Support two pass block partition search

Add square block partition to serve as the first pass partition
search.

Change-Id: Ib637bba205d2cd0f6b0a5e2e91b270e22dce5580

av1/decoder/decodeframe.c

@@ -565,7 +565,6 @@ static void decode_block(AV1Decoder *const pbi, MACROBLOCKD *const xd,
                     partition,
 #endif
                     bsize);
-
   decode_token_and_recon_block(pbi, xd, mi_row, mi_col, r, bsize);
 }
 

av1/encoder/speed_features.c

@@ -147,6 +147,7 @@ static void set_good_speed_features_framesize_independent(AV1_COMP *cpi,
     sf->selective_ref_frame = 1;
     sf->tx_size_search_init_depth_rect = 1;
     sf->tx_size_search_init_depth_sqr = 1;
+    sf->two_pass_partition_search = 1;
 #if CONFIG_EXT_PARTITION_TYPES
     sf->prune_ext_partition_types_search = 1;
 #endif  // CONFIG_EXT_PARTITION_TYPES
@@ -495,6 +496,7 @@ void av1_set_speed_features_framesize_independent(AV1_COMP *cpi) {
   sf->drop_ref = 0;
   sf->skip_intra_in_interframe = 1;
   sf->txb_split_cap = 1;
+  sf->two_pass_partition_search = 0;
 
   for (i = 0; i < TX_SIZES; i++) {
     sf->intra_y_mode_mask[i] = INTRA_ALL;

av1/encoder/speed_features.h

@@ -368,6 +368,9 @@ typedef struct SPEED_FEATURES {
 
   int fast_cdef_search;
 
+  // 2-pass coding block partition search
+  int two_pass_partition_search;
+
   // Skip rectangular partition test when partition type none gives better
   // rd than partition type split.
   int less_rectangular_check;