Fix rate control bug.
Fix rate control bug whereby the rate factor heuristics
were being updated on arf overlays causing a rate surge
for a few frames followed by a corrective drop.
This fix eliminates many of the overshoot problems that
we were seeing on hard clips (even without applying
stricter vbr rate control) and also helps quality on
almost all clips with some hard clips improving by >5%.
Overall quality results measured at speed 2.
Derf +1.78% opsnr , +2.44% SSIM
Stdhd +2.41% opsnr, +2.85% SSIM
Change-Id: I2369df6295c2705963fa6307877f6acb304bcc39
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index f2afc46..806ab93 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -308,6 +308,10 @@
int projected_size_based_on_q = 0;
+ // Do not update the rate factors for arf overlay frames.
+ if (cpi->rc.is_src_frame_alt_ref)
+ return;
+
// Clear down mmx registers to allow floating point in what follows
vp9_clear_system_state();
