rtc: Allow for split to 8x8 blocks for speed >=9 low-resoln
For sf.prefer_large_partition_blocks >= 3 (speed >= 9) and
low-resolutions: split to 8x8 is disallowed. This can
cause visual quality artifacts near moving boundary, as
seen in, for example, desktopqvga_320_240.y4m.
This patch allows for split to 8x8 for some superblocks,
depending on sb source_sad content metrics. The content
metrics are selected try to target superblocks with motion,
but excluding very high motion or lighting changes, etc.
This is a simplified
version of https://aomedia-review.googlesource.com/c/aom/+/162007,
which was reverted due to 4x4 avg function.
This significantly reduces artifact in desktopqvga,
overall small bdrate change, and small speed loss.
Stats changed for speed 9/10 rtc_derf.
avg_psnr/ovr_psnr/ssim, IC speedup
speed 9: -0.15/-0.17/-0.17, -1.2
speed 10: -0.09/-0.10/-0.15, -1.1
Change-Id: I80908c2d281f3e411a920c2095c4758a9dd810e3
diff --git a/av1/encoder/var_based_part.c b/av1/encoder/var_based_part.c
index 3498116..fe050cf 100644
--- a/av1/encoder/var_based_part.c
+++ b/av1/encoder/var_based_part.c
@@ -449,7 +449,9 @@
static AOM_INLINE void set_vbp_thresholds(AV1_COMP *cpi, int64_t thresholds[],
int q, int content_lowsumdiff,
int source_sad_nonrd,
- int source_sad_rd, int segment_id) {
+ int source_sad_rd, int segment_id,
+ uint64_t blk_sad,
+ int lighting_change) {
AV1_COMMON *const cm = &cpi->common;
const int is_key_frame = frame_is_intra_only(cm);
const int threshold_multiplier = is_key_frame ? 120 : 1;
@@ -593,6 +595,15 @@
thresholds[1] <<= 1;
thresholds[2] <<= 3;
}
+ // Allow for split to 8x8 for superblocks where part of it has
+ // moving boudary. So allow for sb with source_sad above threshold,
+ // and avoid very large source_sad or high source content, to avoid
+ // too many 8x8 within superblock.
+ if (segment_id == 0 && cpi->rc.avg_source_sad < 25000 &&
+ blk_sad > 25000 && blk_sad < 50000 && !lighting_change) {
+ thresholds[2] = (3 * thresholds[2]) >> 2;
+ thresholds[3] = thresholds[2] << 3;
+ }
// Condition the increase of partition thresholds on the segment
// and the content. Avoid the increase for superblocks which have
// high source sad, unless the whole frame has very high motion
@@ -916,7 +927,7 @@
return;
} else {
set_vbp_thresholds(cpi, cpi->vbp_info.thresholds, q, content_lowsumdiff, 0,
- 0, 0);
+ 0, 0, 0, 0);
// The threshold below is not changed locally.
cpi->vbp_info.threshold_minmax = 15 + (q >> 3);
}
@@ -1279,6 +1290,17 @@
const int low_res = (cm->width <= 352 && cm->height <= 288);
int variance4x4downsample[64];
const int segment_id = xd->mi[0]->segment_id;
+ uint64_t blk_sad = 0;
+ if (cpi->src_sad_blk_64x64 != NULL) {
+ const int sb_size_by_mb = (cm->seq_params->sb_size == BLOCK_128X128)
+ ? (cm->seq_params->mib_size >> 1)
+ : cm->seq_params->mib_size;
+ const int sb_cols =
+ (cm->mi_params.mi_cols + sb_size_by_mb - 1) / sb_size_by_mb;
+ const int sbi_col = mi_col / sb_size_by_mb;
+ const int sbi_row = mi_row / sb_size_by_mb;
+ blk_sad = cpi->src_sad_blk_64x64[sbi_col + sbi_row * sb_cols];
+ }
if (cpi->oxcf.q_cfg.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled &&
cyclic_refresh_segment_id_boosted(segment_id)) {
@@ -1286,12 +1308,14 @@
av1_get_qindex(&cm->seg, segment_id, cm->quant_params.base_qindex);
set_vbp_thresholds(cpi, thresholds, q, x->content_state_sb.low_sumdiff,
x->content_state_sb.source_sad_nonrd,
- x->content_state_sb.source_sad_rd, 1);
+ x->content_state_sb.source_sad_rd, 1, blk_sad,
+ x->content_state_sb.lighting_change);
} else {
set_vbp_thresholds(cpi, thresholds, cm->quant_params.base_qindex,
x->content_state_sb.low_sumdiff,
x->content_state_sb.source_sad_nonrd,
- x->content_state_sb.source_sad_rd, 0);
+ x->content_state_sb.source_sad_rd, 0, blk_sad,
+ x->content_state_sb.lighting_change);
}
// For non keyframes, disable 4x4 average for low resolution when speed = 8
