gistfile1.cpp

OSStatus TSAudioEngine::render(AudioUnitRenderActionFlags *ioActionFlags,
                               const AudioTimeStamp *inTimeStamp,
                               UInt32 inBusNumber,
                               UInt32 inNumberFrames,
                               AudioBufferList *ioData) {
    OSStatus err = noErr;
    
    for (int ii = 0; ii < ioData->mNumberBuffers; ++ii) {
        vDSP_vclr(static_cast<float *>(ioData->mBuffers[ii].mData), 1, inNumberFrames);
    }
    if (0 == tryLock()) {
        // this is a thin wrapper to ExtAudioFileRead
        audioFileReader.process(ioData, inNumberFrames);

        float * lbuf = static_cast<float *>(ioData->mBuffers[0].mData);
        float * rbuf = static_cast<float *>(ioData->mBuffers[1].mData);

        vDSP_vrvrs(lbuf, 1, inNumberFrames);
        vDSP_vrvrs(rbuf, 1, inNumberFrames);
        
        currentPos -= inNumberFrames;
        // this is a thin wrapper to ExtAudioFileSeek
        err = audioFileReader.seek(currentPos);
        if (currentPos <= 44100) {
            currentPos = 350000;
            err = audioFileReader.seek(currentPos);
        }
        unlock();
    } else {
        printf("couldn't get audio lock\n");
    }
    return err;
}