| /* |
| * 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. |
| */ |
| |
| #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/onyxc_int.h" |
| |
| #include "av1/encoder/encoder.h" |
| #include "av1/encoder/firstpass.h" |
| #include "av1/encoder/gop_structure.h" |
| |
| // 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 |
| double calculate_active_area(const AV1_COMP *cpi, |
| const FIRSTPASS_STATS *this_frame) { |
| double active_pct; |
| |
| active_pct = |
| 1.0 - |
| ((this_frame->intra_skip_pct / 2) + |
| ((this_frame->inactive_zone_rows * 2) / (double)cpi->common.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 |
| double calculate_modified_err(const AV1_COMP *cpi, const TWO_PASS *twopass, |
| const AV1EncoderConfig *oxcf, |
| const FIRSTPASS_STATS *this_frame) { |
| const FIRSTPASS_STATS *const stats = &twopass->total_stats; |
| 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->two_pass_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(cpi, 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_in_end) return EOF; |
| |
| *fps = *p->stats_in; |
| ++p->stats_in; |
| 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_in_end) || |
| (offset < 0 && p->stats_in + offset < p->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; |
| } |
| |
| // Calculate the linear size relative to a baseline of 1080P |
| #define BASE_SIZE 2073600.0 // 1920x1080 |
| static double get_linear_size_factor(const AV1_COMP *cpi) { |
| const double this_area = cpi->initial_width * cpi->initial_height; |
| return pow(this_area / BASE_SIZE, 0.5); |
| } |
| |
| // 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->two_pass_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 double calc_correction_factor(double err_per_mb, double err_divisor, |
| double pt_low, double pt_high, int q, |
| aom_bit_depth_t bit_depth) { |
| const double error_term = err_per_mb / err_divisor; |
| |
| // Adjustment based on actual quantizer to power term. |
| const double power_term = |
| AOMMIN(av1_convert_qindex_to_q(q, bit_depth) * 0.01 + pt_low, pt_high); |
| |
| // Calculate correction factor. |
| if (power_term < 1.0) assert(error_term >= 0.0); |
| |
| return fclamp(pow(error_term, power_term), 0.05, 5.0); |
| } |
| |
| #define ERR_DIVISOR 100.0 |
| #define FACTOR_PT_LOW 0.70 |
| #define FACTOR_PT_HIGH 0.90 |
| |
| // 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, FRAME_TYPE frame_type, |
| double error_per_mb, double ediv_size_correction, |
| double group_weight_factor, 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, ERR_DIVISOR - ediv_size_correction, |
| FACTOR_PT_LOW, FACTOR_PT_HIGH, mid, bit_depth); |
| const int mid_bits_per_mb = av1_rc_bits_per_mb( |
| frame_type, mid, mid_factor * group_weight_factor, bit_depth); |
| if (mid_bits_per_mb > desired_bits_per_mb) { |
| low = mid + 1; |
| } else { |
| high = mid; |
| } |
| } |
| #if CONFIG_DEBUG |
| assert(low == high); |
| const double low_factor = |
| calc_correction_factor(error_per_mb, ERR_DIVISOR - ediv_size_correction, |
| FACTOR_PT_LOW, FACTOR_PT_HIGH, low, bit_depth); |
| const int low_bits_per_mb = av1_rc_bits_per_mb( |
| frame_type, low, low_factor * group_weight_factor, bit_depth); |
| assert(low_bits_per_mb <= desired_bits_per_mb || low == worst_qindex); |
| #endif // CONFIG_DEBUG |
| return low; |
| } |
| |
| static int get_twopass_worst_quality(const AV1_COMP *cpi, |
| const double section_err, |
| double inactive_zone, |
| int section_target_bandwidth, |
| double group_weight_factor) { |
| const RATE_CONTROL *const rc = &cpi->rc; |
| const AV1EncoderConfig *const oxcf = &cpi->oxcf; |
| |
| inactive_zone = fclamp(inactive_zone, 0.0, 1.0); |
| |
| if (section_target_bandwidth <= 0) { |
| return rc->worst_quality; // Highest value allowed |
| } else { |
| const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) |
| ? cpi->initial_mbs |
| : cpi->common.MBs; |
| const int active_mbs = AOMMAX(1, num_mbs - (int)(num_mbs * inactive_zone)); |
| const double av_err_per_mb = section_err / active_mbs; |
| const int target_norm_bits_per_mb = |
| (int)((uint64_t)section_target_bandwidth << BPER_MB_NORMBITS) / |
| active_mbs; |
| |
| // Larger image formats are expected to be a little harder to code |
| // relatively given the same prediction error score. This in part at |
| // least relates to the increased size and hence coding overheads of |
| // motion vectors. Some account of this is made through adjustment of |
| // the error divisor. |
| double ediv_size_correction = |
| AOMMAX(0.2, AOMMIN(5.0, get_linear_size_factor(cpi))); |
| if (ediv_size_correction < 1.0) |
| ediv_size_correction = -(1.0 / ediv_size_correction); |
| ediv_size_correction *= 4.0; |
| |
| // 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, INTER_FRAME, |
| av_err_per_mb, ediv_size_correction, group_weight_factor, |
| rc->best_quality, rc->worst_quality); |
| |
| // Restriction on active max q for constrained quality mode. |
| if (cpi->oxcf.rc_mode == AOM_CQ) q = AOMMAX(q, oxcf->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 AV1_COMP *cpi, |
| const FIRSTPASS_STATS *frame) { |
| const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs |
| : cpi->common.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 AV1_COMP *cpi, |
| const FIRSTPASS_STATS *frame) { |
