Add adaptation option for VBR.
Allow min and maxQ to creep when the undershoot
or overshoot exceeds thresholds controlled by the
command line under_shoot_pct and over_shoot_pct
values.
Default is 100%,100% which ~disables adaptation.
Derf results for example undershoot% / overshoot%:-
Head:- Mean abs (%rate error) = 14.4%
This check in:-
25%/25% - Mean abs (%rate error) = 6.7%
PSNR hit -1% SSIM -0.1%
5% / 5% - Mean abs (%rate error) = 2.2%
PSNR hit -3.3% SSIM - 1.1%
Most of the remaining error and most of the quality hit is
at extreme data rates. The adaptation code still has an
exception for material that is in effect static so that we
don't over adjust and over spend on YT slide show type
content.
Change-Id: If25a2449a415449c150acff23df713e9598d64c9
diff --git a/vp9/encoder/vp9_firstpass.c b/vp9/encoder/vp9_firstpass.c
index adbb57b..f357634 100644
--- a/vp9/encoder/vp9_firstpass.c
+++ b/vp9/encoder/vp9_firstpass.c
@@ -38,15 +38,16 @@
#define OUTPUT_FPF 0
#define ARF_STATS_OUTPUT 0
+#define BOOST_BREAKOUT 12.5
#define BOOST_FACTOR 12.5
-#define ERR_DIVISOR 125.0
+#define ERR_DIVISOR 128.0
#define FACTOR_PT_LOW 0.70
#define FACTOR_PT_HIGH 0.90
#define FIRST_PASS_Q 10.0
#define GF_MAX_BOOST 96.0
#define INTRA_MODE_PENALTY 1024
#define KF_MAX_BOOST 128.0
-#define MIN_ARF_BOOST 240
+#define MIN_ARF_GF_BOOST 240
#define MIN_DECAY_FACTOR 0.01
#define MIN_GF_INTERVAL 4
#define MIN_KF_BOOST 300
@@ -1180,6 +1181,8 @@
// Reset the vbr bits off target counter
cpi->rc.vbr_bits_off_target = 0;
+ cpi->rc.rate_error_estimate = 0;
+
// Static sequence monitor variables.
twopass->kf_zeromotion_pct = 100;
twopass->last_kfgroup_zeromotion_pct = 100;
@@ -1314,11 +1317,14 @@
double this_frame_mv_in_out,
double max_boost) {
double frame_boost;
+ const double lq = vp9_convert_qindex_to_q(cpi->rc.last_q[INTER_FRAME],
+ cpi->common.bit_depth);
+ const double q_correction = MIN((0.8 + (lq * 0.001)), 1.0);
// Underlying boost factor is based on inter error ratio.
frame_boost = (BASELINE_ERR_PER_MB * cpi->common.MBs) /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error);
- frame_boost = frame_boost * BOOST_FACTOR;
+ frame_boost = frame_boost * BOOST_FACTOR * q_correction;
// Increase boost for frames where new data coming into frame (e.g. zoom out).
// Slightly reduce boost if there is a net balance of motion out of the frame
@@ -1329,7 +1335,7 @@
else
frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
- return MIN(frame_boost, max_boost);
+ return MIN(frame_boost, max_boost * q_correction);
}
static int calc_arf_boost(VP9_COMP *cpi, int offset,
@@ -1418,7 +1424,7 @@
arf_boost = (*f_boost + *b_boost);
if (arf_boost < ((b_frames + f_frames) * 20))
arf_boost = ((b_frames + f_frames) * 20);
- arf_boost = MAX(arf_boost, MIN_ARF_BOOST);
+ arf_boost = MAX(arf_boost, MIN_ARF_GF_BOOST);
return arf_boost;
}
@@ -1731,6 +1737,9 @@
int int_max_q =
(int)(vp9_convert_qindex_to_q(twopass->active_worst_quality,
cpi->common.bit_depth));
+ int int_lbq =
+ (int)(vp9_convert_qindex_to_q(rc->last_boosted_qindex,
+ cpi->common.bit_depth));
active_min_gf_interval = MIN_GF_INTERVAL + MIN(2, int_max_q / 200);
if (active_min_gf_interval > rc->max_gf_interval)
active_min_gf_interval = rc->max_gf_interval;
@@ -1742,7 +1751,7 @@
// bits to spare and are better with a smaller interval and smaller boost.
// At high Q when there are few bits to spare we are better with a longer
// interval to spread the cost of the GF.
