Google Git
Sign in
aomedia / aom / e15483f6edb8f172c7747ff5d32c294a4bc25f8a / . / av1 / encoder / pass2_strategy.c
blob: 9752c65aa781271ce5a1dd06b435ddf29ee68eba [file] [log] [blame]
/*
* Copyright (c) 2019, Alliance for Open Media. All rights reserved
*
* This source code is subject to the terms of the BSD 2 Clause License and
* the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
* was not distributed with this source code in the LICENSE file, you can
* obtain it at www.aomedia.org/license/software. If the Alliance for Open
* Media Patent License 1.0 was not distributed with this source code in the
* PATENTS file, you can obtain it at www.aomedia.org/license/patent.
*/
/*!\defgroup gf_group_algo Golden Frame Group
* \ingroup high_level_algo
* Algorithms regarding determining the length of GF groups and defining GF
* group structures.
* @{
*/
/*! @} - end defgroup gf_group_algo */
#include <stdint.h>
#include "config/aom_config.h"
#include "config/aom_scale_rtcd.h"
#include "aom/aom_codec.h"
#include "aom/aom_encoder.h"
#include "aom_ports/system_state.h"
#include "av1/common/av1_common_int.h"
#include "av1/encoder/encoder.h"
#include "av1/encoder/firstpass.h"
#include "av1/encoder/gop_structure.h"
#include "av1/encoder/pass2_strategy.h"
#include "av1/encoder/ratectrl.h"
#include "av1/encoder/rc_utils.h"
#include "av1/encoder/temporal_filter.h"
#include "av1/encoder/tpl_model.h"
#include "av1/encoder/use_flat_gop_model_params.h"
#include "av1/encoder/encode_strategy.h"
#define DEFAULT_KF_BOOST 2300
#define DEFAULT_GF_BOOST 2000
#define GROUP_ADAPTIVE_MAXQ 1
static void init_gf_stats(GF_GROUP_STATS *gf_stats);
// Calculate an active area of the image that discounts formatting
// bars and partially discounts other 0 energy areas.
#define MIN_ACTIVE_AREA 0.5
#define MAX_ACTIVE_AREA 1.0
static double calculate_active_area(const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *this_frame) {
const double active_pct =
1.0 -
((this_frame->intra_skip_pct / 2) +
((this_frame->inactive_zone_rows * 2) / (double)frame_info->mb_rows));
return fclamp(active_pct, MIN_ACTIVE_AREA, MAX_ACTIVE_AREA);
}
// Calculate a modified Error used in distributing bits between easier and
// harder frames.
#define ACT_AREA_CORRECTION 0.5
static double calculate_modified_err(const FRAME_INFO *frame_info,
const TWO_PASS *twopass,
const AV1EncoderConfig *oxcf,
const FIRSTPASS_STATS *this_frame) {
const FIRSTPASS_STATS *const stats = twopass->stats_buf_ctx->total_stats;
if (stats == NULL) {
return 0;
}
const double av_weight = stats->weight / stats->count;
const double av_err = (stats->coded_error * av_weight) / stats->count;
double modified_error =
av_err * pow(this_frame->coded_error * this_frame->weight /
DOUBLE_DIVIDE_CHECK(av_err),
oxcf->rc_cfg.vbrbias / 100.0);
// Correction for active area. Frames with a reduced active area
// (eg due to formatting bars) have a higher error per mb for the
// remaining active MBs. The correction here assumes that coding
// 0.5N blocks of complexity 2X is a little easier than coding N
// blocks of complexity X.
modified_error *=
pow(calculate_active_area(frame_info, this_frame), ACT_AREA_CORRECTION);
return fclamp(modified_error, twopass->modified_error_min,
twopass->modified_error_max);
}
// Resets the first pass file to the given position using a relative seek from
// the current position.
static void reset_fpf_position(TWO_PASS *p, const FIRSTPASS_STATS *position) {
p->stats_in = position;
}
static int input_stats(TWO_PASS *p, FIRSTPASS_STATS *fps) {
if (p->stats_in >= p->stats_buf_ctx->stats_in_end) return EOF;
*fps = *p->stats_in;
++p->stats_in;
return 1;
}
static int input_stats_lap(TWO_PASS *p, FIRSTPASS_STATS *fps) {
if (p->stats_in >= p->stats_buf_ctx->stats_in_end) return EOF;
*fps = *p->stats_in;
/* Move old stats[0] out to accommodate for next frame stats */
memmove(p->frame_stats_arr[0], p->frame_stats_arr[1],
(p->stats_buf_ctx->stats_in_end - p->stats_in - 1) *
sizeof(FIRSTPASS_STATS));
p->stats_buf_ctx->stats_in_end--;
return 1;
}
// Read frame stats at an offset from the current position.
static const FIRSTPASS_STATS *read_frame_stats(const TWO_PASS *p, int offset) {
if ((offset >= 0 && p->stats_in + offset >= p->stats_buf_ctx->stats_in_end) ||
(offset < 0 && p->stats_in + offset < p->stats_buf_ctx->stats_in_start)) {
return NULL;
}
return &p->stats_in[offset];
}
static void subtract_stats(FIRSTPASS_STATS *section,
const FIRSTPASS_STATS *frame) {
section->frame -= frame->frame;
section->weight -= frame->weight;
section->intra_error -= frame->intra_error;
section->frame_avg_wavelet_energy -= frame->frame_avg_wavelet_energy;
section->coded_error -= frame->coded_error;
section->sr_coded_error -= frame->sr_coded_error;
section->pcnt_inter -= frame->pcnt_inter;
section->pcnt_motion -= frame->pcnt_motion;
section->pcnt_second_ref -= frame->pcnt_second_ref;
section->pcnt_neutral -= frame->pcnt_neutral;
section->intra_skip_pct -= frame->intra_skip_pct;
section->inactive_zone_rows -= frame->inactive_zone_rows;
section->inactive_zone_cols -= frame->inactive_zone_cols;
section->MVr -= frame->MVr;
section->mvr_abs -= frame->mvr_abs;
section->MVc -= frame->MVc;
section->mvc_abs -= frame->mvc_abs;
section->MVrv -= frame->MVrv;
section->MVcv -= frame->MVcv;
section->mv_in_out_count -= frame->mv_in_out_count;
section->new_mv_count -= frame->new_mv_count;
section->count -= frame->count;
section->duration -= frame->duration;
}
// This function returns the maximum target rate per frame.
static int frame_max_bits(const RATE_CONTROL *rc,
const AV1EncoderConfig *oxcf) {
int64_t max_bits = ((int64_t)rc->avg_frame_bandwidth *
(int64_t)oxcf->rc_cfg.vbrmax_section) /
100;
if (max_bits < 0)
max_bits = 0;
else if (max_bits > rc->max_frame_bandwidth)
max_bits = rc->max_frame_bandwidth;
return (int)max_bits;
}
static const double q_pow_term[(QINDEX_RANGE >> 5) + 1] = { 0.65, 0.70, 0.75,
0.80, 0.85, 0.90,
0.95, 0.95, 0.95 };
#define ERR_DIVISOR 96.0
static double calc_correction_factor(double err_per_mb, int q) {
const double error_term = err_per_mb / ERR_DIVISOR;
const int index = q >> 5;
// Adjustment to power term based on qindex
const double power_term =
q_pow_term[index] +
(((q_pow_term[index + 1] - q_pow_term[index]) * (q % 32)) / 32.0);
assert(error_term >= 0.0);
return fclamp(pow(error_term, power_term), 0.05, 5.0);
}
// Based on history adjust expectations of bits per macroblock.
static void twopass_update_bpm_factor(AV1_COMP *cpi, int rate_err_tol) {
TWO_PASS *twopass = &cpi->ppi->twopass;
const RATE_CONTROL *const rc = &cpi->rc;
int err_estimate = rc->rate_error_estimate;
// Based on recent history adjust expectations of bits per macroblock.
double damp_fac = AOMMAX(5.0, rate_err_tol / 10.0);
double rate_err_factor = 1.0;
const double adj_limit = AOMMAX(0.20, (double)(100 - rate_err_tol) / 200.0);
const double min_fac = 1.0 - adj_limit;
const double max_fac = 1.0 + adj_limit;
if (rc->vbr_bits_off_target && rc->total_actual_bits > 0) {
if (cpi->ppi->lap_enabled) {
rate_err_factor =
(double)twopass->rolling_arf_group_actual_bits /
DOUBLE_DIVIDE_CHECK((double)twopass->rolling_arf_group_target_bits);
} else {
rate_err_factor =
1.0 - ((double)(rc->vbr_bits_off_target) /
AOMMAX(rc->total_actual_bits, cpi->ppi->twopass.bits_left));
}
rate_err_factor = AOMMAX(min_fac, AOMMIN(max_fac, rate_err_factor));
// Adjustment is damped if this is 1 pass with look ahead processing
// (as there are only ever a few frames of data) and for all but the first
// GOP in normal two pass.
if ((twopass->bpm_factor != 1.0) || cpi->ppi->lap_enabled) {
rate_err_factor = 1.0 + ((rate_err_factor - 1.0) / damp_fac);
}
}
// Is the rate control trending in the right direction. Only make
// an adjustment if things are getting worse.
if ((rate_err_factor < 1.0 && err_estimate > 0) ||
(rate_err_factor > 1.0 && err_estimate < 0)) {
twopass->bpm_factor *= rate_err_factor;
twopass->bpm_factor = AOMMAX(min_fac, AOMMIN(max_fac, twopass->bpm_factor));
}
}
static int qbpm_enumerator(int rate_err_tol) {
return 1200000 + ((300000 * AOMMIN(75, AOMMAX(rate_err_tol - 25, 0))) / 75);
}
// Similar to find_qindex_by_rate() function in ratectrl.c, but includes
// calculation of a correction_factor.
static int find_qindex_by_rate_with_correction(
int desired_bits_per_mb, aom_bit_depth_t bit_depth, double error_per_mb,
double group_weight_factor, int rate_err_tol, int best_qindex,
int worst_qindex) {
assert(best_qindex <= worst_qindex);
int low = best_qindex;
int high = worst_qindex;
while (low < high) {
const int mid = (low + high) >> 1;
const double mid_factor = calc_correction_factor(error_per_mb, mid);
const double q = av1_convert_qindex_to_q(mid, bit_depth);
const int enumerator = qbpm_enumerator(rate_err_tol);
const int mid_bits_per_mb =
(int)((enumerator * mid_factor * group_weight_factor) / q);
if (mid_bits_per_mb > desired_bits_per_mb) {
low = mid + 1;
} else {
high = mid;
}
}
return low;
}
/*!\brief Choose a target maximum Q for a group of frames
*
* \ingroup rate_control
*
* This function is used to estimate a suitable maximum Q for a
* group of frames. Inititally it is called to get a crude estimate
* for the whole clip. It is then called for each ARF/GF group to get
* a revised estimate for that group.
*
* \param[in] cpi Top-level encoder structure
* \param[in] av_frame_err The average per frame coded error score
* for frames making up this section/group.
* \param[in] inactive_zone Used to mask off /ignore part of the
* frame. The most common use case is where
* a wide format video (e.g. 16:9) is
* letter-boxed into a more square format.
* Here we want to ignore the bands at the
* top and bottom.
* \param[in] av_target_bandwidth The target bits per frame
*
* \return The maximum Q for frames in the group.
*/
static int get_twopass_worst_quality(AV1_COMP *cpi, const double av_frame_err,
double inactive_zone,
int av_target_bandwidth) {
const RATE_CONTROL *const rc = &cpi->rc;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;
inactive_zone = fclamp(inactive_zone, 0.0, 1.0);
if (av_target_bandwidth <= 0) {
return rc->worst_quality; // Highest value allowed
} else {
const int num_mbs = (oxcf->resize_cfg.resize_mode != RESIZE_NONE)
? cpi->initial_mbs
: cpi->common.mi_params.MBs;
const int active_mbs = AOMMAX(1, num_mbs - (int)(num_mbs * inactive_zone));
const double av_err_per_mb = av_frame_err / active_mbs;
const int target_norm_bits_per_mb =
(int)((uint64_t)av_target_bandwidth << BPER_MB_NORMBITS) / active_mbs;
int rate_err_tol = AOMMIN(rc_cfg->under_shoot_pct, rc_cfg->over_shoot_pct);
// Update bpm correction factor based on previous GOP rate error.
twopass_update_bpm_factor(cpi, rate_err_tol);
// Try and pick a max Q that will be high enough to encode the
// content at the given rate.
int q = find_qindex_by_rate_with_correction(
target_norm_bits_per_mb, cpi->common.seq_params->bit_depth,
av_err_per_mb, cpi->ppi->twopass.bpm_factor, rate_err_tol,
rc->best_quality, rc->worst_quality);
// Restriction on active max q for constrained quality mode.
if (rc_cfg->mode == AOM_CQ) q = AOMMAX(q, rc_cfg->cq_level);
return q;
}
}
#define SR_DIFF_PART 0.0015
#define MOTION_AMP_PART 0.003
#define INTRA_PART 0.005
#define DEFAULT_DECAY_LIMIT 0.75
#define LOW_SR_DIFF_TRHESH 0.1
#define SR_DIFF_MAX 128.0
#define NCOUNT_FRAME_II_THRESH 5.0
static double get_sr_decay_rate(const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *frame) {
const int num_mbs = frame_info->num_mbs;
double sr_diff = (frame->sr_coded_error - frame->coded_error) / num_mbs;
double sr_decay = 1.0;
double modified_pct_inter;
double modified_pcnt_intra;
const double motion_amplitude_factor =
frame->pcnt_motion * ((frame->mvc_abs + frame->mvr_abs) / 2);
modified_pct_inter = frame->pcnt_inter;
if ((frame->intra_error / DOUBLE_DIVIDE_CHECK(frame->coded_error)) <
(double)NCOUNT_FRAME_II_THRESH) {
modified_pct_inter = frame->pcnt_inter - frame->pcnt_neutral;
}
modified_pcnt_intra = 100 * (1.0 - modified_pct_inter);
if ((sr_diff > LOW_SR_DIFF_TRHESH)) {
sr_diff = AOMMIN(sr_diff, SR_DIFF_MAX);
sr_decay = 1.0 - (SR_DIFF_PART * sr_diff) -
(MOTION_AMP_PART * motion_amplitude_factor) -
(INTRA_PART * modified_pcnt_intra);
}
return AOMMAX(sr_decay, AOMMIN(DEFAULT_DECAY_LIMIT, modified_pct_inter));
}
// This function gives an estimate of how badly we believe the prediction
// quality is decaying from frame to frame.
static double get_zero_motion_factor(const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *frame) {
const double zero_motion_pct = frame->pcnt_inter - frame->pcnt_motion;
double sr_decay = get_sr_decay_rate(frame_info, frame);
return AOMMIN(sr_decay, zero_motion_pct);
}
#define ZM_POWER_FACTOR 0.75
static double get_prediction_decay_rate(const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *next_frame) {
const double sr_decay_rate = get_sr_decay_rate(frame_info, next_frame);
const double zero_motion_factor =
(0.95 * pow((next_frame->pcnt_inter - next_frame->pcnt_motion),
ZM_POWER_FACTOR));
return AOMMAX(zero_motion_factor,
(sr_decay_rate + ((1.0 - sr_decay_rate) * zero_motion_factor)));
}
// Function to test for a condition where a complex transition is followed
// by a static section. For example in slide shows where there is a fade
// between slides. This is to help with more optimal kf and gf positioning.
static int detect_transition_to_still(TWO_PASS *const twopass,
const int min_gf_interval,
const int frame_interval,
const int still_interval,
const double loop_decay_rate,
const double last_decay_rate) {
// Break clause to detect very still sections after motion
// For example a static image after a fade or other transition
// instead of a clean scene cut.
if (frame_interval > min_gf_interval && loop_decay_rate >= 0.999 &&
last_decay_rate < 0.9) {
int j;
// Look ahead a few frames to see if static condition persists...
for (j = 0; j < still_interval; ++j) {
const FIRSTPASS_STATS *stats = &twopass->stats_in[j];
if (stats >= twopass->stats_buf_ctx->stats_in_end) break;
if (stats->pcnt_inter - stats->pcnt_motion < 0.999) break;
}
// Only if it does do we signal a transition to still.
return j == still_interval;
}
return 0;
}
// This function detects a flash through the high relative pcnt_second_ref
// score in the frame following a flash frame. The offset passed in should
// reflect this.
static int detect_flash(const TWO_PASS *twopass, const int offset) {
const FIRSTPASS_STATS *const next_frame = read_frame_stats(twopass, offset);
// What we are looking for here is a situation where there is a
// brief break in prediction (such as a flash) but subsequent frames
// are reasonably well predicted by an earlier (pre flash) frame.
// The recovery after a flash is indicated by a high pcnt_second_ref
// compared to pcnt_inter.
return next_frame != NULL &&
next_frame->pcnt_second_ref > next_frame->pcnt_inter &&
next_frame->pcnt_second_ref >= 0.5;
}
// Update the motion related elements to the GF arf boost calculation.
static void accumulate_frame_motion_stats(const FIRSTPASS_STATS *stats,
GF_GROUP_STATS *gf_stats) {
const double pct = stats->pcnt_motion;
// Accumulate Motion In/Out of frame stats.
gf_stats->this_frame_mv_in_out = stats->mv_in_out_count * pct;
gf_stats->mv_in_out_accumulator += gf_stats->this_frame_mv_in_out;
gf_stats->abs_mv_in_out_accumulator += fabs(gf_stats->this_frame_mv_in_out);
// Accumulate a measure of how uniform (or conversely how random) the motion
// field is (a ratio of abs(mv) / mv).
if (pct > 0.05) {
const double mvr_ratio =
fabs(stats->mvr_abs) / DOUBLE_DIVIDE_CHECK(fabs(stats->MVr));
const double mvc_ratio =
fabs(stats->mvc_abs) / DOUBLE_DIVIDE_CHECK(fabs(stats->MVc));
gf_stats->mv_ratio_accumulator +=
pct * (mvr_ratio < stats->mvr_abs ? mvr_ratio : stats->mvr_abs);
gf_stats->mv_ratio_accumulator +=
pct * (mvc_ratio < stats->mvc_abs ? mvc_ratio : stats->mvc_abs);
}
}
static void accumulate_this_frame_stats(const FIRSTPASS_STATS *stats,
const double mod_frame_err,
GF_GROUP_STATS *gf_stats) {
gf_stats->gf_group_err += mod_frame_err;
#if GROUP_ADAPTIVE_MAXQ
gf_stats->gf_group_raw_error += stats->coded_error;
#endif
gf_stats->gf_group_skip_pct += stats->intra_skip_pct;
gf_stats->gf_group_inactive_zone_rows += stats->inactive_zone_rows;
}
static void accumulate_next_frame_stats(const FIRSTPASS_STATS *stats,
const FRAME_INFO *frame_info,
const int flash_detected,
const int frames_since_key,
const int cur_idx,
GF_GROUP_STATS *gf_stats) {
accumulate_frame_motion_stats(stats, gf_stats);
// sum up the metric values of current gf group
gf_stats->avg_sr_coded_error += stats->sr_coded_error;
gf_stats->avg_tr_coded_error += stats->tr_coded_error;
gf_stats->avg_pcnt_second_ref += stats->pcnt_second_ref;
gf_stats->avg_pcnt_third_ref += stats->pcnt_third_ref;
gf_stats->avg_new_mv_count += stats->new_mv_count;
gf_stats->avg_wavelet_energy += stats->frame_avg_wavelet_energy;
if (fabs(stats->raw_error_stdev) > 0.000001) {
gf_stats->non_zero_stdev_count++;
gf_stats->avg_raw_err_stdev += stats->raw_error_stdev;
}
// Accumulate the effect of prediction quality decay
if (!flash_detected) {
gf_stats->last_loop_decay_rate = gf_stats->loop_decay_rate;
gf_stats->loop_decay_rate = get_prediction_decay_rate(frame_info, stats);
gf_stats->decay_accumulator =
gf_stats->decay_accumulator * gf_stats->loop_decay_rate;
// Monitor for static sections.