| const double zero_motion_pct = frame->pcnt_inter - frame->pcnt_motion; |
| double sr_decay = get_sr_decay_rate(cpi, frame); |
| return AOMMIN(sr_decay, zero_motion_pct); |
| } |
| |
| #define ZM_POWER_FACTOR 0.75 |
| |
| static double get_prediction_decay_rate(const AV1_COMP *cpi, |
| const FIRSTPASS_STATS *next_frame) { |
| const double sr_decay_rate = get_sr_decay_rate(cpi, 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(AV1_COMP *cpi, int frame_interval, |
| int still_interval, |
| double loop_decay_rate, |
| double last_decay_rate) { |
| TWO_PASS *const twopass = &cpi->twopass; |
| RATE_CONTROL *const rc = &cpi->rc; |
| |
| // 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 > rc->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_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, 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, |
| double *mv_in_out, |
| double *mv_in_out_accumulator, |
| double *abs_mv_in_out_accumulator, |
| double *mv_ratio_accumulator) { |
| const double pct = stats->pcnt_motion; |
| |
| // Accumulate Motion In/Out of frame stats. |
| *mv_in_out = stats->mv_in_out_count * pct; |
| *mv_in_out_accumulator += *mv_in_out; |
| *abs_mv_in_out_accumulator += fabs(*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)); |
| |
| *mv_ratio_accumulator += |
| pct * (mvr_ratio < stats->mvr_abs ? mvr_ratio : stats->mvr_abs); |
| *mv_ratio_accumulator += |
| pct * (mvc_ratio < stats->mvc_abs ? mvc_ratio : stats->mvc_abs); |
| } |
| } |
| |
| #define BASELINE_ERR_PER_MB 1000.0 |
| #define BOOST_FACTOR 12.5 |
| |
| static double calc_frame_boost(AV1_COMP *cpi, 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( |
| cpi->rc.avg_frame_qindex[INTER_FRAME], cpi->common.seq_params.bit_depth); |
| const double boost_q_correction = AOMMIN((0.5 + (lq * 0.015)), 1.5); |
| int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs |
| : cpi->common.MBs; |
| |
| // Correct for any inactive region in the image |
| num_mbs = (int)AOMMAX(1, num_mbs * calculate_active_area(cpi, this_frame)); |
| |
| // Underlying boost factor is based on inter error ratio. |
| frame_boost = (BASELINE_ERR_PER_MB * num_mbs) / |
| 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); |
| } |
| |
| #define GF_MAX_BOOST 90.0 |
| #define MIN_ARF_GF_BOOST 240 |
| #define MIN_DECAY_FACTOR 0.01 |
| |
| static int calc_arf_boost(AV1_COMP *cpi, int offset, int f_frames, int b_frames, |
| int *f_boost, int *b_boost) { |
| TWO_PASS *const twopass = &cpi->twopass; |
| int i; |
| double boost_score = 0.0; |
| double mv_ratio_accumulator = 0.0; |
| double decay_accumulator = 1.0; |
| double this_frame_mv_in_out = 0.0; |
| double mv_in_out_accumulator = 0.0; |
| double abs_mv_in_out_accumulator = 0.0; |
| int arf_boost; |
| int flash_detected = 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, &this_frame_mv_in_out, &mv_in_out_accumulator, |
| &abs_mv_in_out_accumulator, &mv_ratio_accumulator); |
| |
| // 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) { |
| decay_accumulator *= get_prediction_decay_rate(cpi, this_frame); |
| decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR |
| ? MIN_DECAY_FACTOR |
| : decay_accumulator; |
| } |
| |
| boost_score += |
| decay_accumulator * |
| calc_frame_boost(cpi, this_frame, this_frame_mv_in_out, GF_MAX_BOOST); |
| } |
| |
| *f_boost = (int)boost_score; |
| |
| // Reset for backward looking loop. |
| boost_score = 0.0; |
| mv_ratio_accumulator = 0.0; |
| decay_accumulator = 1.0; |
| this_frame_mv_in_out = 0.0; |
| mv_in_out_accumulator = 0.0; |
| abs_mv_in_out_accumulator = 0.0; |
| |
| // 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, &this_frame_mv_in_out, &mv_in_out_accumulator, |
| &abs_mv_in_out_accumulator, &mv_ratio_accumulator); |
| |
| // 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) { |
| decay_accumulator *= get_prediction_decay_rate(cpi, this_frame); |
| decay_accumulator = decay_accumulator < MIN_DECAY_FACTOR |
| ? MIN_DECAY_FACTOR |
| : decay_accumulator; |
| } |
| |
| boost_score += |
| decay_accumulator * |
| calc_frame_boost(cpi, this_frame, this_frame_mv_in_out, GF_MAX_BOOST); |
| } |
| *b_boost = (int)boost_score; |
| |
| arf_boost = (*f_boost + *b_boost); |
| if (arf_boost < ((b_frames + f_frames) * 20)) |
| arf_boost = ((b_frames + f_frames) * 20); |
| arf_boost = AOMMAX(arf_boost, MIN_ARF_GF_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)); |
| } |
| |
| // Calculate the total bits to allocate in 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 TWO_PASS *const twopass = &cpi->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 * rc->baseline_gf_interval) |
| total_group_bits = (int64_t)max_bits * rc->baseline_gf_interval; |
| |
| return total_group_bits; |
| } |
| |
| // Calculate the number bits extra 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) || (frame_count <= 0)) return 0; |
| |
| 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); |
| } |
| |
| #define LEAF_REDUCTION_FACTOR 0.75 |
| static double lvl_budget_factor[MAX_PYRAMID_LVL - 1][MAX_PYRAMID_LVL - 1] = { |
| { 1.0, 0.0, 0.0 }, { 0.6, 0.4, 0 }, { 0.45, 0.35, 0.20 } |
| }; |
| static void allocate_gf_group_bits( |
| AV1_COMP *cpi, int64_t gf_group_bits, double group_error, int gf_arf_bits, |
| const EncodeFrameParams *const frame_params) { |
