shithub: libvpx

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Modify update golden reference update under aq-mode=3 mode.

For non-SVC 1 pass CBR: make the GF update interval a multiple of the
cyclic refresh period, and use encoding stats to prevent GF update at certain times.

Change-Id: I4c44cacc2f70f1d27391a47644837e1eaa065017

--- a/vp9/encoder/vp9_aq_cyclicrefresh.c

+++ b/vp9/encoder/vp9_aq_cyclicrefresh.c

@@ -47,6 +47,7 @@

   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) {

@@ -244,7 +245,7 @@

 }

 // 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;

@@ -257,6 +258,47 @@

   }

 }

+// 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

@@ -347,6 +389,8 @@

   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) ||

--- a/vp9/encoder/vp9_aq_cyclicrefresh.h

+++ b/vp9/encoder/vp9_aq_cyclicrefresh.h

@@ -62,7 +62,13 @@

 void vp9_cyclic_refresh_update__map(struct VP9_COMP *const cpi);

 // 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(struct VP9_COMP *const cpi);

+

+// Set golden frame update interval, for non-svc 1 pass CBR mode.

+void vp9_cyclic_refresh_set_golden_update(struct VP9_COMP *cpi);

+

+// Check if we should not update golden reference, based on past refresh stats.

+void vp9_cyclic_refresh_check_golden_update(struct VP9_COMP *const cpi);

 // Set/update global/frame level refresh parameters.

 void vp9_cyclic_refresh_update_parameters(struct VP9_COMP *const cpi);

--- a/vp9/encoder/vp9_encoder.c

+++ b/vp9/encoder/vp9_encoder.c

@@ -2843,6 +2843,14 @@

   // transform / motion compensation build reconstruction frame

   vp9_encode_frame(cpi);

+  // Update some stats from cyclic refresh, and check if we should not update

+  // golden reference, for non-SVC 1 pass CBR.

+  if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ &&

+      cm->frame_type != KEY_FRAME &&

+      !cpi->use_svc &&

+      (cpi->oxcf.pass == 0 && cpi->oxcf.rc_mode == VPX_CBR))

+    vp9_cyclic_refresh_check_golden_update(cpi);

+

   // Update the skip mb flag probabilities based on the distribution

   // seen in the last encoder iteration.

   // update_base_skip_probs(cpi);

@@ -3220,7 +3228,6 @@

   TX_SIZE t;

   set_ext_overrides(cpi);

-

   vp9_clear_system_state();

   // Set the arf sign bias for this frame.

--- a/vp9/encoder/vp9_ratectrl.c

+++ b/vp9/encoder/vp9_ratectrl.c

@@ -1229,7 +1229,7 @@

   const int qindex = cm->base_qindex;

   if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ && cm->seg.enabled) {

-    vp9_cyclic_refresh_update_actual_count(cpi);

+    vp9_cyclic_refresh_postencode(cpi);

   }

   // Update rate control heuristics

@@ -1535,7 +1535,10 @@

     cm->frame_type = INTER_FRAME;

   }

   if (rc->frames_till_gf_update_due == 0) {

-    rc->baseline_gf_interval = DEFAULT_GF_INTERVAL;

+    if (cpi->oxcf.aq_mode == CYCLIC_REFRESH_AQ)

+      vp9_cyclic_refresh_set_golden_update(cpi);

+    else

+      rc->baseline_gf_interval = DEFAULT_GF_INTERVAL;

     rc->frames_till_gf_update_due = rc->baseline_gf_interval;

     // NOTE: frames_till_gf_update_due must be <= frames_to_key.

     if (rc->frames_till_gf_update_due > rc->frames_to_key)

-- 

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