if ((frames_since_key + cur_idx - 1) > 1) {
gf_stats->zero_motion_accumulator =
AOMMIN(gf_stats->zero_motion_accumulator,
get_zero_motion_factor(frame_info, stats));
}
}
}
static void average_gf_stats(const int total_frame,
const FIRSTPASS_STATS *last_stat,
GF_GROUP_STATS *gf_stats) {
if (total_frame) {
gf_stats->avg_sr_coded_error /= total_frame;
gf_stats->avg_tr_coded_error /= total_frame;
gf_stats->avg_pcnt_second_ref /= total_frame;
if (total_frame - 1) {
gf_stats->avg_pcnt_third_ref_nolast =
(gf_stats->avg_pcnt_third_ref - last_stat->pcnt_third_ref) /
(total_frame - 1);
} else {
gf_stats->avg_pcnt_third_ref_nolast =
gf_stats->avg_pcnt_third_ref / total_frame;
}
gf_stats->avg_pcnt_third_ref /= total_frame;
gf_stats->avg_new_mv_count /= total_frame;
gf_stats->avg_wavelet_energy /= total_frame;
}
if (gf_stats->non_zero_stdev_count)
gf_stats->avg_raw_err_stdev /= gf_stats->non_zero_stdev_count;
}
static void get_features_from_gf_stats(const GF_GROUP_STATS *gf_stats,
const GF_FRAME_STATS *first_frame,
const GF_FRAME_STATS *last_frame,
const int num_mbs,
const int constrained_gf_group,
const int kf_zeromotion_pct,
const int num_frames, float *features) {
*features++ = (float)gf_stats->abs_mv_in_out_accumulator;
*features++ = (float)(gf_stats->avg_new_mv_count / num_mbs);
*features++ = (float)gf_stats->avg_pcnt_second_ref;
*features++ = (float)gf_stats->avg_pcnt_third_ref;
*features++ = (float)gf_stats->avg_pcnt_third_ref_nolast;
*features++ = (float)(gf_stats->avg_sr_coded_error / num_mbs);
*features++ = (float)(gf_stats->avg_tr_coded_error / num_mbs);
*features++ = (float)(gf_stats->avg_wavelet_energy / num_mbs);
*features++ = (float)(constrained_gf_group);
*features++ = (float)gf_stats->decay_accumulator;
*features++ = (float)(first_frame->frame_coded_error / num_mbs);
*features++ = (float)(first_frame->frame_sr_coded_error / num_mbs);
*features++ = (float)(first_frame->frame_tr_coded_error / num_mbs);
*features++ = (float)(first_frame->frame_err / num_mbs);
*features++ = (float)(kf_zeromotion_pct);
*features++ = (float)(last_frame->frame_coded_error / num_mbs);
*features++ = (float)(last_frame->frame_sr_coded_error / num_mbs);
*features++ = (float)(last_frame->frame_tr_coded_error / num_mbs);
*features++ = (float)num_frames;
*features++ = (float)gf_stats->mv_ratio_accumulator;
*features++ = (float)gf_stats->non_zero_stdev_count;
}
#define BOOST_FACTOR 12.5
static double baseline_err_per_mb(const FRAME_INFO *frame_info) {
unsigned int screen_area = frame_info->frame_height * frame_info->frame_width;
// Use a different error per mb factor for calculating boost for
// different formats.
if (screen_area <= 640 * 360) {
return 500.0;
} else {
return 1000.0;
}
}
static double calc_frame_boost(const RATE_CONTROL *rc,
const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *this_frame,
double this_frame_mv_in_out, double max_boost) {
double frame_boost;
const double lq = av1_convert_qindex_to_q(rc->avg_frame_qindex[INTER_FRAME],
frame_info->bit_depth);
const double boost_q_correction = AOMMIN((0.5 + (lq * 0.015)), 1.5);
const double active_area = calculate_active_area(frame_info, this_frame);
int num_mbs = frame_info->num_mbs;
// Correct for any inactive region in the image
num_mbs = (int)AOMMAX(1, num_mbs * active_area);
// Underlying boost factor is based on inter error ratio.
frame_boost = AOMMAX(baseline_err_per_mb(frame_info) * num_mbs,
this_frame->intra_error * active_area) /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error);
frame_boost = frame_boost * BOOST_FACTOR * boost_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
// (zoom in). The range for this_frame_mv_in_out is -1.0 to +1.0.
if (this_frame_mv_in_out > 0.0)
frame_boost += frame_boost * (this_frame_mv_in_out * 2.0);
// In the extreme case the boost is halved.
else
frame_boost += frame_boost * (this_frame_mv_in_out / 2.0);
return AOMMIN(frame_boost, max_boost * boost_q_correction);
}
static double calc_kf_frame_boost(const RATE_CONTROL *rc,
const FRAME_INFO *frame_info,
const FIRSTPASS_STATS *this_frame,
double *sr_accumulator, double max_boost) {
double frame_boost;
const double lq = av1_convert_qindex_to_q(rc->avg_frame_qindex[INTER_FRAME],
frame_info->bit_depth);
const double boost_q_correction = AOMMIN((0.50 + (lq * 0.015)), 2.00);
const double active_area = calculate_active_area(frame_info, this_frame);
int num_mbs = frame_info->num_mbs;
// Correct for any inactive region in the image
num_mbs = (int)AOMMAX(1, num_mbs * active_area);
// Underlying boost factor is based on inter error ratio.
frame_boost = AOMMAX(baseline_err_per_mb(frame_info) * num_mbs,
this_frame->intra_error * active_area) /
DOUBLE_DIVIDE_CHECK(
(this_frame->coded_error + *sr_accumulator) * active_area);
// Update the accumulator for second ref error difference.
// This is intended to give an indication of how much the coded error is
// increasing over time.
*sr_accumulator += (this_frame->sr_coded_error - this_frame->coded_error);
*sr_accumulator = AOMMAX(0.0, *sr_accumulator);
// Q correction and scaling
// The 40.0 value here is an experimentally derived baseline minimum.
// This value is in line with the minimum per frame boost in the alt_ref
// boost calculation.
frame_boost = ((frame_boost + 40.0) * boost_q_correction);
return AOMMIN(frame_boost, max_boost * boost_q_correction);
}
static int get_projected_gfu_boost(const PRIMARY_RATE_CONTROL *p_rc,
int gfu_boost, int frames_to_project,
int num_stats_used_for_gfu_boost) {
/*
* If frames_to_project is equal to num_stats_used_for_gfu_boost,
* it means that gfu_boost was calculated over frames_to_project to
* begin with(ie; all stats required were available), hence return
* the original boost.
*/
if (num_stats_used_for_gfu_boost >= frames_to_project) return gfu_boost;
double min_boost_factor = sqrt(p_rc->baseline_gf_interval);
// Get the current tpl factor (number of frames = frames_to_project).
double tpl_factor = av1_get_gfu_boost_projection_factor(
min_boost_factor, MAX_GFUBOOST_FACTOR, frames_to_project);
// Get the tpl factor when number of frames = num_stats_used_for_prior_boost.
double tpl_factor_num_stats = av1_get_gfu_boost_projection_factor(
min_boost_factor, MAX_GFUBOOST_FACTOR, num_stats_used_for_gfu_boost);
int projected_gfu_boost =
(int)rint((tpl_factor * gfu_boost) / tpl_factor_num_stats);
return projected_gfu_boost;
}
#define GF_MAX_BOOST 90.0
#define GF_MIN_BOOST 50
#define MIN_DECAY_FACTOR 0.01
int av1_calc_arf_boost(const TWO_PASS *twopass,
const PRIMARY_RATE_CONTROL *p_rc, const RATE_CONTROL *rc,
FRAME_INFO *frame_info, int offset, int f_frames,
int b_frames, int *num_fpstats_used,
int *num_fpstats_required, int project_gfu_boost) {
int i;
GF_GROUP_STATS gf_stats;
init_gf_stats(&gf_stats);
double boost_score = (double)NORMAL_BOOST;
int arf_boost;
int flash_detected = 0;
if (num_fpstats_used) *num_fpstats_used = 0;
// Search forward from the proposed arf/next gf position.
for (i = 0; i < f_frames; ++i) {
const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset);
if (this_frame == NULL) break;
// Update the motion related elements to the boost calculation.
accumulate_frame_motion_stats(this_frame, &gf_stats);
// We want to discount the flash frame itself and the recovery
// frame that follows as both will have poor scores.
flash_detected = detect_flash(twopass, i + offset) ||
detect_flash(twopass, i + offset + 1);
// Accumulate the effect of prediction quality decay.
if (!flash_detected) {
gf_stats.decay_accumulator *=
get_prediction_decay_rate(frame_info, this_frame);
gf_stats.decay_accumulator = gf_stats.decay_accumulator < MIN_DECAY_FACTOR
? MIN_DECAY_FACTOR
: gf_stats.decay_accumulator;
}
boost_score +=
gf_stats.decay_accumulator *
calc_frame_boost(rc, frame_info, this_frame,
gf_stats.this_frame_mv_in_out, GF_MAX_BOOST);
if (num_fpstats_used) (*num_fpstats_used)++;
}
arf_boost = (int)boost_score;
// Reset for backward looking loop.
boost_score = 0.0;
init_gf_stats(&gf_stats);
// Search backward towards last gf position.
for (i = -1; i >= -b_frames; --i) {
const FIRSTPASS_STATS *this_frame = read_frame_stats(twopass, i + offset);
if (this_frame == NULL) break;
// Update the motion related elements to the boost calculation.
accumulate_frame_motion_stats(this_frame, &gf_stats);
// We want to discount the the flash frame itself and the recovery
// frame that follows as both will have poor scores.
flash_detected = detect_flash(twopass, i + offset) ||
detect_flash(twopass, i + offset + 1);
// Cumulative effect of prediction quality decay.
if (!flash_detected) {
gf_stats.decay_accumulator *=
get_prediction_decay_rate(frame_info, this_frame);
gf_stats.decay_accumulator = gf_stats.decay_accumulator < MIN_DECAY_FACTOR
? MIN_DECAY_FACTOR
: gf_stats.decay_accumulator;
}
boost_score +=
gf_stats.decay_accumulator *
calc_frame_boost(rc, frame_info, this_frame,
gf_stats.this_frame_mv_in_out, GF_MAX_BOOST);
if (num_fpstats_used) (*num_fpstats_used)++;
}
arf_boost += (int)boost_score;
if (project_gfu_boost) {
assert(num_fpstats_required != NULL);
assert(num_fpstats_used != NULL);
*num_fpstats_required = f_frames + b_frames;
arf_boost = get_projected_gfu_boost(p_rc, arf_boost, *num_fpstats_required,
*num_fpstats_used);
}
if (arf_boost < ((b_frames + f_frames) * GF_MIN_BOOST))
arf_boost = ((b_frames + f_frames) * GF_MIN_BOOST);
return arf_boost;
}
// Calculate a section intra ratio used in setting max loop filter.
static int calculate_section_intra_ratio(const FIRSTPASS_STATS *begin,
const FIRSTPASS_STATS *end,
int section_length) {
const FIRSTPASS_STATS *s = begin;
double intra_error = 0.0;
double coded_error = 0.0;
int i = 0;
while (s < end && i < section_length) {
intra_error += s->intra_error;
coded_error += s->coded_error;
++s;
++i;
}
return (int)(intra_error / DOUBLE_DIVIDE_CHECK(coded_error));
}
/*!\brief Calculates the bit target for this GF/ARF group
*
* \ingroup rate_control
*
* Calculates the total bits to allocate in this GF/ARF group.
*
* \param[in] cpi Top-level encoder structure
* \param[in] gf_group_err Cumulative coded error score for the
* frames making up this group.
*
* \return The target total number of bits for this GF/ARF group.
*/
static int64_t calculate_total_gf_group_bits(AV1_COMP *cpi,
double gf_group_err) {
const RATE_CONTROL *const rc = &cpi->rc;
const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
const TWO_PASS *const twopass = &cpi->ppi->twopass;
const int max_bits = frame_max_bits(rc, &cpi->oxcf);
int64_t total_group_bits;
// Calculate the bits to be allocated to the group as a whole.
if ((twopass->kf_group_bits > 0) && (twopass->kf_group_error_left > 0)) {
total_group_bits = (int64_t)(twopass->kf_group_bits *
(gf_group_err / twopass->kf_group_error_left));
} else {
total_group_bits = 0;
}
// Clamp odd edge cases.
total_group_bits = (total_group_bits < 0)
? 0
: (total_group_bits > twopass->kf_group_bits)
? twopass->kf_group_bits
: total_group_bits;
// Clip based on user supplied data rate variability limit.
if (total_group_bits > (int64_t)max_bits * p_rc->baseline_gf_interval)
total_group_bits = (int64_t)max_bits * p_rc->baseline_gf_interval;
return total_group_bits;
}
// Calculate the number of bits to assign to boosted frames in a group.
static int calculate_boost_bits(int frame_count, int boost,
int64_t total_group_bits) {
int allocation_chunks;
// return 0 for invalid inputs (could arise e.g. through rounding errors)
if (!boost || (total_group_bits <= 0)) return 0;
if (frame_count <= 0) return (int)(AOMMIN(total_group_bits, INT_MAX));
allocation_chunks = (frame_count * 100) + boost;
// Prevent overflow.
if (boost > 1023) {
int divisor = boost >> 10;
boost /= divisor;
allocation_chunks /= divisor;
}
// Calculate the number of extra bits for use in the boosted frame or frames.
return AOMMAX((int)(((int64_t)boost * total_group_bits) / allocation_chunks),
0);
}
// Calculate the boost factor based on the number of bits assigned, i.e. the
// inverse of calculate_boost_bits().
static int calculate_boost_factor(int frame_count, int bits,
int64_t total_group_bits) {
aom_clear_system_state();
return (int)(100.0 * frame_count * bits / (total_group_bits - bits));
}
// Reduce the number of bits assigned to keyframe or arf if necessary, to
// prevent bitrate spikes that may break level constraints.
// frame_type: 0: keyframe; 1: arf.
static int adjust_boost_bits_for_target_level(const AV1_COMP *const cpi,
RATE_CONTROL *const rc,
int bits_assigned,
int64_t group_bits,
int frame_type) {
const AV1_COMMON *const cm = &cpi->common;
const SequenceHeader *const seq_params = cm->seq_params;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
const int temporal_layer_id = cm->temporal_layer_id;
const int spatial_layer_id = cm->spatial_layer_id;
for (int index = 0; index < seq_params->operating_points_cnt_minus_1 + 1;
++index) {
if (!is_in_operating_point(seq_params->operating_point_idc[index],
temporal_layer_id, spatial_layer_id)) {
continue;
}
const AV1_LEVEL target_level =
cpi->ppi->level_params.target_seq_level_idx[index];
if (target_level >= SEQ_LEVELS) continue;
assert(is_valid_seq_level_idx(target_level));
const double level_bitrate_limit = av1_get_max_bitrate_for_level(
target_level, seq_params->tier[0], seq_params->profile);
const int target_bits_per_frame =
(int)(level_bitrate_limit / cpi->framerate);
if (frame_type == 0) {
// Maximum bits for keyframe is 8 times the target_bits_per_frame.
const int level_enforced_max_kf_bits = target_bits_per_frame * 8;
if (bits_assigned > level_enforced_max_kf_bits) {
const int frames = rc->frames_to_key - 1;
p_rc->kf_boost = calculate_boost_factor(
frames, level_enforced_max_kf_bits, group_bits);
bits_assigned =
calculate_boost_bits(frames, p_rc->kf_boost, group_bits);
}
} else if (frame_type == 1) {
// Maximum bits for arf is 4 times the target_bits_per_frame.
const int level_enforced_max_arf_bits = target_bits_per_frame * 4;
if (bits_assigned > level_enforced_max_arf_bits) {
p_rc->gfu_boost =
calculate_boost_factor(p_rc->baseline_gf_interval,
level_enforced_max_arf_bits, group_bits);
bits_assigned = calculate_boost_bits(p_rc->baseline_gf_interval,
p_rc->gfu_boost, group_bits);
}
} else {
assert(0);
}
}
return bits_assigned;
}
// Allocate bits to each frame in a GF / ARF group
double layer_fraction[MAX_ARF_LAYERS + 1] = { 1.0, 0.70, 0.55, 0.60,
0.60, 1.0, 1.0 };
static void allocate_gf_group_bits(GF_GROUP *gf_group,
PRIMARY_RATE_CONTROL *const p_rc,
RATE_CONTROL *const rc,
int64_t gf_group_bits, int gf_arf_bits,
int key_frame, int use_arf) {
int64_t total_group_bits = gf_group_bits;
int base_frame_bits;
const int gf_group_size = gf_group->size;
int layer_frames[MAX_ARF_LAYERS + 1] = { 0 };
// For key frames the frame target rate is already set and it
// is also the golden frame.
// === [frame_index == 0] ===
int frame_index = !!key_frame;
// Subtract the extra bits set aside for ARF frames from the Group Total
if (use_arf) total_group_bits -= gf_arf_bits;
int num_frames =
AOMMAX(1, p_rc->baseline_gf_interval - (rc->frames_since_key == 0));
base_frame_bits = (int)(total_group_bits / num_frames);
// Check the number of frames in each layer in case we have a
// non standard group length.
int max_arf_layer = gf_group->max_layer_depth - 1;
for (int idx = frame_index; idx < gf_group_size; ++idx) {
if ((gf_group->update_type[idx] == ARF_UPDATE) ||
(gf_group->update_type[idx] == INTNL_ARF_UPDATE)) {
layer_frames[gf_group->layer_depth[idx]]++;
}
}
// Allocate extra bits to each ARF layer
int i;
int layer_extra_bits[MAX_ARF_LAYERS + 1] = { 0 };
for (i = 1; i <= max_arf_layer; ++i) {
double fraction = (i == max_arf_layer) ? 1.0 : layer_fraction[i];
layer_extra_bits[i] =
(int)((gf_arf_bits * fraction) / AOMMAX(1, layer_frames[i]));
gf_arf_bits -= (int)(gf_arf_bits * fraction);
}
// Now combine ARF layer and baseline bits to give total bits for each frame.
int arf_extra_bits;
for (int idx = frame_index; idx < gf_group_size; ++idx) {
switch (gf_group->update_type[idx]) {
case ARF_UPDATE:
case INTNL_ARF_UPDATE:
arf_extra_bits = layer_extra_bits[gf_group->layer_depth[idx]];
gf_group->bit_allocation[idx] = base_frame_bits + arf_extra_bits;
break;
case INTNL_OVERLAY_UPDATE:
case OVERLAY_UPDATE: gf_group->bit_allocation[idx] = 0; break;
default: gf_group->bit_allocation[idx] = base_frame_bits; break;
}
}
// Set the frame following the current GOP to 0 bit allocation. For ARF
// groups, this next frame will be overlay frame, which is the first frame
// in the next GOP. For GF group, next GOP will overwrite the rate allocation.
// Setting this frame to use 0 bit (of out the current GOP budget) will
// simplify logics in reference frame management.
if (gf_group_size < MAX_STATIC_GF_GROUP_LENGTH)
gf_group->bit_allocation[gf_group_size] = 0;
}
// Returns true if KF group and GF group both are almost completely static.
static INLINE int is_almost_static(double gf_zero_motion, int kf_zero_motion,
int is_lap_enabled) {
if (is_lap_enabled) {
/*
* when LAP enabled kf_zero_motion is not reliable, so use strict
* constraint on gf_zero_motion.
