Limit cyclic refresh on steady background blocks.

Use the existing QP condition on limiting cyclic refresh, and add
addiitonal condition that block has been encoded with zero/small motion
x frames in row (where x is at least several times the refresh period).
Additional condition only affect non-screen content mode.

This helps to improve visual stability for noisy input, where on steady
background areas the application of delta_qp may lead to encoding the noise.

Also added a change to use the true skip (after encoding) to update the
last QP.

Change-Id: I234a1128d017d284cf767fdb58ef6c59d809f679

vp9/encoder/vp9_aq_cyclicrefresh.c

@@ -23,6 +23,7 @@
 
 CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
   size_t last_coded_q_map_size;
+  size_t consec_zero_mv_size;
   CYCLIC_REFRESH *const cr = vpx_calloc(1, sizeof(*cr));
   if (cr == NULL)
     return NULL;
@@ -41,12 +42,20 @@ CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
   assert(MAXQ <= 255);
   memset(cr->last_coded_q_map, MAXQ, last_coded_q_map_size);
 
+  consec_zero_mv_size = mi_rows * mi_cols * sizeof(*cr->consec_zero_mv);
+  cr->consec_zero_mv = vpx_malloc(consec_zero_mv_size);
+  if (cr->consec_zero_mv == NULL) {
+    vpx_free(cr);
+    return NULL;
+  }
+  memset(cr->consec_zero_mv, 0, consec_zero_mv_size);
   return cr;
 }
 
 void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
   vpx_free(cr->map);
   vpx_free(cr->last_coded_q_map);
+  vpx_free(cr->consec_zero_mv);
   vpx_free(cr);
 }
 
@@ -228,22 +237,48 @@ void vp9_cyclic_refresh_update_segment(VP9_COMP *const cpi,
       int map_offset = block_index + y * cm->mi_cols + x;
       cr->map[map_offset] = new_map_value;
       cpi->segmentation_map[map_offset] = mbmi->segment_id;
+    }
+}
+
+void vp9_cyclic_refresh_update_sb_postencode(VP9_COMP *const cpi,
+                                             const MB_MODE_INFO *const mbmi,
+                                             int mi_row, int mi_col,
+                                             BLOCK_SIZE bsize) {
+  const VP9_COMMON *const cm = &cpi->common;
+  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
+  MV mv = mbmi->mv[0].as_mv;
+  const int bw = num_8x8_blocks_wide_lookup[bsize];
+  const int bh = num_8x8_blocks_high_lookup[bsize];
+  const int xmis = VPXMIN(cm->mi_cols - mi_col, bw);
+  const int ymis = VPXMIN(cm->mi_rows - mi_row, bh);
+  const int block_index = mi_row * cm->mi_cols + mi_col;
+  int x, y;
+  for (y = 0; y < ymis; y++)
+    for (x = 0; x < xmis; x++) {
+      int map_offset = block_index + y * cm->mi_cols + x;
       // Inter skip blocks were clearly not coded at the current qindex, so
       // don't update the map for them. For cases where motion is non-zero or
       // the reference frame isn't the previous frame, the previous value in
       // the map for this spatial location is not entirely correct.
-      if ((!is_inter_block(mbmi) || !skip) &&
+      if ((!is_inter_block(mbmi) || !mbmi->skip) &&
           mbmi->segment_id <= CR_SEGMENT_ID_BOOST2) {
         cr->last_coded_q_map[map_offset] = clamp(
             cm->base_qindex + cr->qindex_delta[mbmi->segment_id], 0, MAXQ);
-      } else if (is_inter_block(mbmi) && skip &&
+      } else if (is_inter_block(mbmi) && mbmi->skip &&
                  mbmi->segment_id <= CR_SEGMENT_ID_BOOST2) {
         cr->last_coded_q_map[map_offset] = VPXMIN(
             clamp(cm->base_qindex + cr->qindex_delta[mbmi->segment_id],
                   0, MAXQ),
             cr->last_coded_q_map[map_offset]);
+      // Update the consecutive zero/low_mv count.
+      if (is_inter_block(mbmi) && (abs(mv.row) < 8 && abs(mv.col) < 8)) {
+        if (cr->consec_zero_mv[map_offset] < 255)
+          cr->consec_zero_mv[map_offset]++;
+      } else {
+        cr->consec_zero_mv[map_offset] = 0;
       }
     }
+  }
 }
 
