RGBA to 4x4RGBA

/*by xerpi*/

void pngx_RGBAto4X4RGBA(uint8_t *srcBuff, uint8_t *dstBuff, uint32_t buffWidth, uint32_t buffHeight)
{
    //RGBA format: 0xRRGGBBAA

    /*
    AARRAARR AARRAARR AARRAARR AARRAARR
    AARRAARR AARRAARR AARRAARR AARRAARR
    GGBBGGBB GGBBGGBB GGBBGGBB GGBBGGBB
    GGBBGGBB GGBBGGBB GGBBGGBB GGBBGGBB
    */
    uint8_t *src = srcBuff;
    uint8_t *dst = dstBuff;
    uint32_t y, x, i, j;
    uint8_t *block;

    for(y = 0;  y < buffHeight; y+=4)
    {
        for(x = 0; x < buffWidth; x+=4)
        {
            for(i = 0; i < 4; i++)
            {
                for(j = 0; j < 4; j++)
                {
                    block = src + ((x + j) + (y + i) * buffWidth) * 4;
                    *(dst     ) = *(block + 3);  //Alpha
                    *(dst + 32) = *(block + 1);  //Green
                    dst++;
                    *(dst     ) = *(block);      //Red
                    *(dst + 32) = *(block + 2);  //Blue
                    dst++;
                }
            }
            dst+=32;
        }
    }

    /*for(y = 0;  y < buffHeight; y+=4)
    {
        for(x = 0; x < buffWidth; x+=4)
        {
            for(i = 0; i < 4; i++)
            {
                for(j = 0; j < 4; j++)
                {
                    block = *(uint32_t *)(src + ((x + j) + ((y + i) * buffWidth)) * 4);
                    *(dst++) = (block) & 0xFF;
                    *(dst++) = (block>>24) & 0xFF;
                }
            }
            for(i = 0; i < 4; i++)
            {
                for(j = 0; j < 4; j++)
                {
                    block = *(uint32_t *)(src + ((x + j) + ((y + i) * buffWidth)) * 4);
                    *(dst++) = (block>>16) & 0xFF;
                    *(dst++) = (block>>8) & 0xFF;
                }
            }
        }
    }*/
}