*/
return (gf_zero_motion >= 0.999);
} else {
return (gf_zero_motion >= 0.995) &&
(kf_zero_motion >= STATIC_KF_GROUP_THRESH);
}
}
#define ARF_ABS_ZOOM_THRESH 4.4
static INLINE int detect_gf_cut(AV1_COMP *cpi, int frame_index, int cur_start,
int flash_detected, int active_max_gf_interval,
int active_min_gf_interval,
GF_GROUP_STATS *gf_stats) {
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
InitialDimensions *const initial_dimensions = &cpi->initial_dimensions;
// Motion breakout threshold for loop below depends on image size.
const double mv_ratio_accumulator_thresh =
(initial_dimensions->height + initial_dimensions->width) / 4.0;
if (!flash_detected) {
// Break clause to detect very still sections after motion. For example,
// a static image after a fade or other transition.
if (detect_transition_to_still(
twopass, rc->min_gf_interval, frame_index - cur_start, 5,
gf_stats->loop_decay_rate, gf_stats->last_loop_decay_rate)) {
return 1;
}
}
// Some conditions to breakout after min interval.
if (frame_index - cur_start >= active_min_gf_interval &&
// If possible don't break very close to a kf
(rc->frames_to_key - frame_index >= rc->min_gf_interval) &&
((frame_index - cur_start) & 0x01) && !flash_detected &&
(gf_stats->mv_ratio_accumulator > mv_ratio_accumulator_thresh ||
gf_stats->abs_mv_in_out_accumulator > ARF_ABS_ZOOM_THRESH)) {
return 1;
}
// If almost totally static, we will not use the the max GF length later,
// so we can continue for more frames.
if (((frame_index - cur_start) >= active_max_gf_interval + 1) &&
!is_almost_static(gf_stats->zero_motion_accumulator,
twopass->kf_zeromotion_pct, cpi->ppi->lap_enabled)) {
return 1;
}
return 0;
}
static int is_shorter_gf_interval_better(AV1_COMP *cpi,
EncodeFrameParams *frame_params,
const EncodeFrameInput *frame_input) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
int gop_length_decision_method = cpi->sf.tpl_sf.gop_length_decision_method;
int shorten_gf_interval;
if (gop_length_decision_method == 2) {
// GF group length is decided based on GF boost and tpl stats of ARFs from
// base layer, (base+1) layer.
shorten_gf_interval =
(p_rc->gfu_boost <
p_rc->num_stats_used_for_gfu_boost * GF_MIN_BOOST * 1.4) &&
!av1_tpl_setup_stats(cpi, 3, frame_params, frame_input);
} else {
int do_complete_tpl = 1;
GF_GROUP *const gf_group = &cpi->ppi->gf_group;
int is_temporal_filter_enabled =
(rc->frames_since_key > 0 && gf_group->arf_index > -1);
if (is_temporal_filter_enabled) {
int arf_src_index = gf_group->arf_src_offset[gf_group->arf_index];
FRAME_UPDATE_TYPE arf_update_type =
gf_group->update_type[gf_group->arf_index];
int is_forward_keyframe = 0;
av1_temporal_filter(cpi, arf_src_index, arf_update_type,
is_forward_keyframe, NULL);
aom_extend_frame_borders(&cpi->ppi->alt_ref_buffer,
av1_num_planes(&cpi->common));
}
if (gop_length_decision_method == 1) {
// Check if tpl stats of ARFs from base layer, (base+1) layer,
// (base+2) layer can decide the GF group length.
int gop_length_eval =
av1_tpl_setup_stats(cpi, 2, frame_params, frame_input);
if (gop_length_eval != 2) {
do_complete_tpl = 0;
shorten_gf_interval = !gop_length_eval;
}
}
if (do_complete_tpl) {
// Decide GF group length based on complete tpl stats.
shorten_gf_interval =
!av1_tpl_setup_stats(cpi, 1, frame_params, frame_input);
// Tpl stats is reused when the ARF is temporally filtered and GF
// interval is not shortened.
if (is_temporal_filter_enabled && !shorten_gf_interval)
cpi->tpl_data.skip_tpl_setup_stats = 1;
}
}
return shorten_gf_interval;
}
#define MIN_FWD_KF_INTERVAL 8
#define MIN_SHRINK_LEN 6 // the minimum length of gf if we are shrinking
#define SMOOTH_FILT_LEN 7
#define HALF_FILT_LEN (SMOOTH_FILT_LEN / 2)
#define WINDOW_SIZE 7
#define HALF_WIN (WINDOW_SIZE / 2)
// A 7-tap gaussian smooth filter
const double smooth_filt[SMOOTH_FILT_LEN] = { 0.006, 0.061, 0.242, 0.383,
0.242, 0.061, 0.006 };
// Smooth filter intra_error and coded_error in firstpass stats.
// If stats[i].is_flash==1, the ith element should not be used in the filtering.
static void smooth_filter_stats(const FIRSTPASS_STATS *stats, int start_idx,
int last_idx, double *filt_intra_err,
double *filt_coded_err) {
int i, j;
for (i = start_idx; i <= last_idx; i++) {
double total_wt = 0;
for (j = -HALF_FILT_LEN; j <= HALF_FILT_LEN; j++) {
int idx = AOMMIN(AOMMAX(i + j, start_idx), last_idx);
if (stats[idx].is_flash) continue;
filt_intra_err[i] +=
smooth_filt[j + HALF_FILT_LEN] * stats[idx].intra_error;
total_wt += smooth_filt[j + HALF_FILT_LEN];
}
if (total_wt > 0.01) {
filt_intra_err[i] /= total_wt;
} else {
filt_intra_err[i] = stats[i].intra_error;
}
}
for (i = start_idx; i <= last_idx; i++) {
double total_wt = 0;
for (j = -HALF_FILT_LEN; j <= HALF_FILT_LEN; j++) {
int idx = AOMMIN(AOMMAX(i + j, start_idx), last_idx);
// Coded error involves idx and idx - 1.
if (stats[idx].is_flash || (idx > 0 && stats[idx - 1].is_flash)) continue;
filt_coded_err[i] +=
smooth_filt[j + HALF_FILT_LEN] * stats[idx].coded_error;
total_wt += smooth_filt[j + HALF_FILT_LEN];
}
if (total_wt > 0.01) {
filt_coded_err[i] /= total_wt;
} else {
filt_coded_err[i] = stats[i].coded_error;
}
}
}
// Calculate gradient
static void get_gradient(const double *values, int start, int last,
double *grad) {
if (start == last) {
grad[start] = 0;
return;
}
for (int i = start; i <= last; i++) {
int prev = AOMMAX(i - 1, start);
int next = AOMMIN(i + 1, last);
grad[i] = (values[next] - values[prev]) / (next - prev);
}
}
static int find_next_scenecut(const FIRSTPASS_STATS *const stats_start,
int first, int last) {
// Identify unstable areas caused by scenecuts.
// Find the max and 2nd max coded error, and the average of the rest frames.
// If there is only one frame that yields a huge coded error, it is likely a
// scenecut.
double this_ratio, max_prev_ratio, max_next_ratio, max_prev_coded,
max_next_coded;
if (last - first == 0) return -1;
for (int i = first; i <= last; i++) {
if (stats_start[i].is_flash || (i > 0 && stats_start[i - 1].is_flash))
continue;
double temp_intra = AOMMAX(stats_start[i].intra_error, 0.01);
this_ratio = stats_start[i].coded_error / temp_intra;
// find the avg ratio in the preceding neighborhood
max_prev_ratio = 0;
max_prev_coded = 0;
for (int j = AOMMAX(first, i - HALF_WIN); j < i; j++) {
if (stats_start[j].is_flash || (j > 0 && stats_start[j - 1].is_flash))
continue;
temp_intra = AOMMAX(stats_start[j].intra_error, 0.01);
double temp_ratio = stats_start[j].coded_error / temp_intra;
if (temp_ratio > max_prev_ratio) {
max_prev_ratio = temp_ratio;
}
if (stats_start[j].coded_error > max_prev_coded) {
max_prev_coded = stats_start[j].coded_error;
}
}
// find the avg ratio in the following neighborhood
max_next_ratio = 0;
max_next_coded = 0;
for (int j = i + 1; j <= AOMMIN(i + HALF_WIN, last); j++) {
if (stats_start[i].is_flash || (i > 0 && stats_start[i - 1].is_flash))
continue;
temp_intra = AOMMAX(stats_start[j].intra_error, 0.01);
double temp_ratio = stats_start[j].coded_error / temp_intra;
if (temp_ratio > max_next_ratio) {
max_next_ratio = temp_ratio;
}
if (stats_start[j].coded_error > max_next_coded) {
max_next_coded = stats_start[j].coded_error;
}
}
if (max_prev_ratio < 0.001 && max_next_ratio < 0.001) {
// the ratios are very small, only check a small fixed threshold
if (this_ratio < 0.02) continue;
} else {
// check if this frame has a larger ratio than the neighborhood
double max_sr = stats_start[i].sr_coded_error;
if (i < last) max_sr = AOMMAX(max_sr, stats_start[i + 1].sr_coded_error);
double max_sr_fr_ratio =
max_sr / AOMMAX(stats_start[i].coded_error, 0.01);
if (max_sr_fr_ratio > 1.2) continue;
if (this_ratio < 2 * AOMMAX(max_prev_ratio, max_next_ratio) &&
stats_start[i].coded_error <
2 * AOMMAX(max_prev_coded, max_next_coded)) {
continue;
}
}
return i;
}
return -1;
}
// Remove the region with index next_region.
// parameter merge: 0: merge with previous; 1: merge with next; 2:
// merge with both, take type from previous if possible
// After removing, next_region will be the index of the next region.
static void remove_region(int merge, REGIONS *regions, int *num_regions,
int *next_region) {
int k = *next_region;
assert(k < *num_regions);
if (*num_regions == 1) {
*num_regions = 0;
return;
}
if (k == 0) {
merge = 1;
} else if (k == *num_regions - 1) {
merge = 0;
}
int num_merge = (merge == 2) ? 2 : 1;
switch (merge) {
case 0:
regions[k - 1].last = regions[k].last;
*next_region = k;
break;
case 1:
regions[k + 1].start = regions[k].start;
*next_region = k + 1;
break;
case 2:
regions[k - 1].last = regions[k + 1].last;
*next_region = k;
break;
default: assert(0);
}
*num_regions -= num_merge;
for (k = *next_region - (merge == 1); k < *num_regions; k++) {
regions[k] = regions[k + num_merge];
}
}
// Insert a region in the cur_region_idx. The start and last should both be in
// the current region. After insertion, the cur_region_idx will point to the
// last region that was splitted from the original region.
static void insert_region(int start, int last, REGION_TYPES type,
REGIONS *regions, int *num_regions,
int *cur_region_idx) {
int k = *cur_region_idx;
REGION_TYPES this_region_type = regions[k].type;
int this_region_last = regions[k].last;
int num_add = (start != regions[k].start) + (last != regions[k].last);
// move the following regions further to the back
for (int r = *num_regions - 1; r > k; r--) {
regions[r + num_add] = regions[r];
}
*num_regions += num_add;
if (start > regions[k].start) {
regions[k].last = start - 1;
k++;
regions[k].start = start;
}
regions[k].type = type;
if (last < this_region_last) {
regions[k].last = last;
k++;
regions[k].start = last + 1;
regions[k].last = this_region_last;
regions[k].type = this_region_type;
} else {
regions[k].last = this_region_last;
}
*cur_region_idx = k;
}
// Get the average of stats inside a region.
static void analyze_region(const FIRSTPASS_STATS *stats, int k,
REGIONS *regions) {
int i;
regions[k].avg_cor_coeff = 0;
regions[k].avg_sr_fr_ratio = 0;
regions[k].avg_intra_err = 0;
regions[k].avg_coded_err = 0;
int check_first_sr = (k != 0);
for (i = regions[k].start; i <= regions[k].last; i++) {
if (i > regions[k].start || check_first_sr) {
double num_frames =
(double)(regions[k].last - regions[k].start + check_first_sr);
double max_coded_error =
AOMMAX(stats[i].coded_error, stats[i - 1].coded_error);
double this_ratio =
stats[i].sr_coded_error / AOMMAX(max_coded_error, 0.001);
regions[k].avg_sr_fr_ratio += this_ratio / num_frames;
}
regions[k].avg_intra_err +=
stats[i].intra_error / (double)(regions[k].last - regions[k].start + 1);
regions[k].avg_coded_err +=
stats[i].coded_error / (double)(regions[k].last - regions[k].start + 1);
regions[k].avg_cor_coeff +=
AOMMAX(stats[i].cor_coeff, 0.001) /
(double)(regions[k].last - regions[k].start + 1);
regions[k].avg_noise_var +=
AOMMAX(stats[i].noise_var, 0.001) /
(double)(regions[k].last - regions[k].start + 1);
}
}
// Calculate the regions stats of every region.
static void get_region_stats(const FIRSTPASS_STATS *stats, REGIONS *regions,
int num_regions) {
for (int k = 0; k < num_regions; k++) {
analyze_region(stats, k, regions);
}
}
// Find tentative stable regions
static int find_stable_regions(const FIRSTPASS_STATS *stats,
const double *grad_coded, int this_start,
int this_last, REGIONS *regions) {
int i, j, k = 0;
regions[k].start = this_start;
for (i = this_start; i <= this_last; i++) {
// Check mean and variance of stats in a window
double mean_intra = 0.001, var_intra = 0.001;
double mean_coded = 0.001, var_coded = 0.001;
int count = 0;
for (j = -HALF_WIN; j <= HALF_WIN; j++) {
int idx = AOMMIN(AOMMAX(i + j, this_start), this_last);
if (stats[idx].is_flash || (idx > 0 && stats[idx - 1].is_flash)) continue;
mean_intra += stats[idx].intra_error;
var_intra += stats[idx].intra_error * stats[idx].intra_error;
mean_coded += stats[idx].coded_error;
var_coded += stats[idx].coded_error * stats[idx].coded_error;
count++;
}
REGION_TYPES cur_type;
if (count > 0) {
mean_intra /= (double)count;
var_intra /= (double)count;
mean_coded /= (double)count;
var_coded /= (double)count;
int is_intra_stable = (var_intra / (mean_intra * mean_intra) < 1.03);
int is_coded_stable = (var_coded / (mean_coded * mean_coded) < 1.04 &&
fabs(grad_coded[i]) / mean_coded < 0.05) ||
mean_coded / mean_intra < 0.05;
int is_coded_small = mean_coded < 0.5 * mean_intra;
cur_type = (is_intra_stable && is_coded_stable && is_coded_small)
? STABLE_REGION
: HIGH_VAR_REGION;
} else {
cur_type = HIGH_VAR_REGION;
}
// mark a new region if type changes
if (i == regions[k].start) {
// first frame in the region
regions[k].type = cur_type;
} else if (cur_type != regions[k].type) {
// Append a new region
regions[k].last = i - 1;
regions[k + 1].start = i;
regions[k + 1].type = cur_type;
k++;
}
}
regions[k].last = this_last;
return k + 1;
}
// Clean up regions that should be removed or merged.
static void cleanup_regions(REGIONS *regions, int *num_regions) {
int k = 0;
while (k < *num_regions) {
if ((k > 0 && regions[k - 1].type == regions[k].type &&
regions[k].type != SCENECUT_REGION) ||
regions[k].last < regions[k].start) {
remove_region(0, regions, num_regions, &k);
} else {
k++;
}
}
}
// Remove regions that are of type and shorter than length.
// Merge it with its neighboring regions.
static void remove_short_regions(REGIONS *regions, int *num_regions,
REGION_TYPES type, int length) {
int k = 0;
while (k < *num_regions && (*num_regions) > 1) {
if ((regions[k].last - regions[k].start + 1 < length &&
regions[k].type == type)) {
// merge current region with the previous and next regions
remove_region(2, regions, num_regions, &k);
} else {
k++;
}
}
cleanup_regions(regions, num_regions);
}
static void adjust_unstable_region_bounds(const FIRSTPASS_STATS *stats,
REGIONS *regions, int *num_regions) {
int i, j, k;
// Remove regions that are too short. Likely noise.
remove_short_regions(regions, num_regions, STABLE_REGION, HALF_WIN);
remove_short_regions(regions, num_regions, HIGH_VAR_REGION, HALF_WIN);
get_region_stats(stats, regions, *num_regions);
// Adjust region boundaries. The thresholds are empirically obtained, but
// overall the performance is not very sensitive to small changes to them.
for (k = 0; k < *num_regions; k++) {
if (regions[k].type == STABLE_REGION) continue;
if (k > 0) {
// Adjust previous boundary.
// First find the average intra/coded error in the previous
// neighborhood.
double avg_intra_err = 0;
const int starti = AOMMAX(regions[k - 1].last - WINDOW_SIZE + 1,
regions[k - 1].start + 1);
const int lasti = regions[k - 1].last;
int counti = 0;
for (i = starti; i <= lasti; i++) {
avg_intra_err += stats[i].intra_error;
counti++;
}
if (counti > 0) {
avg_intra_err = AOMMAX(avg_intra_err / (double)counti, 0.001);
int count_coded = 0, count_grad = 0;
for (j = lasti + 1; j <= regions[k].last; j++) {
const int intra_close =
fabs(stats[j].intra_error - avg_intra_err) / avg_intra_err < 0.1;
const int coded_small = stats[j].coded_error / avg_intra_err < 0.1;
const int coeff_close = stats[j].cor_coeff > 0.995;
if (!coeff_close || !coded_small) count_coded--;
if (intra_close && count_coded >= 0 && count_grad >= 0) {
// this frame probably belongs to the previous stable region
regions[k - 1].last = j;
regions[k].start = j + 1;
} else {
break;
}
}
}
} // if k > 0
if (k < *num_regions - 1) {
// Adjust next boundary.
// First find the average intra/coded error in the next neighborhood.
double avg_intra_err = 0;
const int starti = regions[k + 1].start;
const int lasti = AOMMIN(regions[k + 1].last - 1,
regions[k + 1].start + WINDOW_SIZE - 1);
int counti = 0;
for (i = starti; i <= lasti; i++) {
avg_intra_err += stats[i].intra_error;
counti++;
}
if (counti > 0) {
avg_intra_err = AOMMAX(avg_intra_err / (double)counti, 0.001);
// At the boundary, coded error is large, but still the frame is stable
int count_coded = 1, count_grad = 1;
for (j = starti - 1; j >= regions[k].start; j--) {
const int intra_close =
fabs(stats[j].intra_error - avg_intra_err) / avg_intra_err < 0.1;
const int coded_small =
stats[j + 1].coded_error / avg_intra_err < 0.1;
const int coeff_close = stats[j].cor_coeff > 0.995;
if (!coeff_close || !coded_small) count_coded--;
if (intra_close && count_coded >= 0 && count_grad >= 0) {
// this frame probably belongs to the next stable region
regions[k + 1].start = j;
regions[k].last = j - 1;
} else {
break;
}
}
}
} // if k < *num_regions - 1
} // end of loop over all regions
cleanup_regions(regions, num_regions);
remove_short_regions(regions, num_regions, HIGH_VAR_REGION, HALF_WIN);
get_region_stats(stats, regions, *num_regions);
// If a stable regions has higher error than neighboring high var regions,
// or if the stable region has a lower average correlation,
// then it should be merged with them
k = 0;
while (k < *num_regions && (*num_regions) > 1) {
if (regions[k].type == STABLE_REGION &&
(regions[k].last - regions[k].start + 1) < 2 * WINDOW_SIZE &&
((k > 0 && // previous regions
(regions[k].avg_coded_err > regions[k - 1].avg_coded_err * 1.01 ||
regions[k].avg_cor_coeff < regions[k - 1].avg_cor_coeff * 0.999)) &&
(k < *num_regions - 1 && // next region
(regions[k].avg_coded_err > regions[k + 1].avg_coded_err * 1.01 ||
regions[k].avg_cor_coeff < regions[k + 1].avg_cor_coeff * 0.999)))) {
// merge current region with the previous and next regions
remove_region(2, regions, num_regions, &k);
analyze_region(stats, k - 1, regions);
} else if (regions[k].type == HIGH_VAR_REGION &&
(regions[k].last - regions[k].start + 1) < 2 * WINDOW_SIZE &&
((k > 0 && // previous regions
(regions[k].avg_coded_err <
regions[k - 1].avg_coded_err * 0.99 ||
regions[k].avg_cor_coeff >
regions[k - 1].avg_cor_coeff * 1.001)) &&
(k < *num_regions - 1 && // next region
(regions[k].avg_coded_err <
regions[k + 1].avg_coded_err * 0.99 ||
regions[k].avg_cor_coeff >
regions[k + 1].avg_cor_coeff * 1.001)))) {
// merge current region with the previous and next regions
remove_region(2, regions, num_regions, &k);
analyze_region(stats, k - 1, regions);
} else {
k++;
}
}
remove_short_regions(regions, num_regions, STABLE_REGION, WINDOW_SIZE);
remove_short_regions(regions, num_regions, HIGH_VAR_REGION, HALF_WIN);
}
// Identify blending regions.
