From: Paul Wilkins <paulwilkins@google.com>
Date: Wed, 30 Mar 2016 12:29:25 +0000 (+0100)
Subject: Adjustment to prediction decay.
X-Git-Tag: v1.6.0~223^2
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=1c187c4be0cf0437dc924d811db0b4758e8fecec;p=libvpx

Adjustment to prediction decay.

Adjustment to stop excessive prediction decay triggered by blocks
or frames with extremely low spatial complexity which rendered the
comparison of intra and inter coded errors meaningless.

This was causing much shorter than expected groups on some 4k
test content.

Change-Id: I3f2c64200ef6dcef4721fc9f2ec09e480056ffc2
---

diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index b5f52adbf..f91a9a86e 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -65,7 +65,7 @@
 
 #define NCOUNT_INTRA_THRESH 8192
 #define NCOUNT_INTRA_FACTOR 3
-#define NCOUNT_FRAME_II_THRESH 5.0
+
 
 #define DOUBLE_DIVIDE_CHECK(x) ((x) < 0 ? (x) - 0.000001 : (x) + 0.000001)
 
@@ -1382,6 +1382,8 @@ void vp9_init_second_pass(VP9_COMP *cpi) {
 #define DEFAULT_DECAY_LIMIT 0.75
 #define LOW_SR_DIFF_TRHESH 0.1
 #define SR_DIFF_MAX 128.0
+#define LOW_CODED_ERR_PER_MB 10.0
+#define NCOUNT_FRAME_II_THRESH 6.0
 
 static double get_sr_decay_rate(const VP9_COMP *cpi,
                                 const FIRSTPASS_STATS *frame) {
@@ -1398,8 +1400,9 @@ static double get_sr_decay_rate(const VP9_COMP *cpi,
        (cpi->initial_height + cpi->initial_width));
 
   modified_pct_inter = frame->pcnt_inter;
-  if ((frame->intra_error / DOUBLE_DIVIDE_CHECK(frame->coded_error)) <
-      (double)NCOUNT_FRAME_II_THRESH) {
+  if (((frame->coded_error / num_mbs) > LOW_CODED_ERR_PER_MB) &&
+      ((frame->intra_error / DOUBLE_DIVIDE_CHECK(frame->coded_error)) <
+       (double)NCOUNT_FRAME_II_THRESH)) {
     modified_pct_inter = frame->pcnt_inter - frame->pcnt_neutral;
   }
   modified_pcnt_intra = 100 * (1.0 - modified_pct_inter);