- active_max_gf_interval = 12 + MIN(4, (int_max_q / 24));
+ active_max_gf_interval = 12 + MIN(4, (int_lbq / 6));
if (active_max_gf_interval > rc->max_gf_interval)
active_max_gf_interval = rc->max_gf_interval;
}
@@ -1806,7 +1815,7 @@
((mv_ratio_accumulator > mv_ratio_accumulator_thresh) ||
(abs_mv_in_out_accumulator > 3.0) ||
(mv_in_out_accumulator < -2.0) ||
- ((boost_score - old_boost_score) < BOOST_FACTOR)))) {
+ ((boost_score - old_boost_score) < BOOST_BREAKOUT)))) {
boost_score = old_boost_score;
break;
}
@@ -1854,7 +1863,7 @@
(cpi->multi_arf_allowed && (rc->baseline_gf_interval >= 6) &&
(zero_motion_accumulator < 0.995)) ? 1 : 0;
} else {
- rc->gfu_boost = MAX((int)boost_score, 125);
+ rc->gfu_boost = MAX((int)boost_score, MIN_ARF_GF_BOOST);
rc->source_alt_ref_pending = 0;
}
@@ -1871,7 +1880,8 @@
(rc->gfu_boost * gfboost_qadjust(q, cpi->common.bit_depth)) / 100;
// Set max and minimum boost and hence minimum allocation.
- boost = clamp(boost, 125, (rc->baseline_gf_interval + 1) * 200);
+ boost = clamp(boost, MIN_ARF_GF_BOOST,
+ (rc->baseline_gf_interval + 1) * 200);
// Calculate the extra bits to be used for boosted frame(s)
gf_arf_bits = calculate_boost_bits(rc->baseline_gf_interval,
@@ -2224,10 +2234,23 @@
twopass->modified_error_left -= kf_group_err;
}
+#define VBR_PCT_ADJUSTMENT_LIMIT 50
// For VBR...adjustment to the frame target based on error from previous frames
-void vbr_rate_correction(int * this_frame_target,
+void vbr_rate_correction(VP9_COMP *cpi,
+ int * this_frame_target,
const int64_t vbr_bits_off_target) {
- int max_delta = (*this_frame_target * 15) / 100;
+ int max_delta;
+ double position_factor = 1.0;
+
+ // How far through the clip are we.
+ // This number is used to damp the per frame rate correction.
+ // Range 0 - 1.0
+ if (cpi->twopass.total_stats.count) {
+ position_factor = sqrt((double)cpi->common.current_video_frame /
+ cpi->twopass.total_stats.count);
+ }
+ max_delta = (int)(position_factor *
+ ((*this_frame_target * VBR_PCT_ADJUSTMENT_LIMIT) / 100));
// vbr_bits_off_target > 0 means we have extra bits to spend
if (vbr_bits_off_target > 0) {
@@ -2325,7 +2348,7 @@
// Correction to rate target based on prior over or under shoot.
if (cpi->oxcf.rc_mode == VPX_VBR)
- vbr_rate_correction(&target_rate, rc->vbr_bits_off_target);
+ vbr_rate_correction(cpi, &target_rate, rc->vbr_bits_off_target);
vp9_rc_set_frame_target(cpi, target_rate);
cm->frame_type = INTER_FRAME;
@@ -2438,7 +2461,7 @@
// Correction to rate target based on prior over or under shoot.
if (cpi->oxcf.rc_mode == VPX_VBR)
- vbr_rate_correction(&target_rate, rc->vbr_bits_off_target);
+ vbr_rate_correction(cpi, &target_rate, rc->vbr_bits_off_target);
vp9_rc_set_frame_target(cpi, target_rate);
@@ -2446,20 +2469,29 @@
subtract_stats(&twopass->total_left_stats, &this_frame);
}
+#define MINQ_ADJ_LIMIT 32
+#define Q_LIMIT_STEP 1
void vp9_twopass_postencode_update(VP9_COMP *cpi) {
TWO_PASS *const twopass = &cpi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
+ const int bits_used = rc->base_frame_target;
// VBR correction is done through rc->vbr_bits_off_target. Based on the
// sign of this value, a limited % adjustment is made to the target rate
// of subsequent frames, to try and push it back towards 0. This method
// is designed to prevent extreme behaviour at the end of a clip
// or group of frames.
- const int bits_used = rc->base_frame_target;
rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size;
-
twopass->bits_left = MAX(twopass->bits_left - bits_used, 0);
+ // Calculate the pct rc error.
+ if (rc->total_actual_bits) {
+ rc->rate_error_estimate =
+ (int)((rc->vbr_bits_off_target * 100) / rc->total_actual_bits);
+ } else {
+ rc->rate_error_estimate = 0;
+ }
+
if (cpi->common.frame_type != KEY_FRAME &&
!vp9_is_upper_layer_key_frame(cpi)) {
twopass->kf_group_bits -= bits_used;
@@ -2469,4 +2501,32 @@
// Increment the gf group index ready for the next frame.
