// decode DC component
unsigned dc_category = read_huffman_symbol(dc_table, &bits);
- possibly_refill(&bits, dc_category);
+ possibly_refill(&bits, dc_category + DEHUF_TABLE_BITS);
last_dc[c] += extend(read_bits(&bits, dc_category), dc_category);
int16_t coeff[DCTSIZE2] = { 0 };
// decode AC components
for (unsigned i = 1; i < DCTSIZE2; ++i) {
- unsigned rs = read_huffman_symbol(ac_table, &bits);
+ unsigned rs = read_huffman_symbol_no_refill(ac_table, &bits);
unsigned r = rs >> 4;
unsigned s = rs & 0xf;
}
if (rs == 0xf0) {
/* 16 zero coefficients */
+ possibly_refill(&bits, DEHUF_TABLE_BITS);
i += 15;
continue;
}
i += r;
- possibly_refill(&bits, s);
+ possibly_refill(&bits, s + DEHUF_TABLE_BITS);
coeff[unzigzag[i]] = extend(read_bits(&bits, s), s);
}
uint8_t pixdata[DCTSIZE2];
idct_choice(coeff, image->idct_data[image->qtable[cn]], pixdata);
- for (unsigned y = 0; y < DCTSIZE; ++y) {
- unsigned real_x = (mcu_x * image->hsample[cn] + local_xb) * DCTSIZE;
- unsigned real_y = (mcu_y * image->vsample[cn] + local_yb) * DCTSIZE + y;
-
- memcpy(image->pixel_data[cn] + real_y * stride + real_x,
- pixdata + y * DCTSIZE,
- DCTSIZE);
+ unsigned real_x = (mcu_x * image->hsample[cn] + local_xb) * DCTSIZE;
+ unsigned real_y = (mcu_y * image->vsample[cn] + local_yb) * DCTSIZE;
+ uint8_t* dest_pixdata = image->pixel_data[cn] + real_y * stride + real_x;
+ for (unsigned y = 0; y < DCTSIZE; ++y, dest_pixdata += stride) {
+ memcpy(dest_pixdata, pixdata + y * DCTSIZE, DCTSIZE);
}
}
}
const int c = 1;
if (mcu_y == image->num_blocks_vertical) {
unsigned stride = image->num_blocks_horizontal * image->hsample[c] * DCTSIZE;
- printf("P5\n%u %u\n255\n", stride, image->height);
- fwrite(image->pixel_data[c], stride * image->height, 1, stdout);
+ unsigned height = image->num_blocks_vertical * image->vsample[c] * DCTSIZE;
+ printf("P5\n%u %u\n255\n", stride, height);
+ fwrite(image->pixel_data[c], stride * height, 1, stdout);
}
}
}