ref: 587f0cd39d9b949185f148a683db410d4e3f04b0
parent: 3c715863da0afdc42fb44c9f6d04e983d25a8de7
parent: ffa06b37083d028b50f27e67ae6ed0c6ee9953bb
author: Yaowu Xu <yaowu@google.com>
date: Tue Nov 18 11:56:06 EST 2014
Merge "Prevent severe rate control errors in CBR mode"
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -430,7 +430,8 @@
adjustment_limit = 0.75;
break;
case 1:
- adjustment_limit = 0.125 + 0.5 * MIN(1, fabs(log10(0.01 * correction_factor)));
+ adjustment_limit = 0.25 +
+ 0.5 * MIN(1, fabs(log10(0.01 * correction_factor)));
break;
case 2:
default:
@@ -438,12 +439,21 @@
break;
}
+ cpi->rc.q_2_frame = cpi->rc.q_1_frame;
+ cpi->rc.q_1_frame = cm->base_qindex;
+ cpi->rc.rc_2_frame = cpi->rc.rc_1_frame;
+ if (correction_factor > 110)
+ cpi->rc.rc_1_frame = -1;
+ else if (correction_factor < 90)
+ cpi->rc.rc_1_frame = 1;
+ else
+ cpi->rc.rc_1_frame = 0;
+
if (correction_factor > 102) {// We are not already at the worst allowable quality
correction_factor = (int)(100 + ((correction_factor - 100) *
adjustment_limit));
rate_correction_factor = (rate_correction_factor * correction_factor) / 100;
-
// Keep rate_correction_factor within limits
if (rate_correction_factor > MAX_BPB_FACTOR)
rate_correction_factor = MAX_BPB_FACTOR;
@@ -494,6 +504,14 @@
}
} while (++i <= active_worst_quality);
+ // In CBR mode, this makes sure q is between oscillating Qs to prevent
+ // resonance.
+ if (cpi->oxcf.rc_mode == VPX_CBR &&
+ (cpi->rc.rc_1_frame * cpi->rc.rc_2_frame == -1) &&
+ cpi->rc.q_1_frame != cpi->rc.q_2_frame) {+ q = clamp(q, MIN(cpi->rc.q_1_frame, cpi->rc.q_2_frame),
+ MAX(cpi->rc.q_1_frame, cpi->rc.q_2_frame));
+ }
return q;
}
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -99,7 +99,14 @@
int64_t starting_buffer_level;
int64_t optimal_buffer_level;
int64_t maximum_buffer_size;
- // int active_best_quality;
+ // rate control history for last frame(1) and the frame before(2).
+ // -1: undershot
+ // 1: overshoot
+ // 0: not initialized.
+ int rc_1_frame;
+ int rc_2_frame;
+ int q_1_frame;
+ int q_2_frame;
} RATE_CONTROL;
struct VP9_COMP;