shithub: libvpx

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vp9 screen-content: Adjustments for screen content.

Increase search area, use NSTEP, and in some cases avoid
bsize below 16x16. This for base spatial layer when many blocks
in the frame have motion (from scene detection analysis).

Improves quality for scrolling motion.

Change-Id: If77b43e738a6c43610d4727a95712667088db564

--- a/vp9/encoder/vp9_encodeframe.c

+++ b/vp9/encoder/vp9_encodeframe.c

@@ -1378,6 +1378,20 @@

       x->sb_use_mv_part = 1;

       x->sb_mvcol_part = mi->mv[0].as_mv.col;

       x->sb_mvrow_part = mi->mv[0].as_mv.row;

+      if (cpi->oxcf.content == VP9E_CONTENT_SCREEN &&

+          cpi->svc.spatial_layer_id == 0 &&

+          cpi->rc.high_num_blocks_with_motion && !x->zero_temp_sad_source &&

+          cm->width >= 1280 && cm->height >= 720) {

+        // Disable split below 16x16 block size when scroll motion is detected.

+        // TODO(marpan/jianj): Improve this condition: issue is that search

+        // range is hard-coded/limited in vp9_int_pro_motion_estimation() so

+        // scroll motion may not be detected here.

+        if ((abs(x->sb_mvrow_part) >= 48 && abs(x->sb_mvcol_part) <= 8) ||

+            y_sad < 100000) {

+          compute_minmax_variance = 0;

+          thresholds[2] = INT64_MAX;

+        }

+      }

     }

     y_sad_last = y_sad;

--- a/vp9/encoder/vp9_ratectrl.c

+++ b/vp9/encoder/vp9_ratectrl.c

@@ -363,6 +363,7 @@

   rc->high_source_sad = 0;

   rc->reset_high_source_sad = 0;

   rc->high_source_sad_lagindex = -1;

+  rc->high_num_blocks_with_motion = 0;

   rc->hybrid_intra_scene_change = 0;

   rc->re_encode_maxq_scene_change = 0;

   rc->alt_ref_gf_group = 0;

@@ -2670,6 +2671,7 @@

   if (cm->use_highbitdepth) return;

 #endif

   rc->high_source_sad = 0;

+  rc->high_num_blocks_with_motion = 0;

   if (cpi->svc.spatial_layer_id == 0 && src_width == last_src_width &&

       src_height == last_src_height) {

     YV12_BUFFER_CONFIG *frames[MAX_LAG_BUFFERS] = { NULL };

@@ -2788,6 +2790,8 @@

         } else {

           rc->avg_source_sad[lagframe_idx] = avg_sad;

         }

+        if (num_zero_temp_sad < (num_samples >> 1))

+          rc->high_num_blocks_with_motion = 1;

       }

     }

     // For CBR non-screen content mode, check if we should reset the rate

--- a/vp9/encoder/vp9_ratectrl.h

+++ b/vp9/encoder/vp9_ratectrl.h

@@ -175,6 +175,7 @@

   uint64_t avg_source_sad[MAX_LAG_BUFFERS];

   uint64_t prev_avg_source_sad_lag;

   int high_source_sad_lagindex;

+  int high_num_blocks_with_motion;

   int alt_ref_gf_group;

   int last_frame_is_src_altref;

   int high_source_sad;

--- a/vp9/encoder/vp9_speed_features.c

+++ b/vp9/encoder/vp9_speed_features.c

@@ -794,6 +794,13 @@

     sf->partition_search_type = FIXED_PARTITION;

     sf->always_this_block_size = BLOCK_64X64;

   }

+  // Special case for screen content: increase motion search when high motion

+  // is detected.

+  if (cpi->oxcf.content == VP9E_CONTENT_SCREEN && cpi->oxcf.speed > 5 &&

+      cpi->rc.high_num_blocks_with_motion && cpi->svc.spatial_layer_id == 0) {

+    sf->mv.search_method = NSTEP;

+    sf->mv.fullpel_search_step_param = 2;

+  }

 }

 void vp9_set_speed_features_framesize_dependent(VP9_COMP *cpi) {