| RATE_CONTROL *const rc = &cpi->rc; |
| const AV1EncoderConfig *const oxcf = &cpi->oxcf; |
| TWO_PASS *const twopass = &cpi->twopass; |
| GF_GROUP *const gf_group = &twopass->gf_group; |
| const int key_frame = (frame_params->frame_type == KEY_FRAME); |
| const int max_bits = frame_max_bits(&cpi->rc, &cpi->oxcf); |
| int64_t total_group_bits = gf_group_bits; |
| |
| // Check if GF group has any internal arfs. |
| int has_internal_arfs = 0; |
| for (int i = 0; i < gf_group->size; ++i) { |
| if (gf_group->update_type[i] == INTNL_ARF_UPDATE) { |
| has_internal_arfs = 1; |
| break; |
| } |
| } |
| |
| // For key frames the frame target rate is already set and it |
| // is also the golden frame. |
| // === [frame_index == 0] === |
| int frame_index = 0; |
| if (!key_frame) { |
| if (rc->source_alt_ref_active) |
| gf_group->bit_allocation[frame_index] = 0; |
| else |
| gf_group->bit_allocation[frame_index] = gf_arf_bits; |
| |
| // Step over the golden frame / overlay frame |
| FIRSTPASS_STATS frame_stats; |
| if (EOF == input_stats(twopass, &frame_stats)) return; |
| } |
| |
| // Deduct the boost bits for arf (or gf if it is not a key frame) |
| // from the group total. |
| if (rc->source_alt_ref_pending || !key_frame) total_group_bits -= gf_arf_bits; |
| |
| frame_index++; |
| |
| // Store the bits to spend on the ARF if there is one. |
| // === [frame_index == 1] === |
| if (rc->source_alt_ref_pending) { |
| gf_group->bit_allocation[frame_index] = gf_arf_bits; |
| |
| ++frame_index; |
| |
| // Skip all the internal ARFs right after ARF at the starting segment of |
| // the current GF group. |
| if (has_internal_arfs) { |
| while (gf_group->update_type[frame_index] == INTNL_ARF_UPDATE) { |
| ++frame_index; |
| } |
| } |
| } |
| |
| // Save. |
| const int tmp_frame_index = frame_index; |
| int budget_reduced_from_leaf_level = 0; |
| |
| // Allocate bits to frames other than first frame, which is either a keyframe, |
| // overlay frame or golden frame. |
| const int normal_frames = rc->baseline_gf_interval - 1; |
| |
| for (int i = 0; i < normal_frames; ++i) { |
| FIRSTPASS_STATS frame_stats; |
| if (EOF == input_stats(twopass, &frame_stats)) break; |
| |
| const double modified_err = |
| calculate_modified_err(cpi, twopass, oxcf, &frame_stats); |
| const double err_fraction = |
| (group_error > 0) ? modified_err / DOUBLE_DIVIDE_CHECK(group_error) |
| : 0.0; |
| const int target_frame_size = |
| clamp((int)((double)total_group_bits * err_fraction), 0, |
| AOMMIN(max_bits, (int)total_group_bits)); |
| |
| if (gf_group->update_type[frame_index] == INTNL_OVERLAY_UPDATE) { |
| assert(gf_group->pyramid_height <= MAX_PYRAMID_LVL && |
| "non-valid height for a pyramid structure"); |
| |
| const int arf_pos = gf_group->arf_pos_in_gf[frame_index]; |
| gf_group->bit_allocation[frame_index] = 0; |
| |
| gf_group->bit_allocation[arf_pos] = target_frame_size; |
| // Note: Boost, if needed, is added in the next loop. |
| } else { |
| assert(gf_group->update_type[frame_index] == LF_UPDATE); |
| gf_group->bit_allocation[frame_index] = target_frame_size; |
| if (has_internal_arfs) { |
| const int this_budget_reduction = |
| (int)(target_frame_size * LEAF_REDUCTION_FACTOR); |
| gf_group->bit_allocation[frame_index] -= this_budget_reduction; |
| budget_reduced_from_leaf_level += this_budget_reduction; |
| } |
| } |
| |
| ++frame_index; |
| |
| // Skip all the internal ARFs. |
| if (has_internal_arfs) { |
| while (gf_group->update_type[frame_index] == INTNL_ARF_UPDATE) |
| ++frame_index; |
| } |
| } |
| |
| if (budget_reduced_from_leaf_level > 0) { |
| assert(has_internal_arfs); |
| // Restore. |
| frame_index = tmp_frame_index; |
| |
| // Re-distribute this extra budget to overlay frames in the group. |
| for (int i = 0; i < normal_frames; ++i) { |
| if (gf_group->update_type[frame_index] == INTNL_OVERLAY_UPDATE) { |
| assert(gf_group->pyramid_height <= MAX_PYRAMID_LVL && |
| "non-valid height for a pyramid structure"); |
| const int arf_pos = gf_group->arf_pos_in_gf[frame_index]; |
| const int this_lvl = gf_group->pyramid_level[arf_pos]; |
| const int dist2top = gf_group->pyramid_height - 1 - this_lvl; |
| const double lvl_boost_factor = |
| lvl_budget_factor[gf_group->pyramid_height - 2][dist2top]; |
| const int extra_size = |
| (int)(budget_reduced_from_leaf_level * lvl_boost_factor / |
| gf_group->pyramid_lvl_nodes[this_lvl]); |
| gf_group->bit_allocation[arf_pos] += extra_size; |
| } |
| ++frame_index; |
| |
| // Skip all the internal ARFs. |
| if (has_internal_arfs) { |
| while (gf_group->update_type[frame_index] == INTNL_ARF_UPDATE) { |
| ++frame_index; |
| } |
| } |
| } |
| } |
| } |
| |
| // Given the maximum allowed height of the pyramid structure, return the fixed |
| // GF length to be used. |
| static INLINE int get_fixed_gf_length(int max_pyr_height) { |
| (void)max_pyr_height; |
| return MAX_GF_INTERVAL; |
| } |
| |
| // 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) { |
| return (gf_zero_motion >= 0.995) && |
| (kf_zero_motion >= STATIC_KF_GROUP_THRESH); |
| } |
| |
| #define ARF_ABS_ZOOM_THRESH 4.4 |
| #define GROUP_ADAPTIVE_MAXQ 1 |
| #if GROUP_ADAPTIVE_MAXQ |
| #define RC_FACTOR_MIN 0.75 |
| #define RC_FACTOR_MAX 1.75 |
| #endif // GROUP_ADAPTIVE_MAXQ |
| #define MIN_FWD_KF_INTERVAL 8 |
| |
| // Analyse and define a gf/arf group. |
