rgb2rgb.c

ffmpeg的完整源代码和作者自己写的文档。不但有在Linux的工程哦

/**
 * Palette is assumed to contain BGR32.
 */
void palette8torgb24(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
/*
    writes 1 byte o much and might cause alignment issues on some architectures?
    for (i=0; i<num_pixels; i++)
        ((unsigned *)(&dst[i*3])) = ((unsigned *)palette)[ src[i] ];
*/
    for (i=0; i<num_pixels; i++)
    {
        //FIXME slow?
        dst[0]= palette[ src[i]*4+2 ];
        dst[1]= palette[ src[i]*4+1 ];
        dst[2]= palette[ src[i]*4+0 ];
        dst+= 3;
    }
}

void palette8tobgr24(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
/*
    writes 1 byte o much and might cause alignment issues on some architectures?
    for (i=0; i<num_pixels; i++)
        ((unsigned *)(&dst[i*3])) = ((unsigned *)palette)[ src[i] ];
*/
    for (i=0; i<num_pixels; i++)
    {
        //FIXME slow?
        dst[0]= palette[ src[i]*4+0 ];
        dst[1]= palette[ src[i]*4+1 ];
        dst[2]= palette[ src[i]*4+2 ];
        dst+= 3;
    }
}

/**
 * Palette is assumed to contain bgr16, see rgb32to16 to convert the palette
 */
void palette8torgb16(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
    for (i=0; i<num_pixels; i++)
        ((uint16_t *)dst)[i] = ((uint16_t *)palette)[ src[i] ];
}
void palette8tobgr16(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
    for (i=0; i<num_pixels; i++)
        ((uint16_t *)dst)[i] = bswap_16(((uint16_t *)palette)[ src[i] ]);
}

/**
 * Palette is assumed to contain BGR15, see rgb32to15 to convert the palette.
 */
void palette8torgb15(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
    for (i=0; i<num_pixels; i++)
        ((uint16_t *)dst)[i] = ((uint16_t *)palette)[ src[i] ];
}
void palette8tobgr15(const uint8_t *src, uint8_t *dst, long num_pixels, const uint8_t *palette)
{
    long i;
    for (i=0; i<num_pixels; i++)
        ((uint16_t *)dst)[i] = bswap_16(((uint16_t *)palette)[ src[i] ]);
}

void rgb32tobgr24(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size >> 2;
    for (i=0; i<num_pixels; i++)
    {
        #ifdef WORDS_BIGENDIAN
            /* RGB32 (= A,B,G,R) -> BGR24 (= B,G,R) */
            dst[3*i + 0] = src[4*i + 1];
            dst[3*i + 1] = src[4*i + 2];
            dst[3*i + 2] = src[4*i + 3];
        #else
            dst[3*i + 0] = src[4*i + 2];
            dst[3*i + 1] = src[4*i + 1];
            dst[3*i + 2] = src[4*i + 0];
        #endif
    }
}

void rgb24tobgr32(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    for (i=0; 3*i<src_size; i++)
    {
        #ifdef WORDS_BIGENDIAN
            /* RGB24 (= R,G,B) -> BGR32 (= A,R,G,B) */
            dst[4*i + 0] = 0;
            dst[4*i + 1] = src[3*i + 0];
            dst[4*i + 2] = src[3*i + 1];
            dst[4*i + 3] = src[3*i + 2];
        #else
            dst[4*i + 0] = src[3*i + 2];
            dst[4*i + 1] = src[3*i + 1];
            dst[4*i + 2] = src[3*i + 0];
            dst[4*i + 3] = 0;
        #endif
    }
}

void rgb16tobgr32(const uint8_t *src, uint8_t *dst, long src_size)
{
    const uint16_t *end;
    uint8_t *d = (uint8_t *)dst;
    const uint16_t *s = (uint16_t *)src;
    end = s + src_size/2;
    while (s < end)
    {
        register uint16_t bgr;
        bgr = *s++;
        #ifdef WORDS_BIGENDIAN
            *d++ = 0;
            *d++ = (bgr&0x1F)<<3;
            *d++ = (bgr&0x7E0)>>3;
            *d++ = (bgr&0xF800)>>8;
        #else
            *d++ = (bgr&0xF800)>>8;
            *d++ = (bgr&0x7E0)>>3;
            *d++ = (bgr&0x1F)<<3;
            *d++ = 0;
        #endif
    }
}

