| /* | 
 |  * 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 "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/thirdpass.h" | 
 | #include "av1/encoder/tpl_model.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); | 
 | static int define_gf_group_pass3(AV1_COMP *cpi, EncodeFrameParams *frame_params, | 
 |                                  int is_final_pass); | 
 |  | 
 | // 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_new(const FRAME_INFO *frame_info, | 
 |                                          const FIRSTPASS_STATS *total_stats, | 
 |                                          const FIRSTPASS_STATS *this_stats, | 
 |                                          int vbrbias, double modified_error_min, | 
 |                                          double modified_error_max) { | 
 |   if (total_stats == NULL) { | 
 |     return 0; | 
 |   } | 
 |   const double av_weight = total_stats->weight / total_stats->count; | 
 |   const double av_err = | 
 |       (total_stats->coded_error * av_weight) / total_stats->count; | 
 |   double modified_error = | 
 |       av_err * pow(this_stats->coded_error * this_stats->weight / | 
 |                        DOUBLE_DIVIDE_CHECK(av_err), | 
 |                    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_stats), ACT_AREA_CORRECTION); | 
 |  | 
 |   return fclamp(modified_error, modified_error_min, modified_error_max); | 
 | } | 
 |  | 
 | 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 *total_stats = twopass->stats_buf_ctx->total_stats; | 
 |   return calculate_modified_err_new( | 
 |       frame_info, total_stats, this_frame, oxcf->rc_cfg.vbrbias, | 
 |       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_FRAME *p_frame, | 
 |                                const FIRSTPASS_STATS *position) { | 
 |   p_frame->stats_in = position; | 
 | } | 
 |  | 
 | static int input_stats(TWO_PASS *p, TWO_PASS_FRAME *p_frame, | 
 |                        FIRSTPASS_STATS *fps) { | 
 |   if (p_frame->stats_in >= p->stats_buf_ctx->stats_in_end) return EOF; | 
 |  | 
 |   *fps = *p_frame->stats_in; | 
 |   ++p_frame->stats_in; | 
 |   return 1; | 
 | } | 
 |  | 
 | static int input_stats_lap(TWO_PASS *p, TWO_PASS_FRAME *p_frame, | 
 |                            FIRSTPASS_STATS *fps) { | 
 |   if (p_frame->stats_in >= p->stats_buf_ctx->stats_in_end) return EOF; | 
 |  | 
 |   *fps = *p_frame->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_frame->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, | 
 |                                                const TWO_PASS_FRAME *p_frame, | 
 |                                                int offset) { | 
 |   if ((offset >= 0 && | 
 |        p_frame->stats_in + offset >= p->stats_buf_ctx->stats_in_end) || | 
 |       (offset < 0 && | 
 |        p_frame->stats_in + offset < p->stats_buf_ctx->stats_in_start)) { | 
 |     return NULL; | 
 |   } | 
 |  | 
 |   return &p_frame->stats_in[offset]; | 
 | } | 
 |  | 
 | // 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 *const twopass = &cpi->ppi->twopass; | 
 |   const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc; | 
 |  | 
 |   // 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 (cpi->third_pass_ctx && cpi->third_pass_ctx->frame_info_count > 0) { | 
 |     int64_t actual_bits = 0; | 
 |     int64_t target_bits = 0; | 
 |     double factor = 0.0; | 
 |     int count = 0; | 
 |     for (int i = 0; i < cpi->third_pass_ctx->frame_info_count; i++) { | 
 |       actual_bits += cpi->third_pass_ctx->frame_info[i].actual_bits; | 
 |       target_bits += cpi->third_pass_ctx->frame_info[i].bits_allocated; | 
 |       factor += cpi->third_pass_ctx->frame_info[i].bpm_factor; | 
 |       count++; | 
