Superres: Add a flag for exhaustive search
When SUPERRES_RECODE_ALL_RATIOS is on, we try all possible denominators
for all frames (except overlay and internal overlay frames) in
SUPERRES_AUTO mode. (Off by default).
The purpose of the flag is to find out the maximum possible gains from superres
with best strategy of picking superres denominators.
BDRate (PSNR) on hdres at low bitrates
(baseline = fullres, test = SUPERRES_AUTO with SUPERRES_RECODE_ALL_RATIOS
on):
Overall: -0.977
sunflower_720p25.y4m -9.032
night_720p30.y4m -7.556
factory_1080p30.y4m -3.745
cyclists_720p30.y4m -3.745
ped_1080p25.y4m -3.172
stockholm_ter_720p60.y4m -2.613
crew_720p30.y4m -2.501
basketballdrive_1080p50.y4m -2.501
city_720p30.y4m -2.203
tennis_1080p24.y4m -1.604
shields_720p50.y4m -1.359
in_to_tree_1080p50.y4m -1.351
kimono1_1080p24.y4m -1.106
parkrun_720p50.y4m -0.743
dinner_1080p30.y4m -0.571
Change-Id: I0dd8d3112bb81783457672b59105b352cf28ace5
diff --git a/av1/encoder/encoder.c b/av1/encoder/encoder.c
index 086887d..620a4e2 100644
--- a/av1/encoder/encoder.c
+++ b/av1/encoder/encoder.c
@@ -10,6 +10,7 @@
*/
#include <limits.h>
+#include <float.h>
#include <math.h>
#include <stdio.h>
@@ -4341,6 +4342,10 @@
return denom;
}
+// If true, SUPERRES_AUTO mode will exhaustively search over all superres
+// denominators for all frames (except overlay and internal overlay frames).
+#define SUPERRES_RECODE_ALL_RATIOS 0
+
static uint8_t calculate_next_superres_scale(AV1_COMP *cpi) {
// Choose an arbitrary random number
static unsigned int seed = 34567;
@@ -4402,7 +4407,14 @@
if (q <= qthresh) {
new_denom = SCALE_NUMERATOR;
} else {
+#if SUPERRES_RECODE_ALL_RATIOS
+ if (cpi->common.current_frame.frame_type == KEY_FRAME)
+ new_denom = oxcf->superres_kf_scale_denominator;
+ else
+ new_denom = oxcf->superres_scale_denominator;
+#else
new_denom = get_superres_denom_for_qindex(cpi, q, 1, 1);
+#endif // SUPERRES_RECODE_ALL_RATIOS
}
break;
}
@@ -5386,15 +5398,47 @@
save_all_coding_context(cpi);
// Encode with superres.
+#if SUPERRES_RECODE_ALL_RATIOS
+ int64_t superres_sses[SCALE_NUMERATOR];
+ int64_t superres_rates[SCALE_NUMERATOR];
+ int superres_largest_tile_ids[SCALE_NUMERATOR];
+ // Use superres for Key-frames and Alt-ref frames only.
+ const GF_GROUP *const gf_group = &cpi->gf_group;
+ if (gf_group->update_type[gf_group->index] != OVERLAY_UPDATE &&
+ gf_group->update_type[gf_group->index] != INTNL_OVERLAY_UPDATE) {
+ for (int denom = SCALE_NUMERATOR + 1; denom <= 2 * SCALE_NUMERATOR;
+ ++denom) {
+ oxcf->superres_scale_denominator = denom;
+ oxcf->superres_kf_scale_denominator = denom;
+ const int this_index = denom - (SCALE_NUMERATOR + 1);
+ err = encode_with_recode_loop_and_filter(
+ cpi, size, dest, &superres_sses[this_index],
+ &superres_rates[this_index], &superres_largest_tile_ids[this_index]);
+ if (err != AOM_CODEC_OK) return err;
+ restore_all_coding_context(cpi);
+ }
+ // Reset.