++twopass->gf_group.index;
+
+ // If the rate control is drifting consider adjustment ot min or maxq.
+ // Only make adjustments on gf/arf
+ if ((cpi->oxcf.rc_mode == VPX_VBR) &&
+ (cpi->twopass.gf_zeromotion_pct < VLOW_MOTION_THRESHOLD) &&
+ !cpi->rc.is_src_frame_alt_ref) {
+ const int maxq_adj_limit =
+ rc->worst_quality - twopass->active_worst_quality;
+
+ // Undershoot.
+ if (rc->rate_error_estimate > cpi->oxcf.under_shoot_pct) {
+ --twopass->extend_maxq;
+ if (rc->rolling_target_bits >= rc->rolling_actual_bits)
+ twopass->extend_minq += Q_LIMIT_STEP;
+ // Overshoot.
+ } else if (rc->rate_error_estimate < -cpi->oxcf.over_shoot_pct) {
+ --twopass->extend_minq;
+ if (rc->rolling_target_bits < rc->rolling_actual_bits)
+ twopass->extend_maxq += Q_LIMIT_STEP;
+ } else {
+ if (rc->rolling_target_bits < rc->rolling_actual_bits)
+ --twopass->extend_minq;
+ if (rc->rolling_target_bits > rc->rolling_actual_bits)
+ --twopass->extend_maxq;
+ }
+ twopass->extend_minq = clamp(twopass->extend_minq, 0, MINQ_ADJ_LIMIT);
+ twopass->extend_maxq = clamp(twopass->extend_maxq, 0, maxq_adj_limit);
+ }
}
diff --git a/vp9/encoder/vp9_firstpass.h b/vp9/encoder/vp9_firstpass.h
index 0b82d32..2063e35 100644
--- a/vp9/encoder/vp9_firstpass.h
+++ b/vp9/encoder/vp9_firstpass.h
@@ -39,6 +39,8 @@
} FIRSTPASS_MB_STATS;
#endif
+#define VLOW_MOTION_THRESHOLD 950
+
typedef struct {
double frame;
double intra_error;
@@ -112,6 +114,8 @@
int gf_zeromotion_pct;
int active_worst_quality;
+ int extend_minq;
+ int extend_maxq;
GF_GROUP gf_group;
} TWO_PASS;
diff --git a/vp9/encoder/vp9_ratectrl.c b/vp9/encoder/vp9_ratectrl.c
index 9f255b0..208c1cb 100644
--- a/vp9/encoder/vp9_ratectrl.c
+++ b/vp9/encoder/vp9_ratectrl.c
@@ -280,7 +280,7 @@
}
rc->last_q[KEY_FRAME] = oxcf->best_allowed_q;
- rc->last_q[INTER_FRAME] = oxcf->best_allowed_q;
+ rc->last_q[INTER_FRAME] = oxcf->worst_allowed_q;
rc->buffer_level = rc->starting_buffer_level;
rc->bits_off_target = rc->starting_buffer_level;
@@ -302,7 +302,6 @@
rc->source_alt_ref_active = 0;
rc->frames_till_gf_update_due = 0;
-
rc->ni_av_qi = oxcf->worst_allowed_q;
rc->ni_tot_qi = 0;
rc->ni_frames = 0;
@@ -992,6 +991,21 @@
}
}
+ // Extenstion to max or min Q if undershoot or overshoot is outside
+ // the permitted range.
+ if ((cpi->oxcf.rc_mode == VPX_VBR) &&
+ (cpi->twopass.gf_zeromotion_pct < VLOW_MOTION_THRESHOLD)) {
+ 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_worst_quality += (cpi->twopass.extend_maxq / 2);
+ } else {
+ active_best_quality -= cpi->twopass.extend_minq / 2;
+ active_worst_quality += cpi->twopass.extend_maxq;
+ }
+ }
+
#if LIMIT_QRANGE_FOR_ALTREF_AND_KEY
vp9_clear_system_state();
// Static forced key frames Q restrictions dealt with elsewhere.
diff --git a/vp9/encoder/vp9_ratectrl.h b/vp9/encoder/vp9_ratectrl.h
index edfb9fc..bc74129 100644
--- a/vp9/encoder/vp9_ratectrl.h
+++ b/vp9/encoder/vp9_ratectrl.h
@@ -87,6 +87,8 @@
int long_rolling_target_bits;
int long_rolling_actual_bits;
+ int rate_error_estimate;
+
int64_t total_actual_bits;
int64_t total_target_bits;
int64_t total_target_vs_actual;
