www.pudn.com > mixxx-1.5.0.zip > pa_convert.c

/*
 *  pa_conversions.c
 *  portaudio
 *
 *  Created by Phil Burk on Mon Mar 18 2002.
 *
 */
#include 

#include "portaudio.h"
#include "pa_host.h"

#define CLIP( val, min, max )  { val = ((val) < (min)) ? min : (((val) < (max)) ? (max) : (val)); }

/*************************************************************************/
static void PaConvert_Float32_Int16(
    float *sourceBuffer, int sourceStride,
    short *targetBuffer, int targetStride,
    int numSamples )
{
	int i;
	for( i=0; ipast_NativeInputSampleFormat = nativeInputSampleFormat;
    past->past_InputConversionSourceStride = 1;
    past->past_InputConversionTargetStride = 1;
    
    if( nativeInputSampleFormat != past->past_InputSampleFormat )
    {
        int ifDither = (past->past_Flags & paDitherOff) == 0;
        past->past_InputConversionProc = PaConvert_SelectProc( nativeInputSampleFormat,
             past->past_InputSampleFormat, 0, ifDither );
        if( past->past_InputConversionProc == NULL ) return paSampleFormatNotSupported;
    }
    else
    {
        past->past_InputConversionProc = NULL; /* no conversion necessary */
    }
    
    return paNoError;
}

/*************************************************************************/
PaError PaConvert_SetupOutput( internalPortAudioStream   *past,
    PaSampleFormat   nativeOutputSampleFormat )
{

    past->past_NativeOutputSampleFormat = nativeOutputSampleFormat;
    past->past_OutputConversionSourceStride = 1;
    past->past_OutputConversionTargetStride = 1;
    
    if( nativeOutputSampleFormat != past->past_OutputSampleFormat )
    {
        int ifDither = (past->past_Flags & paDitherOff) == 0;
        int ifClip = (past->past_Flags & paClipOff) == 0;

        past->past_OutputConversionProc = PaConvert_SelectProc( past->past_OutputSampleFormat,
            nativeOutputSampleFormat, ifClip, ifDither );
        if( past->past_OutputConversionProc == NULL ) return paSampleFormatNotSupported;
    }
    else
    {
        past->past_OutputConversionProc = NULL; /* no conversion necessary */
    }
    
    return paNoError;
}

/*************************************************************************
** Called by host code.
** Convert input from native format to user format,
** call user code,
** then convert output to native format.
** Returns result from user callback.
*/
long PaConvert_Process( internalPortAudioStream   *past,
                            void *nativeInputBuffer,
                            void *nativeOutputBuffer )
{
    int               userResult;
    void             *inputBuffer = NULL;
    void             *outputBuffer = NULL;

    /* Get native input data. */
    if( (past->past_NumInputChannels > 0) && (nativeInputBuffer != NULL) )
    {
        if( past->past_InputSampleFormat == past->past_NativeInputSampleFormat )
        {
        /*  Already in native format so just read directly from native buffer. */
            inputBuffer =  nativeInputBuffer;
        }
        else
        {
            inputBuffer = past->past_InputBuffer;
        /* Convert input data to user format. */
            (*past->past_InputConversionProc)(nativeInputBuffer, past->past_InputConversionSourceStride,
                inputBuffer, past->past_InputConversionTargetStride,
                past->past_FramesPerUserBuffer * past->past_NumInputChannels );
        }
    }

    /* Are we doing output? */
    if( (past->past_NumOutputChannels > 0) && (nativeOutputBuffer != NULL) )
    {
        outputBuffer = (past->past_OutputConversionProc == NULL) ?
                       nativeOutputBuffer : past->past_OutputBuffer;
    }
    /*
     AddTraceMessage("Pa_CallConvertInt16: inputBuffer = ", (int) inputBuffer );
     AddTraceMessage("Pa_CallConvertInt16: outputBuffer = ", (int) outputBuffer );
    */
    /* Call user callback routine. */
    userResult = past->past_Callback(
                     inputBuffer,
                     outputBuffer,
                     past->past_FramesPerUserBuffer,
                     past->past_FrameCount,
                     past->past_UserData );

    /* Advance frame counter for timestamp. */
    past->past_FrameCount += past->past_FramesPerUserBuffer; // FIXME - should this be in here?

    /* Convert to native format if necessary. */
    if( (past->past_OutputConversionProc != NULL ) && (outputBuffer != NULL) )
    {
        (*past->past_OutputConversionProc)( outputBuffer, past->past_OutputConversionSourceStride,
            nativeOutputBuffer, past->past_OutputConversionTargetStride,
            past->past_FramesPerUserBuffer * past->past_NumOutputChannels );
    }

    return userResult;
}