| static void define_gf_group(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame, |
| const EncodeFrameParams *const frame_params) { |
| AV1_COMMON *const cm = &cpi->common; |
| RATE_CONTROL *const rc = &cpi->rc; |
| AV1EncoderConfig *const oxcf = &cpi->oxcf; |
| TWO_PASS *const twopass = &cpi->twopass; |
| FIRSTPASS_STATS next_frame; |
| const FIRSTPASS_STATS *const start_pos = twopass->stats_in; |
| int i; |
| |
| double boost_score = 0.0; |
| double gf_group_err = 0.0; |
| #if GROUP_ADAPTIVE_MAXQ |
| double gf_group_raw_error = 0.0; |
| #endif |
| double gf_group_skip_pct = 0.0; |
| double gf_group_inactive_zone_rows = 0.0; |
| double gf_first_frame_err = 0.0; |
| double mod_frame_err = 0.0; |
| |
| double mv_ratio_accumulator = 0.0; |
| double decay_accumulator = 1.0; |
| double zero_motion_accumulator = 1.0; |
| |
| double loop_decay_rate = 1.00; |
| double last_loop_decay_rate = 1.00; |
| |
| double this_frame_mv_in_out = 0.0; |
| double mv_in_out_accumulator = 0.0; |
| double abs_mv_in_out_accumulator = 0.0; |
| |
| unsigned int allow_alt_ref = is_altref_enabled(cpi); |
| |
| int f_boost = 0; |
| int b_boost = 0; |
| int flash_detected; |
| int64_t gf_group_bits; |
| double gf_group_error_left; |
| int gf_arf_bits; |
| const int is_intra_only = frame_params->frame_type == KEY_FRAME || |
| frame_params->frame_type == INTRA_ONLY_FRAME; |
| const int arf_active_or_kf = is_intra_only || rc->source_alt_ref_active; |
| |
| cpi->internal_altref_allowed = (oxcf->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(twopass->gf_group); |
| } |
| |
| aom_clear_system_state(); |
| av1_zero(next_frame); |
| |
| // Load stats for the current frame. |
| mod_frame_err = calculate_modified_err(cpi, 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. |
| gf_first_frame_err = mod_frame_err; |
| |
| // 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. |
| if (arf_active_or_kf) { |
| gf_group_err -= gf_first_frame_err; |
| #if GROUP_ADAPTIVE_MAXQ |
| gf_group_raw_error -= this_frame->coded_error; |
| #endif |
| gf_group_skip_pct -= this_frame->intra_skip_pct; |
| gf_group_inactive_zone_rows -= this_frame->inactive_zone_rows; |
| } |
| // Motion breakout threshold for loop below depends on image size. |
| const double mv_ratio_accumulator_thresh = |
| (cpi->initial_height + cpi->initial_width) / 4.0; |
| |
| // 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, get_fixed_gf_length(oxcf->gf_max_pyr_height)); |
| |
| double avg_sr_coded_error = 0; |
| double avg_raw_err_stdev = 0; |
| int non_zero_stdev_count = 0; |
| |
| i = 0; |
| while (i < rc->static_scene_max_gf_interval && i < rc->frames_to_key) { |
| ++i; |
| |
| // Accumulate error score of frames in this gf group. |
| mod_frame_err = calculate_modified_err(cpi, twopass, oxcf, this_frame); |
| gf_group_err += mod_frame_err; |
| #if GROUP_ADAPTIVE_MAXQ |
| gf_group_raw_error += this_frame->coded_error; |
| #endif |
| gf_group_skip_pct += this_frame->intra_skip_pct; |
| gf_group_inactive_zone_rows += this_frame->inactive_zone_rows; |
| |
| 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); |
| |
| // Update the motion related elements to the boost calculation. |
| accumulate_frame_motion_stats( |
| &next_frame, &this_frame_mv_in_out, &mv_in_out_accumulator, |
| &abs_mv_in_out_accumulator, &mv_ratio_accumulator); |
| // sum up the metric values of current gf group |
| avg_sr_coded_error += next_frame.sr_coded_error; |
| if (fabs(next_frame.raw_error_stdev) > 0.000001) { |
| non_zero_stdev_count++; |
| avg_raw_err_stdev += next_frame.raw_error_stdev; |
| } |
| |
| // Accumulate the effect of prediction quality decay. |
| if (!flash_detected) { |
| last_loop_decay_rate = loop_decay_rate; |
| loop_decay_rate = get_prediction_decay_rate(cpi, &next_frame); |
| |
| decay_accumulator = decay_accumulator * loop_decay_rate; |
| |
| // Monitor for static sections. |
| if ((rc->frames_since_key + i - 1) > 1) { |
| zero_motion_accumulator = AOMMIN( |
| zero_motion_accumulator, get_zero_motion_factor(cpi, &next_frame)); |
| } |
| |
| // 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(cpi, i, 5, loop_decay_rate, |
| last_loop_decay_rate)) { |
| allow_alt_ref = 0; |
| break; |
| } |
| } |
| |
| // Calculate a boost number for this frame. |
| boost_score += |
| decay_accumulator * |
| calc_frame_boost(cpi, &next_frame, this_frame_mv_in_out, GF_MAX_BOOST); |
| // If almost totally static, we will not use the the max GF length later, |
| // so we can continue for more frames. |
| if ((i >= active_max_gf_interval + 1) && |
| !is_almost_static(zero_motion_accumulator, |
| twopass->kf_zeromotion_pct)) { |
| break; |
| } |
| |
| // Some conditions to breakout after min interval. |
| if (i >= active_min_gf_interval && |
| // If possible don't break very close to a kf |
| (rc->frames_to_key - i >= rc->min_gf_interval) && (i & 0x01) && |
| !flash_detected && |
| (mv_ratio_accumulator > mv_ratio_accumulator_thresh || |
| abs_mv_in_out_accumulator > ARF_ABS_ZOOM_THRESH)) { |
| break; |
| } |
| *this_frame = next_frame; |
| } |
| |
| // Was the group length constrained by the requirement for a new KF? |
| rc->constrained_gf_group = (i >= rc->frames_to_key) ? 1 : 0; |
| |
| const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) ? cpi->initial_mbs |
| : cpi->common.MBs; |
