//printf("post-flush = %08x\n", rans);
uint32_t num_rans_bytes = out_end - ptr;
-#if 0
- if (num_rans_bytes == 4) {
- uint32_t block;
- memcpy(&block, ptr, 4);
-
- if (block == last_block) {
- write_varint(0, codedfp);
- clear();
- return 1;
- }
-
- last_block = block;
+ if (num_rans_bytes == last_block.size() &&
+ memcmp(last_block.data(), ptr, last_block.size()) == 0) {
+ write_varint(0, codedfp);
+ clear();
+ return 1;
} else {
- last_block = 0;
+ last_block = string((const char *)ptr, num_rans_bytes);
}
-#endif
write_varint(num_rans_bytes, codedfp);
//fwrite(&num_rans_bytes, 1, 4, codedfp);
RansEncSymbol esyms[NUM_SYMS];
uint32_t sign_bias;
- uint32_t last_block = 0; // Not a valid 4-byte rANS block (?)
+ std::string last_block;
};
static constexpr int dc_scalefac = 8; // Matches the FDCT's gain.
//double last_cb_cfl_fac = 0.0;
//double last_cr_cfl_fac = 0.0;
+ int max_val_x[8] = {0}, min_val_x[8] = {0};
+ int max_val_y[8] = {0}, min_val_y[8] = {0};
+
// DCT and quantize luma
for (unsigned yb = 0; yb < HEIGHT; yb += 8) {
for (unsigned xb = 0; xb < WIDTH; xb += 8) {
int k = quantize(in_y[coeff_idx], coeff_idx);
coeff_y[(yb + y) * WIDTH + (xb + x)] = k;
+ max_val_x[x] = std::max(max_val_x[x], k);
+ min_val_x[x] = std::min(min_val_x[x], k);
+ max_val_y[y] = std::max(max_val_y[y], k);
+ min_val_y[y] = std::min(min_val_y[y], k);
+
// Store back for reconstruction / PSNR calculation
in_y[coeff_idx] = unquantize(k, coeff_idx);
}
extra_bits,
extra_bits / 8,
tot_bytes);
+
+#if 0
+ printf("Max coefficient ranges (as a function of x):\n\n");
+ for (unsigned x = 0; x < 8; ++x) {
+ int range = std::max(max_val_x[x], -min_val_x[x]);
+ printf(" [%4d, %4d] (%.2f bits)\n", min_val_x[x], max_val_x[x], log2(range * 2 + 1));
+ }
+
+ printf("Max coefficient ranges (as a function of y):\n\n");
+ for (unsigned y = 0; y < 8; ++y) {
+ int range = std::max(max_val_y[y], -min_val_y[y]);
+ printf(" [%4d, %4d] (%.2f bits)\n", min_val_y[y], max_val_y[y], log2(range * 2 + 1));
+ }
+#endif
}