Further work on ext-comp-refs for ref frame coding
(1) Work with var-refs to remove redundant bits in ref frame
coding;
(2) Add a new uni-directional compound reference pair:
(LAST_FRAME, LAST3_FRAME);
(3) Redesign the contexts for encoding uni-directional reference frame
pairs;
(4) Use aom_entropy_optimizer to collect stats for all the default
probability setups related to the coding of reference frames.
Compared against the baseline (default enabled tools excluding ext-tx
and global-motion for encoder speed concern) with one-sided-compound,
the coding gain of ext-comp-refs + var-refs - one-sided-compound is:
lowres: avg_psnr -0.385%; ovr_psnr -0.378% ssim -0.344%
midres: avg_psnr -0.466%; ovr_psnr -0.447% ssim -0.513%
AWCY - High Latency:
PSNR | PSNR Cb | PSNR Cr | PSNR HVS | SSIM | MS SSIM | CIEDE 2000
-0.2758 | -0.1526 | -0.0965 | -0.2581 | -0.2492 | -0.2534 | -0.2118
AWCY - Low Latency:
PSNR | PSNR Cb | PSNR Cr | PSNR HVS | SSIM | MS SSIM | CIEDE 2000
-1.0467 | -1.4500 | -0.9732 | -0.9928 | -1.0407 | -1.0180 | -1.0049
Compared against the baseline (default enabled tools excluding ext-tx
and global-motion for encoder speed concern) without
one-sided-compound, the coding gain of
ext-comp-refs + var-refs - one-sided-compound is:
lowres: avg_psnr -0.875%; ovr_psnr -0.877% ssim -0.895%
midres: avg_psnr -0.824%; ovr_psnr -0.802% ssim -0.843%
Change-Id: I8de774c9a74c20632ea93ccb0c17779fa94431cb
diff --git a/av1/common/pred_common.c b/av1/common/pred_common.c
index 01e7f41..4b98a8c 100644
--- a/av1/common/pred_common.c
+++ b/av1/common/pred_common.c
@@ -263,6 +263,9 @@
#define IS_BACKWARD_REF_FRAME(ref_frame) ((ref_frame) == cm->comp_fixed_ref)
#endif // CONFIG_EXT_REFS
+#define CHECK_GOLDEN_OR_LAST3(ref_frame) \
+ (((ref_frame) == GOLDEN_FRAME) || ((ref_frame) == LAST3_FRAME))
+
int av1_get_reference_mode_context(const AV1_COMMON *cm,
const MACROBLOCKD *xd) {
int ctx;
@@ -313,16 +316,15 @@
#if CONFIG_EXT_COMP_REFS
#define CHECK_BWDREF_OR_ALTREF(ref_frame) \
((ref_frame) == BWDREF_FRAME || (ref_frame) == ALTREF_FRAME)
-int av1_get_comp_reference_type_context(const AV1_COMMON *cm,
- const MACROBLOCKD *xd) {
+// TODO(zoeliu): To try on the design of 3 contexts, instead of 5:
+// COMP_REF_TYPE_CONTEXTS = 3
+int av1_get_comp_reference_type_context(const MACROBLOCKD *xd) {
int pred_context;
const MB_MODE_INFO *const above_mbmi = xd->above_mbmi;
const MB_MODE_INFO *const left_mbmi = xd->left_mbmi;
const int above_in_image = xd->up_available;
const int left_in_image = xd->left_available;
- (void)cm;
-
if (above_in_image && left_in_image) { // both edges available
const int above_intra = !is_inter_block(above_mbmi);
const int left_intra = !is_inter_block(left_mbmi);
@@ -388,197 +390,165 @@
}
// Returns a context number for the given MB prediction signal
-// Signal the uni-directional compound reference frame pair as
-// either (BWDREF, ALTREF), or (LAST, LAST2)/(LAST, GOLDEN),
+//
+// Signal the uni-directional compound reference frame pair as either
+// (BWDREF, ALTREF), or (LAST, LAST2) / (LAST, LAST3) / (LAST, GOLDEN),
// conditioning on the pair is known as uni-directional.
