Skip the partition search for the frame with no motion
This patch allows the encoder to skip the partition search for the
frame if it is an inter frame and only zero motion vectors have
been detected in the first pass. The partition size is directly
assigned according to the difference variance.
Borg tests show overall little performance changes in term of PSNR
(derf -0.027%, yt 0.152%, hd 0.078%, stdhd 0%). The worst case of
PSNR loss is -0.514% from yt. The best PSNR gain is 4.293% from yt.
The second pass encoding speedup for slideshow clips is 15%-40%.
Change-Id: I881f347d286553ee5594a9ea09ba1a61ac684045
diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index dcd0be6..e64d402 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -2309,7 +2309,8 @@
sf->always_this_block_size);
rd_use_partition(cpi, tile, mi, tp, mi_row, mi_col, BLOCK_64X64,
&dummy_rate, &dummy_dist, 1, cpi->pc_root);
- } else if (sf->partition_search_type == VAR_BASED_FIXED_PARTITION) {
+ } else if (cpi->skippable_frame ||
+ sf->partition_search_type == VAR_BASED_FIXED_PARTITION) {
BLOCK_SIZE bsize;
set_offsets(cpi, tile, mi_row, mi_col, BLOCK_64X64);
bsize = get_rd_var_based_fixed_partition(cpi, mi_row, mi_col);
diff --git a/vp9/encoder/vp9_encoder.c b/vp9/encoder/vp9_encoder.c
index bc240ff..571ad0c 100644
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -743,6 +743,8 @@
cpi->alt_is_last = 0;
cpi->gold_is_alt = 0;
+ cpi->skippable_frame = 0;
+
// Create the encoder segmentation map and set all entries to 0
CHECK_MEM_ERROR(cm, cpi->segmentation_map,
vpx_calloc(cm->mi_rows * cm->mi_cols, 1));
@@ -1972,6 +1974,29 @@
}
}
+static void configure_skippable_frame(VP9_COMP *cpi) {
+ // If the current frame does not have non-zero motion vector detected in the
+ // first pass, and so do its previous and forward frames, then this frame
+ // can be skipped for partition check, and the partition size is assigned
+ // according to the variance
+
+ SVC *const svc = &cpi->svc;
+ const int is_spatial_svc = (svc->number_spatial_layers > 1) &&
+ (svc->number_temporal_layers == 1);
+ TWO_PASS *const twopass = is_spatial_svc ?
+ &svc->layer_context[svc->spatial_layer_id].twopass
+ : &cpi->twopass;
+
+ cpi->skippable_frame = (!frame_is_intra_only(&cpi->common) &&
+ twopass->stats_in - 2 > twopass->stats_in_start &&
+ twopass->stats_in < twopass->stats_in_end &&
+ (twopass->stats_in - 1)->pcnt_inter - (twopass->stats_in - 1)->pcnt_motion
+ == 1 &&
+ (twopass->stats_in - 2)->pcnt_inter - (twopass->stats_in - 2)->pcnt_motion
+ == 1 &&
+ twopass->stats_in->pcnt_inter - twopass->stats_in->pcnt_motion == 1);
+}
+
static void encode_frame_to_data_rate(VP9_COMP *cpi,
size_t *size,
uint8_t *dest,
@@ -2067,6 +2092,13 @@
if (cpi->pass == 2 && cpi->sf.static_segmentation)
configure_static_seg_features(cpi);
+ // Check if the current frame is skippable for the partition search in the
+ // second pass according to the first pass stats
+ if (cpi->pass == 2 &&
+ (!cpi->use_svc || cpi->svc.number_temporal_layers == 1)) {
+ configure_skippable_frame(cpi);
+ }
+
// For 1 pass CBR, check if we are dropping this frame.
// Never drop on key frame.
if (cpi->pass == 0 &&
diff --git a/vp9/encoder/vp9_encoder.h b/vp9/encoder/vp9_encoder.h
index a80ab1b..a5b465a 100644
--- a/vp9/encoder/vp9_encoder.h
+++ b/vp9/encoder/vp9_encoder.h
@@ -266,6 +266,8 @@
int alt_is_last; // Alt same as last ( short circuit altref search)
int gold_is_alt; // don't do both alt and gold search ( just do gold).
+ int skippable_frame;
+
int scaled_ref_idx[3];
int lst_fb_idx;
int gld_fb_idx;
