Function lodepng_encode

dependency/densecrf/examples/lodepng.cpp:5634–5825

#endif /*LODEPNG_COMPILE_ANCILLARY_CHUNKS*/

unsigned lodepng_encode(unsigned char** out, size_t* outsize,
                        const unsigned char* image, unsigned w, unsigned h,
                        LodePNGState* state)
{
    LodePNGInfo info;
    ucvector outv;
    unsigned char* data = 0; /*uncompressed version of the IDAT chunk data*/
    size_t datasize = 0;
    
    /*provide some proper output values if error will happen*/
    *out = 0;
    *outsize = 0;
    state->error = 0;
    
    lodepng_info_init(&info);
    lodepng_info_copy(&info, &state->info_png);
    
    if((info.color.colortype == LCT_PALETTE || state->encoder.force_palette)
       && (info.color.palettesize == 0 || info.color.palettesize > 256))
    {
        state->error = 68; /*invalid palette size, it is only allowed to be 1-256*/
        return state->error;
    }
    
    if(state->encoder.auto_convert)
    {
        state->error = lodepng_auto_choose_color(&info.color, image, w, h, &state->info_raw);
    }
    if(state->error) return state->error;
    
    if(state->encoder.zlibsettings.btype > 2)
    {
        CERROR_RETURN_ERROR(state->error, 61); /*error: unexisting btype*/
    }
    if(state->info_png.interlace_method > 1)
    {
        CERROR_RETURN_ERROR(state->error, 71); /*error: unexisting interlace mode*/
    }
    
    state->error = checkColorValidity(info.color.colortype, info.color.bitdepth);
    if(state->error) return state->error; /*error: unexisting color type given*/
    state->error = checkColorValidity(state->info_raw.colortype, state->info_raw.bitdepth);
    if(state->error) return state->error; /*error: unexisting color type given*/
    
    if(!lodepng_color_mode_equal(&state->info_raw, &info.color))
    {
        unsigned char* converted;
        size_t size = (w * h * (size_t)lodepng_get_bpp(&info.color) + 7) / 8;
        
        converted = (unsigned char*)lodepng_malloc(size);
        if(!converted && size) state->error = 83; /*alloc fail*/
        if(!state->error)
        {
            state->error = lodepng_convert(converted, image, &info.color, &state->info_raw, w, h);
        }
        if(!state->error) preProcessScanlines(&data, &datasize, converted, w, h, &info, &state->encoder);
        lodepng_free(converted);
    }