Merge "Non-rd partition: Use force split on 16x16 for low resolutions."

vp9/encoder/vp9_encodeframe.c

diff --git a/vp9/encoder/vp9_encodeframe.c b/vp9/encoder/vp9_encodeframe.c
index e9b62bb..17ba956 100644
--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -401,7 +401,6 @@
   variance_node vt;
   const int block_width = num_8x8_blocks_wide_lookup[bsize];
   const int block_height = num_8x8_blocks_high_lookup[bsize];
-  const int low_res = (cm->width <= 352 && cm->height <= 288);
 
   assert(block_height == block_width);
   tree_to_node(data, bsize, &vt);
@@ -414,7 +413,7 @@
   // No check for vert/horiz split as too few samples for variance.
   if (bsize == bsize_min) {
     // Variance already computed to set the force_split.
-    if (low_res || cm->frame_type == KEY_FRAME)
+    if (cm->frame_type == KEY_FRAME)
       get_variance(&vt.part_variances->none);
     if (mi_col + block_width / 2 < cm->mi_cols &&
         mi_row + block_height / 2 < cm->mi_rows &&
@@ -425,7 +424,7 @@
     return 0;
   } else if (bsize > bsize_min) {
     // Variance already computed to set the force_split.
-    if (low_res || cm->frame_type == KEY_FRAME)
+    if (cm->frame_type == KEY_FRAME)
       get_variance(&vt.part_variances->none);
     // For key frame: take split for bsize above 32X32 or very high variance.
     if (cm->frame_type == KEY_FRAME &&
@@ -897,6 +896,14 @@
         for (m = 0; m < 4; m++)
           fill_variance_tree(&vtemp->split[m], BLOCK_8X8);
         fill_variance_tree(vtemp, BLOCK_16X16);
+        // If variance of this 16x16 block is above the threshold, force block
+        // to split. This also forces a split on the upper levels.
+        get_variance(&vtemp->part_variances.none);
+        if (vtemp->part_variances.none.variance > thresholds[2]) {
+          force_split[5 + i2 + j] = 1;
+          force_split[i + 1] = 1;
+          force_split[0] = 1;
+        }
       }
     }
     fill_variance_tree(&vt.split[i], BLOCK_32X32);