/* Load a JPEG type image from an SDL datasource */
SDL_Surface *IMG_LoadJPG_RW(SDL_RWops *src)
{
int start;
struct jpeg_decompress_struct cinfo;
JSAMPROW rowptr[1];
SDL_Surface *volatile surface = NULL;
struct my_error_mgr jerr;
if ( !src ) {
/* The error message has been set in SDL_RWFromFile */
return NULL;
}
start = SDL_RWtell(src);
if ( IMG_InitJPG() < 0 ) {
return NULL;
}
/* Create a decompression structure and load the JPEG header */
cinfo.err = lib.jpeg_std_error(&jerr.errmgr);
jerr.errmgr.error_exit = my_error_exit;
jerr.errmgr.output_message = output_no_message;
if(setjmp(jerr.escape)) {
/* If we get here, libjpeg found an error */
lib.jpeg_destroy_decompress(&cinfo);
if ( surface != NULL ) {
SDL_FreeSurface(surface);
}
SDL_RWseek(src, start, SEEK_SET);
IMG_QuitJPG();
IMG_SetError("JPEG loading error");
return NULL;
}
lib.jpeg_create_decompress(&cinfo);
jpeg_SDL_RW_src(&cinfo, src);
lib.jpeg_read_header(&cinfo, TRUE);
if(cinfo.num_components == 4) {
/* Set 32-bit Raw output */
cinfo.out_color_space = JCS_CMYK;
cinfo.quantize_colors = FALSE;
lib.jpeg_calc_output_dimensions(&cinfo);
/* Allocate an output surface to hold the image */
surface = SDL_AllocSurface(SDL_SWSURFACE,
cinfo.output_width, cinfo.output_height, 32,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
0x00FF0000, 0x0000FF00, 0x000000FF, 0xFF000000);
#else
0x0000FF00, 0x00FF0000, 0xFF000000, 0x000000FF);
#endif
} else {
/* Load a JPEG type image from an SDL datasource */
SDL_Surface *IMG_LoadJPG_RW(SDL_RWops *src)
{
struct jpeg_decompress_struct cinfo;
JSAMPROW rowptr[1];
SDL_Surface *volatile surface = NULL;
struct my_error_mgr jerr;
/* Create a decompression structure and load the JPEG header */
cinfo.err = jpeg_std_error(&jerr.errmgr);
jerr.errmgr.error_exit = my_error_exit;
jerr.errmgr.output_message = output_no_message;
if(setjmp(jerr.escape)) {
/* If we get here, libjpeg found an error */
jpeg_destroy_decompress(&cinfo);
IMG_SetError("JPEG loading error");
SDL_FreeSurface(surface);
return NULL;
}
jpeg_create_decompress(&cinfo);
jpeg_SDL_RW_src(&cinfo, src);
jpeg_read_header(&cinfo, TRUE);
/* Set 24-bit RGB output */
cinfo.out_color_space = JCS_RGB;
cinfo.quantize_colors = FALSE;
#ifdef FAST_JPEG
cinfo.scale_num = 1;
cinfo.scale_denom = 1;
cinfo.dct_method = JDCT_FASTEST;
cinfo.do_fancy_upsampling = FALSE;
#endif
jpeg_calc_output_dimensions(&cinfo);
/* Allocate an output surface to hold the image */
surface = SDL_AllocSurface(SDL_SWSURFACE,
cinfo.output_width, cinfo.output_height, 24,
#if SDL_BYTEORDER == SDL_LIL_ENDIAN
0x0000FF, 0x00FF00, 0xFF0000,
#else
0xFF0000, 0x00FF00, 0x0000FF,
#endif
0);
if ( surface == NULL ) {
IMG_SetError("Out of memory");
goto done;
}
/* Decompress the image */
jpeg_start_decompress(&cinfo);
while ( cinfo.output_scanline < cinfo.output_height ) {
rowptr[0] = (JSAMPROW)(Uint8 *)surface->pixels +
cinfo.output_scanline * surface->pitch;
jpeg_read_scanlines(&cinfo, rowptr, (JDIMENSION) 1);
}
jpeg_finish_decompress(&cinfo);
/* Clean up and return */
done:
jpeg_destroy_decompress(&cinfo);
return(surface);
}
