VBR: Improve bit re-allocation per pyramid level.
Earlier, bits were reduced for leaf level frames and added for
internal ARF frames in the same loop. This meant that number of bits
reduced may NOT equal the number of bits added.
Now, we reduce bits from leaf level in the first loop, and then the
total of those bits is then reallocated to internal ARFs in a separate
loop. So, it's guaranteed that number of bits reduced = number of bits
added.
Overall BDRate (PSNR) improvement:
lowres: -0.594%
(garden_sif: -8.60%
crew_cif: -5.80%)
midres: -0.186%
(crew_4cif_30fps: -3.76%
speed_bag_480p: -1.45%)
STATS_CHANGED
Change-Id: I3cec7eaa980bc7a524e0a6ffdd50ee86327b7c04
diff --git a/av1/encoder/firstpass.c b/av1/encoder/firstpass.c
index 6176492..601e8ce 100644
--- a/av1/encoder/firstpass.c
+++ b/av1/encoder/firstpass.c
@@ -2133,9 +2133,7 @@
#if NEW_MULTI_LVL_BOOST_VBR_ALLOC
#define LEAF_REDUCTION_FACTOR 0.75
static double lvl_budget_factor[MAX_PYRAMID_LVL - 1][MAX_PYRAMID_LVL - 1] = {
- { 1.0, 0.0, 0.0 },
- { 1.0, 0.5, 0.0 },
- { 1.0, 0.5, 0.25 },
+ { 1.0, 0.0, 0.0 }, { 0.6, 0.4, 0 }, { 0.45, 0.35, 0.20 }
};
#endif // NEW_MULTI_LVL_BOOST_VBR_ALLOC
#endif // USE_SYMM_MULTI_LAYER
@@ -2145,15 +2143,11 @@
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->twopass;
GF_GROUP *const gf_group = &twopass->gf_group;
- FIRSTPASS_STATS frame_stats;
int i;
int frame_index = 0;
- int target_frame_size;
int key_frame;
const int max_bits = frame_max_bits(&cpi->rc, &cpi->oxcf);
int64_t total_group_bits = gf_group_bits;
- double modified_err = 0.0;
- double err_fraction;
int ext_arf_boost[MAX_EXT_ARFS];
define_gf_group_structure(cpi);
@@ -2172,6 +2166,7 @@
gf_group->bit_allocation[frame_index] = gf_arf_bits;
// Step over the golden frame / overlay frame
+ FIRSTPASS_STATS frame_stats;
if (EOF == input_stats(twopass, &frame_stats)) return;
}
@@ -2196,21 +2191,23 @@
}
}
+ // Save.
+ const int tmp_frame_index = frame_index;
+ int budget_reduced_from_leaf_level = 0;
+
// Allocate bits to the other frames in the group.
for (i = 0; i < rc->baseline_gf_interval - rc->source_alt_ref_pending; ++i) {
+ FIRSTPASS_STATS frame_stats;
if (EOF == input_stats(twopass, &frame_stats)) break;
- modified_err = calculate_modified_err(cpi, twopass, oxcf, &frame_stats);
-
- if (group_error > 0)
- err_fraction = modified_err / DOUBLE_DIVIDE_CHECK(group_error);
- else
- err_fraction = 0.0;
-
- target_frame_size = (int)((double)total_group_bits * err_fraction);
-
- target_frame_size =
- clamp(target_frame_size, 0, AOMMIN(max_bits, (int)total_group_bits));
+ const double modified_err =
+ calculate_modified_err(cpi, twopass, oxcf, &frame_stats);
+ const double err_fraction =
+ (group_error > 0) ? modified_err / DOUBLE_DIVIDE_CHECK(group_error)
+ : 0.0;
+ const int target_frame_size =
+ clamp((int)((double)total_group_bits * err_fraction), 0,
+ AOMMIN(max_bits, (int)total_group_bits));
if (gf_group->update_type[frame_index] == BRF_UPDATE) {
// Boost up the allocated bits on BWDREF_FRAME
@@ -2231,25 +2228,11 @@
gf_group->pyramid_height >= 0 &&
"non-valid height for a pyramid structure");
- int arf_pos = gf_group->arf_pos_in_gf[frame_index];
+ const int arf_pos = gf_group->arf_pos_in_gf[frame_index];
gf_group->bit_allocation[frame_index] = 0;
gf_group->bit_allocation[arf_pos] = target_frame_size;
-#if MULTI_LVL_BOOST_VBR_CQ
- const int this_lvl = gf_group->pyramid_level[arf_pos];
- const int dist2top = gf_group->pyramid_height - 1 - this_lvl;
-#if NEW_MULTI_LVL_BOOST_VBR_ALLOC
- const double lvl_ratio = LEAF_REDUCTION_FACTOR *
- (double)gf_group->pyramid_lvl_nodes[0] /
- (double)gf_group->pyramid_lvl_nodes[this_lvl];
- const double lvl_boost =
- AOMMIN(lvl_ratio, 3.0) *
- lvl_budget_factor[gf_group->pyramid_height - 2][dist2top];
- gf_group->bit_allocation[arf_pos] += (int)(target_frame_size * lvl_boost);
-#else
- gf_group->bit_allocation[arf_pos] += (target_frame_size >> dist2top);
-#endif // NEW_MULTI_LVL_BOOST_VBR_ALLOC
-#endif // MULTI_LVL_BOOST_VBR_CQ
+ // Note: Boost, if needed, is added in the next loop.
