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

1 files changed, 14 insertions, 0 deletions

diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index fb25fbc5c..4aae37706 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -1378,6 +1378,20 @@ static int choose_partitioning(VP9_COMP *cpi, const TileInfo *const tile,
       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;