rtc: Adjust cyclic refresh for screen

Reset the refresh on slide change and set larger
refresh period for some frames after scene change
that is encoded at high Q for faster cleanup.

Also make sure source_sad speed feature is always on
for screen mode.

Visual quality improvement after scene change,
average psnr increase of ~0.25dB on 1850x1110 slide change
clip, with little/no change in speed/fps.

Change-Id: If9d29a830a3f1b9483e112de65b3d650d7148fa1

av1/encoder/aq_cyclicrefresh.c

diff --git a/av1/encoder/aq_cyclicrefresh.c b/av1/encoder/aq_cyclicrefresh.c
index 71393dc..9d95788 100644
--- a/av1/encoder/aq_cyclicrefresh.c
+++ b/av1/encoder/aq_cyclicrefresh.c
@@ -25,6 +25,7 @@
   if (cr == NULL) return NULL;
 
   cr->map = aom_calloc(mi_rows * mi_cols, sizeof(*cr->map));
+  cr->counter_encode_maxq_scene_change = 0;
   if (cr->map == NULL) {
     av1_cyclic_refresh_free(cr);
     return NULL;
@@ -426,11 +427,18 @@
     return;
   }
   cr->percent_refresh = 10;
-  if (cpi->svc.number_temporal_layers > 2) cr->percent_refresh = 15;
+  // Increase the amount of refresh for #temporal_layers > 2, and for some
+  // frames after scene change that is encoded at high Q.
+  if (cpi->svc.number_temporal_layers > 2)
+    cr->percent_refresh = 15;
+  else if (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN &&
+           cr->counter_encode_maxq_scene_change < 20)
+    cr->percent_refresh = 20;
   cr->max_qdelta_perc = 60;
   cr->time_for_refresh = 0;
   cr->motion_thresh = 32;
-  cr->rate_boost_fac = 15;
+  cr->rate_boost_fac =
+      (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN) ? 10 : 15;
   // Use larger delta-qp (increase rate_ratio_qdelta) for first few (~4)
   // periods of the refresh cycle, after a key frame.
   // Account for larger interval on base layer for temporal layers.
@@ -491,7 +499,10 @@
   const RATE_CONTROL *const rc = &cpi->rc;
   CYCLIC_REFRESH *const cr = cpi->cyclic_refresh;
   struct segmentation *const seg = &cm->seg;
-  int resolution_change =
+  const int scene_change_detected =
+      cpi->rc.high_source_sad ||
+      (cpi->ppi->use_svc && cpi->svc.high_source_sad_superframe);
+  const int resolution_change =
       cm->prev_frame && (cm->width != cm->prev_frame->width ||
                          cm->height != cm->prev_frame->height);
   if (resolution_change) av1_cyclic_refresh_reset_resize(cpi);
@@ -500,11 +511,13 @@
     unsigned char *const seg_map = cpi->enc_seg.map;
     memset(seg_map, 0, cm->mi_params.mi_rows * cm->mi_params.mi_cols);
     av1_disable_segmentation(&cm->seg);
-    if (cm->current_frame.frame_type == KEY_FRAME) {
+    if (cm->current_frame.frame_type == KEY_FRAME || scene_change_detected) {
       cr->sb_index = 0;
+      cr->counter_encode_maxq_scene_change = 0;
     }
     return;
   } else {
+    cr->counter_encode_maxq_scene_change++;
     const double q = av1_convert_qindex_to_q(cm->quant_params.base_qindex,
                                              cm->seq_params->bit_depth);
     // Set rate threshold to some multiple (set to 2 for now) of the target
@@ -578,4 +591,5 @@
   cr->sb_index = 0;
   cpi->refresh_frame.golden_frame = true;
   cr->apply_cyclic_refresh = 0;
+  cr->counter_encode_maxq_scene_change = 0;
 }

av1/encoder/aq_cyclicrefresh.h

diff --git a/av1/encoder/aq_cyclicrefresh.h b/av1/encoder/aq_cyclicrefresh.h
index 4e4e1f2..484f88f 100644
--- a/av1/encoder/aq_cyclicrefresh.h
+++ b/av1/encoder/aq_cyclicrefresh.h
@@ -108,6 +108,7 @@
   double weight_segment;
   int apply_cyclic_refresh;
   int skip_over4x4;
+  int counter_encode_maxq_scene_change;
   /*!\endcond */
 };
 

av1/encoder/ratectrl.c

diff --git a/av1/encoder/ratectrl.c b/av1/encoder/ratectrl.c
index b5448d5..8b4abc9 100644
--- a/av1/encoder/ratectrl.c
+++ b/av1/encoder/ratectrl.c
@@ -3084,6 +3084,7 @@
     double q2;
     int enumerator;
     *q = (3 * cpi->rc.worst_quality + *q) >> 2;
+    cpi->cyclic_refresh->counter_encode_maxq_scene_change = 0;
     // Adjust avg_frame_qindex, buffer_level, and rate correction factors, as
     // these parameters will affect QP selection for subsequent frames. If they
     // have settled down to a very different (low QP) state, then not adjusting

av1/encoder/speed_features.c

diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index 8ab710c..7dbabbc 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -1289,8 +1289,10 @@
           cpi->svc.ref_frame_comp[2] && cpi->svc.reference[ALTREF_FRAME - 1];
     }
   }
-  if (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN)
+  if (cpi->oxcf.tune_cfg.content == AOM_CONTENT_SCREEN) {
     sf->rt_sf.use_comp_ref_nonrd = 0;
+    sf->rt_sf.source_metrics_sb_nonrd = 1;
+  }
 }
 
 // TODO(kyslov): now this is very similar to