-int av1_get_pred_context_uni_comp_ref_p(const AV1_COMMON *cm,
- const MACROBLOCKD *xd) {
+//
+// 3 contexts: Voting is used to compare the count of forward references with
+// that of backward references from the spatial neighbors.
+int av1_get_pred_context_uni_comp_ref_p(const MACROBLOCKD *xd) {
int pred_context;
const MB_MODE_INFO *const above_mbmi = xd->above_mbmi;
const MB_MODE_INFO *const left_mbmi = xd->left_mbmi;
const int above_in_image = xd->up_available;
const int left_in_image = xd->left_available;
- (void)cm;
+ // Count of forward references (L, L2, L3, or G)
+ int frf_count = 0;
+ // Count of backward references (B or A)
+ int brf_count = 0;
- if (above_in_image && left_in_image) { // both edges available
- const int above_intra = !is_inter_block(above_mbmi);
- const int left_intra = !is_inter_block(left_mbmi);
-
- if (above_intra && left_intra) { // intra/intra
- pred_context = 2;
- } else if (above_intra || left_intra) { // intra/inter
- const MB_MODE_INFO *inter_mbmi = above_intra ? left_mbmi : above_mbmi;
-
- if (!has_second_ref(inter_mbmi)) { // single pred
- pred_context =
- 1 + 2 * (!CHECK_BWDREF_OR_ALTREF(inter_mbmi->ref_frame[0]));
- } else { // comp pred
- if (has_uni_comp_refs(inter_mbmi)) // comp unidir
- pred_context = 4 * (inter_mbmi->ref_frame[0] != BWDREF_FRAME);
- else // comp_bidir
- pred_context = 2;
- }
- } else { // inter/inter
- const int a_sg = !has_second_ref(above_mbmi);
- const int l_sg = !has_second_ref(left_mbmi);
- const MV_REFERENCE_FRAME frfa = above_mbmi->ref_frame[0];
- const MV_REFERENCE_FRAME frfl = left_mbmi->ref_frame[0];
-
- if (CHECK_BWDREF_OR_ALTREF(frfa) && CHECK_BWDREF_OR_ALTREF(frfl)) {
- pred_context = 0;
- } else if (a_sg && l_sg) { // single/single
- pred_context = 2 + (!CHECK_BWDREF_OR_ALTREF(frfa) &&
- !CHECK_BWDREF_OR_ALTREF(frfl));
- } else if (l_sg || a_sg) { // single/comp
- const MV_REFERENCE_FRAME frfc = a_sg ? frfl : frfa;
- const MV_REFERENCE_FRAME rfs = a_sg ? frfa : frfl;
- const int uni_rfc =
- a_sg ? has_uni_comp_refs(left_mbmi) : has_uni_comp_refs(above_mbmi);
-
- if (uni_rfc && (frfc == BWDREF_FRAME))
- pred_context = 1;
- else if (uni_rfc && (frfc == LAST_FRAME))
- pred_context = 3 + (!CHECK_BWDREF_OR_ALTREF(rfs));
- else if (CHECK_BWDREF_OR_ALTREF(rfs))
- pred_context = 2;
- else
- pred_context = 3;
- } else { // comp/comp
- const int a_uni_rfc = has_uni_comp_refs(above_mbmi);
- const int l_uni_rfc = has_uni_comp_refs(left_mbmi);
-
- if (a_uni_rfc && l_uni_rfc)
- pred_context = 2 + 2 * (frfa != BWDREF_FRAME && frfl != BWDREF_FRAME);
- else if (a_uni_rfc || l_uni_rfc)
- pred_context = 1 + 2 * (frfa != BWDREF_FRAME && frfl != BWDREF_FRAME);
- else
- pred_context = 2;
- }
+ if (above_in_image && is_inter_block(above_mbmi)) {
+ if (above_mbmi->ref_frame[0] <= GOLDEN_FRAME)
+ ++frf_count;
+ else
+ ++brf_count;
+ if (has_second_ref(above_mbmi)) {
+ if (above_mbmi->ref_frame[1] <= GOLDEN_FRAME)