void rgb16tobgr24(const uint8_t *src, uint8_t *dst, long src_size)
{
    const uint16_t *end;
    uint8_t *d = (uint8_t *)dst;
    const uint16_t *s = (const uint16_t *)src;
    end = s + src_size/2;
    while (s < end)
    {
        register uint16_t bgr;
        bgr = *s++;
        *d++ = (bgr&0xF800)>>8;
        *d++ = (bgr&0x7E0)>>3;
        *d++ = (bgr&0x1F)<<3;
    }
}

void rgb16tobgr16(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size >> 1;

    for (i=0; i<num_pixels; i++)
    {
        unsigned b,g,r;
        register uint16_t rgb;
        rgb = src[2*i];
        r = rgb&0x1F;
        g = (rgb&0x7E0)>>5;
        b = (rgb&0xF800)>>11;
        dst[2*i] = (b&0x1F) | ((g&0x3F)<<5) | ((r&0x1F)<<11);
    }
}

void rgb16tobgr15(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size >> 1;

    for (i=0; i<num_pixels; i++)
    {
        unsigned b,g,r;
        register uint16_t rgb;
        rgb = src[2*i];
        r = rgb&0x1F;
        g = (rgb&0x7E0)>>5;
        b = (rgb&0xF800)>>11;
        dst[2*i] = (b&0x1F) | ((g&0x1F)<<5) | ((r&0x1F)<<10);
    }
}

void rgb15tobgr32(const uint8_t *src, uint8_t *dst, long src_size)
{
    const uint16_t *end;
    uint8_t *d = (uint8_t *)dst;
    const uint16_t *s = (const uint16_t *)src;
    end = s + src_size/2;
    while (s < end)
    {
        register uint16_t bgr;
        bgr = *s++;
        #ifdef WORDS_BIGENDIAN
            *d++ = 0;
            *d++ = (bgr&0x1F)<<3;
            *d++ = (bgr&0x3E0)>>2;
            *d++ = (bgr&0x7C00)>>7;
        #else
            *d++ = (bgr&0x7C00)>>7;
            *d++ = (bgr&0x3E0)>>2;
            *d++ = (bgr&0x1F)<<3;
            *d++ = 0;
        #endif
    }
}

void rgb15tobgr24(const uint8_t *src, uint8_t *dst, long src_size)
{
    const uint16_t *end;
    uint8_t *d = (uint8_t *)dst;
    const uint16_t *s = (uint16_t *)src;
    end = s + src_size/2;
    while (s < end)
    {
        register uint16_t bgr;
        bgr = *s++;
        *d++ = (bgr&0x7C00)>>7;
        *d++ = (bgr&0x3E0)>>2;
        *d++ = (bgr&0x1F)<<3;
    }
}

void rgb15tobgr16(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size >> 1;

    for (i=0; i<num_pixels; i++)
    {
        unsigned b,g,r;
        register uint16_t rgb;
        rgb = src[2*i];
        r = rgb&0x1F;
        g = (rgb&0x3E0)>>5;
        b = (rgb&0x7C00)>>10;
        dst[2*i] = (b&0x1F) | ((g&0x3F)<<5) | ((r&0x1F)<<11);
    }
}

void rgb15tobgr15(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size >> 1;

    for (i=0; i<num_pixels; i++)
    {
        unsigned b,g,r;
        register uint16_t rgb;
        rgb = src[2*i];
        r = rgb&0x1F;
        g = (rgb&0x3E0)>>5;
        b = (rgb&0x7C00)>>10;
        dst[2*i] = (b&0x1F) | ((g&0x1F)<<5) | ((r&0x1F)<<10);
    }
}

void rgb8tobgr8(const uint8_t *src, uint8_t *dst, long src_size)
{
    long i;
    long num_pixels = src_size;
    for (i=0; i<num_pixels; i++)
    {
        unsigned b,g,r;
        register uint8_t rgb;
        rgb = src[i];
        r = (rgb&0x07);
        g = (rgb&0x38)>>3;
        b = (rgb&0xC0)>>6;
        dst[i] = ((b<<1)&0x07) | ((g&0x07)<<3) | ((r&0x03)<<6);
    }
}