sprdata = malloc(height * 2 * sizeof *sprdata);
conv_img_data(i, sprdata, img, width, height, pitch);
for(j=0; j<height; j++) {
sprdata = malloc(height * 2 * sizeof *sprdata);
conv_img_data(i, sprdata, img, width, height, pitch);
for(j=0; j<height; j++) {