| assert(num_mbs > 0); |
| if (i) avg_sr_coded_error /= i; |
| |
| if (non_zero_stdev_count) avg_raw_err_stdev /= non_zero_stdev_count; |
| |
| // 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. |
| if (zero_motion_accumulator > MIN_ZERO_MOTION && |
| avg_sr_coded_error / num_mbs < MAX_SR_CODED_ERROR && |
| avg_raw_err_stdev < MAX_RAW_ERR_VAR) { |
| cpi->internal_altref_allowed = 0; |
| } |
| |
| const int use_alt_ref = |
| !is_almost_static(zero_motion_accumulator, twopass->kf_zeromotion_pct) && |
| allow_alt_ref && (i < cpi->oxcf.lag_in_frames) && |
| (i >= rc->min_gf_interval) && |
| (cpi->oxcf.gf_max_pyr_height > MIN_PYRAMID_LVL); |
| |
| #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 = |
| ((cpi->oxcf.rc_mode == AOM_Q && cpi->oxcf.cq_level <= 128) || |
| !cpi->internal_altref_allowed) && |
| !is_lossless_requested(&cpi->oxcf); |
| |
| 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; |
| } |
| } |
| } |
| |
| // Should we use the alternate reference frame. |
| if (use_alt_ref) { |
| // Calculate the boost for alt ref. |
| rc->gfu_boost = |
| calc_arf_boost(cpi, alt_offset, (i - 1), (i - 1), &f_boost, &b_boost); |
| rc->source_alt_ref_pending = 1; |
| |
| // do not replace ARFs with overlay frames, and keep it as GOLDEN_REF |
| cpi->preserve_arf_as_gld = 1; |
| } else { |
| rc->gfu_boost = AOMMAX((int)boost_score, MIN_ARF_GF_BOOST); |
| rc->source_alt_ref_pending = 0; |
| cpi->preserve_arf_as_gld = 0; |
| } |
| |
| // Set the interval until the next gf. |
| // If forward keyframes are enabled, ensure the final gf group obeys the |
| // MIN_FWD_KF_INTERVAL. |
| if (cpi->oxcf.fwd_kf_enabled && |
| ((twopass->stats_in - i + rc->frames_to_key) < twopass->stats_in_end)) { |
| if (i == rc->frames_to_key) { |
| rc->baseline_gf_interval = i; |
| // if the last gf group will be smaller than MIN_FWD_KF_INTERVAL |
| } else if ((rc->frames_to_key - i < |
| AOMMAX(MIN_FWD_KF_INTERVAL, rc->min_gf_interval)) && |
| (rc->frames_to_key != i)) { |
| // if possible, merge the last two gf groups |
| if (rc->frames_to_key <= active_max_gf_interval) { |
| rc->baseline_gf_interval = rc->frames_to_key; |
| // 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 { |
| rc->baseline_gf_interval = rc->frames_to_key - MIN_FWD_KF_INTERVAL; |
| } |
| } else { |
| rc->baseline_gf_interval = i - rc->source_alt_ref_pending; |
| } |
| } else { |
| rc->baseline_gf_interval = i - rc->source_alt_ref_pending; |
| } |
| |
| #define LAST_ALR_BOOST_FACTOR 0.2f |
| rc->arf_boost_factor = 1.0; |
| if (rc->source_alt_ref_pending && !is_lossless_requested(&cpi->oxcf)) { |
| // Reduce the boost of altref in the last gf group |
| if (rc->frames_to_key - i == REDUCE_GF_LENGTH_BY || |
| rc->frames_to_key - i == 0) { |
| rc->arf_boost_factor = LAST_ALR_BOOST_FACTOR; |
| } |
| } |
| |
| rc->frames_till_gf_update_due = rc->baseline_gf_interval; |
| |
| // Reset the file position. |
| reset_fpf_position(twopass, start_pos); |
| |
| // Calculate the bits to be allocated to the gf/arf group as a whole |
| gf_group_bits = calculate_total_gf_group_bits(cpi, gf_group_err); |
| |
| #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 ((cpi->oxcf.rc_mode != AOM_Q) && (rc->baseline_gf_interval > 1)) { |
| const int vbr_group_bits_per_frame = |
| (int)(gf_group_bits / rc->baseline_gf_interval); |
| const double group_av_err = gf_group_raw_error / rc->baseline_gf_interval; |
| const double group_av_skip_pct = |
| gf_group_skip_pct / rc->baseline_gf_interval; |
| const double group_av_inactive_zone = |
| ((gf_group_inactive_zone_rows * 2) / |
| (rc->baseline_gf_interval * (double)cm->mb_rows)); |
| |
| int tmp_q; |
| // rc factor is a weight factor that corrects for local rate control drift. |
| double rc_factor = 1.0; |
| if (rc->rate_error_estimate > 0) { |
| rc_factor = AOMMAX(RC_FACTOR_MIN, |
| (double)(100 - rc->rate_error_estimate) / 100.0); |
| } else { |
| rc_factor = AOMMIN(RC_FACTOR_MAX, |
| (double)(100 - rc->rate_error_estimate) / 100.0); |
| } |
| tmp_q = get_twopass_worst_quality( |
| cpi, group_av_err, (group_av_skip_pct + group_av_inactive_zone), |
| vbr_group_bits_per_frame, twopass->kfgroup_inter_fraction * rc_factor); |
| twopass->active_worst_quality = |
| AOMMAX(tmp_q, twopass->active_worst_quality >> 1); |
| } |
| #endif |
| |
| // Calculate the extra bits to be used for boosted frame(s) |
| gf_arf_bits = calculate_boost_bits(rc->baseline_gf_interval, rc->gfu_boost, |
| gf_group_bits); |
| |
| // Adjust KF group bits and error remaining. |
| twopass->kf_group_error_left -= (int64_t)gf_group_err; |
| |
| // If this is an arf update we want to remove the score for the overlay |
| // frame at the end which will usually be very cheap to code. |
| // The overlay frame has already, in effect, been coded so we want to spread |
| // the remaining bits among the other frames. |
| // For normal GFs remove the score for the GF itself unless this is |
| // also a key frame in which case it has already been accounted for. |
| if (rc->source_alt_ref_pending) { |
| gf_group_error_left = gf_group_err - mod_frame_err; |
| } else if (!is_intra_only) { |
| gf_group_error_left = gf_group_err - gf_first_frame_err; |
| } else { |
| gf_group_error_left = gf_group_err; |
| } |
| |
| // Set up the structure of this Group-Of-Pictures (same as GF_GROUP) |
