Revision701 JPEG Test

Nature of the test

libjpeg has been compiled with the 五SDK, and I wanted to test the result.

Code

void jpeg_test() {
  struct jpeg_decompress_struct cinfo;
  struct jpeg_error_mgr jerr;
  unsigned char *image;
  FILE *img = fopen("root:/girl_742.jpg", "rb");
 
  if (img == NULL) {
    perror("open jpeg image");
    return;
  }
 
  cinfo.err = jpeg_std_error(&jerr);
  jpeg_create_decompress(&cinfo);
  jpeg_stdio_src(&cinfo, img);
  jpeg_read_header(&cinfo, TRUE);
  jpeg_start_decompress(&cinfo);
 
  image = malloc(cinfo.output_width * cinfo.output_height * 3);
  for(int i=0; i < cinfo.output_height; i++)
  {
    unsigned char * ptr = image + i * 3 * cinfo.output_width;
    jpeg_read_scanlines(&cinfo, &ptr, 1);
  }
 
  printf("JPEG image loaded: %ix%i\n", cinfo.output_width, cinfo.output_height);
 
  // we assume gfx mode is at 0xffffffffe0000000, with 1024x768x32 mode pixels
  FILE *out = fopen("memory://ffffffffe0000000/25165824", "wb");
  if (out == NULL) {
    perror("opening ram");
    fclose(img);
    free(image);
    return;
  }
 
  // write to memory. Memory is RGBA, we have RGB
  for(int i = 0; i < cinfo.output_width * cinfo.output_height; i++) {
    int offset = i*3;
    for(int j = 0; j < 3; j++) {
      fwrite(image+offset+(2-j), 1, 1, out);
    }
    offset = 0;
    fwrite(&offset, 1, 1, out); // write "0"
  }
  free(image);
  fclose(out);
  fclose(img);
  sleep(2);
  return;
}

Result