shithub: libvpx

Download patch

ref: e88a28057311c24d61f1b122cdf7aa4d2685434e
parent: 23ccf7192434399e5db3a981fbfde40e1712ed5f
author: Jingning Han <jingning@google.com>
date: Tue Apr 15 07:41:39 EDT 2014 

Enable more precise background detection for partition decision

This commit compares the current original frame to the previous
original frame at 64x64 block level and decides if the entire
block belongs to background area. If it is in the background area,
skip non-RD partition search and copy the partition types of the
collocated block in the previous frame.

For vidyo1 in the rtc set, this makes the speed -5 coding speed
about 8% faster. The overall compression performance is down by
1.37% for rtc set.

Change-Id: Iccf920562fcc88f21d377fb6a44c547c8689b7ea


--- a/vp9/encoder/vp9_encodeframe.c
+++ b/vp9/encoder/vp9_encodeframe.c
@@ -1565,6 +1565,42 @@
   }
 }
 
+static int is_background(VP9_COMP *cpi, const TileInfo *const tile,
+                         int mi_row, int mi_col) {
+  MACROBLOCK *const x = &cpi->mb;
+  uint8_t *src, *pre;
+  int src_stride, pre_stride;
+
+  const int row8x8_remaining = tile->mi_row_end - mi_row;
+  const int col8x8_remaining = tile->mi_col_end - mi_col;
+
+  int this_sad = 0;
+  int threshold = 0;
+
+  vp9_setup_src_planes(x, cpi->Source, mi_row, mi_col);
+  src_stride = x->plane[0].src.stride;
+  src = x->plane[0].src.buf;
+  pre_stride = cpi->Last_Source->y_stride;
+  pre = cpi->Last_Source->y_buffer + (mi_row * MI_SIZE) * pre_stride +
+          (mi_col * MI_SIZE);
+
+  if (row8x8_remaining >= MI_BLOCK_SIZE &&
+      col8x8_remaining >= MI_BLOCK_SIZE) {
+    this_sad = cpi->fn_ptr[BLOCK_64X64].sdf(src, src_stride,
+                                            pre, pre_stride, 0x7fffffff);
+    threshold = (1 << 12);
+  } else {
+    int r, c;
+    for (r = 0; r < row8x8_remaining; r += 2)
+      for (c = 0; c < col8x8_remaining; c += 2)
+        this_sad += cpi->fn_ptr[BLOCK_16X16].sdf(src, src_stride, pre,
+                                                 pre_stride, 0x7fffffff);
+    threshold = (row8x8_remaining * col8x8_remaining) << 6;
+  }
+
+  return (this_sad < 2 * threshold);
+}
+
 static int sb_has_motion(const VP9_COMMON *cm, MODE_INFO **prev_mi_8x8) {
   const int mis = cm->mi_stride;
   int block_row, block_col;
@@ -3216,7 +3252,8 @@
                             1, &dummy_rate, &dummy_dist);
         break;
       case REFERENCE_PARTITION:
-        if (cpi->sf.partition_check || sb_has_motion(cm, prev_mi_8x8)) {
+        if (cpi->sf.partition_check ||
+            !is_background(cpi, tile, mi_row, mi_col)) {
           nonrd_pick_partition(cpi, tile, tp, mi_row, mi_col, BLOCK_64X64,
                                &dummy_rate, &dummy_dist, 1, INT64_MAX);
         } else {
-- 
⑨