+ ++frf_count;
+ else
+ ++brf_count;
}
- } else if (above_in_image || left_in_image) { // one edge available
- const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;
-
- if (!is_inter_block(edge_mbmi)) { // intra
- pred_context = 2;
- } else { // inter
- if (!has_second_ref(edge_mbmi)) { // single pred
- pred_context =
- 1 + 2 * (!CHECK_BWDREF_OR_ALTREF(edge_mbmi->ref_frame[0]));
- } else { // comp pred
- if (has_uni_comp_refs(edge_mbmi)) // comp unidir
- pred_context = 4 * (edge_mbmi->ref_frame[0] != BWDREF_FRAME);
- else // comp bidir
- pred_context = 2;
- }
- }
- } else { // no edges available
- pred_context = 2;
}
+ if (left_in_image && is_inter_block(left_mbmi)) {
+ if (left_mbmi->ref_frame[0] <= GOLDEN_FRAME)
+ ++frf_count;
+ else
+ ++brf_count;
+ if (has_second_ref(left_mbmi)) {
+ if (left_mbmi->ref_frame[1] <= GOLDEN_FRAME)
+ ++frf_count;
+ else
+ ++brf_count;
+ }
+ }
+
+ pred_context =
+ (frf_count == brf_count) ? 1 : ((frf_count < brf_count) ? 0 : 2);
+
assert(pred_context >= 0 && pred_context < UNI_COMP_REF_CONTEXTS);
return pred_context;
}
// Returns a context number for the given MB prediction signal
+//
// Signal the uni-directional compound reference frame pair as
-// either (BWDREF, ALTREF), or (LAST, LAST2)/(LAST, GOLDEN),
-// conditioning on the pair is known as uni-directional.
-#define CHECK_LAST2_OR_GOLDEN(ref_frame) \
- ((ref_frame) == LAST2_FRAME || (ref_frame) == GOLDEN_FRAME)
-int av1_get_pred_context_uni_comp_ref_p1(const AV1_COMMON *cm,
- const MACROBLOCKD *xd) {
+// either (LAST, LAST2), or (LAST, LAST3) / (LAST, GOLDEN),
+// conditioning on the pair is known as one of the above three.
+//
+// 3 contexts: Voting is used to compare the count of LAST2_FRAME with the
+// total count of LAST3/GOLDEN from the spatial neighbors.
+int av1_get_pred_context_uni_comp_ref_p1(const MACROBLOCKD *xd) {
int pred_context;
const MB_MODE_INFO *const above_mbmi = xd->above_mbmi;
const MB_MODE_INFO *const left_mbmi = xd->left_mbmi;
const int above_in_image = xd->up_available;
const int left_in_image = xd->left_available;
- (void)cm;
+ // Count of LAST2
+ int last2_count = 0;
+ // Count of LAST3 or GOLDEN
+ int last3_or_gld_count = 0;
- if (above_in_image && left_in_image) { // both edges available
- const int above_intra = !is_inter_block(above_mbmi);
- const int left_intra = !is_inter_block(left_mbmi);
-
- if (above_intra && left_intra) { // intra/intra
- pred_context = 2;
- } else if (above_intra || left_intra) { // intra/inter
- const MB_MODE_INFO *inter_mbmi = above_intra ? left_mbmi : above_mbmi;
-
- if (!has_second_ref(inter_mbmi)) { // single pred
- if (CHECK_LAST2_OR_GOLDEN(inter_mbmi->ref_frame[0]))
- pred_context = 1 + 2 * (inter_mbmi->ref_frame[0] == LAST2_FRAME);
- else
- pred_context = 2;
- } else { // comp pred
- if (CHECK_LAST2_OR_GOLDEN(inter_mbmi->ref_frame[1]))
- pred_context = 4 * (inter_mbmi->ref_frame[1] == LAST2_FRAME);
- else