static void find_blending_regions(const FIRSTPASS_STATS *stats,
REGIONS *regions, int *num_regions) {
int i, k = 0;
// Blending regions will have large content change, therefore will have a
// large consistent change in intra error.
int count_stable = 0;
while (k < *num_regions) {
if (regions[k].type == STABLE_REGION) {
k++;
count_stable++;
continue;
}
int dir = 0;
int start = 0, last;
for (i = regions[k].start; i <= regions[k].last; i++) {
// First mark the regions that has consistent large change of intra error.
if (k == 0 && i == regions[k].start) continue;
if (stats[i].is_flash || (i > 0 && stats[i - 1].is_flash)) continue;
double grad = stats[i].intra_error - stats[i - 1].intra_error;
int large_change = fabs(grad) / AOMMAX(stats[i].intra_error, 0.01) > 0.05;
int this_dir = 0;
if (large_change) {
this_dir = (grad > 0) ? 1 : -1;
}
// the current trend continues
if (dir == this_dir) continue;
if (dir != 0) {
// Mark the end of a new large change group and add it
last = i - 1;
insert_region(start, last, BLENDING_REGION, regions, num_regions, &k);
}
dir = this_dir;
if (k == 0 && i == regions[k].start + 1) {
start = i - 1;
} else {
start = i;
}
}
if (dir != 0) {
last = regions[k].last;
insert_region(start, last, BLENDING_REGION, regions, num_regions, &k);
}
k++;
}
// If the blending region has very low correlation, mark it as high variance
// since we probably cannot benefit from it anyways.
get_region_stats(stats, regions, *num_regions);
for (k = 0; k < *num_regions; k++) {
if (regions[k].type != BLENDING_REGION) continue;
if (regions[k].last == regions[k].start || regions[k].avg_cor_coeff < 0.6 ||
count_stable == 0)
regions[k].type = HIGH_VAR_REGION;
}
get_region_stats(stats, regions, *num_regions);
// It is possible for blending to result in a "dip" in intra error (first
// decrease then increase). Therefore we need to find the dip and combine the
// two regions.
k = 1;
while (k < *num_regions) {
if (k < *num_regions - 1 && regions[k].type == HIGH_VAR_REGION) {
// Check if this short high variance regions is actually in the middle of
// a blending region.
if (regions[k - 1].type == BLENDING_REGION &&
regions[k + 1].type == BLENDING_REGION &&
regions[k].last - regions[k].start < 3) {
int prev_dir = (stats[regions[k - 1].last].intra_error -
stats[regions[k - 1].last - 1].intra_error) > 0
? 1
: -1;
int next_dir = (stats[regions[k + 1].last].intra_error -
stats[regions[k + 1].last - 1].intra_error) > 0
? 1
: -1;
if (prev_dir < 0 && next_dir > 0) {
// This is possibly a mid region of blending. Check the ratios
double ratio_thres = AOMMIN(regions[k - 1].avg_sr_fr_ratio,
regions[k + 1].avg_sr_fr_ratio) *
0.95;
if (regions[k].avg_sr_fr_ratio > ratio_thres) {
regions[k].type = BLENDING_REGION;
remove_region(2, regions, num_regions, &k);
analyze_region(stats, k - 1, regions);
continue;
}
}
}
}
// Check if we have a pair of consecutive blending regions.
if (regions[k - 1].type == BLENDING_REGION &&
regions[k].type == BLENDING_REGION) {
int prev_dir = (stats[regions[k - 1].last].intra_error -
stats[regions[k - 1].last - 1].intra_error) > 0
? 1
: -1;
int next_dir = (stats[regions[k].last].intra_error -
stats[regions[k].last - 1].intra_error) > 0
? 1
: -1;
// if both are too short, no need to check
int total_length = regions[k].last - regions[k - 1].start + 1;
if (total_length < 4) {
regions[k - 1].type = HIGH_VAR_REGION;
k++;
continue;
}
int to_merge = 0;
if (prev_dir < 0 && next_dir > 0) {
// In this case we check the last frame in the previous region.
double prev_length =
(double)(regions[k - 1].last - regions[k - 1].start + 1);
double last_ratio, ratio_thres;
if (prev_length < 2.01) {
// if the previous region is very short
double max_coded_error =
AOMMAX(stats[regions[k - 1].last].coded_error,
stats[regions[k - 1].last - 1].coded_error);
last_ratio = stats[regions[k - 1].last].sr_coded_error /
AOMMAX(max_coded_error, 0.001);
ratio_thres = regions[k].avg_sr_fr_ratio * 0.95;
} else {
double max_coded_error =
AOMMAX(stats[regions[k - 1].last].coded_error,
stats[regions[k - 1].last - 1].coded_error);
last_ratio = stats[regions[k - 1].last].sr_coded_error /
AOMMAX(max_coded_error, 0.001);
double prev_ratio =
(regions[k - 1].avg_sr_fr_ratio * prev_length - last_ratio) /
(prev_length - 1.0);
ratio_thres = AOMMIN(prev_ratio, regions[k].avg_sr_fr_ratio) * 0.95;
}
if (last_ratio > ratio_thres) {
to_merge = 1;
}
}
if (to_merge) {
remove_region(0, regions, num_regions, &k);
analyze_region(stats, k - 1, regions);
continue;
} else {
// These are possibly two separate blending regions. Mark the boundary
// frame as HIGH_VAR_REGION to separate the two.
int prev_k = k - 1;
insert_region(regions[prev_k].last, regions[prev_k].last,
HIGH_VAR_REGION, regions, num_regions, &prev_k);
analyze_region(stats, prev_k, regions);
k = prev_k + 1;
analyze_region(stats, k, regions);
}
}
k++;
}
cleanup_regions(regions, num_regions);
}
// Clean up decision for blendings. Remove blending regions that are too short.
// Also if a very short high var region is between a blending and a stable
// region, just merge it with one of them.
static void cleanup_blendings(REGIONS *regions, int *num_regions) {
int k = 0;
while (k<*num_regions && * num_regions> 1) {
int is_short_blending = regions[k].type == BLENDING_REGION &&
regions[k].last - regions[k].start + 1 < 5;
int is_short_hv = regions[k].type == HIGH_VAR_REGION &&
regions[k].last - regions[k].start + 1 < 5;
int has_stable_neighbor =
((k > 0 && regions[k - 1].type == STABLE_REGION) ||
(k < *num_regions - 1 && regions[k + 1].type == STABLE_REGION));
int has_blend_neighbor =
((k > 0 && regions[k - 1].type == BLENDING_REGION) ||
(k < *num_regions - 1 && regions[k + 1].type == BLENDING_REGION));
int total_neighbors = (k > 0) + (k < *num_regions - 1);
if (is_short_blending ||
(is_short_hv &&
has_stable_neighbor + has_blend_neighbor >= total_neighbors)) {
// Remove this region.Try to determine whether to combine it with the
// previous or next region.
int merge;
double prev_diff =
(k > 0)
? fabs(regions[k].avg_cor_coeff - regions[k - 1].avg_cor_coeff)
: 1;
double next_diff =
(k < *num_regions - 1)
? fabs(regions[k].avg_cor_coeff - regions[k + 1].avg_cor_coeff)
: 1;
// merge == 0 means to merge with previous, 1 means to merge with next
merge = prev_diff > next_diff;
remove_region(merge, regions, num_regions, &k);
} else {
k++;
}
}
cleanup_regions(regions, num_regions);
}
// Identify stable and unstable regions from first pass stats.
// Stats_start points to the first frame to analyze.
// Offset is the offset from the current frame to the frame stats_start is
// pointing to.
static void identify_regions(const FIRSTPASS_STATS *const stats_start,
int total_frames, int offset, REGIONS *regions,
int *total_regions) {
int k;
if (total_frames <= 1) return;
// store the initial decisions
REGIONS temp_regions[MAX_FIRSTPASS_ANALYSIS_FRAMES];
av1_zero_array(temp_regions, MAX_FIRSTPASS_ANALYSIS_FRAMES);
// buffers for filtered stats
double filt_intra_err[MAX_FIRSTPASS_ANALYSIS_FRAMES] = { 0 };
double filt_coded_err[MAX_FIRSTPASS_ANALYSIS_FRAMES] = { 0 };
double grad_coded[MAX_FIRSTPASS_ANALYSIS_FRAMES] = { 0 };
int cur_region = 0, this_start = 0, this_last;
int next_scenecut = -1;
do {
// first get the obvious scenecuts
next_scenecut =
find_next_scenecut(stats_start, this_start, total_frames - 1);
this_last = (next_scenecut >= 0) ? (next_scenecut - 1) : total_frames - 1;
// low-pass filter the needed stats
smooth_filter_stats(stats_start, this_start, this_last, filt_intra_err,
filt_coded_err);
get_gradient(filt_coded_err, this_start, this_last, grad_coded);
// find tentative stable regions and unstable regions
int num_regions = find_stable_regions(stats_start, grad_coded, this_start,
this_last, temp_regions);
adjust_unstable_region_bounds(stats_start, temp_regions, &num_regions);
get_region_stats(stats_start, temp_regions, num_regions);
// Try to identify blending regions in the unstable regions
find_blending_regions(stats_start, temp_regions, &num_regions);
cleanup_blendings(temp_regions, &num_regions);
// The flash points should all be considered high variance points
k = 0;
while (k < num_regions) {
if (temp_regions[k].type != STABLE_REGION) {
k++;
continue;
}
int start = temp_regions[k].start;
int last = temp_regions[k].last;
for (int i = start; i <= last; i++) {
if (stats_start[i].is_flash) {
insert_region(i, i, HIGH_VAR_REGION, temp_regions, &num_regions, &k);
}
}
k++;
}
cleanup_regions(temp_regions, &num_regions);
// copy the regions in the scenecut group
for (k = 0; k < num_regions; k++) {
if (temp_regions[k].last < temp_regions[k].start &&
k == num_regions - 1) {
num_regions--;
break;
}
regions[k + cur_region] = temp_regions[k];
}
cur_region += num_regions;
// add the scenecut region
if (next_scenecut > -1) {
// add the scenecut region, and find the next scenecut
regions[cur_region].type = SCENECUT_REGION;
regions[cur_region].start = next_scenecut;
regions[cur_region].last = next_scenecut;
cur_region++;
this_start = next_scenecut + 1;
}
} while (next_scenecut >= 0);
*total_regions = cur_region;
get_region_stats(stats_start, regions, *total_regions);
for (k = 0; k < *total_regions; k++) {
// If scenecuts are very minor, mark them as high variance.
if (regions[k].type != SCENECUT_REGION ||
regions[k].avg_cor_coeff *
(1 - stats_start[regions[k].start].noise_var /
regions[k].avg_intra_err) <
0.8) {
continue;
}
regions[k].type = HIGH_VAR_REGION;
}
cleanup_regions(regions, total_regions);
get_region_stats(stats_start, regions, *total_regions);
for (k = 0; k < *total_regions; k++) {
regions[k].start += offset;
regions[k].last += offset;
}
}
static int find_regions_index(const REGIONS *regions, int num_regions,
int frame_idx) {
for (int k = 0; k < num_regions; k++) {
if (regions[k].start <= frame_idx && regions[k].last >= frame_idx) {
return k;
}
}
return -1;
}
/*!\brief Determine the length of future GF groups.
*
* \ingroup gf_group_algo
* This function decides the gf group length of future frames in batch
*
* \param[in] cpi Top-level encoder structure
* \param[in] max_gop_length Maximum length of the GF group
* \param[in] max_intervals Maximum number of intervals to decide
*
* \return Nothing is returned. Instead, cpi->ppi->rc.gf_intervals is
* changed to store the decided GF group lengths.
*/
static void calculate_gf_length(AV1_COMP *cpi, int max_gop_length,
int max_intervals) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
FIRSTPASS_STATS next_frame;
const FIRSTPASS_STATS *const start_pos = twopass->stats_in;
const FIRSTPASS_STATS *const stats = start_pos - (rc->frames_since_key == 0);
FRAME_INFO *frame_info = &cpi->frame_info;
int i;
int flash_detected;
aom_clear_system_state();
av1_zero(next_frame);
if (has_no_stats_stage(cpi)) {
for (i = 0; i < MAX_NUM_GF_INTERVALS; i++) {
p_rc->gf_intervals[i] = AOMMIN(rc->max_gf_interval, max_gop_length);
}
p_rc->cur_gf_index = 0;
rc->intervals_till_gf_calculate_due = MAX_NUM_GF_INTERVALS;
return;
}
// TODO(urvang): Try logic to vary min and max interval based on q.
const int active_min_gf_interval = rc->min_gf_interval;
const int active_max_gf_interval =
AOMMIN(rc->max_gf_interval, max_gop_length);
const int min_shrink_int = AOMMAX(MIN_SHRINK_LEN, active_min_gf_interval);
i = (rc->frames_since_key == 0);
max_intervals = cpi->ppi->lap_enabled ? 1 : max_intervals;
int count_cuts = 1;
// If cpi->gf_state.arf_gf_boost_lst is 0, we are starting with a KF or GF.
int cur_start = -1 + !cpi->ppi->gf_state.arf_gf_boost_lst, cur_last;
int cut_pos[MAX_NUM_GF_INTERVALS + 1] = { -1 };
int cut_here;
GF_GROUP_STATS gf_stats;
init_gf_stats(&gf_stats);
while (count_cuts < max_intervals + 1) {
// reaches next key frame, break here
if (i >= rc->frames_to_key + p_rc->next_is_fwd_key) {
cut_here = 2;
} else if (i - cur_start >= rc->static_scene_max_gf_interval) {
// reached maximum len, but nothing special yet (almost static)
// let's look at the next interval
cut_here = 1;
} else if (EOF == input_stats(twopass, &next_frame)) {
// reaches last frame, break
cut_here = 2;
} else {
// Test for the case where there is a brief flash but the prediction
// quality back to an earlier frame is then restored.
flash_detected = detect_flash(twopass, 0);
// TODO(bohanli): remove redundant accumulations here, or unify
// this and the ones in define_gf_group
accumulate_next_frame_stats(&next_frame, frame_info, flash_detected,
rc->frames_since_key, i, &gf_stats);
cut_here = detect_gf_cut(cpi, i, cur_start, flash_detected,
active_max_gf_interval, active_min_gf_interval,
&gf_stats);
}
if (cut_here) {
cur_last = i - 1; // the current last frame in the gf group
int ori_last = cur_last;
// The region frame idx does not start from the same frame as cur_start
// and cur_last. Need to offset them.
int offset = rc->frames_since_key - p_rc->regions_offset;
REGIONS *regions = p_rc->regions;
int num_regions = p_rc->num_regions;
if (cpi->oxcf.kf_cfg.fwd_kf_enabled && p_rc->next_is_fwd_key) {
const int frames_left = rc->frames_to_key - i;
const int min_int = AOMMIN(MIN_FWD_KF_INTERVAL, active_min_gf_interval);
if (frames_left < min_int && frames_left > 0) {
cur_last = rc->frames_to_key - min_int - 1;
}
}
int scenecut_idx = -1;
// only try shrinking if interval smaller than active_max_gf_interval
if (cur_last - cur_start <= active_max_gf_interval &&
cur_last > cur_start) {
// find the region indices of where the first and last frame belong.
int k_start =
find_regions_index(regions, num_regions, cur_start + offset);
int k_last =
find_regions_index(regions, num_regions, cur_last + offset);
if (cur_start + offset == 0) k_start = 0;
// See if we have a scenecut in between
for (int r = k_start + 1; r <= k_last; r++) {
if (regions[r].type == SCENECUT_REGION &&
regions[r].last - offset - cur_start > active_min_gf_interval) {
scenecut_idx = r;
break;
}
}
// if the found scenecut is very close to the end, ignore it.
if (regions[num_regions - 1].last - regions[scenecut_idx].last < 4) {
scenecut_idx = -1;
}
if (scenecut_idx != -1) {
// If we have a scenecut, then stop at it.
// TODO(bohanli): add logic here to stop before the scenecut and for
// the next gop start from the scenecut with GF
int is_minor_sc =
(regions[scenecut_idx].avg_cor_coeff *
(1 - stats[regions[scenecut_idx].start - offset].noise_var /
regions[scenecut_idx].avg_intra_err) >
0.6);
cur_last = regions[scenecut_idx].last - offset - !is_minor_sc;
} else {
int is_last_analysed = (k_last == num_regions - 1) &&
(cur_last + offset == regions[k_last].last);
int not_enough_regions =
k_last - k_start <=
1 + (regions[k_start].type == SCENECUT_REGION);
// if we are very close to the end, then do not shrink since it may
// introduce intervals that are too short
if (!(is_last_analysed && not_enough_regions)) {
const double arf_length_factor = 0.1;
double best_score = 0;
int best_j = -1;
const int first_frame = regions[0].start - offset;
const int last_frame = regions[num_regions - 1].last - offset;
// score of how much the arf helps the whole GOP
double base_score = 0.0;
// Accumulate base_score in
for (int j = cur_start + 1; j < cur_start + min_shrink_int; j++) {
if (stats + j >= twopass->stats_buf_ctx->stats_in_end) break;
base_score = (base_score + 1.0) * stats[j].cor_coeff;
}
int met_blending = 0; // Whether we have met blending areas before
int last_blending = 0; // Whether the previous frame if blending
for (int j = cur_start + min_shrink_int; j <= cur_last; j++) {
if (stats + j >= twopass->stats_buf_ctx->stats_in_end) break;
base_score = (base_score + 1.0) * stats[j].cor_coeff;
int this_reg =
find_regions_index(regions, num_regions, j + offset);
if (this_reg < 0) continue;
// A GOP should include at most 1 blending region.
if (regions[this_reg].type == BLENDING_REGION) {
last_blending = 1;
if (met_blending) {
break;
} else {
base_score = 0;
continue;
}
} else {
if (last_blending) met_blending = 1;
last_blending = 0;
}
// Add the factor of how good the neighborhood is for this
// candidate arf.
double this_score = arf_length_factor * base_score;
double temp_accu_coeff = 1.0;
// following frames
int count_f = 0;
for (int n = j + 1; n <= j + 3 && n <= last_frame; n++) {
if (stats + n >= twopass->stats_buf_ctx->stats_in_end) break;
temp_accu_coeff *= stats[n].cor_coeff;
this_score +=
temp_accu_coeff *
(1 - stats[n].noise_var /
AOMMAX(regions[this_reg].avg_intra_err, 0.001));
count_f++;
}
// preceding frames
temp_accu_coeff = 1.0;
for (int n = j; n > j - 3 * 2 + count_f && n > first_frame; n--) {
if (stats + n < twopass->stats_buf_ctx->stats_in_start) break;
temp_accu_coeff *= stats[n].cor_coeff;
this_score +=
temp_accu_coeff *
(1 - stats[n].noise_var /
AOMMAX(regions[this_reg].avg_intra_err, 0.001));
}
if (this_score > best_score) {
best_score = this_score;
best_j = j;
}
}
// For blending areas, move one more frame in case we missed the
// first blending frame.
int best_reg =
find_regions_index(regions, num_regions, best_j + offset);
if (best_reg < num_regions - 1 && best_reg > 0) {
if (regions[best_reg - 1].type == BLENDING_REGION &&
regions[best_reg + 1].type == BLENDING_REGION) {
if (best_j + offset == regions[best_reg].start &&
best_j + offset < regions[best_reg].last) {
best_j += 1;
} else if (best_j + offset == regions[best_reg].last &&
best_j + offset > regions[best_reg].start) {
best_j -= 1;
}
}
}
if (cur_last - best_j < 2) best_j = cur_last;
if (best_j > 0 && best_score > 0.1) cur_last = best_j;
// if cannot find anything, just cut at the original place.
