pa_converters.c

一个开源SIP协议栈

    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;
        signed long samp = (signed long) dithered;
        *dest = (signed char) samp;

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

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

static void Float32_To_Int8_Clip(
    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 long samp = (signed long)(*src * (127.0f));
        PA_CLIP_( samp, -0x80, 0x7F );
        *dest = (signed char) samp;

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

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

static void Float32_To_Int8_DitherClip(
    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;
        signed long samp = (signed long) dithered;
        PA_CLIP_( samp, -0x80, 0x7F );
        *dest = (signed char) samp;

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

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

static void Float32_To_UInt8(
    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;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        unsigned char samp = (unsigned char)(128 + ((unsigned char) (*src * (127.0f))));
        *dest = samp;

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

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

static void Float32_To_UInt8_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;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        /* IMPLEMENT ME */

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

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

static void Float32_To_UInt8_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;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        /* IMPLEMENT ME */

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

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

static void Float32_To_UInt8_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;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        /* IMPLEMENT ME */

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

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

static void Int32_To_Float32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    float *dest =  (float*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        *dest = (float) ((double)*src * const_1_div_2147483648_);

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

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

static void Int32_To_Int24(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src    = (signed long*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    (void) ditherGenerator; /* unused parameter */
    
	while( count-- )
    {
		/* REVIEW */
#if defined(PA_LITTLE_ENDIAN)
        dest[0] = (unsigned char)(*src >> 8);
        dest[1] = (unsigned char)(*src >> 16);
        dest[2] = (unsigned char)(*src >> 24);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(*src >> 24);
        dest[1] = (unsigned char)(*src >> 16);
        dest[2] = (unsigned char)(*src >> 8);
#endif
        src += sourceStride;
        dest += destinationStride * 3;
    }
}

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

static void Int32_To_Int24_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    (void) destinationBuffer; /* unused parameters */
    (void) destinationStride; /* unused parameters */
    (void) sourceBuffer; /* unused parameters */
    (void) sourceStride; /* unused parameters */
    (void) count; /* unused parameters */
    (void) ditherGenerator; /* unused parameters */
    /* IMPLEMENT ME */
}

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

static void Int32_To_Int16(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    signed short *dest =  (signed short*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        *dest = (signed short) ((*src) >> 16);

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

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

static void Int32_To_Int16_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    signed short *dest =  (signed short*)destinationBuffer;
    signed long dither;

    while( count-- )
    {
        /* REVIEW */
        dither = PaUtil_Generate16BitTriangularDither( ditherGenerator );
        *dest = (signed short) ((((*src)>>1) + dither) >> 15);

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

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

static void Int32_To_Int8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        *dest = (signed char) ((*src) >> 24);

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

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

static void Int32_To_Int8_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    signed long dither;

    while( count-- )
    {
        /* REVIEW */
        dither = PaUtil_Generate16BitTriangularDither( ditherGenerator );
        *dest = (signed char) ((((*src)>>1) + dither) >> 23);

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

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

static void Int32_To_UInt8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    unsigned char *dest =  (unsigned char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
		(*dest) = (unsigned char)(((*src) >> 24) + 128); 

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

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

static void Int32_To_UInt8_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed long *src = (signed long*)sourceBuffer;
    unsigned char *dest =  (unsigned char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        /* IMPLEMENT ME */

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

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

static void Int24_To_Float32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    unsigned char *src = (unsigned char*)sourceBuffer;
    float *dest = (float*)destinationBuffer;
    signed long temp;

    (void) ditherGenerator; /* unused parameter */
    
    while( count-- )
    {

#if defined(PA_LITTLE_ENDIAN)
        temp = (((long)src[0]) << 8);  
        temp = temp | (((long)src[1]) << 16);
        temp = temp | (((long)src[2]) << 24);
#elif defined(PA_BIG_ENDIAN)
        temp = (((long)src[0]) << 24);