 // Update the actual number of blocks that were applied the segment delta q.
@@ -380,9 +415,10 @@ static void cyclic_refresh_update_map(VP9_COMP *const cpi) {
     int mi_row = sb_row_index * MI_BLOCK_SIZE;
     int mi_col = sb_col_index * MI_BLOCK_SIZE;
     int qindex_thresh =
-        cpi->oxcf.content == VP9E_CONTENT_SCREEN
-            ? vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST2, cm->base_qindex)
-            : 0;
+        vp9_get_qindex(&cm->seg, CR_SEGMENT_ID_BOOST2, cm->base_qindex);
+    int consec_zero_mv_thresh =
+        cpi->oxcf.content == VP9E_CONTENT_SCREEN ? 0
+        : 10 * (100 / cr->percent_refresh);
     assert(mi_row >= 0 && mi_row < cm->mi_rows);
     assert(mi_col >= 0 && mi_col < cm->mi_cols);
     bl_index = mi_row * cm->mi_cols + mi_col;
@@ -398,7 +434,8 @@ static void cyclic_refresh_update_map(VP9_COMP *const cpi) {
         // for possible boost/refresh (segment 1). The segment id may get
         // reset to 0 later if block gets coded anything other than ZEROMV.
         if (cr->map[bl_index2] == 0) {
-          if (cr->last_coded_q_map[bl_index2] > qindex_thresh)
+          if (cr->last_coded_q_map[bl_index2] > qindex_thresh ||
+              cr->consec_zero_mv[bl_index2] < consec_zero_mv_thresh)
             sum_map++;
         } else if (cr->map[bl_index2] < 0) {
           cr->map[bl_index2]++;
@@ -475,6 +512,8 @@ void vp9_cyclic_refresh_setup(VP9_COMP *const cpi) {
     if (cm->frame_type == KEY_FRAME) {
       memset(cr->last_coded_q_map, MAXQ,
              cm->mi_rows * cm->mi_cols * sizeof(*cr->last_coded_q_map));
+      memset(cr->consec_zero_mv, 0,
+             cm->mi_rows * cm->mi_cols * sizeof(*cr->consec_zero_mv));
       cr->sb_index = 0;
     }
     return;
@@ -544,6 +583,8 @@ void vp9_cyclic_refresh_reset_resize(VP9_COMP *const cpi) {
   const VP9_COMMON *const cm = &cpi->common;
   CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
   memset(cr->map, 0, cm->mi_rows * cm->mi_cols);
+  memset(cr->last_coded_q_map, MAXQ, cm->mi_rows * cm->mi_cols);
+  memset(cr->consec_zero_mv, 0, cm->mi_rows * cm->mi_cols);
   cr->sb_index = 0;
   cpi->refresh_golden_frame = 1;
 }

vp9/encoder/vp9_aq_cyclicrefresh.h

@@ -51,6 +51,8 @@ struct CYCLIC_REFRESH {
   signed char *map;
   // Map of the last q a block was coded at.
   uint8_t *last_coded_q_map;
+  // Count on how many consecutive times a block uses ZER0MV for encoding.
+  uint8_t *consec_zero_mv;
   // Thresholds applied to the projected rate/distortion of the coding block,
   // when deciding whether block should be refreshed.
   int64_t thresh_rate_sb;
@@ -92,6 +94,11 @@ void vp9_cyclic_refresh_update_segment(struct VP9_COMP *const cpi,
                                        int mi_row, int mi_col, BLOCK_SIZE bsize,
                                        int64_t rate, int64_t dist, int skip);
 
+void vp9_cyclic_refresh_update_sb_postencode(struct VP9_COMP *const cpi,
+                                             const MB_MODE_INFO *const mbmi,
+                                             int mi_row, int mi_col,
+                                             BLOCK_SIZE bsize);
+
 // Update the segmentation map, and related quantities: cyclic refresh map,
 // refresh sb_index, and target number of blocks to be refreshed.
 void vp9_cyclic_refresh_update__map(struct VP9_COMP *const cpi);

vp9/encoder/vp9_encodeframe.c

@@ -4213,5 +4213,7 @@ static void encode_superblock(VP9_COMP *cpi, ThreadData *td,
     }
     ++td->counts->tx.tx_totals[mbmi->tx_size];
     ++td->counts->tx.tx_totals[get_uv_tx_size(mbmi, &xd->plane[1])];
+    if (cm->seg.enabled && cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ)
+      vp9_cyclic_refresh_update_sb_postencode(cpi, mbmi, mi_row, mi_col, bsize);
   }
 }