commit 4b65d782f96ab30b542d121846d75e1f8a794a6d
author chiyotsai <chiyotsai@google.com> Thu Sep 12 13:52:51 2019 -0700
committer Chi Yo Tsai <chiyotsai@google.com> Thu Sep 12 22:25:17 2019 +0000
tree 77045fa8178f8b2ec2c151cf47cdfbb6e7e833be
parent 4871f42cdd222935a4060b27b0118a4a1109d11f

Allow more flexible recoding options on speed 5

Currently the ALLOW_RECODE_KFMAXBW setting gives a significant quality
loss on some sequences in vbr mode, especially those sequences with scene
changes.  For instance, on shields_720p50.y4m, a loss of 72% is observed.

Disabling it also leads to slightly less over/under-shooting. We also
expect a large slow down in the low bitrate regime. A slow down of ~20%
on some clips under low bitrate condition is expected.

Performance on hdres:
 AVG_PSNR | OVR_PSNR |   SSIM  | AVG_SPD | OVR_SPD
  -6.371% |  -7.201% | -9.338% | -6.264% | -4.516%

Note: there is a large variance in the performance stats due to recoding
being sensitive to bitrate and sequence complexity.

STATS_CHANGED

Change-Id: If28c60cdd2238f157dfbdf224ea409c0851c627c

av1/encoder/speed_features.c

diff --git a/av1/encoder/speed_features.c b/av1/encoder/speed_features.c
index add9421..d612fd0 100644
--- a/av1/encoder/speed_features.c
+++ b/av1/encoder/speed_features.c
@@ -405,9 +405,6 @@
   }
 
   if (speed >= 5) {
-    // Note(yunqing): This recode feature causes big quality drop in vbr
-    // encoding. Need to work on it.
-    sf->recode_loop = ALLOW_RECODE_KFMAXBW;
     sf->intra_y_mode_mask[TX_64X64] = INTRA_DC_H_V;
     sf->intra_uv_mode_mask[TX_64X64] = UV_INTRA_DC_H_V_CFL;
     sf->intra_y_mode_mask[TX_32X32] = INTRA_DC_H_V;