}
}
}
cut_pos[count_cuts] = cur_last;
count_cuts++;
// reset pointers to the shrinked location
twopass->stats_in = start_pos + cur_last;
cur_start = cur_last;
int cur_region_idx =
find_regions_index(regions, num_regions, cur_start + 1 + offset);
if (cur_region_idx >= 0)
if (regions[cur_region_idx].type == SCENECUT_REGION) cur_start++;
i = cur_last;
if (cut_here > 1 && cur_last == ori_last) break;
// reset accumulators
init_gf_stats(&gf_stats);
}
++i;
}
// save intervals
rc->intervals_till_gf_calculate_due = count_cuts - 1;
for (int n = 1; n < count_cuts; n++) {
p_rc->gf_intervals[n - 1] = cut_pos[n] - cut_pos[n - 1];
}
p_rc->cur_gf_index = 0;
twopass->stats_in = start_pos;
}
static void correct_frames_to_key(AV1_COMP *cpi) {
int lookahead_size =
(int)av1_lookahead_depth(cpi->ppi->lookahead, cpi->compressor_stage);
if (lookahead_size <
av1_lookahead_pop_sz(cpi->ppi->lookahead, cpi->compressor_stage)) {
assert(IMPLIES(cpi->oxcf.pass != 0 && cpi->ppi->frames_left > 0,
lookahead_size == cpi->ppi->frames_left));
cpi->rc.frames_to_key = AOMMIN(cpi->rc.frames_to_key, lookahead_size);
} else if (cpi->ppi->frames_left > 0) {
// Correct frames to key based on limit
cpi->rc.frames_to_key =
AOMMIN(cpi->rc.frames_to_key, cpi->ppi->frames_left);
}
}
/*!\brief Define a GF group in one pass mode when no look ahead stats are
* available.
*
* \ingroup gf_group_algo
* This function defines the structure of a GF group, along with various
* parameters regarding bit-allocation and quality setup in the special
* case of one pass encoding where no lookahead stats are avialable.
*
* \param[in] cpi Top-level encoder structure
*
* \return Nothing is returned. Instead, cpi->ppi->gf_group is changed.
*/
static void define_gf_group_pass0(AV1_COMP *cpi) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
GF_GROUP *const gf_group = &cpi->ppi->gf_group;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
const GFConfig *const gf_cfg = &oxcf->gf_cfg;
int target;
if (oxcf->q_cfg.aq_mode == CYCLIC_REFRESH_AQ) {
av1_cyclic_refresh_set_golden_update(cpi);
} else {
p_rc->baseline_gf_interval = p_rc->gf_intervals[p_rc->cur_gf_index];
rc->intervals_till_gf_calculate_due--;
p_rc->cur_gf_index++;
}
// correct frames_to_key when lookahead queue is flushing
correct_frames_to_key(cpi);
if (p_rc->baseline_gf_interval > rc->frames_to_key)
p_rc->baseline_gf_interval = rc->frames_to_key;
p_rc->gfu_boost = DEFAULT_GF_BOOST;
p_rc->constrained_gf_group =
(p_rc->baseline_gf_interval >= rc->frames_to_key) ? 1 : 0;
gf_group->max_layer_depth_allowed = oxcf->gf_cfg.gf_max_pyr_height;
// Rare case when the look-ahead is less than the target GOP length, can't
// generate ARF frame.
if (p_rc->baseline_gf_interval > gf_cfg->lag_in_frames ||
!is_altref_enabled(gf_cfg->lag_in_frames, gf_cfg->enable_auto_arf) ||
p_rc->baseline_gf_interval < rc->min_gf_interval)
gf_group->max_layer_depth_allowed = 0;
// Set up the structure of this Group-Of-Pictures (same as GF_GROUP)
av1_gop_setup_structure(cpi);
// Allocate bits to each of the frames in the GF group.
// TODO(sarahparker) Extend this to work with pyramid structure.
for (int cur_index = 0; cur_index < gf_group->size; ++cur_index) {
const FRAME_UPDATE_TYPE cur_update_type = gf_group->update_type[cur_index];
if (oxcf->rc_cfg.mode == AOM_CBR) {
if (cur_update_type == KF_UPDATE) {
target = av1_calc_iframe_target_size_one_pass_cbr(cpi);
} else {
target = av1_calc_pframe_target_size_one_pass_cbr(cpi, cur_update_type);
}
} else {
if (cur_update_type == KF_UPDATE) {
target = av1_calc_iframe_target_size_one_pass_vbr(cpi);
} else {
target = av1_calc_pframe_target_size_one_pass_vbr(cpi, cur_update_type);
}
}
gf_group->bit_allocation[cur_index] = target;
}
}
static INLINE void set_baseline_gf_interval(AV1_COMP *cpi, int arf_position,
int active_max_gf_interval,
int use_alt_ref,
int is_final_pass) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
// Set the interval until the next gf.
// If forward keyframes are enabled, ensure the final gf group obeys the
// MIN_FWD_KF_INTERVAL.
const int is_last_kf =
(twopass->stats_in - arf_position + rc->frames_to_key) >=
twopass->stats_buf_ctx->stats_in_end;
if (cpi->oxcf.kf_cfg.fwd_kf_enabled && use_alt_ref && !is_last_kf &&
cpi->ppi->p_rc.next_is_fwd_key) {
if (arf_position == rc->frames_to_key + 1) {
p_rc->baseline_gf_interval = arf_position;
// if the last gf group will be smaller than MIN_FWD_KF_INTERVAL
} else if (rc->frames_to_key + 1 - arf_position <
AOMMAX(MIN_FWD_KF_INTERVAL, rc->min_gf_interval)) {
// if possible, merge the last two gf groups
if (rc->frames_to_key + 1 <= active_max_gf_interval) {
p_rc->baseline_gf_interval = rc->frames_to_key + 1;
if (is_final_pass) rc->intervals_till_gf_calculate_due = 0;
// if merging the last two gf groups creates a group that is too long,
// split them and force the last gf group to be the MIN_FWD_KF_INTERVAL
} else {
p_rc->baseline_gf_interval =
rc->frames_to_key + 1 - MIN_FWD_KF_INTERVAL;
if (is_final_pass) rc->intervals_till_gf_calculate_due = 0;
}
} else {
p_rc->baseline_gf_interval = arf_position;
}
} else {
p_rc->baseline_gf_interval = arf_position;
}
}
// initialize GF_GROUP_STATS
static void init_gf_stats(GF_GROUP_STATS *gf_stats) {
gf_stats->gf_group_err = 0.0;
gf_stats->gf_group_raw_error = 0.0;
gf_stats->gf_group_skip_pct = 0.0;
gf_stats->gf_group_inactive_zone_rows = 0.0;
gf_stats->mv_ratio_accumulator = 0.0;
gf_stats->decay_accumulator = 1.0;
gf_stats->zero_motion_accumulator = 1.0;
gf_stats->loop_decay_rate = 1.0;
gf_stats->last_loop_decay_rate = 1.0;
gf_stats->this_frame_mv_in_out = 0.0;
gf_stats->mv_in_out_accumulator = 0.0;
gf_stats->abs_mv_in_out_accumulator = 0.0;
gf_stats->avg_sr_coded_error = 0.0;
gf_stats->avg_tr_coded_error = 0.0;
gf_stats->avg_pcnt_second_ref = 0.0;
gf_stats->avg_pcnt_third_ref = 0.0;
gf_stats->avg_pcnt_third_ref_nolast = 0.0;
gf_stats->avg_new_mv_count = 0.0;
gf_stats->avg_wavelet_energy = 0.0;
gf_stats->avg_raw_err_stdev = 0.0;
gf_stats->non_zero_stdev_count = 0;
}
// Analyse and define a gf/arf group.
#define MAX_GF_BOOST 5400
/*!\brief Define a GF group.
*
* \ingroup gf_group_algo
* This function defines the structure of a GF group, along with various
* parameters regarding bit-allocation and quality setup.
*
* \param[in] cpi Top-level encoder structure
* \param[in] this_frame First pass statistics structure
* \param[in] frame_params Structure with frame parameters
* \param[in] max_gop_length Maximum length of the GF group
* \param[in] is_final_pass Whether this is the final pass for the
* GF group, or a trial (non-zero)
*
* \return Nothing is returned. Instead, cpi->ppi->gf_group is changed.
*/
static void define_gf_group(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame,
EncodeFrameParams *frame_params, int max_gop_length,
int is_final_pass) {
AV1_COMMON *const cm = &cpi->common;
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->ppi->twopass;
FIRSTPASS_STATS next_frame;
const FIRSTPASS_STATS *const start_pos = twopass->stats_in;
GF_GROUP *gf_group = &cpi->ppi->gf_group;
FRAME_INFO *frame_info = &cpi->frame_info;
const GFConfig *const gf_cfg = &oxcf->gf_cfg;
const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;
int i;
int flash_detected;
int64_t gf_group_bits;
const int is_intra_only = rc->frames_since_key == 0;
cpi->ppi->internal_altref_allowed = (gf_cfg->gf_max_pyr_height > 1);
// Reset the GF group data structures unless this is a key
// frame in which case it will already have been done.
if (!is_intra_only) {
av1_zero(cpi->ppi->gf_group);
cpi->gf_frame_index = 0;
}
aom_clear_system_state();
av1_zero(next_frame);
if (has_no_stats_stage(cpi)) {
define_gf_group_pass0(cpi);
return;
}
// correct frames_to_key when lookahead queue is emptying
if (cpi->ppi->lap_enabled) {
correct_frames_to_key(cpi);
}
GF_GROUP_STATS gf_stats;
init_gf_stats(&gf_stats);
GF_FRAME_STATS first_frame_stats, last_frame_stats;
const int can_disable_arf = !gf_cfg->gf_min_pyr_height;
// Load stats for the current frame.
double mod_frame_err =
calculate_modified_err(frame_info, twopass, oxcf, this_frame);
// Note the error of the frame at the start of the group. This will be
// the GF frame error if we code a normal gf.
first_frame_stats.frame_err = mod_frame_err;
first_frame_stats.frame_coded_error = this_frame->coded_error;
first_frame_stats.frame_sr_coded_error = this_frame->sr_coded_error;
first_frame_stats.frame_tr_coded_error = this_frame->tr_coded_error;
// If this is a key frame or the overlay from a previous arf then
// the error score / cost of this frame has already been accounted for.
// TODO(urvang): Try logic to vary min and max interval based on q.
const int active_min_gf_interval = rc->min_gf_interval;
const int active_max_gf_interval =
AOMMIN(rc->max_gf_interval, max_gop_length);
i = is_intra_only;
// get the determined gf group length from p_rc->gf_intervals
while (i < p_rc->gf_intervals[p_rc->cur_gf_index]) {
// read in the next frame
if (EOF == input_stats(twopass, &next_frame)) break;
// Accumulate error score of frames in this gf group.
mod_frame_err =
calculate_modified_err(frame_info, twopass, oxcf, &next_frame);
// accumulate stats for this frame
accumulate_this_frame_stats(&next_frame, mod_frame_err, &gf_stats);
if (i == 0) {
first_frame_stats.frame_err = mod_frame_err;
first_frame_stats.frame_coded_error = next_frame.coded_error;
first_frame_stats.frame_sr_coded_error = next_frame.sr_coded_error;
first_frame_stats.frame_tr_coded_error = next_frame.tr_coded_error;
}
++i;
}
reset_fpf_position(twopass, start_pos);
i = is_intra_only;
input_stats(twopass, &next_frame);
while (i < p_rc->gf_intervals[p_rc->cur_gf_index]) {
// read in the next frame
if (EOF == input_stats(twopass, &next_frame)) break;
// Test for the case where there is a brief flash but the prediction
// quality back to an earlier frame is then restored.
flash_detected = detect_flash(twopass, 0);
// accumulate stats for next frame
accumulate_next_frame_stats(&next_frame, frame_info, flash_detected,
rc->frames_since_key, i, &gf_stats);
++i;
}
i = p_rc->gf_intervals[p_rc->cur_gf_index];
// save the errs for the last frame
last_frame_stats.frame_coded_error = next_frame.coded_error;
last_frame_stats.frame_sr_coded_error = next_frame.sr_coded_error;
last_frame_stats.frame_tr_coded_error = next_frame.tr_coded_error;
if (is_final_pass) {
rc->intervals_till_gf_calculate_due--;
p_rc->cur_gf_index++;
}
// Was the group length constrained by the requirement for a new KF?
p_rc->constrained_gf_group = (i >= rc->frames_to_key) ? 1 : 0;
const int num_mbs = (oxcf->resize_cfg.resize_mode != RESIZE_NONE)
? cpi->initial_mbs
: cm->mi_params.MBs;
assert(num_mbs > 0);
average_gf_stats(i, &next_frame, &gf_stats);
// Disable internal ARFs for "still" gf groups.
// zero_motion_accumulator: minimum percentage of (0,0) motion;
// avg_sr_coded_error: average of the SSE per pixel of each frame;
// avg_raw_err_stdev: average of the standard deviation of (0,0)
// motion error per block of each frame.
const int can_disable_internal_arfs = gf_cfg->gf_min_pyr_height <= 1;
if (can_disable_internal_arfs &&
gf_stats.zero_motion_accumulator > MIN_ZERO_MOTION &&
gf_stats.avg_sr_coded_error / num_mbs < MAX_SR_CODED_ERROR &&
gf_stats.avg_raw_err_stdev < MAX_RAW_ERR_VAR) {
cpi->ppi->internal_altref_allowed = 0;
}
int use_alt_ref;
if (can_disable_arf) {
use_alt_ref =
!is_almost_static(gf_stats.zero_motion_accumulator,
twopass->kf_zeromotion_pct, cpi->ppi->lap_enabled) &&
p_rc->use_arf_in_this_kf_group && (i < gf_cfg->lag_in_frames) &&
(i >= MIN_GF_INTERVAL);
// TODO(urvang): Improve and use model for VBR, CQ etc as well.
if (use_alt_ref && rc_cfg->mode == AOM_Q && rc_cfg->cq_level <= 200) {
aom_clear_system_state();
float features[21];
get_features_from_gf_stats(
&gf_stats, &first_frame_stats, &last_frame_stats, num_mbs,
p_rc->constrained_gf_group, twopass->kf_zeromotion_pct, i, features);
// Infer using ML model.
float score;
av1_nn_predict(features, &av1_use_flat_gop_nn_config, 1, &score);
use_alt_ref = (score <= 0.0);
}
} else {
use_alt_ref = p_rc->use_arf_in_this_kf_group &&
(i < gf_cfg->lag_in_frames) && (i > 2);
}
#define REDUCE_GF_LENGTH_THRESH 4
#define REDUCE_GF_LENGTH_TO_KEY_THRESH 9
#define REDUCE_GF_LENGTH_BY 1
int alt_offset = 0;
// The length reduction strategy is tweaked for certain cases, and doesn't
// work well for certain other cases.
const int allow_gf_length_reduction =
((rc_cfg->mode == AOM_Q && rc_cfg->cq_level <= 128) ||
!cpi->ppi->internal_altref_allowed) &&
!is_lossless_requested(rc_cfg);
if (allow_gf_length_reduction && use_alt_ref) {
// adjust length of this gf group if one of the following condition met
// 1: only one overlay frame left and this gf is too long
// 2: next gf group is too short to have arf compared to the current gf
// maximum length of next gf group
const int next_gf_len = rc->frames_to_key - i;
const int single_overlay_left =
next_gf_len == 0 && i > REDUCE_GF_LENGTH_THRESH;
// the next gf is probably going to have a ARF but it will be shorter than
// this gf
const int unbalanced_gf =
i > REDUCE_GF_LENGTH_TO_KEY_THRESH &&
next_gf_len + 1 < REDUCE_GF_LENGTH_TO_KEY_THRESH &&
next_gf_len + 1 >= rc->min_gf_interval;
if (single_overlay_left || unbalanced_gf) {
const int roll_back = REDUCE_GF_LENGTH_BY;
// Reduce length only if active_min_gf_interval will be respected later.
if (i - roll_back >= active_min_gf_interval + 1) {
alt_offset = -roll_back;
i -= roll_back;
if (is_final_pass) rc->intervals_till_gf_calculate_due = 0;
}
}
}
// Should we use the alternate reference frame.
int ext_len = i - is_intra_only;
if (use_alt_ref) {
gf_group->max_layer_depth_allowed = gf_cfg->gf_max_pyr_height;
set_baseline_gf_interval(cpi, i, active_max_gf_interval, use_alt_ref,
is_final_pass);
const int forward_frames = (rc->frames_to_key - i >= ext_len)
? ext_len
: AOMMAX(0, rc->frames_to_key - i);
// Calculate the boost for alt ref.
p_rc->gfu_boost = av1_calc_arf_boost(
twopass, p_rc, rc, frame_info, alt_offset, forward_frames, ext_len,
&p_rc->num_stats_used_for_gfu_boost,
&p_rc->num_stats_required_for_gfu_boost, cpi->ppi->lap_enabled);
} else {
reset_fpf_position(twopass, start_pos);
gf_group->max_layer_depth_allowed = 0;
set_baseline_gf_interval(cpi, i, active_max_gf_interval, use_alt_ref,
is_final_pass);
p_rc->gfu_boost = AOMMIN(
MAX_GF_BOOST,
av1_calc_arf_boost(twopass, p_rc, rc, frame_info, alt_offset, ext_len,
0, &p_rc->num_stats_used_for_gfu_boost,
&p_rc->num_stats_required_for_gfu_boost,
cpi->ppi->lap_enabled));
}
#define LAST_ALR_BOOST_FACTOR 0.2f
p_rc->arf_boost_factor = 1.0;
if (use_alt_ref && !is_lossless_requested(rc_cfg)) {
// Reduce the boost of altref in the last gf group
if (rc->frames_to_key - ext_len == REDUCE_GF_LENGTH_BY ||
rc->frames_to_key - ext_len == 0) {
p_rc->arf_boost_factor = LAST_ALR_BOOST_FACTOR;
}
}
rc->frames_till_gf_update_due = p_rc->baseline_gf_interval;
// Reset the file position.
reset_fpf_position(twopass, start_pos);
if (cpi->ppi->lap_enabled) {
// Since we don't have enough stats to know the actual error of the
// gf group, we assume error of each frame to be equal to 1 and set
// the error of the group as baseline_gf_interval.
gf_stats.gf_group_err = p_rc->baseline_gf_interval;
}
// Calculate the bits to be allocated to the gf/arf group as a whole
gf_group_bits = calculate_total_gf_group_bits(cpi, gf_stats.gf_group_err);
p_rc->gf_group_bits = gf_group_bits;
#if GROUP_ADAPTIVE_MAXQ
// Calculate an estimate of the maxq needed for the group.
