ref: 883fdd45cfbb1b12ff746fbb88df88522e20b5c1
parent: ade9693a30821af5c28b947090aa6d41cb27ea20
author: paulwilkins <paulwilkins@google.com>
date: Thu May 7 07:55:53 EDT 2015
Fast feedback of bits on undershoot. This patch provides a partial rapid feedback of bits resulting from extreme undershoot. Some improvement on some problem animated material but in its current form only a small impact on the metrics results of our standard test sets. Change-Id: Ie03036ea8123bc2553437cb8c8c9e7a9fc5dac5d
--- a/vp9/encoder/vp9_encoder.c
+++ b/vp9/encoder/vp9_encoder.c
@@ -2796,8 +2796,9 @@
if (cpi->twopass.total_left_stats.coded_error != 0.0)
fprintf(f, "%10u %dx%d %d %d %10d %10d %10d %10d"
- "%10"PRId64" %10"PRId64" %10"PRId64" %10"PRId64" %10d "
- "%7.2lf %7.2lf %7.2lf %7.2lf %7.2lf"
+ "%10"PRId64" %10"PRId64" %5d %5d %10"PRId64" "
+ "%10"PRId64" %10"PRId64" %10d "
+ "%7.2lf %7.2lf %7.2lf %7.2lf %7.2lf"
"%6d %6d %5d %5d %5d "
"%10"PRId64" %10.3lf"
"%10lf %8u %10"PRId64" %10d %10d\n",
@@ -2810,6 +2811,9 @@
cpi->rc.projected_frame_size / cpi->common.MBs,
(cpi->rc.projected_frame_size - cpi->rc.this_frame_target),
cpi->rc.vbr_bits_off_target,
+ cpi->rc.vbr_bits_off_target_fast,
+ cpi->twopass.extend_minq,
+ cpi->twopass.extend_minq_fast,
cpi->rc.total_target_vs_actual,
(cpi->rc.starting_buffer_level - cpi->rc.bits_off_target),
cpi->rc.total_actual_bits, cm->base_qindex,
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -1247,8 +1247,9 @@
twopass->modified_error_left = modified_error_total;
}
- // Reset the vbr bits off target counter
+ // Reset the vbr bits off target counters
cpi->rc.vbr_bits_off_target = 0;
+ cpi->rc.vbr_bits_off_target_fast = 0;
cpi->rc.rate_error_estimate = 0;
@@ -2650,6 +2651,7 @@
#define MINQ_ADJ_LIMIT 48
#define MINQ_ADJ_LIMIT_CQ 20
+#define HIGH_UNDERSHOOT_RATIO 2
void vp9_twopass_postencode_update(VP9_COMP *cpi) {TWO_PASS *const twopass = &cpi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
@@ -2716,5 +2718,32 @@
twopass->extend_minq = clamp(twopass->extend_minq, 0, minq_adj_limit);
twopass->extend_maxq = clamp(twopass->extend_maxq, 0, maxq_adj_limit);
+
+ // If there is a big and undexpected undershoot then feed the extra
+ // bits back in quickly. One situation where this may happen is if a
+ // frame is unexpectedly almost perfectly predicted by the ARF or GF
+ // but not very well predcited by the previous frame.
+ if (!frame_is_kf_gf_arf(cpi) && !cpi->rc.is_src_frame_alt_ref) {+ int fast_extra_thresh = rc->base_frame_target / HIGH_UNDERSHOOT_RATIO;
+ if (rc->projected_frame_size < fast_extra_thresh) {+ rc->vbr_bits_off_target_fast +=
+ fast_extra_thresh - rc->projected_frame_size;
+ rc->vbr_bits_off_target_fast =
+ MIN(rc->vbr_bits_off_target_fast, (4 * rc->avg_frame_bandwidth));
+
+ // Fast adaptation of minQ if necessary to use up the extra bits.