| av1_gop_setup_structure(cpi, frame_params); |
| |
| // Allocate bits to each of the frames in the GF group. |
| allocate_gf_group_bits(cpi, gf_group_bits, gf_group_error_left, gf_arf_bits, |
| frame_params); |
| |
| // Reset the file position. |
| reset_fpf_position(twopass, start_pos); |
| |
| // Calculate a section intra ratio used in setting max loop filter. |
| if (frame_params->frame_type != KEY_FRAME) { |
| twopass->section_intra_rating = calculate_section_intra_ratio( |
| start_pos, twopass->stats_in_end, rc->baseline_gf_interval); |
| } |
| } |
| |
| // 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 2.5 |
| // 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 |
| |
| // 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) { |
| 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); |
| |
| // 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 ((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) || |
| ((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; |
| FIRSTPASS_STATS local_next_frame = *next_frame; |
| 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 < 16; ++i) { |
| 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; |
| |
| // Get the next frame details |
| if (EOF == input_stats(twopass, &local_next_frame)) break; |
| } |
| |
| // 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 > 3)) { |
| is_viable_kf = 1; |
| } else { |
| // Reset the file position |
| reset_fpf_position(twopass, start_pos); |
| |
| is_viable_kf = 0; |
| } |
| } |
| |
| 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 300 // Minimum boost for non-static KF interval |
| #define MIN_STATIC_KF_BOOST 5400 // Minimum boost for static KF interval |
| |
| static void find_next_key_frame(AV1_COMP *cpi, FIRSTPASS_STATS *this_frame) { |
| int i, j; |
| RATE_CONTROL *const rc = &cpi->rc; |
| TWO_PASS *const twopass = &cpi->twopass; |
| GF_GROUP *const gf_group = &twopass->gf_group; |
| const AV1EncoderConfig *const oxcf = &cpi->oxcf; |
| const FIRSTPASS_STATS first_frame = *this_frame; |
| const FIRSTPASS_STATS *const start_position = twopass->stats_in; |
| FIRSTPASS_STATS next_frame; |
| FIRSTPASS_STATS last_frame; |
| int kf_bits = 0; |
| int loop_decay_counter = 0; |
| double decay_accumulator = 1.0; |
| double av_decay_accumulator = 0.0; |
| double zero_motion_accumulator = 1.0; |
| double boost_score = 0.0; |
| double kf_mod_err = 0.0; |
| double kf_group_err = 0.0; |
| double recent_loop_decay[FRAMES_TO_CHECK_DECAY]; |
| |
| av1_zero(next_frame); |
| |
| rc->frames_since_key = 0; |
| |
| // Reset the GF group data structures. |
| av1_zero(*gf_group); |
| |
| // Is this a forced key frame by interval. |
| rc->this_key_frame_forced = rc->next_key_frame_forced; |
| |
| // Clear the alt ref active flag and last group multi arf flags as they |
| // can never be set for a key frame. |
| rc->source_alt_ref_active = 0; |
| |
| // KF is always a GF so clear frames till next gf counter. |
| rc->frames_till_gf_update_due = 0; |
| |
| rc->frames_to_key = 1; |
| |
| twopass->kf_group_bits = 0; // Total bits available to kf group |
| twopass->kf_group_error_left = 0; // Group modified error score. |
| |
| kf_mod_err = calculate_modified_err(cpi, twopass, oxcf, this_frame); |
| |
| // 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; |
| |
| // Find the next keyframe. |
| i = 0; |
| while (twopass->stats_in < twopass->stats_in_end && |
| rc->frames_to_key < cpi->oxcf.key_freq) { |
| // Accumulate kf group error. |
| kf_group_err += calculate_modified_err(cpi, 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->oxcf.auto_key && twopass->stats_in < twopass->stats_in_end) { |
| double loop_decay_rate; |
| |
| // Check for a scene cut. |
| if (test_candidate_kf(twopass, &last_frame, this_frame, twopass->stats_in, |
| rc->frames_to_key)) |
| break; |
| |
| // How fast is the prediction quality decaying? |
| loop_decay_rate = get_prediction_decay_rate(cpi, 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 (detect_transition_to_still(cpi, i, cpi->oxcf.key_freq - i, |
| loop_decay_rate, decay_accumulator)) |
| break; |
| |
| // Step on to the next frame. |
| ++rc->frames_to_key; |
| |
| // If we don't have a real key frame within the next two |
| // key_freq intervals then break out of the loop. |
| if (rc->frames_to_key >= 2 * cpi->oxcf.key_freq) break; |
| } else { |
| ++rc->frames_to_key; |
| } |
| ++i; |
| } |
| |
| // 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 (cpi->oxcf.auto_key && rc->frames_to_key > cpi->oxcf.key_freq) { |
| 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(cpi, twopass, oxcf, &tmp_frame); |
| input_stats(twopass, &tmp_frame); |
| } |
| rc->next_key_frame_forced = 1; |
| } else if (twopass->stats_in == twopass->stats_in_end || |
| rc->frames_to_key >= cpi->oxcf.key_freq) { |
| rc->next_key_frame_forced = 1; |
| } else { |
| rc->next_key_frame_forced = 0; |
| } |
| |
| // Special case for the last key frame of the file. |
| if (twopass->stats_in >= twopass->stats_in_end) { |
| // Accumulate kf group error. |
| kf_group_err += calculate_modified_err(cpi, twopass, oxcf, this_frame); |
| } |
| |
| // Calculate the number of bits that should be assigned to the kf group. |
| if (twopass->bits_left > 0 && twopass->modified_error_left > 0.0) { |
