Palette: Don't store tokens for pixels outside image boundary.
If part of a block falls outside right and/or bottom image boundary,
then only store tokens for the part of it within the boundary.
Also, consider only the part of the block within the boundary when
calculating the number of colors in the image, deciding the base
colors for palette, RD calculation etc.
The part of color map corresponding to pixels outside the image
boundary is padded with color indices copied from same row/column.
This behavior is similar to how pixels outside the boundary are padded.
For screen_content set, this is improves compression performance by
0.038 overall. One clip, in particular, has a significant gain of 0.8.
Change-Id: I745ca032f313c5041aacc98c03ae4bfc33d840de
diff --git a/av1/encoder/rdopt.c b/av1/encoder/rdopt.c
index b9516be..12e9468 100644
--- a/av1/encoder/rdopt.c
+++ b/av1/encoder/rdopt.c
@@ -2270,6 +2270,30 @@
}
#if CONFIG_PALETTE
+// Extends 'color_map' array from 'orig_width x orig_height' to 'new_width x
+// new_height'. Extra rows and columns are filled in by copying last valid
+// row/column.
+static void extend_palette_color_map(uint8_t *const color_map, int orig_width,
+ int orig_height, int new_width,
+ int new_height) {
+ int j;
+ assert(new_width >= orig_width);
+ assert(new_height >= orig_height);
+ if (new_width == orig_width && new_height == orig_height) return;
+
+ for (j = orig_height - 1; j >= 0; --j) {
+ memmove(color_map + j * new_width, color_map + j * orig_width, orig_width);
+ // Copy last column to extra columns.
+ memset(color_map + j * new_width + orig_width,
+ color_map[j * new_width + orig_width - 1], new_width - orig_width);
+ }
+ // Copy last row to extra rows.
+ for (j = orig_height; j < new_height; ++j) {
+ memcpy(color_map + j * new_width, color_map + (orig_height - 1) * new_width,
+ new_width);
+ }
+}
+
static int rd_pick_palette_intra_sby(const AV1_COMP *const cpi, MACROBLOCK *x,
BLOCK_SIZE bsize, int palette_ctx,
int dc_mode_cost, MB_MODE_INFO *best_mbmi,
@@ -2281,12 +2305,13 @@
MACROBLOCKD *const xd = &x->e_mbd;
MODE_INFO *const mic = xd->mi[0];
MB_MODE_INFO *const mbmi = &mic->mbmi;
- const int rows = block_size_high[bsize];
- const int cols = block_size_wide[bsize];
int this_rate, colors, n;
const int src_stride = x->plane[0].src.stride;
const uint8_t *const src = x->plane[0].src.buf;
uint8_t *const color_map = xd->plane[0].color_index_map;
+ int block_width, block_height, rows, cols;
+ av1_get_block_dimensions(bsize, 0, xd, &block_width, &block_height, &rows,
+ &cols);
assert(cpi->common.allow_screen_content_tools);
@@ -2373,6 +2398,8 @@
pmi->palette_size[0] = k;
av1_calc_indices(data, centroids, color_map, rows * cols, k, 1);
+ extend_palette_color_map(color_map, cols, rows, block_width,
+ block_height);
palette_mode_cost =
dc_mode_cost + cpi->common.bit_depth * k * av1_cost_bit(128, 0) +
cpi->palette_y_size_cost[bsize - BLOCK_8X8][k - 2] +
@@ -2384,7 +2411,7 @@
for (j = (i == 0 ? 1 : 0); j < cols; ++j) {
int color_idx;
const int color_ctx = av1_get_palette_color_context(
- color_map, cols, i, j, k, color_order, &color_idx);
+ color_map, cols, block_width, i, j, k, color_order, &color_idx);
assert(color_idx >= 0 && color_idx < k);
palette_mode_cost +=
cpi->palette_y_color_cost[k - 2][color_ctx][color_idx];