// We are more agressive about correcting for sections
// where there could be significant overshoot than for easier
// sections where we do not wish to risk creating an overshoot
// of the allocated bit budget.
if ((rc_cfg->mode != AOM_Q) && (p_rc->baseline_gf_interval > 1) &&
is_final_pass) {
const int vbr_group_bits_per_frame =
(int)(gf_group_bits / p_rc->baseline_gf_interval);
const double group_av_err =
gf_stats.gf_group_raw_error / p_rc->baseline_gf_interval;
const double group_av_skip_pct =
gf_stats.gf_group_skip_pct / p_rc->baseline_gf_interval;
const double group_av_inactive_zone =
((gf_stats.gf_group_inactive_zone_rows * 2) /
(p_rc->baseline_gf_interval * (double)cm->mi_params.mb_rows));
int tmp_q;
tmp_q = get_twopass_worst_quality(
cpi, group_av_err, (group_av_skip_pct + group_av_inactive_zone),
vbr_group_bits_per_frame);
rc->active_worst_quality = AOMMAX(tmp_q, rc->active_worst_quality >> 1);
}
#endif
// Adjust KF group bits and error remaining.
if (is_final_pass)
twopass->kf_group_error_left -= (int64_t)gf_stats.gf_group_err;
// Set up the structure of this Group-Of-Pictures (same as GF_GROUP)
av1_gop_setup_structure(cpi);
// Reset the file position.
reset_fpf_position(twopass, start_pos);
// Calculate a section intra ratio used in setting max loop filter.
if (rc->frames_since_key != 0) {
twopass->section_intra_rating = calculate_section_intra_ratio(
start_pos, twopass->stats_buf_ctx->stats_in_end,
p_rc->baseline_gf_interval);
}
av1_gop_bit_allocation(cpi, rc, gf_group, rc->frames_since_key == 0,
use_alt_ref, gf_group_bits);
frame_params->frame_type =
rc->frames_since_key == 0 ? KEY_FRAME : INTER_FRAME;
frame_params->show_frame =
!(gf_group->update_type[cpi->gf_frame_index] == ARF_UPDATE ||
gf_group->update_type[cpi->gf_frame_index] == INTNL_ARF_UPDATE);
// TODO(jingning): Generalize this condition.
if (is_final_pass) {
cpi->ppi->gf_state.arf_gf_boost_lst = use_alt_ref;
// Reset rolling actual and target bits counters for ARF groups.
twopass->rolling_arf_group_target_bits = 1;
twopass->rolling_arf_group_actual_bits = 1;
}
}
// #define FIXED_ARF_BITS
#ifdef FIXED_ARF_BITS
#define ARF_BITS_FRACTION 0.75
#endif
void av1_gop_bit_allocation(const AV1_COMP *cpi, RATE_CONTROL *const rc,
GF_GROUP *gf_group, int is_key_frame, int use_arf,
int64_t gf_group_bits) {
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
// Calculate the extra bits to be used for boosted frame(s)
#ifdef FIXED_ARF_BITS
int gf_arf_bits = (int)(ARF_BITS_FRACTION * gf_group_bits);
#else
int gf_arf_bits = calculate_boost_bits(
p_rc->baseline_gf_interval - (rc->frames_since_key == 0), p_rc->gfu_boost,
gf_group_bits);
#endif
gf_arf_bits = adjust_boost_bits_for_target_level(cpi, rc, gf_arf_bits,
gf_group_bits, 1);
// Allocate bits to each of the frames in the GF group.
allocate_gf_group_bits(gf_group, p_rc, rc, gf_group_bits, gf_arf_bits,
is_key_frame, use_arf);
}
// Minimum % intra coding observed in first pass (1.0 = 100%)
#define MIN_INTRA_LEVEL 0.25
// Minimum ratio between the % of intra coding and inter coding in the first
// pass after discounting neutral blocks (discounting neutral blocks in this
// way helps catch scene cuts in clips with very flat areas or letter box
// format clips with image padding.
#define INTRA_VS_INTER_THRESH 2.0
// Hard threshold where the first pass chooses intra for almost all blocks.
// In such a case even if the frame is not a scene cut coding a key frame
// may be a good option.
#define VERY_LOW_INTER_THRESH 0.05
// Maximum threshold for the relative ratio of intra error score vs best
// inter error score.
#define KF_II_ERR_THRESHOLD 1.9
// In real scene cuts there is almost always a sharp change in the intra
// or inter error score.
#define ERR_CHANGE_THRESHOLD 0.4
// For real scene cuts we expect an improvment in the intra inter error
// ratio in the next frame.
#define II_IMPROVEMENT_THRESHOLD 3.5
#define KF_II_MAX 128.0
// Intra / Inter threshold very low
#define VERY_LOW_II 1.5
// Clean slide transitions we expect a sharp single frame spike in error.
#define ERROR_SPIKE 5.0
// Slide show transition detection.
// Tests for case where there is very low error either side of the current frame
// but much higher just for this frame. This can help detect key frames in
// slide shows even where the slides are pictures of different sizes.
// Also requires that intra and inter errors are very similar to help eliminate
// harmful false positives.
// It will not help if the transition is a fade or other multi-frame effect.
static int slide_transition(const FIRSTPASS_STATS *this_frame,
const FIRSTPASS_STATS *last_frame,
const FIRSTPASS_STATS *next_frame) {
return (this_frame->intra_error < (this_frame->coded_error * VERY_LOW_II)) &&
(this_frame->coded_error > (last_frame->coded_error * ERROR_SPIKE)) &&
(this_frame->coded_error > (next_frame->coded_error * ERROR_SPIKE));
}
// Threshold for use of the lagging second reference frame. High second ref
// usage may point to a transient event like a flash or occlusion rather than
// a real scene cut.
// We adapt the threshold based on number of frames in this key-frame group so
// far.
static double get_second_ref_usage_thresh(int frame_count_so_far) {
const int adapt_upto = 32;
const double min_second_ref_usage_thresh = 0.085;
const double second_ref_usage_thresh_max_delta = 0.035;
if (frame_count_so_far >= adapt_upto) {
return min_second_ref_usage_thresh + second_ref_usage_thresh_max_delta;
}
return min_second_ref_usage_thresh +
((double)frame_count_so_far / (adapt_upto - 1)) *
second_ref_usage_thresh_max_delta;
}
static int test_candidate_kf(TWO_PASS *twopass,
const FIRSTPASS_STATS *last_frame,
const FIRSTPASS_STATS *this_frame,
const FIRSTPASS_STATS *next_frame,
int frame_count_so_far, enum aom_rc_mode rc_mode,
int scenecut_mode) {
int is_viable_kf = 0;
double pcnt_intra = 1.0 - this_frame->pcnt_inter;
double modified_pcnt_inter =
this_frame->pcnt_inter - this_frame->pcnt_neutral;
const double second_ref_usage_thresh =
get_second_ref_usage_thresh(frame_count_so_far);
int total_frames_to_test = SCENE_CUT_KEY_TEST_INTERVAL;
int count_for_tolerable_prediction = 3;
int num_future_frames = 0;
FIRSTPASS_STATS curr_frame;
if (scenecut_mode == ENABLE_SCENECUT_MODE_1) {
curr_frame = *this_frame;
const FIRSTPASS_STATS *const start_position = twopass->stats_in;
for (num_future_frames = 0; num_future_frames < SCENE_CUT_KEY_TEST_INTERVAL;
num_future_frames++)
if (EOF == input_stats(twopass, &curr_frame)) break;
reset_fpf_position(twopass, start_position);
if (num_future_frames < 3) {
return 0;
} else {
total_frames_to_test = 3;
count_for_tolerable_prediction = 1;
}
}
// Does the frame satisfy the primary criteria of a key frame?
// See above for an explanation of the test criteria.
// If so, then examine how well it predicts subsequent frames.
if (IMPLIES(rc_mode == AOM_Q, frame_count_so_far >= 3) &&
(this_frame->pcnt_second_ref < second_ref_usage_thresh) &&
(next_frame->pcnt_second_ref < second_ref_usage_thresh) &&
((this_frame->pcnt_inter < VERY_LOW_INTER_THRESH) ||
slide_transition(this_frame, last_frame, next_frame) ||
((pcnt_intra > MIN_INTRA_LEVEL) &&
(pcnt_intra > (INTRA_VS_INTER_THRESH * modified_pcnt_inter)) &&
((this_frame->intra_error /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error)) <
KF_II_ERR_THRESHOLD) &&
((fabs(last_frame->coded_error - this_frame->coded_error) /
DOUBLE_DIVIDE_CHECK(this_frame->coded_error) >
ERR_CHANGE_THRESHOLD) ||
(fabs(last_frame->intra_error - this_frame->intra_error) /
DOUBLE_DIVIDE_CHECK(this_frame->intra_error) >
ERR_CHANGE_THRESHOLD) ||
((next_frame->intra_error /
DOUBLE_DIVIDE_CHECK(next_frame->coded_error)) >
II_IMPROVEMENT_THRESHOLD))))) {
int i;
const FIRSTPASS_STATS *start_pos = twopass->stats_in;
double boost_score = 0.0;
double old_boost_score = 0.0;
double decay_accumulator = 1.0;
// Examine how well the key frame predicts subsequent frames.
for (i = 0; i < total_frames_to_test; ++i) {
// Get the next frame details
FIRSTPASS_STATS local_next_frame;
if (EOF == input_stats(twopass, &local_next_frame)) break;
double next_iiratio = (BOOST_FACTOR * local_next_frame.intra_error /
DOUBLE_DIVIDE_CHECK(local_next_frame.coded_error));
if (next_iiratio > KF_II_MAX) next_iiratio = KF_II_MAX;
// Cumulative effect of decay in prediction quality.
if (local_next_frame.pcnt_inter > 0.85)
decay_accumulator *= local_next_frame.pcnt_inter;
else
decay_accumulator *= (0.85 + local_next_frame.pcnt_inter) / 2.0;
// Keep a running total.
boost_score += (decay_accumulator * next_iiratio);
// Test various breakout clauses.
if ((local_next_frame.pcnt_inter < 0.05) || (next_iiratio < 1.5) ||
(((local_next_frame.pcnt_inter - local_next_frame.pcnt_neutral) <
0.20) &&
(next_iiratio < 3.0)) ||
((boost_score - old_boost_score) < 3.0) ||
(local_next_frame.intra_error < 200)) {
break;
}
old_boost_score = boost_score;
}
// If there is tolerable prediction for at least the next 3 frames then
// break out else discard this potential key frame and move on
if (boost_score > 30.0 && (i > count_for_tolerable_prediction)) {
is_viable_kf = 1;
} else {
is_viable_kf = 0;
}
// Reset the file position
reset_fpf_position(twopass, start_pos);
}
return is_viable_kf;
}
#define FRAMES_TO_CHECK_DECAY 8
#define KF_MIN_FRAME_BOOST 80.0
#define KF_MAX_FRAME_BOOST 128.0
#define MIN_KF_BOOST 600 // Minimum boost for non-static KF interval
#define MAX_KF_BOOST 3200
#define MIN_STATIC_KF_BOOST 5400 // Minimum boost for static KF interval
static int detect_app_forced_key(AV1_COMP *cpi) {
if (cpi->oxcf.kf_cfg.fwd_kf_enabled) cpi->ppi->p_rc.next_is_fwd_key = 1;
int num_frames_to_app_forced_key = is_forced_keyframe_pending(
cpi->ppi->lookahead, cpi->ppi->lookahead->max_sz, cpi->compressor_stage);
if (num_frames_to_app_forced_key != -1) cpi->ppi->p_rc.next_is_fwd_key = 0;
return num_frames_to_app_forced_key;
}
static int get_projected_kf_boost(AV1_COMP *cpi) {
/*
* If num_stats_used_for_kf_boost >= frames_to_key, then
* all stats needed for prior boost calculation are available.
* Hence projecting the prior boost is not needed in this cases.
*/
if (cpi->ppi->p_rc.num_stats_used_for_kf_boost >= cpi->rc.frames_to_key)
return cpi->ppi->p_rc.kf_boost;
// Get the current tpl factor (number of frames = frames_to_key).
double tpl_factor = av1_get_kf_boost_projection_factor(cpi->rc.frames_to_key);
// Get the tpl factor when number of frames = num_stats_used_for_kf_boost.
double tpl_factor_num_stats = av1_get_kf_boost_projection_factor(
cpi->ppi->p_rc.num_stats_used_for_kf_boost);
int projected_kf_boost =
(int)rint((tpl_factor * cpi->ppi->p_rc.kf_boost) / tpl_factor_num_stats);
return projected_kf_boost;
}
/*!\brief Determine the location of the next key frame
*
* \ingroup gf_group_algo
* This function decides the placement of the next key frame when a
* scenecut is detected or the maximum key frame distance is reached.
*
* \param[in] cpi Top-level encoder structure
* \param[in] this_frame Pointer to first pass stats
* \param[out] kf_group_err The total error in the KF group
* \param[in] num_frames_to_detect_scenecut Maximum lookahead frames.
*
* \return Number of frames to the next key.
*/
static int define_kf_interval(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame,
double *kf_group_err,
int num_frames_to_detect_scenecut) {
TWO_PASS *const twopass = &cpi->ppi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
const KeyFrameCfg *const kf_cfg = &oxcf->kf_cfg;
double recent_loop_decay[FRAMES_TO_CHECK_DECAY];
FIRSTPASS_STATS last_frame;
double decay_accumulator = 1.0;
int i = 0, j;
int frames_to_key = 1;
int frames_since_key = rc->frames_since_key + 1;
FRAME_INFO *const frame_info = &cpi->frame_info;
int num_stats_used_for_kf_boost = 1;
int scenecut_detected = 0;
int num_frames_to_next_key = detect_app_forced_key(cpi);
if (num_frames_to_detect_scenecut == 0) {
if (num_frames_to_next_key != -1)
return num_frames_to_next_key;
else
return rc->frames_to_key;
}
if (num_frames_to_next_key != -1)
num_frames_to_detect_scenecut =
AOMMIN(num_frames_to_detect_scenecut, num_frames_to_next_key);
// Initialize the decay rates for the recent frames to check
for (j = 0; j < FRAMES_TO_CHECK_DECAY; ++j) recent_loop_decay[j] = 1.0;
i = 0;
while (twopass->stats_in < twopass->stats_buf_ctx->stats_in_end &&
frames_to_key < num_frames_to_detect_scenecut) {
// Accumulate total number of stats available till next key frame
num_stats_used_for_kf_boost++;
// Accumulate kf group error.
if (kf_group_err != NULL)
*kf_group_err +=
calculate_modified_err(frame_info, twopass, oxcf, this_frame);
// Load the next frame's stats.
last_frame = *this_frame;
input_stats(twopass, this_frame);
// Provided that we are not at the end of the file...
if ((cpi->ppi->p_rc.enable_scenecut_detection > 0) && kf_cfg->auto_key &&
twopass->stats_in < twopass->stats_buf_ctx->stats_in_end) {
double loop_decay_rate;
// Check for a scene cut.
if (frames_since_key >= kf_cfg->key_freq_min &&
test_candidate_kf(twopass, &last_frame, this_frame, twopass->stats_in,
frames_since_key, oxcf->rc_cfg.mode,
cpi->ppi->p_rc.enable_scenecut_detection)) {
scenecut_detected = 1;
break;
}
// How fast is the prediction quality decaying?
loop_decay_rate =
get_prediction_decay_rate(frame_info, twopass->stats_in);
// We want to know something about the recent past... rather than
// as used elsewhere where we are concerned with decay in prediction
// quality since the last GF or KF.
recent_loop_decay[i % FRAMES_TO_CHECK_DECAY] = loop_decay_rate;
decay_accumulator = 1.0;
for (j = 0; j < FRAMES_TO_CHECK_DECAY; ++j)
decay_accumulator *= recent_loop_decay[j];
// Special check for transition or high motion followed by a
// static scene.
if (frames_since_key >= kf_cfg->key_freq_min &&
detect_transition_to_still(twopass, rc->min_gf_interval, i,
kf_cfg->key_freq_max - i, loop_decay_rate,
decay_accumulator)) {
scenecut_detected = 1;
// In the case of transition followed by a static scene, the key frame
// could be a good predictor for the following frames, therefore we
// do not use an arf.
p_rc->use_arf_in_this_kf_group = 0;
break;
}
// Step on to the next frame.
++frames_to_key;
++frames_since_key;
// If we don't have a real key frame within the next two
// key_freq_max intervals then break out of the loop.
if (frames_to_key >= 2 * kf_cfg->key_freq_max) break;
} else {
++frames_to_key;
++frames_since_key;
}
++i;
}
if (kf_group_err != NULL)
p_rc->num_stats_used_for_kf_boost = num_stats_used_for_kf_boost;
if (cpi->ppi->lap_enabled && !scenecut_detected)
frames_to_key = num_frames_to_next_key;
if (!kf_cfg->fwd_kf_enabled || scenecut_detected ||
twopass->stats_in >= twopass->stats_buf_ctx->stats_in_end)
p_rc->next_is_fwd_key = 0;
return frames_to_key;
}
static double get_kf_group_avg_error(TWO_PASS *twopass,
const FIRSTPASS_STATS *first_frame,
const FIRSTPASS_STATS *start_position,
int frames_to_key) {
FIRSTPASS_STATS cur_frame = *first_frame;
int num_frames, i;
double kf_group_avg_error = 0.0;
reset_fpf_position(twopass, start_position);
for (i = 0; i < frames_to_key; ++i) {
kf_group_avg_error += cur_frame.coded_error;
if (EOF == input_stats(twopass, &cur_frame)) break;
}
num_frames = i + 1;
num_frames = AOMMIN(num_frames, frames_to_key);
kf_group_avg_error = kf_group_avg_error / num_frames;
return (kf_group_avg_error);
}
static int64_t get_kf_group_bits(AV1_COMP *cpi, double kf_group_err,
double kf_group_avg_error) {
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
int64_t kf_group_bits;
if (cpi->ppi->lap_enabled) {
kf_group_bits = (int64_t)rc->frames_to_key * rc->avg_frame_bandwidth;
if (cpi->oxcf.rc_cfg.vbr_corpus_complexity_lap) {
const int num_mbs = (cpi->oxcf.resize_cfg.resize_mode != RESIZE_NONE)
? cpi->initial_mbs
: cpi->common.mi_params.MBs;
double vbr_corpus_complexity_lap =
cpi->oxcf.rc_cfg.vbr_corpus_complexity_lap / 10.0;
/* Get the average corpus complexity of the frame */
vbr_corpus_complexity_lap = vbr_corpus_complexity_lap * num_mbs;
kf_group_bits = (int64_t)(
kf_group_bits * (kf_group_avg_error / vbr_corpus_complexity_lap));
}
} else {
kf_group_bits = (int64_t)(twopass->bits_left *
(kf_group_err / twopass->modified_error_left));
}
return kf_group_bits;
}
static int calc_avg_stats(AV1_COMP *cpi, FIRSTPASS_STATS *avg_frame_stat) {
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
FIRSTPASS_STATS cur_frame;
av1_zero(cur_frame);
int num_frames = 0;
// Accumulate total stat using available number of stats.
for (num_frames = 0; num_frames < (rc->frames_to_key - 1); ++num_frames) {
if (EOF == input_stats(twopass, &cur_frame)) break;
av1_accumulate_stats(avg_frame_stat, &cur_frame);
}
if (num_frames < 2) {
return num_frames;
}
// Average the total stat
avg_frame_stat->weight = avg_frame_stat->weight / num_frames;
avg_frame_stat->intra_error = avg_frame_stat->intra_error / num_frames;
avg_frame_stat->frame_avg_wavelet_energy =
avg_frame_stat->frame_avg_wavelet_energy / num_frames;
avg_frame_stat->coded_error = avg_frame_stat->coded_error / num_frames;
avg_frame_stat->sr_coded_error = avg_frame_stat->sr_coded_error / num_frames;
avg_frame_stat->pcnt_inter = avg_frame_stat->pcnt_inter / num_frames;
avg_frame_stat->pcnt_motion = avg_frame_stat->pcnt_motion / num_frames;
avg_frame_stat->pcnt_second_ref =
avg_frame_stat->pcnt_second_ref / num_frames;
avg_frame_stat->pcnt_neutral = avg_frame_stat->pcnt_neutral / num_frames;
avg_frame_stat->intra_skip_pct = avg_frame_stat->intra_skip_pct / num_frames;
avg_frame_stat->inactive_zone_rows =
avg_frame_stat->inactive_zone_rows / num_frames;
avg_frame_stat->inactive_zone_cols =
avg_frame_stat->inactive_zone_cols / num_frames;
avg_frame_stat->MVr = avg_frame_stat->MVr / num_frames;
avg_frame_stat->mvr_abs = avg_frame_stat->mvr_abs / num_frames;
avg_frame_stat->MVc = avg_frame_stat->MVc / num_frames;
avg_frame_stat->mvc_abs = avg_frame_stat->mvc_abs / num_frames;
avg_frame_stat->MVrv = avg_frame_stat->MVrv / num_frames;
avg_frame_stat->MVcv = avg_frame_stat->MVcv / num_frames;
avg_frame_stat->mv_in_out_count =
avg_frame_stat->mv_in_out_count / num_frames;
avg_frame_stat->new_mv_count = avg_frame_stat->new_mv_count / num_frames;
avg_frame_stat->count = avg_frame_stat->count / num_frames;
avg_frame_stat->duration = avg_frame_stat->duration / num_frames;
return num_frames;
}
static double get_kf_boost_score(AV1_COMP *cpi, double kf_raw_err,
double *zero_motion_accumulator,
double *sr_accumulator, int use_avg_stat) {
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
FRAME_INFO *const frame_info = &cpi->frame_info;
FIRSTPASS_STATS frame_stat;
av1_zero(frame_stat);
int i = 0, num_stat_used = 0;
double boost_score = 0.0;
const double kf_max_boost =
cpi->oxcf.rc_cfg.mode == AOM_Q
? AOMMIN(AOMMAX(rc->frames_to_key * 2.0, KF_MIN_FRAME_BOOST),
KF_MAX_FRAME_BOOST)
: KF_MAX_FRAME_BOOST;
// Calculate the average using available number of stats.
if (use_avg_stat) num_stat_used = calc_avg_stats(cpi, &frame_stat);
for (i = num_stat_used; i < (rc->frames_to_key - 1); ++i) {
if (!use_avg_stat && EOF == input_stats(twopass, &frame_stat)) break;
// Monitor for static sections.