+ oxcf->superres_scale_denominator = SCALE_NUMERATOR;
+ oxcf->superres_kf_scale_denominator = SCALE_NUMERATOR;
+ } else {
+ for (int denom = SCALE_NUMERATOR + 1; denom <= 2 * SCALE_NUMERATOR;
+ ++denom) {
+ const int this_index = denom - (SCALE_NUMERATOR + 1);
+ superres_sses[this_index] = INT64_MAX;
+ superres_rates[this_index] = INT64_MAX;
+ }
+ }
+#else
int64_t sse1 = INT64_MAX;
int64_t rate1 = INT64_MAX;
int largest_tile_id1;
err = encode_with_recode_loop_and_filter(cpi, size, dest, &sse1, &rate1,
&largest_tile_id1);
if (err != AOM_CODEC_OK) return err;
+ restore_all_coding_context(cpi);
+#endif // SUPERRES_RECODE_ALL_RATIOS
// Encode without superres.
- restore_all_coding_context(cpi);
int64_t sse2 = INT64_MAX;
int64_t rate2 = INT64_MAX;
int largest_tile_id2;
@@ -5407,7 +5451,34 @@
// Note: Both use common rdmult based on base qindex of fullres.
const int64_t rdmult =
av1_compute_rd_mult_based_on_qindex(cpi, cm->base_qindex);
+
+#if SUPERRES_RECODE_ALL_RATIOS
+ // Find the best rdcost among all superres denoms.
+ double proj_rdcost1 = DBL_MAX;
+ int64_t sse1 = INT64_MAX;
+ int64_t rate1 = INT64_MAX;
+ int largest_tile_id1 = 0;
+ (void)sse1;
+ (void)rate1;
+ (void)largest_tile_id1;
+ int best_denom = -1;
+ for (int denom = SCALE_NUMERATOR + 1; denom <= 2 * SCALE_NUMERATOR; ++denom) {
+ const int this_index = denom - (SCALE_NUMERATOR + 1);
+ const int64_t this_sse = superres_sses[this_index];
+ const int64_t this_rate = superres_rates[this_index];
+ const int this_largest_tile_id = superres_largest_tile_ids[this_index];
+ const double this_rdcost = RDCOST_DBL(rdmult, this_rate, this_sse);
+ if (this_rdcost < proj_rdcost1) {
+ sse1 = this_sse;
+ rate1 = this_rate;
+ largest_tile_id1 = this_largest_tile_id;
+ proj_rdcost1 = this_rdcost;
+ best_denom = denom;
+ }
+ }
+#else
const double proj_rdcost1 = RDCOST_DBL(rdmult, rate1, sse1);
+#endif // SUPERRES_RECODE_ALL_RATIOS
const double proj_rdcost2 = RDCOST_DBL(rdmult, rate2, sse2);
// Re-encode with superres if it's better.
@@ -5416,6 +5487,11 @@
// TODO(urvang): We should avoid rerunning the recode loop by saving
// previous output+state, or running encode only for the selected 'q' in
// previous step.
+#if SUPERRES_RECODE_ALL_RATIOS
+ // Again, temporarily force the best denom.
+ oxcf->superres_scale_denominator = best_denom;
+ oxcf->superres_kf_scale_denominator = best_denom;
+#endif // SUPERRES_RECODE_ALL_RATIOS
int64_t sse3 = INT64_MAX;
int64_t rate3 = INT64_MAX;
err = encode_with_recode_loop_and_filter(cpi, size, dest, &sse3, &rate3,
@@ -5423,6 +5499,11 @@
assert(sse1 == sse3);
assert(rate1 == rate3);
assert(largest_tile_id1 == *largest_tile_id);
+#if SUPERRES_RECODE_ALL_RATIOS
+ // Reset.
+ oxcf->superres_scale_denominator = SCALE_NUMERATOR;
+ oxcf->superres_kf_scale_denominator = SCALE_NUMERATOR;
+#endif // SUPERRES_RECODE_ALL_RATIOS
} else {
*largest_tile_id = largest_tile_id2;
}
