Disable use_intra_txb_hash in speed 1, 2

The speed feature use_intra_txb_hash was
non-performing for speed 1 and 2, and hence
the speed feature is disabled for these
two speed levels

STATS_CHANGED

Change-Id: If93f957f0c9baaeb6be820c8b7b5fa38701e25a8
diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index 337a707..482141c 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -467,7 +467,6 @@
     sf->tx_sf.tx_type_search.ml_tx_split_thresh = 4000;
     sf->tx_sf.tx_type_search.prune_2d_txfm_mode = TX_TYPE_PRUNE_2;
     sf->tx_sf.tx_type_search.skip_tx_search = 1;
-    sf->tx_sf.use_intra_txb_hash = 1;
 
     sf->rd_sf.perform_coeff_opt = boosted ? 2 : 3;
     sf->rd_sf.tx_domain_dist_level = boosted ? 1 : 2;
@@ -575,6 +574,7 @@
 
     sf->tx_sf.adaptive_txb_search_level = boosted ? 2 : 3;
     sf->tx_sf.tx_type_search.use_skip_flag_prediction = 2;
+    sf->tx_sf.use_intra_txb_hash = 1;
 
     // TODO(any): Refactor the code related to following winner mode speed
     // features
@@ -1355,6 +1355,13 @@
         (sf->inter_sf.disable_interintra_wedge_var_thresh != UINT_MAX);
   }
 
+  // Enable use_intra_txb_hash in speed 1,2 for intra-only encoding.
+  // TODO(any) This speed feature may be useful for image encoding.
+  // Experiment and enable for image encoding later.
+  if (cpi->oxcf.kf_cfg.key_freq_max == 0 && speed <= 2) {
+    sf->tx_sf.use_intra_txb_hash = 1;
+  }
+
   // sf->part_sf.partition_search_breakout_dist_thr is set assuming max 64x64
   // blocks. Normalise this if the blocks are bigger.
   if (MAX_SB_SIZE_LOG2 > 6) {