libvpx: Pull from upstream

source/libvpx/vp9/encoder/vp9_aq_cyclicrefresh.c

 /*
  *  Copyright (c) 2014 The WebM project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
@@ skipping 29 matching lines @@
   signed char *map;
   // Thresholds applied to the projected rate/distortion of the coding block,
   // when deciding whether block should be refreshed.
   int64_t thresh_rate_sb;
   int64_t thresh_dist_sb;
   // Threshold applied to the motion vector (in units of 1/8 pel) of the
   // coding block, when deciding whether block should be refreshed.
   int16_t motion_thresh;
   // Rate target ratio to set q delta.
   double rate_ratio_qdelta;
+  double low_content_avg;
 };
 
 CYCLIC_REFRESH *vp9_cyclic_refresh_alloc(int mi_rows, int mi_cols) {
   CYCLIC_REFRESH *const cr = vpx_calloc(1, sizeof(*cr));
   if (cr == NULL)
     return NULL;
 
   cr->map = vpx_calloc(mi_rows * mi_cols, sizeof(*cr->map));
   if (cr->map == NULL) {
     vpx_free(cr);
     return NULL;
   }
 
   return cr;
 }
 
 void vp9_cyclic_refresh_free(CYCLIC_REFRESH *cr) {
   vpx_free(cr->map);
   vpx_free(cr);
 }
 
 // Check if we should turn off cyclic refresh based on bitrate condition.
 static int apply_cyclic_refresh_bitrate(const VP9_COMMON *cm,
                                         const RATE_CONTROL *rc) {
   // Turn off cyclic refresh if bits available per frame is not sufficiently
   // larger than bit cost of segmentation. Segment map bit cost should scale
   // with number of seg blocks, so compare available bits to number of blocks.
   // Average bits available per frame = avg_frame_bandwidth
   // Number of (8x8) blocks in frame = mi_rows * mi_cols;
-  const float factor  = 0.5;
+  const float factor = 0.25;
   const int number_blocks = cm->mi_rows  * cm->mi_cols;
   // The condition below corresponds to turning off at target bitrates:
-  // ~24kbps for CIF, 72kbps for VGA (at 30fps).
+  // (at 30fps), ~12kbps for CIF, 36kbps for VGA, 100kps for HD/720p.
   // Also turn off at very small frame sizes, to avoid too large fraction of
   // superblocks to be refreshed per frame. Threshold below is less than QCIF.
   if (rc->avg_frame_bandwidth < factor * number_blocks ||
       number_blocks / 64 < 5)
     return 0;
   else
     return 1;
 }
 
 // Check if this coding block, of size bsize, should be considered for refresh
@@ skipping 113 matching lines @@
   const int ymis = MIN(cm->mi_rows - mi_row, bh);
   const int block_index = mi_row * cm->mi_cols + mi_col;
   const int refresh_this_block = candidate_refresh_aq(cr, mbmi, rate, dist,
                                                       bsize);
   // Default is to not update the refresh map.
   int new_map_value = cr->map[block_index];
   int x = 0; int y = 0;
 
   // If this block is labeled for refresh, check if we should reset the
   // segment_id.
-  if (mbmi->segment_id != CR_SEGMENT_ID_BASE)
+  if (cyclic_refresh_segment_id_boosted(mbmi->segment_id))
     mbmi->segment_id = refresh_this_block;
 
   // Update the cyclic refresh map, to be used for setting segmentation map
   // for the next frame. If the block  will be refreshed this frame, mark it
   // as clean. The magnitude of the -ve influences how long before we consider
   // it for refresh again.
-  if (mbmi->segment_id != CR_SEGMENT_ID_BASE) {
+  if (cyclic_refresh_segment_id_boosted(mbmi->segment_id)) {
     new_map_value = -cr->time_for_refresh;
   } else if (refresh_this_block) {
     // Else if it is accepted as candidate for refresh, and has not already
     // been refreshed (marked as 1) then mark it as a candidate for cleanup
     // for future time (marked as 0), otherwise don't update it.
     if (cr->map[block_index] == 1)
       new_map_value = 0;
   } else {
     // Leave it marked as block that is not candidate for refresh.
     new_map_value = 1;
   }
 
   // Update entries in the cyclic refresh map with new_map_value, and
   // copy mbmi->segment_id into global segmentation map.
   for (y = 0; y < ymis; y++)
     for (x = 0; x < xmis; x++) {
       cr->map[block_index + y * cm->mi_cols + x] = new_map_value;
       cpi->segmentation_map[block_index + y * cm->mi_cols + x] =
           mbmi->segment_id;
     }
 }
 