@@ -2405,7 +2432,7 @@
if (this_rd < *best_rd) {
*best_rd = this_rd;
memcpy(best_palette_color_map, color_map,
- rows * cols * sizeof(color_map[0]));
+ block_width * block_height * sizeof(color_map[0]));
*best_mbmi = *mbmi;
rate_overhead = this_rate - tokenonly_rd_stats.rate;
if (rate) *rate = this_rate;
@@ -4339,8 +4366,6 @@
MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
PALETTE_MODE_INFO *const pmi = &mbmi->palette_mode_info;
const BLOCK_SIZE bsize = mbmi->sb_type;
- const int rows = block_size_high[bsize] >> (xd->plane[1].subsampling_y);
- const int cols = block_size_wide[bsize] >> (xd->plane[1].subsampling_x);
int this_rate;
int64_t this_rd;
int colors_u, colors_v, colors;
@@ -4349,7 +4374,9 @@
const uint8_t *const src_v = x->plane[2].src.buf;
uint8_t *const color_map = xd->plane[1].color_index_map;
RD_STATS tokenonly_rd_stats;
-
+ int plane_block_width, plane_block_height, rows, cols;
+ av1_get_block_dimensions(bsize, 1, xd, &plane_block_width,
+ &plane_block_height, &rows, &cols);
if (rows * cols > PALETTE_MAX_BLOCK_SIZE) return;
#if CONFIG_FILTER_INTRA
@@ -4437,6 +4464,8 @@
centroids[i * 2 + 1] = lb_v + (2 * i + 1) * (ub_v - lb_v) / n / 2;
}
av1_k_means(data, centroids, color_map, rows * cols, n, 2, max_itr);
+ extend_palette_color_map(color_map, cols, rows, plane_block_width,
+ plane_block_height);
pmi->palette_size[1] = n;
for (i = 1; i < 3; ++i) {
for (j = 0; j < n; ++j) {
@@ -4464,8 +4493,9 @@
for (i = 0; i < rows; ++i) {
for (j = (i == 0 ? 1 : 0); j < cols; ++j) {
int color_idx;
- const int color_ctx = av1_get_palette_color_context(
- color_map, cols, i, j, n, color_order, &color_idx);
+ const int color_ctx =
+ av1_get_palette_color_context(color_map, cols, plane_block_width,
+ i, j, n, color_order, &color_idx);
assert(color_idx >= 0 && color_idx < n);
this_rate += cpi->palette_uv_color_cost[n - 2][color_ctx][color_idx];
}
@@ -4476,7 +4506,8 @@
*best_rd = this_rd;
*palette_mode_info = *pmi;
memcpy(best_palette_color_map, color_map,
- rows * cols * sizeof(best_palette_color_map[0]));
+ plane_block_width * plane_block_height *
+ sizeof(best_palette_color_map[0]));
*mode_selected = DC_PRED;
*rate = this_rate;
*distortion = tokenonly_rd_stats.dist;
@@ -9039,8 +9070,6 @@
MB_MODE_INFO *const mbmi = &xd->mi[0]->mbmi;
PALETTE_MODE_INFO *const pmi = &mbmi->palette_mode_info;
const BLOCK_SIZE bsize = mbmi->sb_type;
- const int rows = block_size_high[bsize] >> (xd->plane[1].subsampling_y);
- const int cols = block_size_wide[bsize] >> (xd->plane[1].subsampling_x);
int src_stride = x->plane[1].src.stride;
const uint8_t *const src_u = x->plane[1].src.buf;
const uint8_t *const src_v = x->plane[2].src.buf;
@@ -9052,6 +9081,9 @@
const uint16_t *const src_u16 = CONVERT_TO_SHORTPTR(src_u);
const uint16_t *const src_v16 = CONVERT_TO_SHORTPTR(src_v);
#endif // CONFIG_AOM_HIGHBITDEPTH
+ int plane_block_width, plane_block_height, rows, cols;
+ av1_get_block_dimensions(bsize, 1, xd, &plane_block_width,
+ &plane_block_height, &rows, &cols);
(void)cpi;
for (r = 0; r < rows; ++r) {
@@ -9078,6 +9110,8 @@
av1_calc_indices(data, centroids, color_map, rows * cols,
pmi->palette_size[1], 2);
+ extend_palette_color_map(color_map, cols, rows, plane_block_width,
+ plane_block_height);
}
#endif // CONFIG_PALETTE