// For the first frame in kf group, the second ref indicator is invalid.
if (i > 0) {
*zero_motion_accumulator =
AOMMIN(*zero_motion_accumulator,
get_zero_motion_factor(frame_info, &frame_stat));
} else {
*zero_motion_accumulator = frame_stat.pcnt_inter - frame_stat.pcnt_motion;
}
// Not all frames in the group are necessarily used in calculating boost.
if ((*sr_accumulator < (kf_raw_err * 1.50)) &&
(i <= rc->max_gf_interval * 2)) {
double frame_boost;
double zm_factor;
// Factor 0.75-1.25 based on how much of frame is static.
zm_factor = (0.75 + (*zero_motion_accumulator / 2.0));
if (i < 2) *sr_accumulator = 0.0;
frame_boost = calc_kf_frame_boost(rc, frame_info, &frame_stat,
sr_accumulator, kf_max_boost);
boost_score += frame_boost * zm_factor;
}
}
return boost_score;
}
/*!\brief Interval(in seconds) to clip key-frame distance to in LAP.
*/
#define MAX_KF_BITS_INTERVAL_SINGLE_PASS 5
/*!\brief Determine the next key frame group
*
* \ingroup gf_group_algo
* This function decides the placement of the next key frame, and
* calculates the bit allocation of the KF group and the keyframe itself.
*
* \param[in] cpi Top-level encoder structure
* \param[in] this_frame Pointer to first pass stats
*
* \return Nothing is returned.
*/
static void find_next_key_frame(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
GF_GROUP *const gf_group = &cpi->ppi->gf_group;
FRAME_INFO *const frame_info = &cpi->frame_info;
AV1_COMMON *const cm = &cpi->common;
CurrentFrame *const current_frame = &cm->current_frame;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
const KeyFrameCfg *const kf_cfg = &oxcf->kf_cfg;
const FIRSTPASS_STATS first_frame = *this_frame;
FIRSTPASS_STATS next_frame;
av1_zero(next_frame);
rc->frames_since_key = 0;
// Use arfs if possible.
p_rc->use_arf_in_this_kf_group = is_altref_enabled(
oxcf->gf_cfg.lag_in_frames, oxcf->gf_cfg.enable_auto_arf);
// Reset the GF group data structures.
av1_zero(*gf_group);
cpi->gf_frame_index = 0;
// KF is always a GF so clear frames till next gf counter.
rc->frames_till_gf_update_due = 0;
if (has_no_stats_stage(cpi)) {
int num_frames_to_app_forced_key = detect_app_forced_key(cpi);
p_rc->this_key_frame_forced =
current_frame->frame_number != 0 && rc->frames_to_key == 0;
if (num_frames_to_app_forced_key != -1)
rc->frames_to_key = num_frames_to_app_forced_key;
else
rc->frames_to_key = AOMMAX(1, kf_cfg->key_freq_max);
correct_frames_to_key(cpi);
p_rc->kf_boost = DEFAULT_KF_BOOST;
gf_group->update_type[0] = KF_UPDATE;
return;
}
int i;
const FIRSTPASS_STATS *const start_position = twopass->stats_in;
int kf_bits = 0;
double zero_motion_accumulator = 1.0;
double boost_score = 0.0;
double kf_raw_err = 0.0;
double kf_mod_err = 0.0;
double kf_group_err = 0.0;
double sr_accumulator = 0.0;
double kf_group_avg_error = 0.0;
int frames_to_key, frames_to_key_clipped = INT_MAX;
int64_t kf_group_bits_clipped = INT64_MAX;
// Is this a forced key frame by interval.
p_rc->this_key_frame_forced = p_rc->next_key_frame_forced;
twopass->kf_group_bits = 0; // Total bits available to kf group
twopass->kf_group_error_left = 0; // Group modified error score.
kf_raw_err = this_frame->intra_error;
kf_mod_err = calculate_modified_err(frame_info, twopass, oxcf, this_frame);
frames_to_key =
define_kf_interval(cpi, this_frame, &kf_group_err, kf_cfg->key_freq_max);
if (frames_to_key != -1)
rc->frames_to_key = AOMMIN(kf_cfg->key_freq_max, frames_to_key);
else
rc->frames_to_key = kf_cfg->key_freq_max;
if (cpi->ppi->lap_enabled) correct_frames_to_key(cpi);
// If there is a max kf interval set by the user we must obey it.
// We already breakout of the loop above at 2x max.
// This code centers the extra kf if the actual natural interval
// is between 1x and 2x.
if (kf_cfg->auto_key && rc->frames_to_key > kf_cfg->key_freq_max) {
FIRSTPASS_STATS tmp_frame = first_frame;
rc->frames_to_key /= 2;
// Reset to the start of the group.
reset_fpf_position(twopass, start_position);
kf_group_err = 0.0;
// Rescan to get the correct error data for the forced kf group.
for (i = 0; i < rc->frames_to_key; ++i) {
kf_group_err +=
calculate_modified_err(frame_info, twopass, oxcf, &tmp_frame);
if (EOF == input_stats(twopass, &tmp_frame)) break;
}
p_rc->next_key_frame_forced = 1;
} else if ((twopass->stats_in == twopass->stats_buf_ctx->stats_in_end &&
is_stat_consumption_stage_twopass(cpi)) ||
rc->frames_to_key >= kf_cfg->key_freq_max) {
p_rc->next_key_frame_forced = 1;
} else {
p_rc->next_key_frame_forced = 0;
}
if (kf_cfg->fwd_kf_enabled)
p_rc->next_is_fwd_key |= p_rc->next_key_frame_forced;
// Special case for the last key frame of the file.
if (twopass->stats_in >= twopass->stats_buf_ctx->stats_in_end) {
// Accumulate kf group error.
kf_group_err +=
calculate_modified_err(frame_info, twopass, oxcf, this_frame);
p_rc->next_is_fwd_key = 0;
}
// Calculate the number of bits that should be assigned to the kf group.
if ((twopass->bits_left > 0 && twopass->modified_error_left > 0.0) ||
(cpi->ppi->lap_enabled && oxcf->rc_cfg.mode != AOM_Q)) {
// Maximum number of bits for a single normal frame (not key frame).
const int max_bits = frame_max_bits(rc, oxcf);
// Maximum number of bits allocated to the key frame group.
int64_t max_grp_bits;
if (oxcf->rc_cfg.vbr_corpus_complexity_lap) {
kf_group_avg_error = get_kf_group_avg_error(
twopass, &first_frame, start_position, rc->frames_to_key);
}
// Default allocation based on bits left and relative
// complexity of the section.
twopass->kf_group_bits =
get_kf_group_bits(cpi, kf_group_err, kf_group_avg_error);
// Clip based on maximum per frame rate defined by the user.
max_grp_bits = (int64_t)max_bits * (int64_t)rc->frames_to_key;
if (twopass->kf_group_bits > max_grp_bits)
twopass->kf_group_bits = max_grp_bits;
} else {
twopass->kf_group_bits = 0;
}
twopass->kf_group_bits = AOMMAX(0, twopass->kf_group_bits);
if (cpi->ppi->lap_enabled) {
// In the case of single pass based on LAP, frames to key may have an
// inaccurate value, and hence should be clipped to an appropriate
// interval.
frames_to_key_clipped =
(int)(MAX_KF_BITS_INTERVAL_SINGLE_PASS * cpi->framerate);
// This variable calculates the bits allocated to kf_group with a clipped
// frames_to_key.
if (rc->frames_to_key > frames_to_key_clipped) {
kf_group_bits_clipped =
(int64_t)((double)twopass->kf_group_bits * frames_to_key_clipped /
rc->frames_to_key);
}
}
// Reset the first pass file position.
reset_fpf_position(twopass, start_position);
// Scan through the kf group collating various stats used to determine
// how many bits to spend on it.
boost_score = get_kf_boost_score(cpi, kf_raw_err, &zero_motion_accumulator,
&sr_accumulator, 0);
reset_fpf_position(twopass, start_position);
// Store the zero motion percentage
twopass->kf_zeromotion_pct = (int)(zero_motion_accumulator * 100.0);
// Calculate a section intra ratio used in setting max loop filter.
twopass->section_intra_rating = calculate_section_intra_ratio(
start_position, twopass->stats_buf_ctx->stats_in_end, rc->frames_to_key);
p_rc->kf_boost = (int)boost_score;
if (cpi->ppi->lap_enabled) {
if (oxcf->rc_cfg.mode == AOM_Q) {
p_rc->kf_boost = get_projected_kf_boost(cpi);
} else {
// TODO(any): Explore using average frame stats for AOM_Q as well.
boost_score = get_kf_boost_score(
cpi, kf_raw_err, &zero_motion_accumulator, &sr_accumulator, 1);
reset_fpf_position(twopass, start_position);
p_rc->kf_boost += (int)boost_score;
}
}
// Special case for static / slide show content but don't apply
// if the kf group is very short.
if ((zero_motion_accumulator > STATIC_KF_GROUP_FLOAT_THRESH) &&
(rc->frames_to_key > 8)) {
p_rc->kf_boost = AOMMAX(p_rc->kf_boost, MIN_STATIC_KF_BOOST);
} else {
// Apply various clamps for min and max boost
p_rc->kf_boost = AOMMAX(p_rc->kf_boost, (rc->frames_to_key * 3));
p_rc->kf_boost = AOMMAX(p_rc->kf_boost, MIN_KF_BOOST);
#ifdef STRICT_RC
p_rc->kf_boost = AOMMIN(p_rc->kf_boost, MAX_KF_BOOST);
#endif
}
// Work out how many bits to allocate for the key frame itself.
// In case of LAP enabled for VBR, if the frames_to_key value is
// very high, we calculate the bits based on a clipped value of
// frames_to_key.
kf_bits = calculate_boost_bits(
AOMMIN(rc->frames_to_key, frames_to_key_clipped) - 1, p_rc->kf_boost,
AOMMIN(twopass->kf_group_bits, kf_group_bits_clipped));
// printf("kf boost = %d kf_bits = %d kf_zeromotion_pct = %d\n",
// p_rc->kf_boost,
// kf_bits, twopass->kf_zeromotion_pct);
kf_bits = adjust_boost_bits_for_target_level(cpi, rc, kf_bits,
twopass->kf_group_bits, 0);
twopass->kf_group_bits -= kf_bits;
// Save the bits to spend on the key frame.
gf_group->bit_allocation[0] = kf_bits;
gf_group->update_type[0] = KF_UPDATE;
// Note the total error score of the kf group minus the key frame itself.
if (cpi->ppi->lap_enabled)
// As we don't have enough stats to know the actual error of the group,
// we assume the complexity of each frame to be equal to 1, and set the
// error as the number of frames in the group(minus the keyframe).
twopass->kf_group_error_left = (int)(rc->frames_to_key - 1);
else
twopass->kf_group_error_left = (int)(kf_group_err - kf_mod_err);
// Adjust the count of total modified error left.
// The count of bits left is adjusted elsewhere based on real coded frame
// sizes.
twopass->modified_error_left -= kf_group_err;
}
static int is_skippable_frame(const AV1_COMP *cpi) {
if (has_no_stats_stage(cpi)) return 0;
// If the current frame does not have non-zero motion vector detected in the
// first pass, and so do its previous and forward frames, then this frame
// can be skipped for partition check, and the partition size is assigned
// according to the variance
const TWO_PASS *const twopass = &cpi->ppi->twopass;
return (!frame_is_intra_only(&cpi->common) &&
twopass->stats_in - 2 > twopass->stats_buf_ctx->stats_in_start &&
twopass->stats_in < twopass->stats_buf_ctx->stats_in_end &&
(twopass->stats_in - 1)->pcnt_inter -
(twopass->stats_in - 1)->pcnt_motion ==
1 &&
(twopass->stats_in - 2)->pcnt_inter -
(twopass->stats_in - 2)->pcnt_motion ==
1 &&
twopass->stats_in->pcnt_inter - twopass->stats_in->pcnt_motion == 1);
}
#define ARF_STATS_OUTPUT 0
#if ARF_STATS_OUTPUT
unsigned int arf_count = 0;
#endif
static int get_section_target_bandwidth(AV1_COMP *cpi) {
AV1_COMMON *const cm = &cpi->common;
CurrentFrame *const current_frame = &cm->current_frame;
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
int section_target_bandwidth;
const int frames_left = (int)(twopass->stats_buf_ctx->total_stats->count -
current_frame->frame_number);
if (cpi->ppi->lap_enabled)
section_target_bandwidth = (int)rc->avg_frame_bandwidth;
else
section_target_bandwidth = (int)(twopass->bits_left / frames_left);
return section_target_bandwidth;
}
static void process_first_pass_stats(AV1_COMP *cpi,
FIRSTPASS_STATS *this_frame) {
AV1_COMMON *const cm = &cpi->common;
CurrentFrame *const current_frame = &cm->current_frame;
RATE_CONTROL *const rc = &cpi->rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
if (cpi->oxcf.rc_cfg.mode != AOM_Q && current_frame->frame_number == 0 &&
cpi->gf_frame_index == 0 &&
cpi->ppi->twopass.stats_buf_ctx->total_stats &&
cpi->ppi->twopass.stats_buf_ctx->total_left_stats) {
if (cpi->ppi->lap_enabled) {
/*
* Accumulate total_stats using available limited number of stats,
* and assign it to total_left_stats.
*/
*cpi->ppi->twopass.stats_buf_ctx->total_left_stats =
*cpi->ppi->twopass.stats_buf_ctx->total_stats;
}
// Special case code for first frame.
const int section_target_bandwidth = get_section_target_bandwidth(cpi);
const double section_length =
twopass->stats_buf_ctx->total_left_stats->count;
const double section_error =
twopass->stats_buf_ctx->total_left_stats->coded_error / section_length;
const double section_intra_skip =
twopass->stats_buf_ctx->total_left_stats->intra_skip_pct /
section_length;
const double section_inactive_zone =
(twopass->stats_buf_ctx->total_left_stats->inactive_zone_rows * 2) /
((double)cm->mi_params.mb_rows * section_length);
const int tmp_q = get_twopass_worst_quality(
cpi, section_error, section_intra_skip + section_inactive_zone,
section_target_bandwidth);
rc->active_worst_quality = tmp_q;
rc->ni_av_qi = tmp_q;
rc->last_q[INTER_FRAME] = tmp_q;
rc->avg_q = av1_convert_qindex_to_q(tmp_q, cm->seq_params->bit_depth);
rc->avg_frame_qindex[INTER_FRAME] = tmp_q;
rc->last_q[KEY_FRAME] = (tmp_q + cpi->oxcf.rc_cfg.best_allowed_q) / 2;
rc->avg_frame_qindex[KEY_FRAME] = rc->last_q[KEY_FRAME];
}
int err = 0;
if (cpi->ppi->lap_enabled) {
err = input_stats_lap(twopass, this_frame);
} else {
err = input_stats(twopass, this_frame);
}
if (err == EOF) return;
{
const int num_mbs = (cpi->oxcf.resize_cfg.resize_mode != RESIZE_NONE)
? cpi->initial_mbs
: cm->mi_params.MBs;
// The multiplication by 256 reverses a scaling factor of (>> 8)
// applied when combining MB error values for the frame.
twopass->mb_av_energy = log((this_frame->intra_error / num_mbs) + 1.0);
twopass->frame_avg_haar_energy =
log((this_frame->frame_avg_wavelet_energy / num_mbs) + 1.0);
}
// Set the frame content type flag.
if (this_frame->intra_skip_pct >= FC_ANIMATION_THRESH)
twopass->fr_content_type = FC_GRAPHICS_ANIMATION;
else
twopass->fr_content_type = FC_NORMAL;
}
static void setup_target_rate(AV1_COMP *cpi) {
RATE_CONTROL *const rc = &cpi->rc;
GF_GROUP *const gf_group = &cpi->ppi->gf_group;
int target_rate = gf_group->bit_allocation[cpi->gf_frame_index];
if (has_no_stats_stage(cpi)) {
av1_rc_set_frame_target(cpi, target_rate, cpi->common.width,
cpi->common.height);
}
rc->base_frame_target = target_rate;
}
static void mark_flashes(FIRSTPASS_STATS *first_stats,
FIRSTPASS_STATS *last_stats) {
FIRSTPASS_STATS *this_stats = first_stats, *next_stats;
while (this_stats < last_stats - 1) {
next_stats = this_stats + 1;
if (next_stats->pcnt_second_ref > next_stats->pcnt_inter &&
next_stats->pcnt_second_ref >= 0.5) {
this_stats->is_flash = 1;
} else {
this_stats->is_flash = 0;
}
this_stats = next_stats;
}
// We always treat the last one as none flash.
if (last_stats - 1 >= first_stats) {
(last_stats - 1)->is_flash = 0;
}
}
// Estimate the noise variance of each frame from the first pass stats
static void estimate_noise(FIRSTPASS_STATS *first_stats,
FIRSTPASS_STATS *last_stats) {
FIRSTPASS_STATS *this_stats, *next_stats;
double C1, C2, C3, noise;
int count = 0;
for (this_stats = first_stats + 2; this_stats < last_stats; this_stats++) {
this_stats->noise_var = 0.0;
// flashes tend to have high correlation of innovations, so ignore them.
if (this_stats->is_flash || (this_stats - 1)->is_flash ||
(this_stats - 2)->is_flash)
continue;
C1 = (this_stats - 1)->intra_error *
(this_stats->intra_error - this_stats->coded_error);
C2 = (this_stats - 2)->intra_error *
((this_stats - 1)->intra_error - (this_stats - 1)->coded_error);
C3 = (this_stats - 2)->intra_error *
(this_stats->intra_error - this_stats->sr_coded_error);
if (C1 <= 0 || C2 <= 0 || C3 <= 0) continue;
C1 = sqrt(C1);
C2 = sqrt(C2);
C3 = sqrt(C3);
noise = (this_stats - 1)->intra_error - C1 * C2 / C3;
noise = AOMMAX(noise, 0.01);
this_stats->noise_var = noise;
count++;
}
// Copy noise from the neighbor if the noise value is not trustworthy
for (this_stats = first_stats + 2; this_stats < last_stats; this_stats++) {
if (this_stats->is_flash || (this_stats - 1)->is_flash ||
(this_stats - 2)->is_flash)
continue;
if (this_stats->noise_var < 1.0) {
int found = 0;
// TODO(bohanli): consider expanding to two directions at the same time
for (next_stats = this_stats + 1; next_stats < last_stats; next_stats++) {
if (next_stats->is_flash || (next_stats - 1)->is_flash ||
(next_stats - 2)->is_flash || next_stats->noise_var < 1.0)
continue;
found = 1;
this_stats->noise_var = next_stats->noise_var;
break;
}
if (found) continue;
for (next_stats = this_stats - 1; next_stats >= first_stats + 2;
next_stats--) {
if (next_stats->is_flash || (next_stats - 1)->is_flash ||
(next_stats - 2)->is_flash || next_stats->noise_var < 1.0)
continue;
this_stats->noise_var = next_stats->noise_var;
break;
}
}
}
// copy the noise if this is a flash
for (this_stats = first_stats + 2; this_stats < last_stats; this_stats++) {
if (this_stats->is_flash || (this_stats - 1)->is_flash ||
(this_stats - 2)->is_flash) {
int found = 0;
for (next_stats = this_stats + 1; next_stats < last_stats; next_stats++) {
if (next_stats->is_flash || (next_stats - 1)->is_flash ||
(next_stats - 2)->is_flash)
continue;
found = 1;
this_stats->noise_var = next_stats->noise_var;
break;
}
if (found) continue;
for (next_stats = this_stats - 1; next_stats >= first_stats + 2;
next_stats--) {
if (next_stats->is_flash || (next_stats - 1)->is_flash ||
(next_stats - 2)->is_flash)
continue;
this_stats->noise_var = next_stats->noise_var;
break;
}
}
}
// if we are at the first 2 frames, copy the noise
for (this_stats = first_stats;
this_stats < first_stats + 2 && (first_stats + 2) < last_stats;
this_stats++) {
this_stats->noise_var = (first_stats + 2)->noise_var;
}
}
// Estimate correlation coefficient of each frame with its previous frame.