- pred_context = 2;
- }
- } else { // inter/inter
- const int a_sg = !has_second_ref(above_mbmi);
- const int l_sg = !has_second_ref(left_mbmi);
- const MV_REFERENCE_FRAME frfa = above_mbmi->ref_frame[0];
- const MV_REFERENCE_FRAME frfl = left_mbmi->ref_frame[0];
- const MV_REFERENCE_FRAME brfa = above_mbmi->ref_frame[1];
- const MV_REFERENCE_FRAME brfl = left_mbmi->ref_frame[1];
-
- if (a_sg && l_sg) { // single/single
- if (CHECK_LAST2_OR_GOLDEN(frfa) && (frfa == frfl || frfl == LAST_FRAME))
- pred_context = 1 + 2 * (frfa == LAST2_FRAME);
- else if (frfa == LAST_FRAME && CHECK_LAST2_OR_GOLDEN(frfl))
- pred_context = 1 + 2 * (frfl == LAST2_FRAME);
- else
- pred_context = 2;
- } else if (l_sg || a_sg) { // single/comp
- const MV_REFERENCE_FRAME brfc = a_sg ? brfl : brfa;
-
- if (CHECK_LAST2_OR_GOLDEN(brfc))
- pred_context = 4 * (brfc == LAST2_FRAME);
- if (CHECK_LAST2_OR_GOLDEN(frfa) && (frfa == frfl || frfl == LAST_FRAME))
- pred_context = 1 + 2 * (frfa == LAST2_FRAME);
- else if (frfa == LAST_FRAME && CHECK_LAST2_OR_GOLDEN(frfl))
- pred_context = 1 + 2 * (frfl == LAST2_FRAME);
- else
- pred_context = 2;
- } else { // comp/comp
- if (CHECK_LAST2_OR_GOLDEN(brfa) &&
- (brfa == brfl || !CHECK_LAST2_OR_GOLDEN(brfl)))
- pred_context = 4 * (brfa == LAST2_FRAME);
- else if (!CHECK_LAST2_OR_GOLDEN(brfa) && CHECK_LAST2_OR_GOLDEN(brfl))
- pred_context = 4 * (brfl == LAST2_FRAME);
- else if (CHECK_LAST2_OR_GOLDEN(frfa) &&
- (frfa == frfl || frfl == LAST_FRAME))
- pred_context = 1 + 2 * (frfa == LAST2_FRAME);
- else if (frfa == LAST_FRAME && CHECK_LAST2_OR_GOLDEN(frfl))
- pred_context = 1 + 2 * (frfl == LAST2_FRAME);
- else
- pred_context = 2;
- }
+ if (above_in_image && is_inter_block(above_mbmi)) {
+ last2_count = (above_mbmi->ref_frame[0] == LAST2_FRAME) ? last2_count + 1
+ : last2_count;
+ last3_or_gld_count = CHECK_GOLDEN_OR_LAST3(above_mbmi->ref_frame[0])
+ ? last3_or_gld_count + 1
+ : last3_or_gld_count;
+ if (has_second_ref(above_mbmi)) {
+ last2_count = (above_mbmi->ref_frame[1] == LAST2_FRAME) ? last2_count + 1
+ : last2_count;
+ last3_or_gld_count = CHECK_GOLDEN_OR_LAST3(above_mbmi->ref_frame[1])
+ ? last3_or_gld_count + 1
+ : last3_or_gld_count;
}
- } else if (above_in_image || left_in_image) { // one edge available
- const MB_MODE_INFO *edge_mbmi = above_in_image ? above_mbmi : left_mbmi;
-
- if (!is_inter_block(edge_mbmi)) { // intra
- pred_context = 2;
- } else { // inter
- if (!has_second_ref(edge_mbmi)) { // single pred
- if (CHECK_LAST2_OR_GOLDEN(edge_mbmi->ref_frame[0]))
- pred_context = 1 + 2 * (edge_mbmi->ref_frame[0] == LAST2_FRAME);
- else
- pred_context = 2;
- } else { // comp pred
- if (CHECK_LAST2_OR_GOLDEN(edge_mbmi->ref_frame[1]))
- pred_context = 4 * (edge_mbmi->ref_frame[1] == LAST2_FRAME);
- else
- pred_context = 2;
- }
- }
- } else { // no edges available
- pred_context = 2;
}
+ if (left_in_image && is_inter_block(left_mbmi)) {