+ if (rc->avg_frame_bandwidth) {+ twopass->extend_minq_fast =
+ (int)(rc->vbr_bits_off_target_fast * 8 / rc->avg_frame_bandwidth);
+ }
+ twopass->extend_minq_fast = MIN(twopass->extend_minq_fast,
+ minq_adj_limit - twopass->extend_minq);
+ } else if (rc->vbr_bits_off_target_fast) {+ twopass->extend_minq_fast = MIN(twopass->extend_minq_fast,
+ minq_adj_limit - twopass->extend_minq);
+ } else {+ twopass->extend_minq_fast = 0;
+ }
+ }
}
}
--- a/vp9/encoder/vp9_firstpass.h
+++ b/vp9/encoder/vp9_firstpass.h
@@ -122,6 +122,7 @@
int baseline_active_worst_quality;
int extend_minq;
int extend_maxq;
+ int extend_minq_fast;
GF_GROUP gf_group;
} TWO_PASS;
@@ -135,6 +136,7 @@
void vp9_init_second_pass(struct VP9_COMP *cpi);
void vp9_rc_get_second_pass_params(struct VP9_COMP *cpi);
+void vp9_twopass_postencode_update(struct VP9_COMP *cpi);
// Post encode update of the rate control parameters for 2-pass
void vp9_twopass_postencode_update(struct VP9_COMP *cpi);
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -1061,10 +1061,12 @@
if (frame_is_intra_only(cm) ||
(!rc->is_src_frame_alt_ref &&
(cpi->refresh_golden_frame || cpi->refresh_alt_ref_frame))) {- active_best_quality -= cpi->twopass.extend_minq;
+ active_best_quality -=
+ (cpi->twopass.extend_minq + cpi->twopass.extend_minq_fast);
active_worst_quality += (cpi->twopass.extend_maxq / 2);
} else {- active_best_quality -= cpi->twopass.extend_minq / 2;
+ active_best_quality -=
+ (cpi->twopass.extend_minq + cpi->twopass.extend_minq_fast) / 2;
active_worst_quality += cpi->twopass.extend_maxq;
}
}
@@ -1671,9 +1673,9 @@
#define VBR_PCT_ADJUSTMENT_LIMIT 50
// For VBR...adjustment to the frame target based on error from previous frames
-static void vbr_rate_correction(VP9_COMP *cpi,
- int *this_frame_target,
- int64_t vbr_bits_off_target) {+static void vbr_rate_correction(VP9_COMP *cpi, int *this_frame_target) {+ RATE_CONTROL *const rc = &cpi->rc;
+ int64_t vbr_bits_off_target = rc->vbr_bits_off_target;
int max_delta;
double position_factor = 1.0;
@@ -1697,6 +1699,20 @@
(vbr_bits_off_target < -max_delta) ? max_delta
: (int)-vbr_bits_off_target;
}
+
+ // Fast redistribution of bits arising from massive local undershoot.
+ // Dont do it for kf,arf,gf or overlay frames.
+ if (!frame_is_kf_gf_arf(cpi) && !rc->is_src_frame_alt_ref &&
+ rc->vbr_bits_off_target_fast) {+ int one_frame_bits = MAX(rc->avg_frame_bandwidth, *this_frame_target);
+ int fast_extra_bits;
+ fast_extra_bits =
+ (int)MIN(rc->vbr_bits_off_target_fast, one_frame_bits);
+ fast_extra_bits = (int)MIN(fast_extra_bits,
+ MAX(one_frame_bits / 8, rc->vbr_bits_off_target_fast / 8));
+ *this_frame_target += (int)fast_extra_bits;
+ rc->vbr_bits_off_target_fast -= fast_extra_bits;
+ }
}
void vp9_set_target_rate(VP9_COMP *cpi) {@@ -1705,6 +1721,6 @@
// Correction to rate target based on prior over or under shoot.
if (cpi->oxcf.rc_mode == VPX_VBR || cpi->oxcf.rc_mode == VPX_CQ)
- vbr_rate_correction(cpi, &target_rate, rc->vbr_bits_off_target);
+ vbr_rate_correction(cpi, &target_rate);
vp9_rc_set_frame_target(cpi, target_rate);
}
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -100,6 +100,7 @@
int64_t buffer_level;
int64_t bits_off_target;
int64_t vbr_bits_off_target;
+ int64_t vbr_bits_off_target_fast;
int decimation_factor;
int decimation_count;