Allintra: Introduce sf prune_h_pred_using_best_mode_so_far
This CL introduces a speed feature
prune_h_pred_using_best_mode_so_far to prune H_PRED mode if
V_PRED is the best mode so far. This speed feature is enabled
for allintra, speed 9.
For AVIF still-image encode,
Encode Time BD-Rate Loss(%)
cpu-used Reduction(%) psnr ssim
9 1.034 0.0834 0.0691
STATS_CHANGED
Change-Id: I3a108379b57ce294268549ebaca3abcda3cb7c95
diff --git a/av1/encoder/nonrd_pickmode.c b/av1/encoder/nonrd_pickmode.c
index 95dba0f..c44aef2 100644
--- a/av1/encoder/nonrd_pickmode.c
+++ b/av1/encoder/nonrd_pickmode.c
@@ -2005,6 +2005,17 @@
// mode tests.
for (int i = 0; i < 4; ++i) {
PREDICTION_MODE this_mode = intra_mode_list[i];
+
+ // As per the statistics generated for intra mode evaluation in the nonrd
+ // path, it is found that the probability of H_PRED mode being the winner is
+ // very less when the best mode so far is V_PRED (out of DC_PRED and
+ // V_PRED). If V_PRED is the winner mode out of DC_PRED and V_PRED, it could
+ // imply the presence of a vertically dominant pattern. Hence, H_PRED mode
+ // is not evaluated.
+ if (cpi->sf.rt_sf.prune_h_pred_using_best_mode_so_far &&
+ this_mode == H_PRED && best_mode == V_PRED)
+ continue;
+
this_rdc.dist = this_rdc.rate = 0;
args.mode = this_mode;
args.skippable = 1;
diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index 9a5e684..0ea12eb 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -554,6 +554,7 @@
sf->rt_sf.hybrid_intra_pickmode = 0;
sf->rt_sf.var_part_split_threshold_shift = 9;
sf->rt_sf.vbp_prune_16x16_split_using_min_max_sub_blk_var = true;
+ sf->rt_sf.prune_h_pred_using_best_mode_so_far = true;
}
// As the speed feature prune_chroma_modes_using_luma_winner already
@@ -2050,6 +2051,7 @@
rt_sf->vbp_prune_16x16_split_using_min_max_sub_blk_var = false;
rt_sf->prune_compoundmode_with_singlecompound_var = false;
rt_sf->frame_level_mode_cost_update = false;
+ rt_sf->prune_h_pred_using_best_mode_so_far = false;
rt_sf->check_only_zero_zeromv_on_large_blocks = false;
rt_sf->disable_cdf_update_non_reference_frame = false;
rt_sf->prune_compoundmode_with_singlemode_var = false;
diff --git a/av1/encoder/speed_features.h b/av1/encoder/speed_features.h
index 62d248a..d53d4cf 100644
--- a/av1/encoder/speed_features.h
+++ b/av1/encoder/speed_features.h
@@ -1588,6 +1588,16 @@
// except on key frame and first delta).
bool frame_level_mode_cost_update;
+ // Prune H_PRED during intra mode evaluation in the nonrd path based on best
+ // mode so far.
+ //
+ // For allintra encode, this speed feature reduces instruction count by 1.10%
+ // for speed 9 with coding performance change less than 0.04%.
+ // For AVIF image encode, this speed feature reduces encode time by 1.03% for
+ // speed 9 on a typical image dataset with coding performance change less than
+ // 0.08%.
+ bool prune_h_pred_using_best_mode_so_far;
+
// If compound is enabled, and the current block size is \geq BLOCK_16X16,
// limit the compound modes to GLOBAL_GLOBALMV. This does not apply to the
// base layer of svc.