+ last2_count = (left_mbmi->ref_frame[0] == LAST2_FRAME) ? last2_count + 1
+ : last2_count;
+ last3_or_gld_count = CHECK_GOLDEN_OR_LAST3(left_mbmi->ref_frame[0])
+ ? last3_or_gld_count + 1
+ : last3_or_gld_count;
+ if (has_second_ref(left_mbmi)) {
+ last2_count = (left_mbmi->ref_frame[1] == LAST2_FRAME) ? last2_count + 1
+ : last2_count;
+ last3_or_gld_count = CHECK_GOLDEN_OR_LAST3(left_mbmi->ref_frame[1])
+ ? last3_or_gld_count + 1
+ : last3_or_gld_count;
+ }
+ }
+
+ pred_context = (last2_count == last3_or_gld_count)
+ ? 1
+ : ((last2_count < last3_or_gld_count) ? 0 : 2);
+
+ assert(pred_context >= 0 && pred_context < UNI_COMP_REF_CONTEXTS);
+ return pred_context;
+}
+
+// Returns a context number for the given MB prediction signal
+//
+// Signal the uni-directional compound reference frame pair as
+// either (LAST, LAST3) or (LAST, GOLDEN),
+// conditioning on the pair is known as one of the above two.
+//
+// 3 contexts: Voting is used to compare the count of LAST3_FRAME with the
+// total count of GOLDEN_FRAME from the spatial neighbors.
+int av1_get_pred_context_uni_comp_ref_p2(const MACROBLOCKD *xd) {
+ int pred_context;
+ const MB_MODE_INFO *const above_mbmi = xd->above_mbmi;
+ const MB_MODE_INFO *const left_mbmi = xd->left_mbmi;
+ const int above_in_image = xd->up_available;
+ const int left_in_image = xd->left_available;
+
+ // Count of LAST3
+ int last3_count = 0;
+ // Count of GOLDEN
+ int gld_count = 0;
+
+ if (above_in_image && is_inter_block(above_mbmi)) {
+ last3_count = (above_mbmi->ref_frame[0] == LAST3_FRAME) ? last3_count + 1
+ : last3_count;
+ gld_count =
+ (above_mbmi->ref_frame[0] == GOLDEN_FRAME) ? gld_count + 1 : gld_count;
+ if (has_second_ref(above_mbmi)) {
+ last3_count = (above_mbmi->ref_frame[1] == LAST3_FRAME) ? last3_count + 1
+ : last3_count;
+ gld_count = (above_mbmi->ref_frame[1] == GOLDEN_FRAME) ? gld_count + 1
+ : gld_count;
+ }
+ }
+
+ if (left_in_image && is_inter_block(left_mbmi)) {
+ last3_count = (left_mbmi->ref_frame[0] == LAST3_FRAME) ? last3_count + 1
+ : last3_count;
+ gld_count =
+ (left_mbmi->ref_frame[0] == GOLDEN_FRAME) ? gld_count + 1 : gld_count;
+ if (has_second_ref(left_mbmi)) {
+ last3_count = (left_mbmi->ref_frame[1] == LAST3_FRAME) ? last3_count + 1
+ : last3_count;
+ gld_count =
+ (left_mbmi->ref_frame[1] == GOLDEN_FRAME) ? gld_count + 1 : gld_count;
+ }
+ }
+
+ pred_context =
+ (last3_count == gld_count) ? 1 : ((last3_count < gld_count) ? 0 : 2);
+
assert(pred_context >= 0 && pred_context < UNI_COMP_REF_CONTEXTS);
return pred_context;
}
@@ -592,9 +562,6 @@
#define CHECK_LAST_OR_LAST2(ref_frame) \
((ref_frame == LAST_FRAME) || (ref_frame == LAST2_FRAME))
-#define CHECK_GOLDEN_OR_LAST3(ref_frame) \
- ((ref_frame == GOLDEN_FRAME) || (ref_frame == LAST3_FRAME))
-
// Returns a context number for the given MB prediction signal
// Signal the first reference frame for a compound mode be either
// GOLDEN/LAST3, or LAST/LAST2.