| // Maximum number of bits for a single normal frame (not key frame). |
| const int max_bits = frame_max_bits(rc, &cpi->oxcf); |
| |
| // Maximum number of bits allocated to the key frame group. |
| int64_t max_grp_bits; |
| |
| // Default allocation based on bits left and relative |
| // complexity of the section. |
| twopass->kf_group_bits = (int64_t)( |
| twopass->bits_left * (kf_group_err / twopass->modified_error_left)); |
| |
| // 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); |
| |
| // 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. |
| decay_accumulator = 1.0; |
| boost_score = 0.0; |
| const double kf_max_boost = |
| cpi->oxcf.rc_mode == AOM_Q |
| ? AOMMIN(AOMMAX(rc->frames_to_key * 2.0, KF_MIN_FRAME_BOOST), |
| KF_MAX_FRAME_BOOST) |
| : KF_MAX_FRAME_BOOST; |
| for (i = 0; i < (rc->frames_to_key - 1); ++i) { |
| if (EOF == input_stats(twopass, &next_frame)) 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(cpi, &next_frame)); |
| } else { |
| zero_motion_accumulator = next_frame.pcnt_inter - next_frame.pcnt_motion; |
| } |
| |
| // Not all frames in the group are necessarily used in calculating boost. |
| if ((i <= rc->max_gf_interval) || |
| ((i <= (rc->max_gf_interval * 4)) && (decay_accumulator > 0.5))) { |
| const double frame_boost = |
| calc_frame_boost(cpi, this_frame, 0, kf_max_boost); |
| |
| // How fast is prediction quality decaying. |
| if (!detect_flash(twopass, 0)) { |
| const double loop_decay_rate = |
| get_prediction_decay_rate(cpi, &next_frame); |
| decay_accumulator *= loop_decay_rate; |
| decay_accumulator = AOMMAX(decay_accumulator, MIN_DECAY_FACTOR); |
| av_decay_accumulator += decay_accumulator; |
| ++loop_decay_counter; |
| } |
| boost_score += (decay_accumulator * frame_boost); |
| } |
| } |
| if (loop_decay_counter > 0) |
| av_decay_accumulator /= (double)loop_decay_counter; |
| |
| 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_in_end, rc->frames_to_key); |
| |
| rc->kf_boost = (int)(av_decay_accumulator * 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)) { |
| rc->kf_boost = AOMMAX(rc->kf_boost, MIN_STATIC_KF_BOOST); |
| } else { |
| // Apply various clamps for min and max boost |
| rc->kf_boost = AOMMAX(rc->kf_boost, (rc->frames_to_key * 3)); |
| rc->kf_boost = AOMMAX(rc->kf_boost, MIN_KF_BOOST); |
| } |
| |
| // Work out how many bits to allocate for the key frame itself. |
| kf_bits = calculate_boost_bits((rc->frames_to_key - 1), rc->kf_boost, |
| twopass->kf_group_bits); |
| // printf("kf boost = %d kf_bits = %d kf_zeromotion_pct = %d\n", rc->kf_boost, |
| // kf_bits, twopass->kf_zeromotion_pct); |
| |
| // Work out the fraction of the kf group bits reserved for the inter frames |
| // within the group after discounting the bits for the kf itself. |
| if (twopass->kf_group_bits) { |
| twopass->kfgroup_inter_fraction = |
| (double)(twopass->kf_group_bits - kf_bits) / |
| (double)twopass->kf_group_bits; |
| } else { |
| twopass->kfgroup_inter_fraction = 1.0; |
| } |
| |
| 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. |
| 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 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->twopass; |
| |
| return (!frame_is_intra_only(&cpi->common) && |
| twopass->stats_in - 2 > twopass->stats_in_start && |
| twopass->stats_in < twopass->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 |
| #define DEFAULT_GRP_WEIGHT 1.0 |
| |
| void av1_get_second_pass_params(AV1_COMP *cpi, |
| EncodeFrameParams *const frame_params, |
| unsigned int frame_flags) { |
| AV1_COMMON *const cm = &cpi->common; |
| CurrentFrame *const current_frame = &cm->current_frame; |
| RATE_CONTROL *const rc = &cpi->rc; |
| TWO_PASS *const twopass = &cpi->twopass; |
| GF_GROUP *const gf_group = &twopass->gf_group; |
| int frames_left; |
| FIRSTPASS_STATS this_frame; |
| |
| int target_rate; |
| |
| frames_left = (int)(twopass->total_stats.count - current_frame->frame_number); |
| |
| if (!twopass->stats_in) return; |
| |
| // 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 (gf_group->update_type[gf_group->index] == ARF_UPDATE || |
| gf_group->update_type[gf_group->index] == INTNL_ARF_UPDATE) { |
| target_rate = gf_group->bit_allocation[gf_group->index]; |
| target_rate = av1_rc_clamp_pframe_target_size( |
| cpi, target_rate, gf_group->update_type[gf_group->index]); |
| rc->base_frame_target = target_rate; |
| |
| if (cpi->no_show_kf) { |
| assert(gf_group->update_type[gf_group->index] == ARF_UPDATE); |
| frame_params->frame_type = KEY_FRAME; |
| } else { |
| frame_params->frame_type = INTER_FRAME; |
| } |
| |
| // Do the firstpass stats indicate that this frame is skippable for the |
| // partition search? |
| if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2) { |
| cpi->partition_search_skippable_frame = is_skippable_frame(cpi); |
| } |
| |
| return; |
| } |
| |
| aom_clear_system_state(); |
| |
| if (cpi->oxcf.rc_mode == AOM_Q) { |
| twopass->active_worst_quality = cpi->oxcf.cq_level; |
| } else if (current_frame->frame_number == 0) { |
| // Special case code for first frame. |
| const int section_target_bandwidth = |
| (int)(twopass->bits_left / frames_left); |
| const double section_length = twopass->total_left_stats.count; |
| const double section_error = |
| twopass->total_left_stats.coded_error / section_length; |
| const double section_intra_skip = |
