Merge "Skip the partition search for the frame with no motion"

vp9/encoder/vp9_encodeframe.c

@@ -2256,7 +2256,8 @@ static void encode_rd_sb_row(VP9_COMP *cpi, const TileInfo *const tile,
                                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);

vp9/encoder/vp9_encoder.c

@@ -740,6 +740,8 @@ VP9_COMP *vp9_create_compressor(VP9EncoderConfig *oxcf) {
   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));
@@ -1967,6 +1969,29 @@ YV12_BUFFER_CONFIG *vp9_scale_if_required(VP9_COMMON *cm,
   }
 }
 
+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,
@@ -2062,6 +2087,13 @@ static void encode_frame_to_data_rate(VP9_COMP *cpi,
   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 &&

vp9/encoder/vp9_encoder.h

@@ -262,6 +262,8 @@ typedef struct VP9_COMP {
   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;