+void decode_ac_coefficients(const struct huffman_table* tbl, struct bit_source* bits, int16_t* coeff)
+{
+ for (unsigned i = 0; i < DCTSIZE2 - 1; ) {
+ possibly_refill(bits, DEHUF_AC_TABLE_BITS);
+ unsigned lookup = peek_bits(bits, DEHUF_AC_TABLE_BITS);
+ int code = tbl->ac_table_codes[lookup];
+
+ if (__builtin_expect(code == AC_DEHUF_SLOW_PATH, 0)) {
+ unsigned rs = read_huffman_symbol_no_refill(tbl, bits);
+ unsigned r = rs >> 4;
+ unsigned s = rs & 0xf;
+ i += r + 1;
+ possibly_refill(bits, s);
+
+ if (rs == 0x00) {
+ /* end of block */
+ break;
+ }
+ if (rs == 0xf0) {
+ /* 16 zero coefficients */
+ continue;
+ }
+
+ coeff[unzigzag[i]] = extend(read_bits(bits, s), s);
+ } else {
+ unsigned length = tbl->ac_table_length[lookup];
+ int r = tbl->ac_table_skip[lookup];
+ assert(r >= 1);
+ i += r;
+ assert(bits->bits_available >= length);
+ read_bits(bits, length);
+ if (code == AC_END_OF_BLOCK) {
+ break;
+ }
+ coeff[unzigzag[i]] = code;
+ }
+ }
+}
+