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Add adaptation option for VBR.

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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
This commit is contained in:
Paul Wilkins 2014-10-09 14:49:41 +01:00
parent 0e1068a4bd
commit 869d4ca519
4 changed files with 97 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

90
vp9/encoder/vp9_firstpass.c
View File

@ -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 @@ void vp9_init_second_pass(VP9_COMP *cpi) {
// 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 @@ static double calc_frame_boost(VP9_COMP *cpi,
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 @@ static double calc_frame_boost(VP9_COMP *cpi,
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 @@ static int calc_arf_boost(VP9_COMP *cpi, int offset,
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 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
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 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
// 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 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
((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 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
(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 @@ static void define_gf_group(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
(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 @@ static void find_next_key_frame(VP9_COMP *cpi, FIRSTPASS_STATS *this_frame) {
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 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
// 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 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
// 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 @@ void vp9_rc_get_second_pass_params(VP9_COMP *cpi) {
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 @@ void vp9_twopass_postencode_update(VP9_COMP *cpi) {
// 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);
}
}

4
vp9/encoder/vp9_firstpass.h
View File

@ -39,6 +39,8 @@ typedef struct {
} FIRSTPASS_MB_STATS;
#endif
#define VLOW_MOTION_THRESHOLD 950
typedef struct {
double frame;
double intra_error;
@ -112,6 +114,8 @@ typedef struct {
int gf_zeromotion_pct;
int active_worst_quality;
int extend_minq;
int extend_maxq;
GF_GROUP gf_group;
} TWO_PASS;

18
vp9/encoder/vp9_ratectrl.c
View File

@ -280,7 +280,7 @@ void vp9_rc_init(const VP9EncoderConfig *oxcf, int pass, RATE_CONTROL *rc) {
}
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 @@ void vp9_rc_init(const VP9EncoderConfig *oxcf, int pass, RATE_CONTROL *rc) {
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 @@ static int rc_pick_q_and_bounds_two_pass(const VP9_COMP *cpi,
}
}
// 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.

2
vp9/encoder/vp9_ratectrl.h
View File

@ -87,6 +87,8 @@ typedef struct {
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;