Change the eval order of luma palette_size
The order of luma palette_size evaluation in
av1_rd_pick_palette_intra_sby() for sf
prune_palette_search_level=2 is changed from descending
followed by ascending order to ascending followed by
descending order in order to facilitate early exit based
on palette header rdcost.
This change is verified to be bit-exact for speed < 3 in good
and allintra encoding modes.
For allintra video encode (on screen content set),
Instruction Count BD-Rate Loss(%)
cpu-used Reduction(%) avg.psnr ovr.psnr ssim
3 -0.040 -0.1802 -0.1811 -0.7997
4 -0.055 -0.2912 -0.2835 -1.0394
5 0.023 -0.3423 -0.3413 -1.0311
6 -0.157 -0.3567 -0.3550 -0.7304
For good video encode (on screen content set),
Instruction Count BD-Rate Loss(%)
cpu-used Reduction(%) avg.psnr ovr.psnr ssim
3 -1.034 -0.5324 -0.5500 -0.8091
4 0.051 -0.1340 -0.1007 -0.1401
5 -0.046 0.0997 0.0828 0.1359
6 -0.252 0.0895 0.0500 -0.1844
For AVIF still image encode,
Instruction Count BD-Rate Loss(%)
cpu-used Reduction(%) psnr ssim
3 -0.004 -0.0030 -0.0116
4 0.004 -0.0030 -0.0055
5 -0.002 -0.0049 -0.0085
6 -0.007 -0.0061 -0.0173
BUG=aomedia:3096
STATS_CHANGED
Change-Id: Ia26c826bc27d7ebf907f4e3c7512526e88b744af
diff --git a/av1/encoder/palette.c b/av1/encoder/palette.c
index 1b0bf62..af8a255 100644
--- a/av1/encoder/palette.c
+++ b/av1/encoder/palette.c
@@ -632,20 +632,19 @@
} else {
const int max_n = AOMMIN(colors, PALETTE_MAX_SIZE),
min_n = PALETTE_MIN_SIZE;
- // Perform top color palette search in descending order
- int last_n_searched = max_n;
+ // Perform top color palette search in ascending order
+ int last_n_searched = min_n;
perform_top_color_palette_search(
- cpi, x, mbmi, bsize, dc_mode_cost, data, top_colors, max_n, min_n - 1,
- -1, /*do_header_rd_based_gating=*/false, &last_n_searched,
- color_cache, n_cache, best_mbmi, best_palette_color_map, best_rd,
- rate, rate_tokenonly, distortion, skippable, beat_best_rd, ctx,
+ cpi, x, mbmi, bsize, dc_mode_cost, data, top_colors, min_n, max_n + 1,
+ 1, /*do_header_rd_based_gating=*/false, &last_n_searched, color_cache,
+ n_cache, best_mbmi, best_palette_color_map, best_rd, rate,
+ rate_tokenonly, distortion, skippable, beat_best_rd, ctx,
best_blk_skip, tx_type_map);
-
- if (last_n_searched > min_n) {
- // Search in ascending order until we get to the previous best
+ if (last_n_searched < max_n) {
+ // Search in descending order until we get to the previous best
perform_top_color_palette_search(
- cpi, x, mbmi, bsize, dc_mode_cost, data, top_colors, min_n,
- last_n_searched, 1, /*do_header_rd_based_gating=*/false, &unused,
+ cpi, x, mbmi, bsize, dc_mode_cost, data, top_colors, max_n,
+ last_n_searched, -1, /*do_header_rd_based_gating=*/false, &unused,
color_cache, n_cache, best_mbmi, best_palette_color_map, best_rd,
rate, rate_tokenonly, distortion, skippable, beat_best_rd, ctx,
best_blk_skip, tx_type_map);
@@ -662,20 +661,20 @@
rate_tokenonly, distortion, skippable, beat_best_rd, ctx,
best_blk_skip, tx_type_map, NULL, NULL);
} else {
- // Perform k-means palette search in descending order
- last_n_searched = max_n;
+ // Perform k-means palette search in ascending order
+ last_n_searched = min_n;
perform_k_means_palette_search(
cpi, x, mbmi, bsize, dc_mode_cost, data, lower_bound, upper_bound,
- max_n, min_n - 1, -1, /*do_header_rd_based_gating=*/false,
+ min_n, max_n + 1, 1, /*do_header_rd_based_gating=*/false,
&last_n_searched, color_cache, n_cache, best_mbmi,
best_palette_color_map, best_rd, rate, rate_tokenonly, distortion,
skippable, beat_best_rd, ctx, best_blk_skip, tx_type_map, color_map,
rows * cols);
- if (last_n_searched > min_n) {
- // Search in ascending order until we get to the previous best
+ if (last_n_searched < max_n) {
+ // Search in descending order until we get to the previous best
perform_k_means_palette_search(
cpi, x, mbmi, bsize, dc_mode_cost, data, lower_bound, upper_bound,
- min_n, last_n_searched, 1, /*do_header_rd_based_gating=*/false,
+ max_n, last_n_searched, -1, /*do_header_rd_based_gating=*/false,
&unused, color_cache, n_cache, best_mbmi, best_palette_color_map,
best_rd, rate, rate_tokenonly, distortion, skippable,
beat_best_rd, ctx, best_blk_skip, tx_type_map, color_map,
