pa_converters.c

一个开源的sip源代码

        float dithered = ((float)*src * (2147483646.0f)) + dither;
        *dest = lrintf(dithered - 0.5f);
#else
        double dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        double dithered = ((double)*src * (2147483646.0)) + dither;
        *dest = (PaInt32) dithered;
#endif
        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int32_Clip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt32 *dest =  (PaInt32*)destinationBuffer;
    (void) ditherGenerator; /* unused parameter */
    
    while( count-- )
    {
        /* REVIEW */
#ifdef PA_USE_C99_LRINTF
        float scaled = *src * 0x7FFFFFFF;
        PA_CLIP_( scaled, -2147483648.f, 2147483647.f  );
        *dest = lrintf(scaled-0.5f);
#else
        double scaled = *src * 0x7FFFFFFF;
        PA_CLIP_( scaled, -2147483648., 2147483647.  );
        *dest = (PaInt32) scaled;
#endif

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int32_DitherClip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt32 *dest =  (PaInt32*)destinationBuffer;

    while( count-- )
    {
        /* REVIEW */
#ifdef PA_USE_C99_LRINTF
        float dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        float dithered = ((float)*src * (2147483646.0f)) + dither;
        PA_CLIP_( dithered, -2147483648.f, 2147483647.f  );
        *dest = lrintf(dithered-0.5f);
#else
        double dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        double dithered = ((double)*src * (2147483646.0)) + dither;
        PA_CLIP_( dithered, -2147483648., 2147483647.  );
        *dest = (PaInt32) dithered;
#endif

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int24(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    PaInt32 temp;

    (void) ditherGenerator; /* unused parameter */
    
    while( count-- )
    {
        /* convert to 32 bit and drop the low 8 bits */
        double scaled = *src * 0x7FFFFFFF;
        temp = (PaInt32) scaled;
        
#if defined(PA_LITTLE_ENDIAN)
        dest[0] = (unsigned char)(temp >> 8);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 24);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(temp >> 24);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 8);
#endif

        src += sourceStride;
        dest += destinationStride * 3;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int24_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    PaInt32 temp;

    while( count-- )
    {
        /* convert to 32 bit and drop the low 8 bits */

        double dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        double dithered = ((double)*src * (2147483646.0)) + dither;
        
        temp = (PaInt32) dithered;

#if defined(PA_LITTLE_ENDIAN)
        dest[0] = (unsigned char)(temp >> 8);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 24);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(temp >> 24);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 8);
#endif

        src += sourceStride;
        dest += destinationStride * 3;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int24_Clip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    PaInt32 temp;

    (void) ditherGenerator; /* unused parameter */
    
    while( count-- )
    {
        /* convert to 32 bit and drop the low 8 bits */
        double scaled = *src * 0x7FFFFFFF;
        PA_CLIP_( scaled, -2147483648., 2147483647.  );
        temp = (PaInt32) scaled;

#if defined(PA_LITTLE_ENDIAN)
        dest[0] = (unsigned char)(temp >> 8);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 24);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(temp >> 24);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 8);
#endif

        src += sourceStride;
        dest += destinationStride * 3;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int24_DitherClip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    PaInt32 temp;
    
    while( count-- )
    {
        /* convert to 32 bit and drop the low 8 bits */
        
        double dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        double dithered = ((double)*src * (2147483646.0)) + dither;
        PA_CLIP_( dithered, -2147483648., 2147483647.  );
        
        temp = (PaInt32) dithered;

#if defined(PA_LITTLE_ENDIAN)
        dest[0] = (unsigned char)(temp >> 8);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 24);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(temp >> 24);
        dest[1] = (unsigned char)(temp >> 16);
        dest[2] = (unsigned char)(temp >> 8);
#endif

        src += sourceStride;
        dest += destinationStride * 3;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int16(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt16 *dest =  (PaInt16*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
#ifdef PA_USE_C99_LRINTF
        float tempf = (*src * (32767.0f)) ;
        *dest = lrintf(tempf-0.5f);
#else
        short samp = (short) (*src * (32767.0f));
        *dest = samp;
#endif

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int16_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt16 *dest = (PaInt16*)destinationBuffer;

    while( count-- )
    {

        float dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        float dithered = (*src * (32766.0f)) + dither;

#ifdef PA_USE_C99_LRINTF
        *dest = lrintf(dithered-0.5f);
#else
        *dest = (PaInt16) dithered;
#endif

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int16_Clip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt16 *dest =  (PaInt16*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
#ifdef PA_USE_C99_LRINTF
        long samp = lrintf((*src * (32767.0f)) -0.5f);
#else
        long samp = (PaInt32) (*src * (32767.0f));
#endif
        PA_CLIP_( samp, -0x8000, 0x7FFF );
        *dest = (PaInt16) samp;

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int16_DitherClip(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    PaInt16 *dest =  (PaInt16*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {

        float dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        float dithered = (*src * (32766.0f)) + dither;
        PaInt32 samp = (PaInt32) dithered;
        PA_CLIP_( samp, -0x8000, 0x7FFF );
#ifdef PA_USE_C99_LRINTF
        *dest = lrintf(samp-0.5f);
#else
        *dest = (PaInt16) samp;
#endif

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        signed char samp = (signed char) (*src * (127.0f));
        *dest = samp;

        src += sourceStride;
        dest += destinationStride;
    }
}

/* -------------------------------------------------------------------------- */

static void Float32_To_Int8_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    float *src = (float*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        float dither  = PaUtil_GenerateFloatTriangularDither( ditherGenerator );
        /* use smaller scaler to prevent overflow when we add the dither */
        float dithered = (*src * (126.0f)) + dither;
        PaInt32 samp = (PaInt32) dithered;
        *dest = (signed char) samp;

        src += sourceStride;
        dest += destinationStride;
    }
}