Turning model based reverse update on for coefs

Turns model based reverse updates on for coefficients in an
effort to reduce the memory requirement for counters.

With this patch the counters needed will be reduced by about
75% since only 3 counts are needed instead of 12.

The impact in performance is:
derf300: -0.252%
stdhd250: -0.046%

However retraining should alleviate some of the drop in
performance.

Change-Id: I6f2b3e13f6d5520aa3400b0b228fb5e8b4a43caa

diff --git a/vp9/common/vp9_entropy.c b/vp9/common/vp9_entropy.c
index 16ef14fec2023f219fc0e51841b7e5d15ce9edc2..faa45bd5f284c9dda356f9680156f5be7f893819 100644 (file)
--- a/vp9/common/vp9_entropy.c
+++ b/vp9/common/vp9_entropy.c
@@ -1555,6 +1555,7 @@ static void adapt_coef_probs(vp9_coeff_probs *dst_coef_probs,
 }
 
 void vp9_adapt_coef_probs(VP9_COMMON *cm) {
+#ifndef DISABLE_COEF_ADAPT
   int count_sat;
   int update_factor; /* denominator 256 */
 
@@ -1585,6 +1586,7 @@ void vp9_adapt_coef_probs(VP9_COMMON *cm) {
                    cm->base_qindex, cm->fc.coef_counts_32x32,
                    cm->fc.eob_branch_counts[TX_32X32],
                    count_sat, update_factor);
+#endif
 }
 
 #if CONFIG_CODE_ZEROGROUP

diff --git a/vp9/common/vp9_entropy.h b/vp9/common/vp9_entropy.h
index 06641dcdf6b0112ab5cff11aa9ea3a995e0f6fec..f35384b79818ddafdcfcf11acd0523db2e5a3083 100644 (file)
--- a/vp9/common/vp9_entropy.h
+++ b/vp9/common/vp9_entropy.h
@@ -84,6 +84,9 @@ extern vp9_extra_bit vp9_extra_bits[12];    /* indexed by token value */
 /*# define DC_TOKEN_CONTEXTS        3*/ /* 00, 0!0, !0!0 */
 #define PREV_COEF_CONTEXTS          6
 
+// Disables backward coef probs adaption
+// #define DISABLE_COEF_ADAPT
+
 typedef unsigned int vp9_coeff_count[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
                                     [MAX_ENTROPY_TOKENS];
 typedef unsigned int vp9_coeff_stats[REF_TYPES][COEF_BANDS][PREV_COEF_CONTEXTS]
@@ -158,7 +161,7 @@ const int *vp9_get_coef_neighbors_handle(const int *scan, int *pad);
 // if model-based how many nodes are unconstrained
 #define UNCONSTRAINED_UPDATE_NODES  3
 // whether backward updates are model-based
-#define MODEL_BASED_ADAPT           0
+#define MODEL_BASED_ADAPT           1
 #define UNCONSTRAINED_ADAPT_NODES   3
 
 typedef vp9_prob vp9_coeff_probs_model[REF_TYPES][COEF_BANDS]