 // Update the actual number of blocks that were applied the segment delta q.
-void vp9_cyclic_refresh_update_actual_count(struct VP9_COMP *const cpi) {
+void vp9_cyclic_refresh_postencode(VP9_COMP *const cpi) {
   VP9_COMMON *const cm = &cpi->common;
   CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
   unsigned char *const seg_map = cpi->segmentation_map;
   int mi_row, mi_col;
   cr->actual_num_seg_blocks = 0;
   for (mi_row = 0; mi_row < cm->mi_rows; mi_row++)
-  for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {
-    if (seg_map[mi_row * cm->mi_cols + mi_col] != CR_SEGMENT_ID_BASE)
-      cr->actual_num_seg_blocks++;
+    for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {
+      if (cyclic_refresh_segment_id_boosted(
+              seg_map[mi_row * cm->mi_cols + mi_col]))
+        cr->actual_num_seg_blocks++;
+    }
+}
+
+// Set golden frame update interval, for non-svc 1 pass CBR mode.
+void vp9_cyclic_refresh_set_golden_update(VP9_COMP *const cpi) {
+  RATE_CONTROL *const rc = &cpi->rc;
+  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
+  // Set minimum gf_interval for GF update to a multiple (== 2) of refresh
+  // period. Depending on past encoding stats, GF flag may be reset and update
+  // may not occur until next baseline_gf_interval.
+  if (cr->percent_refresh > 0)
+    rc->baseline_gf_interval = 2 * (100 / cr->percent_refresh);
+  else
+    rc->baseline_gf_interval = 20;
+}
+
+// Update some encoding stats (from the just encoded frame), and if the golden
+// reference is to be updated check if we should NOT update the golden ref.
+void vp9_cyclic_refresh_check_golden_update(VP9_COMP *const cpi) {
+  VP9_COMMON *const cm = &cpi->common;
+  CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
+  int mi_row, mi_col;
+  double fraction_low = 0.0;
+  int low_content_frame = 0;
+  for (mi_row = 0; mi_row < cm->mi_rows; mi_row++)
+    for (mi_col = 0; mi_col < cm->mi_cols; mi_col++) {
+      if (cr->map[mi_row * cm->mi_cols + mi_col] < 1)
+        low_content_frame++;
+    }
+  fraction_low =
+      (double)low_content_frame / (cm->mi_rows * cm->mi_cols);
+  // Update average.
+  cr->low_content_avg = (fraction_low + 3 * cr->low_content_avg) / 4;
+  if (cpi->refresh_golden_frame == 1) {
+    // Don't update golden reference if the amount of low_content for the
+    // current encoded frame is small, or if the recursive average of the
+    // low_content over the update interval window falls below threshold.
+    if (fraction_low < 0.8 || cr->low_content_avg < 0.7)
+      cpi->refresh_golden_frame = 0;
+    // Reset for next internal.
+    cr->low_content_avg = fraction_low;
   }
 }
 
 // Update the segmentation map, and related quantities: cyclic refresh map,
 // refresh sb_index, and target number of blocks to be refreshed.
 // The map is set to either 0/CR_SEGMENT_ID_BASE (no refresh) or to
 // 1/CR_SEGMENT_ID_BOOST1 (refresh) for each superblock.
 // Blocks labeled as BOOST1 may later get set to BOOST2 (during the
 // encoding of the superblock).
 void vp9_cyclic_refresh_update_map(VP9_COMP *const cpi) {
@@ skipping 73 matching lines @@
     cr->rate_ratio_qdelta = 2.0;
 }
 
 // Setup cyclic background refresh: set delta q and segmentation map.
 void vp9_cyclic_refresh_setup(VP9_COMP *const cpi) {
   VP9_COMMON *const cm = &cpi->common;
   const RATE_CONTROL *const rc = &cpi->rc;
   CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
   struct segmentation *const seg = &cm->seg;
   const int apply_cyclic_refresh  = apply_cyclic_refresh_bitrate(cm, rc);
+  if (cm->current_video_frame == 0)
+    cr->low_content_avg = 0.0;
   // Don't apply refresh on key frame or enhancement layer frames.
   if (!apply_cyclic_refresh ||
       (cm->frame_type == KEY_FRAME) ||
       (cpi->svc.temporal_layer_id > 0) ||
       (cpi->svc.spatial_layer_id > 0)) {
     // Set segmentation map to 0 and disable.
     unsigned char *const seg_map = cpi->segmentation_map;
     vpx_memset(seg_map, 0, cm->mi_rows * cm->mi_cols);
     vp9_disable_segmentation(&cm->seg);
     if (cm->frame_type == KEY_FRAME)
@@ skipping 51 matching lines @@
     vp9_set_segdata(seg, CR_SEGMENT_ID_BOOST2, SEG_LVL_ALT_Q, qindex_delta);
 
     // Update the segmentation and refresh map.
     vp9_cyclic_refresh_update_map(cpi);
   }
 }
 
 int vp9_cyclic_refresh_get_rdmult(const CYCLIC_REFRESH *cr) {
   return cr->rdmult;
 }