static void estimate_coeff(FIRSTPASS_STATS *first_stats,
FIRSTPASS_STATS *last_stats) {
FIRSTPASS_STATS *this_stats;
for (this_stats = first_stats + 1; this_stats < last_stats; this_stats++) {
const double C =
sqrt(AOMMAX((this_stats - 1)->intra_error *
(this_stats->intra_error - this_stats->coded_error),
0.001));
const double cor_coeff =
C /
AOMMAX((this_stats - 1)->intra_error - this_stats->noise_var, 0.001);
this_stats->cor_coeff =
cor_coeff *
sqrt(AOMMAX((this_stats - 1)->intra_error - this_stats->noise_var,
0.001) /
AOMMAX(this_stats->intra_error - this_stats->noise_var, 0.001));
// clip correlation coefficient.
this_stats->cor_coeff = AOMMIN(AOMMAX(this_stats->cor_coeff, 0), 1);
}
first_stats->cor_coeff = 1.0;
}
void av1_get_second_pass_params(AV1_COMP *cpi,
EncodeFrameParams *const frame_params,
const EncodeFrameInput *const frame_input,
unsigned int frame_flags) {
RATE_CONTROL *const rc = &cpi->rc;
PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;
TWO_PASS *const twopass = &cpi->ppi->twopass;
GF_GROUP *const gf_group = &cpi->ppi->gf_group;
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
const FIRSTPASS_STATS *const start_pos = twopass->stats_in;
if (is_stat_consumption_stage(cpi) && !twopass->stats_in) return;
const int update_type = gf_group->update_type[cpi->gf_frame_index];
frame_params->frame_type = gf_group->frame_type[cpi->gf_frame_index];
if (cpi->gf_frame_index < gf_group->size && !(frame_flags & FRAMEFLAGS_KEY)) {
assert(cpi->gf_frame_index < gf_group->size);
setup_target_rate(cpi);
// If this is an arf frame then we dont want to read the stats file or
// advance the input pointer as we already have what we need.
if (update_type == ARF_UPDATE || update_type == INTNL_ARF_UPDATE) {
// Do the firstpass stats indicate that this frame is skippable for the
// partition search?
if (cpi->sf.part_sf.allow_partition_search_skip && oxcf->pass == 2) {
cpi->partition_search_skippable_frame = is_skippable_frame(cpi);
}
return;
}
}
aom_clear_system_state();
if (oxcf->rc_cfg.mode == AOM_Q)
rc->active_worst_quality = oxcf->rc_cfg.cq_level;
FIRSTPASS_STATS this_frame;
av1_zero(this_frame);
// call above fn
if (is_stat_consumption_stage(cpi)) {
if (cpi->gf_frame_index < gf_group->size || rc->frames_to_key == 0)
process_first_pass_stats(cpi, &this_frame);
} else {
rc->active_worst_quality = oxcf->rc_cfg.cq_level;
}
// Keyframe and section processing.
FIRSTPASS_STATS this_frame_copy;
this_frame_copy = this_frame;
int is_overlay_forward_kf =
rc->frames_to_key == 0 &&
gf_group->update_type[cpi->gf_frame_index] == OVERLAY_UPDATE;
if (rc->frames_to_key <= 0 && !is_overlay_forward_kf) {
assert(rc->frames_to_key >= -1);
// Define next KF group and assign bits to it.
int kf_offset = rc->frames_to_key;
if (rc->frames_to_key < 0) {
this_frame = *(twopass->stats_in - 1);
} else {
frame_params->frame_type = KEY_FRAME;
}
find_next_key_frame(cpi, &this_frame);
rc->frames_since_key -= kf_offset;
rc->frames_to_key += kf_offset;
this_frame = this_frame_copy;
} else {
const int altref_enabled = is_altref_enabled(oxcf->gf_cfg.lag_in_frames,
oxcf->gf_cfg.enable_auto_arf);
const int sframe_dist = oxcf->kf_cfg.sframe_dist;
const int sframe_mode = oxcf->kf_cfg.sframe_mode;
CurrentFrame *const current_frame = &cpi->common.current_frame;
if (sframe_dist != 0) {
if (altref_enabled) {
if (sframe_mode == 1) {
// sframe_mode == 1: insert sframe if it matches altref frame.
if (current_frame->frame_number % sframe_dist == 0 &&
current_frame->frame_number != 0 && update_type == ARF_UPDATE) {
frame_params->frame_type = S_FRAME;
}
} else {
// sframe_mode != 1: if sframe will be inserted at the next available
// altref frame
if (current_frame->frame_number % sframe_dist == 0 &&
current_frame->frame_number != 0) {
rc->sframe_due = 1;
}
if (rc->sframe_due && update_type == ARF_UPDATE) {
frame_params->frame_type = S_FRAME;
rc->sframe_due = 0;
}
}
} else {
if (current_frame->frame_number % sframe_dist == 0 &&
current_frame->frame_number != 0) {
frame_params->frame_type = S_FRAME;
}
}
}
}
// Define a new GF/ARF group. (Should always enter here for key frames).
if (cpi->gf_frame_index == gf_group->size) {
assert(cpi->common.current_frame.frame_number == 0 ||
cpi->gf_frame_index == gf_group->size);
const FIRSTPASS_STATS *const start_position = twopass->stats_in;
if (cpi->ppi->lap_enabled && cpi->ppi->p_rc.enable_scenecut_detection) {
int num_frames_to_detect_scenecut, frames_to_key;
num_frames_to_detect_scenecut = MAX_GF_LENGTH_LAP + 1;
frames_to_key = define_kf_interval(cpi, &this_frame, NULL,
num_frames_to_detect_scenecut);
if (frames_to_key != -1)
rc->frames_to_key = AOMMIN(rc->frames_to_key, frames_to_key);
}
reset_fpf_position(twopass, start_position);
int max_gop_length =
(oxcf->gf_cfg.lag_in_frames >= 32 &&
is_stat_consumption_stage_twopass(cpi))
? AOMMIN(MAX_GF_INTERVAL, oxcf->gf_cfg.lag_in_frames -
oxcf->algo_cfg.arnr_max_frames / 2)
: MAX_GF_LENGTH_LAP;
// Identify regions if needed.
// TODO(bohanli): identify regions for all stats available.
if (rc->frames_since_key == 0 || rc->frames_since_key == 1 ||
(p_rc->frames_till_regions_update - rc->frames_since_key <
rc->frames_to_key &&
p_rc->frames_till_regions_update - rc->frames_since_key <
max_gop_length + 1)) {
// how many frames we can analyze from this frame
int rest_frames = AOMMIN(rc->frames_to_key + p_rc->next_is_fwd_key,
MAX_FIRSTPASS_ANALYSIS_FRAMES);
rest_frames = AOMMIN(
rest_frames, (int)(twopass->stats_buf_ctx->stats_in_end -
twopass->stats_in + (rc->frames_since_key == 0)));
p_rc->frames_till_regions_update = rest_frames;
if (cpi->ppi->lap_enabled) {
mark_flashes(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
estimate_noise(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
estimate_coeff(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
identify_regions(twopass->stats_in, rest_frames,
(rc->frames_since_key == 0), p_rc->regions,
&p_rc->num_regions);
} else {
identify_regions(twopass->stats_in - (rc->frames_since_key == 0),
rest_frames, 0, p_rc->regions, &p_rc->num_regions);
}
}
int cur_region_idx =
find_regions_index(p_rc->regions, p_rc->num_regions,
rc->frames_since_key - p_rc->regions_offset);
if ((cur_region_idx >= 0 &&
p_rc->regions[cur_region_idx].type == SCENECUT_REGION) ||
rc->frames_since_key == 0) {
// If we start from a scenecut, then the last GOP's arf boost is not
// needed for this GOP.
cpi->ppi->gf_state.arf_gf_boost_lst = 0;
}
// TODO(jingning): Resoleve the redundant calls here.
if (rc->intervals_till_gf_calculate_due == 0 || 1) {
calculate_gf_length(cpi, max_gop_length, MAX_NUM_GF_INTERVALS);
}
if (max_gop_length > 16 && oxcf->algo_cfg.enable_tpl_model &&
cpi->sf.tpl_sf.gop_length_decision_method != 3) {
int this_idx = rc->frames_since_key +
p_rc->gf_intervals[p_rc->cur_gf_index] -
p_rc->regions_offset - 1;
int this_region =
find_regions_index(p_rc->regions, p_rc->num_regions, this_idx);
int next_region =
find_regions_index(p_rc->regions, p_rc->num_regions, this_idx + 1);
int is_last_scenecut =
(p_rc->gf_intervals[p_rc->cur_gf_index] >= rc->frames_to_key ||
p_rc->regions[this_region].type == SCENECUT_REGION ||
p_rc->regions[next_region].type == SCENECUT_REGION);
int ori_gf_int = p_rc->gf_intervals[p_rc->cur_gf_index];
if (p_rc->gf_intervals[p_rc->cur_gf_index] > 16) {
// The calculate_gf_length function is previously used with
// max_gop_length = 32 with look-ahead gf intervals.
define_gf_group(cpi, &this_frame, frame_params, max_gop_length, 0);
this_frame = this_frame_copy;
if (is_shorter_gf_interval_better(cpi, frame_params, frame_input)) {
// A shorter gf interval is better.
// TODO(jingning): Remove redundant computations here.
max_gop_length = 16;
calculate_gf_length(cpi, max_gop_length, 1);
if (is_last_scenecut &&
(ori_gf_int - p_rc->gf_intervals[p_rc->cur_gf_index] < 4)) {
p_rc->gf_intervals[p_rc->cur_gf_index] = ori_gf_int;
}
}
}
}
define_gf_group(cpi, &this_frame, frame_params, max_gop_length, 0);
if (gf_group->update_type[cpi->gf_frame_index] != ARF_UPDATE &&
rc->frames_since_key > 0)
process_first_pass_stats(cpi, &this_frame);
define_gf_group(cpi, &this_frame, frame_params, max_gop_length, 1);
rc->frames_till_gf_update_due = p_rc->baseline_gf_interval;
assert(cpi->gf_frame_index == 0);
#if ARF_STATS_OUTPUT
{
FILE *fpfile;
fpfile = fopen("arf.stt", "a");
++arf_count;
fprintf(fpfile, "%10d %10d %10d %10d %10d\n",
cpi->common.current_frame.frame_number,
rc->frames_till_gf_update_due, cpi->ppi->p_rc.kf_boost, arf_count,
p_rc->gfu_boost);
fclose(fpfile);
}
#endif
}
assert(cpi->gf_frame_index < gf_group->size);
if (gf_group->update_type[cpi->gf_frame_index] == ARF_UPDATE ||
gf_group->update_type[cpi->gf_frame_index] == INTNL_ARF_UPDATE) {
reset_fpf_position(twopass, start_pos);
} else {
// Update the total stats remaining structure.
if (twopass->stats_buf_ctx->total_left_stats)
subtract_stats(twopass->stats_buf_ctx->total_left_stats,
&this_frame_copy);
}
frame_params->frame_type = gf_group->frame_type[cpi->gf_frame_index];
// Do the firstpass stats indicate that this frame is skippable for the
// partition search?
if (cpi->sf.part_sf.allow_partition_search_skip && oxcf->pass == 2) {
cpi->partition_search_skippable_frame = is_skippable_frame(cpi);
}
setup_target_rate(cpi);
}
void av1_init_second_pass(AV1_COMP *cpi) {
const AV1EncoderConfig *const oxcf = &cpi->oxcf;
TWO_PASS *const twopass = &cpi->ppi->twopass;
FRAME_INFO *const frame_info = &cpi->frame_info;
double frame_rate;
FIRSTPASS_STATS *stats;
if (!twopass->stats_buf_ctx->stats_in_end) return;
mark_flashes(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
estimate_noise(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
estimate_coeff(twopass->stats_buf_ctx->stats_in_start,
twopass->stats_buf_ctx->stats_in_end);
stats = twopass->stats_buf_ctx->total_stats;
*stats = *twopass->stats_buf_ctx->stats_in_end;
*twopass->stats_buf_ctx->total_left_stats = *stats;
frame_rate = 10000000.0 * stats->count / stats->duration;
// Each frame can have a different duration, as the frame rate in the source
// isn't guaranteed to be constant. The frame rate prior to the first frame
// encoded in the second pass is a guess. However, the sum duration is not.
// It is calculated based on the actual durations of all frames from the
// first pass.
av1_new_framerate(cpi, frame_rate);
twopass->bits_left =
(int64_t)(stats->duration * oxcf->rc_cfg.target_bandwidth / 10000000.0);
// This variable monitors how far behind the second ref update is lagging.
twopass->sr_update_lag = 1;
// Scan the first pass file and calculate a modified total error based upon
// the bias/power function used to allocate bits.
{
const double avg_error =
stats->coded_error / DOUBLE_DIVIDE_CHECK(stats->count);
const FIRSTPASS_STATS *s = twopass->stats_in;
double modified_error_total = 0.0;
twopass->modified_error_min =
(avg_error * oxcf->rc_cfg.vbrmin_section) / 100;
twopass->modified_error_max =
(avg_error * oxcf->rc_cfg.vbrmax_section) / 100;
while (s < twopass->stats_buf_ctx->stats_in_end) {
modified_error_total +=
calculate_modified_err(frame_info, twopass, oxcf, s);
++s;
}
twopass->modified_error_left = modified_error_total;
}
// 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;
// Static sequence monitor variables.
twopass->kf_zeromotion_pct = 100;
twopass->last_kfgroup_zeromotion_pct = 100;
// Initialize bits per macro_block estimate correction factor.
twopass->bpm_factor = 1.0;
// Initialize actual and target bits counters for ARF groups so that
// at the start we have a neutral bpm adjustment.
twopass->rolling_arf_group_target_bits = 1;
twopass->rolling_arf_group_actual_bits = 1;
}
void av1_init_single_pass_lap(AV1_COMP *cpi) {
TWO_PASS *const twopass = &cpi->ppi->twopass;
if (!twopass->stats_buf_ctx->stats_in_end) return;
// This variable monitors how far behind the second ref update is lagging.
twopass->sr_update_lag = 1;
twopass->bits_left = 0;
twopass->modified_error_min = 0.0;
twopass->modified_error_max = 0.0;
twopass->modified_error_left = 0.0;
// 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;
// Static sequence monitor variables.
twopass->kf_zeromotion_pct = 100;
twopass->last_kfgroup_zeromotion_pct = 100;
// Initialize bits per macro_block estimate correction factor.
twopass->bpm_factor = 1.0;
// Initialize actual and target bits counters for ARF groups so that
// at the start we have a neutral bpm adjustment.
twopass->rolling_arf_group_target_bits = 1;
twopass->rolling_arf_group_actual_bits = 1;
}
#define MINQ_ADJ_LIMIT 48
#define MINQ_ADJ_LIMIT_CQ 20
#define HIGH_UNDERSHOOT_RATIO 2
void av1_twopass_postencode_update(AV1_COMP *cpi) {
TWO_PASS *const twopass = &cpi->ppi->twopass;
RATE_CONTROL *const rc = &cpi->rc;
const RateControlCfg *const rc_cfg = &cpi->oxcf.rc_cfg;
// 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.
rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size;
twopass->bits_left = AOMMAX(twopass->bits_left - rc->base_frame_target, 0);
// Target vs actual bits for this arf group.
twopass->rolling_arf_group_target_bits += rc->base_frame_target;
twopass->rolling_arf_group_actual_bits += rc->projected_frame_size;
// 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);
rc->rate_error_estimate = clamp(rc->rate_error_estimate, -100, 100);
} else {
rc->rate_error_estimate = 0;
}
// Update the active best quality pyramid.
if (!rc->is_src_frame_alt_ref) {
const int pyramid_level =
cpi->ppi->gf_group.layer_depth[cpi->gf_frame_index];
int i;
for (i = pyramid_level; i <= MAX_ARF_LAYERS; ++i) {
rc->active_best_quality[i] = cpi->common.quant_params.base_qindex;
#if CONFIG_TUNE_VMAF
if (cpi->vmaf_info.original_qindex != -1 &&
(cpi->oxcf.tune_cfg.tuning >= AOM_TUNE_VMAF_WITH_PREPROCESSING &&
cpi->oxcf.tune_cfg.tuning <= AOM_TUNE_VMAF_NEG_MAX_GAIN)) {
rc->active_best_quality[i] = cpi->vmaf_info.original_qindex;
}
#endif
}
}
#if 0
{
AV1_COMMON *cm = &cpi->common;
FILE *fpfile;
fpfile = fopen("details.stt", "a");
fprintf(fpfile,
"%10d %10d %10d %10" PRId64 " %10" PRId64
" %10d %10d %10d %10.4lf %10.4lf %10.4lf %10.4lf\n",
cm->current_frame.frame_number, rc->base_frame_target,
rc->projected_frame_size, rc->total_actual_bits,
rc->vbr_bits_off_target, rc->rate_error_estimate,
twopass->rolling_arf_group_target_bits,
twopass->rolling_arf_group_actual_bits,
(double)twopass->rolling_arf_group_actual_bits /
(double)twopass->rolling_arf_group_target_bits,
twopass->bpm_factor,
av1_convert_qindex_to_q(cpi->common.quant_params.base_qindex,
cm->seq_params->bit_depth),
av1_convert_qindex_to_q(rc->active_worst_quality,
cm->seq_params->bit_depth));
fclose(fpfile);
}
#endif
if (cpi->common.current_frame.frame_type != KEY_FRAME) {
twopass->kf_group_bits -= rc->base_frame_target;
twopass->last_kfgroup_zeromotion_pct = twopass->kf_zeromotion_pct;
}
twopass->kf_group_bits = AOMMAX(twopass->kf_group_bits, 0);
// If the rate control is drifting consider adjustment to min or maxq.
if ((rc_cfg->mode != AOM_Q) && !cpi->rc.is_src_frame_alt_ref) {
const int maxq_adj_limit = rc->worst_quality - rc->active_worst_quality;
const int minq_adj_limit =
(rc_cfg->mode == AOM_CQ ? MINQ_ADJ_LIMIT_CQ : MINQ_ADJ_LIMIT);
// Undershoot.
if (rc->rate_error_estimate > rc_cfg->under_shoot_pct) {
--twopass->extend_maxq;
if (rc->rolling_target_bits >= rc->rolling_actual_bits)
++twopass->extend_minq;
// Overshoot.
} else if (rc->rate_error_estimate < -rc_cfg->over_shoot_pct) {
--twopass->extend_minq;
if (rc->rolling_target_bits < rc->rolling_actual_bits)
++twopass->extend_maxq;
} else {
// Adjustment for extreme local overshoot.
if (rc->projected_frame_size > (2 * rc->base_frame_target) &&
rc->projected_frame_size > (2 * rc->avg_frame_bandwidth))
++twopass->extend_maxq;
// Unwind undershoot or overshoot adjustment.
if (rc->rolling_target_bits < rc->rolling_actual_bits)
--twopass->extend_minq;
else 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);
// 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 =
AOMMIN(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 = AOMMIN(
twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq);
} else if (rc->vbr_bits_off_target_fast) {
twopass->extend_minq_fast = AOMMIN(
twopass->extend_minq_fast, minq_adj_limit - twopass->extend_minq);
} else {
twopass->extend_minq_fast = 0;
}
}
}
}