void PaUtil_BeginBufferProcessing( PaUtilBufferProcessor* bp,
        PaStreamCallbackTimeInfo* timeInfo, PaStreamCallbackFlags callbackStatusFlags )
{
    bp->timeInfo = timeInfo;

    /* the first streamCallback will be called to process samples which are
        currently in the input buffer before the ones starting at the timeInfo time */
        
    bp->timeInfo->inputBufferAdcTime -= bp->framesInTempInputBuffer * bp->samplePeriod;
    
    bp->timeInfo->currentTime = 0; /** FIXME: @todo time info currentTime not implemented */

    /* the first streamCallback will be called to generate samples which will be
        outputted after the frames currently in the output buffer have been
        outputted. */
    bp->timeInfo->outputBufferDacTime += bp->framesInTempOutputBuffer * bp->samplePeriod;

    bp->callbackStatusFlags = callbackStatusFlags;

    bp->hostInputFrameCount[1] = 0;
    bp->hostOutputFrameCount[1] = 0;
}