil::doubleMonoToDualMono(sampleBuffer, readFrameCount);
return readFrameCount;
}
case 2: // stereo channel(s)
{
return readSampleFrames(numberOfFrames, sampleBuffer);
}
default: // multiple (3 or more) channels
{
const SINT numberOfSamplesToRead = frames2samples(numberOfFrames);
if (numberOfSamplesToRead <= sampleBufferSize) {
// efficient in-place transformation
const SINT readFrameCount = readSampleFrames(
numberOfFrames, sampleBuffer);
SampleUtil::copyMultiToStereo(sampleBuffer, sampleBuffer,
readFrameCount, getChannelCount());
return readFrameCount;
} else {
// inefficient transformation through a temporary buffer
qDebug() << "Performance warning:"
<< "Allocating a temporary buffer of size"
<< numberOfSamplesToRead << "for reading stereo samples."
<< "The size of the provided sample buffer is"
<< sampleBufferSize;
SampleBuffer tempBuffer(numberOfSamplesToRead);
const SINT readFrameCount = readSampleFrames(
numberOfFrames, tempBuffer.data());
SampleUtil::copyMultiToStereo(sampleBuffer, tempBuffer.data(),
readFrameCount, getChannelCount());
return readFrameCount;
}
}
}
}
SINT SoundSourceCoreAudio::seekSampleFrame(SINT frameIndex) {
DEBUG_ASSERT(isValidFrameIndex(frameIndex));
// See comments above on kMp3StabilizationFrames.
const SINT stabilization_frames = m_bFileIsMp3 ? math_min<SINT>(
kMp3StabilizationFrames, frameIndex + m_headerFrames) : 0;
OSStatus err = ExtAudioFileSeek(
m_audioFile, frameIndex + m_headerFrames - stabilization_frames);
if (stabilization_frames > 0) {
readSampleFrames(stabilization_frames,
&kMp3StabilizationScratchBuffer[0]);
}
//_ThrowExceptionIfErr(@"ExtAudioFileSeek", err);
//qDebug() << "SSCA: Seeking to" << frameIndex;
if (err != noErr) {
qDebug() << "SSCA: Error seeking to" << frameIndex; // << GetMacOSStatusErrorString(err) << GetMacOSStatusCommentString(err);
}
return frameIndex;
}
SINT SoundSourceMp3::readSampleFrames(
SINT numberOfFrames, CSAMPLE* sampleBuffer) {
return readSampleFrames(numberOfFrames,
sampleBuffer, frames2samples(numberOfFrames),
false);
}
