vp9-rtc: Add intra speed feature for speed >= 8

Add intra speed feature to force DC only under intra mode
testing when source sad for superblock is not high.
Feature is only enable at speed >=8. With this feature
enabled at speed 8 we now allow for H/V intra check as
well for speed 8.

This helps to redude artifacts for speed 8, by allowing H/V mode
to be checked for blocks when the superblock has high
source sad/content change.

Change-Id: I0495ce96b4cc844e8c625b5183eef180dbaaaa72

3 files changed, 16 insertions, 6 deletions

diff --git a/vp9/encoder/vp9_pickmode.c b/vp9/encoder/vp9_pickmode.c
index 513b9f678..cfcf4f7af 100644
--- a/vp9/encoder/vp9_pickmode.c
+++ b/vp9/encoder/vp9_pickmode.c
@@ -2554,6 +2554,10 @@ void vp9_pick_inter_mode(VP9_COMP *cpi, MACROBLOCK *x, TileDataEnc *tile_data,
       if (!((1 << this_mode) & cpi->sf.intra_y_mode_bsize_mask[bsize]))
         continue;
 
+      if (cpi->sf.rt_intra_dc_only_low_content && this_mode != DC_PRED &&
+          x->content_state_sb != kVeryHighSad)
+        continue;
+
       if ((cpi->sf.adaptive_rd_thresh_row_mt &&
            rd_less_than_thresh_row_mt(best_rdc.rdcost, mode_rd_thresh,
                                       &rd_thresh_freq_fact[mode_index])) ||
diff --git a/vp9/encoder/vp9_speed_features.c b/vp9/encoder/vp9_speed_features.c
index 529dca040..cccafd85c 100644
--- a/vp9/encoder/vp9_speed_features.c
+++ b/vp9/encoder/vp9_speed_features.c
@@ -456,6 +456,7 @@ static void set_rt_speed_feature_framesize_independent(
   sf->variance_part_thresh_mult = 1;
   sf->cb_pred_filter_search = 0;
   sf->force_smooth_interpol = 0;
+  sf->rt_intra_dc_only_low_content = 0;
 
   if (speed >= 1) {
     sf->allow_txfm_domain_distortion = 1;
@@ -740,12 +741,7 @@ static void set_rt_speed_feature_framesize_independent(
       sf->nonrd_use_ml_partition = 0;
 #endif
     if (content == VP9E_CONTENT_SCREEN) sf->mv.subpel_force_stop = HALF_PEL;
-    // Only keep INTRA_DC mode for speed 8.
-    if (!is_keyframe) {
-      int i = 0;
-      for (i = 0; i < BLOCK_SIZES; ++i)
-        sf->intra_y_mode_bsize_mask[i] = INTRA_DC;
-    }
+    sf->rt_intra_dc_only_low_content = 1;
     if (!cpi->use_svc && cpi->oxcf.rc_mode == VPX_CBR &&
         content != VP9E_CONTENT_SCREEN) {
       // More aggressive short circuit for speed 8.
@@ -771,6 +767,12 @@ static void set_rt_speed_feature_framesize_independent(
   }
 
   if (speed >= 9) {
+    // Only keep INTRA_DC mode for speed 9.
+    if (!is_keyframe) {
+      int i = 0;
+      for (i = 0; i < BLOCK_SIZES; ++i)
+        sf->intra_y_mode_bsize_mask[i] = INTRA_DC;
+    }
     sf->cb_pred_filter_search = 1;
     sf->mv.enable_adaptive_subpel_force_stop = 1;
     sf->mv.adapt_subpel_force_stop.mv_thresh = 1;
diff --git a/vp9/encoder/vp9_speed_features.h b/vp9/encoder/vp9_speed_features.h
index eb0628199..ca284ded8 100644
--- a/vp9/encoder/vp9_speed_features.h
+++ b/vp9/encoder/vp9_speed_features.h
@@ -608,6 +608,10 @@ typedef struct SPEED_FEATURES {
 
   // Force subpel motion filter to always use SMOOTH_FILTER.
   int force_smooth_interpol;
+
+  // For real-time mode: force DC only under intra search when content
+  // does not have high souce SAD.
+  int rt_intra_dc_only_low_content;
 } SPEED_FEATURES;
 
 struct VP9_COMP;