pa_converters.c

一个开源的sip源代码

        temp = temp | (((long)src[1]) << 16);
        temp = temp | (((long)src[2]) << 8);
#endif

        *dest = temp;

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

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

static void Int24_To_Int16(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    unsigned char *src = (unsigned char*)sourceBuffer;
    PaInt16 *dest = (PaInt16*)destinationBuffer;
    
    PaInt16 temp;

    (void) ditherGenerator; /* unused parameter */
        
    while( count-- )
    {
		
#if defined(PA_LITTLE_ENDIAN)
		/* src[0] is discarded */
        temp = (((PaInt16)src[1]));
        temp = temp | (PaInt16)(((PaInt16)src[2]) << 8);
#elif defined(PA_BIG_ENDIAN)
		/* src[2] is discarded */
        temp = (PaInt16)(((PaInt16)src[0]) << 8);
        temp = temp | (((PaInt16)src[1]));
#endif

        *dest = temp;

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

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

static void Int24_To_Int16_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 Int24_To_Int8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    unsigned char *src = (unsigned char*)sourceBuffer;
    signed char  *dest = (signed char*)destinationBuffer;
    
    (void) ditherGenerator; /* unused parameter */
        
    while( count-- )
    {	
	
#if defined(PA_LITTLE_ENDIAN)
		/* src[0] is discarded */
		/* src[1] is discarded */
        *dest = src[2];
#elif defined(PA_BIG_ENDIAN)
		/* src[2] is discarded */
		/* src[1] is discarded */
		*dest = src[0];
#endif

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

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

static void Int24_To_Int8_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 Int24_To_UInt8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    unsigned char *src = (unsigned char*)sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    
    (void) ditherGenerator; /* unused parameter */
        
    while( count-- )
    {
		
#if defined(PA_LITTLE_ENDIAN)
		/* src[0] is discarded */
		/* src[1] is discarded */
        *dest = (unsigned char)(src[2] + 128);
#elif defined(PA_BIG_ENDIAN)
        *dest = (unsigned char)(src[0] + 128);
		/* src[1] is discarded */
		/* src[2] is discarded */		
#endif

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

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

static void Int24_To_UInt8_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 Int16_To_Float32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    float *dest =  (float*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        float samp = *src * const_1_div_32768_; /* FIXME: i'm concerned about this being asymetrical with float->int16 -rb */
        *dest = samp;

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

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

static void Int16_To_Int32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    PaInt32 *dest =  (PaInt32*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        /* REVIEW: we should consider something like
            (*src << 16) | (*src & 0xFFFF)
        */
        
        *dest = *src << 16;

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

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

static void Int16_To_Int24(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src   = (PaInt16*) sourceBuffer;
    unsigned char *dest = (unsigned char*)destinationBuffer;
    PaInt16 temp;

    (void) ditherGenerator; /* unused parameter */
    
    while( count-- )
    {
        temp = *src;
        
#if defined(PA_LITTLE_ENDIAN)
        dest[0] = 0;
        dest[1] = (unsigned char)(temp);
        dest[2] = (unsigned char)(temp >> 8);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (unsigned char)(temp >> 8);
        dest[1] = (unsigned char)(temp);
        dest[2] = 0;
#endif

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

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

static void Int16_To_Int8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        (*dest) = (signed char)((*src) >> 8);

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

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

static void Int16_To_Int8_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    signed char *dest =  (signed char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

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

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

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

static void Int16_To_UInt8(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    unsigned char *dest =  (unsigned char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
		(*dest) = (unsigned char)(((*src) >> 8) + 128); 

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

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

static void Int16_To_UInt8_Dither(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    PaInt16 *src = (PaInt16*)sourceBuffer;
    unsigned char *dest =  (unsigned char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

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

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

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

static void Int8_To_Float32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed char *src = (signed char*)sourceBuffer;
    float *dest =  (float*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
        float samp = *src * const_1_div_128_;
        *dest = samp;

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

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

static void Int8_To_Int32(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed char *src = (signed char*)sourceBuffer;
    PaInt32 *dest =  (PaInt32*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {
		(*dest) = (*src) << 24;

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

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

static void Int8_To_Int24(
    void *destinationBuffer, signed int destinationStride,
    void *sourceBuffer, signed int sourceStride,
    unsigned int count, struct PaUtilTriangularDitherGenerator *ditherGenerator )
{
    signed char *src = (signed char*)sourceBuffer;
    unsigned char *dest =  (unsigned char*)destinationBuffer;
    (void)ditherGenerator; /* unused parameter */

    while( count-- )
    {

#if defined(PA_LITTLE_ENDIAN)
        dest[0] = 0;
        dest[1] = 0;
        dest[2] = (*src);
#elif defined(PA_BIG_ENDIAN)
        dest[0] = (*src);