Rework coeff probability model update for rtc coding

This commit reworks the ONE_LOOP_REDUCED coefficient probability
model update process. It allows model update for every coefficient
across the spectrum at a coarser resolution, instead of performing
precise update only for certain subset of probability models.

The overall runtime remains nearly same (<1% change) for speed -6.
The compression performance is improved by 7.5% in PSNR for speed
-5 and 4.57% for speed -6, respectively.

Change-Id: Ifb17136382ee7e39a9f34ff4a4f09a753125c8d1

1 files changed, 3 insertions, 0 deletions

diff --git a/vp9/encoder/vp9_speed_features.h b/vp9/encoder/vp9_speed_features.h
index efea50387..26bd68330 100644
--- a/vp9/encoder/vp9_speed_features.h
+++ b/vp9/encoder/vp9_speed_features.h
@@ -236,6 +236,9 @@ typedef struct SPEED_FEATURES {
   // level within a frame.
   int allow_skip_recode;
 
+  // Coefficient probability model approximation step size
+  int coeff_prob_appx_step;
+
   // The threshold is to determine how slow the motino is, it is used when
   // use_lastframe_partitioning is set to LAST_FRAME_PARTITION_LOW_MOTION
   MOTION_THRESHOLD lf_motion_threshold;