| twopass->total_left_stats.intra_skip_pct / section_length; |
| const double section_inactive_zone = |
| (twopass->total_left_stats.inactive_zone_rows * 2) / |
| ((double)cm->mb_rows * section_length); |
| const int tmp_q = get_twopass_worst_quality( |
| cpi, section_error, section_intra_skip + section_inactive_zone, |
| section_target_bandwidth, DEFAULT_GRP_WEIGHT); |
| |
| twopass->active_worst_quality = tmp_q; |
| twopass->baseline_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.best_allowed_q) / 2; |
| rc->avg_frame_qindex[KEY_FRAME] = rc->last_q[KEY_FRAME]; |
| } |
| |
| av1_zero(this_frame); |
| if (EOF == input_stats(twopass, &this_frame)) return; |
| |
| // 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; |
| |
| // Keyframe and section processing. |
| if (rc->frames_to_key == 0 || (frame_flags & FRAMEFLAGS_KEY)) { |
| FIRSTPASS_STATS this_frame_copy; |
| this_frame_copy = this_frame; |
| frame_params->frame_type = KEY_FRAME; |
| // Define next KF group and assign bits to it. |
| find_next_key_frame(cpi, &this_frame); |
| this_frame = this_frame_copy; |
| } else { |
| frame_params->frame_type = INTER_FRAME; |
| } |
| |
| // Define a new GF/ARF group. (Should always enter here for key frames). |
| if (rc->frames_till_gf_update_due == 0) { |
| define_gf_group(cpi, &this_frame, frame_params); |
| |
| rc->frames_till_gf_update_due = rc->baseline_gf_interval; |
| |
| #if ARF_STATS_OUTPUT |
| { |
| FILE *fpfile; |
| fpfile = fopen("arf.stt", "a"); |
| ++arf_count; |
| fprintf(fpfile, "%10d %10d %10d %10d %10d\n", current_frame->frame_number, |
| rc->frames_till_gf_update_due, rc->kf_boost, arf_count, |
| rc->gfu_boost); |
| |
| fclose(fpfile); |
| } |
| #endif |
| } |
| |
| // Do the firstpass stats indicate that this frame is skippable for the |
| // partition search? |
| if (cpi->sf.allow_partition_search_skip && cpi->oxcf.pass == 2) { |
| cpi->partition_search_skippable_frame = is_skippable_frame(cpi); |
| } |
| |
| target_rate = gf_group->bit_allocation[gf_group->index]; |
| |
| if (frame_params->frame_type == KEY_FRAME) { |
| target_rate = av1_rc_clamp_iframe_target_size(cpi, target_rate); |
| } else { |
| target_rate = av1_rc_clamp_pframe_target_size( |
| cpi, target_rate, gf_group->update_type[gf_group->index]); |
| } |
| |
| rc->base_frame_target = target_rate; |
| |
| { |
| const int num_mbs = (cpi->oxcf.resize_mode != RESIZE_NONE) |
| ? cpi->initial_mbs |
| : cpi->common.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); |
| } |
| |
| // Update the total stats remaining structure. |
| subtract_stats(&twopass->total_left_stats, &this_frame); |
| } |
| |
| void av1_init_second_pass(AV1_COMP *cpi) { |
| const AV1EncoderConfig *const oxcf = &cpi->oxcf; |
| TWO_PASS *const twopass = &cpi->twopass; |
| double frame_rate; |
| FIRSTPASS_STATS *stats; |
| |
| av1_twopass_zero_stats(&twopass->total_stats); |
| av1_twopass_zero_stats(&twopass->total_left_stats); |
| |
| if (!twopass->stats_in_end) return; |
| |
| stats = &twopass->total_stats; |
| |
| *stats = *twopass->stats_in_end; |
| twopass->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->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->two_pass_vbrmin_section) / 100; |
| twopass->modified_error_max = |
| (avg_error * oxcf->two_pass_vbrmax_section) / 100; |
| while (s < twopass->stats_in_end) { |
| modified_error_total += calculate_modified_err(cpi, 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; |
| } |
| |
| #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->twopass; |
| RATE_CONTROL *const rc = &cpi->rc; |
| const int bits_used = rc->base_frame_target; |
| |
| // VBR correction is done through rc->vbr_bits_off_target. Based on the |
| // sign of this value, a limited % adjustment is made to the target rate |
| // of subsequent frames, to try and push it back towards 0. This method |
| // is designed to prevent extreme behaviour at the end of a clip |
| // or group of frames. |
| rc->vbr_bits_off_target += rc->base_frame_target - rc->projected_frame_size; |
| twopass->bits_left = AOMMAX(twopass->bits_left - bits_used, 0); |
| |
| // Calculate the pct rc error. |
| if (rc->total_actual_bits) { |
| rc->rate_error_estimate = |
| (int)((rc->vbr_bits_off_target * 100) / rc->total_actual_bits); |
| rc->rate_error_estimate = clamp(rc->rate_error_estimate, -100, 100); |
| } else { |
| rc->rate_error_estimate = 0; |
| } |
| |
| if (cpi->common.current_frame.frame_type != KEY_FRAME) { |
| twopass->kf_group_bits -= bits_used; |
| 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 ((cpi->oxcf.rc_mode != AOM_Q) && !cpi->rc.is_src_frame_alt_ref) { |
| const int maxq_adj_limit = |
| rc->worst_quality - twopass->active_worst_quality; |
| const int minq_adj_limit = |
| (cpi->oxcf.rc_mode == AOM_CQ ? MINQ_ADJ_LIMIT_CQ : MINQ_ADJ_LIMIT); |
| |
| // Undershoot. |
| if (rc->rate_error_estimate > cpi->oxcf.under_shoot_pct) { |
| --twopass->extend_maxq; |
| if (rc->rolling_target_bits >= rc->rolling_actual_bits) |
| ++twopass->extend_minq; |
| // Overshoot. |
| } else if (rc->rate_error_estimate < -cpi->oxcf.over_shoot_pct) { |
| --twopass->extend_minq; |
| if (rc->rolling_target_bits < rc->rolling_actual_bits) |
| ++twopass->extend_maxq; |
| } 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; |
| } |
| } |
| } |
| } |