From 992c41d2fd7e078855fa7353d1262ef85167d41c Mon Sep 17 00:00:00 2001
From: Paul Wilkins <paulwilkins@google.com>
Date: Fri, 28 Mar 2014 16:56:14 +0000
Subject: [PATCH] Speed setting correction to max q estimate.
Use a crude correction factor to correct for
lower compression efficiency at higher encode
speeds when estimating the max Q for the
clip.
Change-Id: I5ae377647f4adf5e91d700a8791fb3b8f70efc73
---
vp9/encoder/vp9_firstpass.c | 5 +++--
vp9/encoder/vp9_ratectrl.c | 2 +-
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index 6d36b7cf55..b5d08d2eb2 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -911,6 +911,7 @@ int vp9_twopass_worst_quality(VP9_COMP *cpi, FIRSTPASS_STATS *fpstats,
const double section_err = fpstats->coded_error / fpstats->count;
const double err_per_mb = section_err / num_mbs;
+ const double speed_term = 1.0 + ((double)cpi->speed * 0.04);
if (section_target_bandwitdh <= 0)
return rc->worst_quality; // Highest value allowed
@@ -924,8 +925,8 @@ int vp9_twopass_worst_quality(VP9_COMP *cpi, FIRSTPASS_STATS *fpstats,
for (q = rc->best_quality; q < rc->worst_quality; ++q) {
const double err_correction_factor = calc_correction_factor(err_per_mb,
ERR_DIVISOR, 0.5, 0.90, q);
- const int bits_per_mb_at_this_q = vp9_rc_bits_per_mb(INTER_FRAME, q,
- err_correction_factor);
+ const int bits_per_mb_at_this_q =
+ vp9_rc_bits_per_mb(INTER_FRAME, q, (err_correction_factor * speed_term));
if (bits_per_mb_at_this_q <= target_norm_bits_per_mb)
break;
}
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index c62d31293c..36edba5f30 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -1010,7 +1010,7 @@ void vp9_rc_compute_frame_size_bounds(const VP9_COMP *cpi,
*frame_over_shoot_limit = this_frame_target * 9 / 8;
*frame_under_shoot_limit = this_frame_target * 7 / 8;
} else {
- // Stron overshoot limit for constrained quality
+ // Strong overshoot limit for constrained quality
if (cpi->oxcf.end_usage == USAGE_CONSTRAINED_QUALITY) {
*frame_over_shoot_limit = this_frame_target * 11 / 8;
*frame_under_shoot_limit = this_frame_target * 2 / 8;
--
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