#endif // USE_SYMM_MULTI_LAYER
} else {
assert(gf_group->update_type[frame_index] == LF_UPDATE ||
@@ -2258,8 +2241,10 @@
#if MULTI_LVL_BOOST_VBR_CQ
if (cpi->new_bwdref_update_rule) {
#if NEW_MULTI_LVL_BOOST_VBR_ALLOC
- gf_group->bit_allocation[frame_index] -=
+ const int this_budget_reduction =
(int)(target_frame_size * LEAF_REDUCTION_FACTOR);
+ gf_group->bit_allocation[frame_index] -= this_budget_reduction;
+ budget_reduced_from_leaf_level += this_budget_reduction;
#else
gf_group->bit_allocation[frame_index] -= (target_frame_size >> 1);
#endif // NEW_MULTI_LVL_BOOST_VBR_ALLOC
@@ -2277,6 +2262,47 @@
}
#if USE_SYMM_MULTI_LAYER
+#if MULTI_LVL_BOOST_VBR_CQ
+ if (budget_reduced_from_leaf_level > 0) {
+ // Restore.
+ frame_index = tmp_frame_index;
+
+ // Re-distribute this extra budget to overlay frames in the group.
+ for (i = 0; i < rc->baseline_gf_interval - rc->source_alt_ref_pending;
+ ++i) {
+ if (cpi->new_bwdref_update_rule &&
+ gf_group->update_type[frame_index] == INTNL_OVERLAY_UPDATE) {
+ assert(gf_group->pyramid_height <= MAX_PYRAMID_LVL &&
+ gf_group->pyramid_height >= 0 &&
+ "non-valid height for a pyramid structure");
+ const int arf_pos = gf_group->arf_pos_in_gf[frame_index];
+ const int this_lvl = gf_group->pyramid_level[arf_pos];
+ const int dist2top = gf_group->pyramid_height - 1 - this_lvl;
+#if NEW_MULTI_LVL_BOOST_VBR_ALLOC
+ const double lvl_boost_factor =
+ lvl_budget_factor[gf_group->pyramid_height - 2][dist2top];
+ const int extra_size =
+ (int)(budget_reduced_from_leaf_level * lvl_boost_factor /
+ gf_group->pyramid_lvl_nodes[this_lvl]);
+#else
+ const int target_frame_size = gf_group->bit_allocation[arf_pos];
+ const int extra_size = target_frame_size >> dist2top;
+#endif // NEW_MULTI_LVL_BOOST_VBR_ALLOC
+ gf_group->bit_allocation[arf_pos] += extra_size;
+ }
+ ++frame_index;
+
+ // Skip all the extra-ARF's.
+ if (cpi->num_extra_arfs) {
+ while (gf_group->update_type[frame_index] == INTNL_ARF_UPDATE)
+ ++frame_index;
+ }
+ }
+ }
+#endif // MULTI_LVL_BOOST_VBR_CQ
+#endif // USE_SYMM_MULTI_LAYER
+
+#if USE_SYMM_MULTI_LAYER
if (cpi->new_bwdref_update_rule == 0 && rc->source_alt_ref_pending) {
#else
if (rc->source_alt_ref_pending) {