 |     } | 
 |  | 
 |     if (count == 0) { | 
 |       factor = 1.0; | 
 |     } else { | 
 |       factor /= (double)count; | 
 |     } | 
 |  | 
 |     factor *= (double)actual_bits / DOUBLE_DIVIDE_CHECK((double)target_bits); | 
 |  | 
 |     if ((twopass->bpm_factor <= 1 && factor < twopass->bpm_factor) || | 
 |         (twopass->bpm_factor >= 1 && factor > twopass->bpm_factor)) { | 
 |       twopass->bpm_factor = factor; | 
 |       twopass->bpm_factor = | 
 |           AOMMAX(min_fac, AOMMIN(max_fac, twopass->bpm_factor)); | 
 |     } | 
 |   } | 
 |  | 
 |   int err_estimate = p_rc->rate_error_estimate; | 
 |   int64_t bits_left = twopass->bits_left; | 
 |   int64_t total_actual_bits = p_rc->total_actual_bits; | 
 |   int64_t bits_off_target = p_rc->vbr_bits_off_target; | 
 |   double rolling_arf_group_actual_bits = | 
 |       (double)twopass->rolling_arf_group_actual_bits; | 
 |   double rolling_arf_group_target_bits = | 
 |       (double)twopass->rolling_arf_group_target_bits; | 
 |  | 
 | #if CONFIG_FPMT_TEST | 
 |   const int is_parallel_frame = | 
 |       cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0 ? 1 : 0; | 
 |   const int simulate_parallel_frame = | 
 |       cpi->ppi->fpmt_unit_test_cfg == PARALLEL_SIMULATION_ENCODE | 
 |           ? is_parallel_frame | 
 |           : 0; | 
 |   total_actual_bits = simulate_parallel_frame ? p_rc->temp_total_actual_bits | 
 |                                               : p_rc->total_actual_bits; | 
 |   bits_off_target = simulate_parallel_frame ? p_rc->temp_vbr_bits_off_target | 
 |                                             : p_rc->vbr_bits_off_target; | 
 |   bits_left = | 
 |       simulate_parallel_frame ? p_rc->temp_bits_left : twopass->bits_left; | 
 |   rolling_arf_group_target_bits = | 
 |       (double)(simulate_parallel_frame | 
 |                    ? p_rc->temp_rolling_arf_group_target_bits | 
 |                    : twopass->rolling_arf_group_target_bits); | 
 |   rolling_arf_group_actual_bits = | 
 |       (double)(simulate_parallel_frame | 
 |                    ? p_rc->temp_rolling_arf_group_actual_bits | 
 |                    : twopass->rolling_arf_group_actual_bits); | 
 |   err_estimate = simulate_parallel_frame ? p_rc->temp_rate_error_estimate | 
 |                                          : p_rc->rate_error_estimate; | 
 | #endif | 
 |  | 
 |   if (p_rc->bits_off_target && total_actual_bits > 0) { | 
 |     if (cpi->ppi->lap_enabled) { | 
 |       rate_err_factor = rolling_arf_group_actual_bits / | 
 |                         DOUBLE_DIVIDE_CHECK(rolling_arf_group_target_bits); | 
 |     } else { | 
 |       rate_err_factor = 1.0 - ((double)(bits_off_target) / | 
 |                                AOMMAX(total_actual_bits, 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, 0.9999); | 
 |  | 
 |   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 / (1.0 - inactive_zone); | 
 |     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 INTRA_PART 0.005 | 
 | #define DEFAULT_DECAY_LIMIT 0.75 | 
 | #define LOW_SR_DIFF_TRHESH 0.01 | 
 | #define NCOUNT_FRAME_II_THRESH 5.0 | 
 | #define LOW_CODED_ERR_PER_MB 0.01 | 
 |  | 
 | /* This function considers how the quality of prediction may be deteriorating | 
 |  * with distance. It comapres the coded error for the last frame and the | 
 |  * second reference frame (usually two frames old) and also applies a factor | 
 |  * based on the extent of INTRA coding. | 
 |  * | 
 |  * The decay factor is then used to reduce the contribution of frames further | 
 |  * from the alt-ref or golden frame, to the bitframe boost calculation for that | 
 |  * alt-ref or golden frame. | 
 |  */ | 
 | static double get_sr_decay_rate(const FIRSTPASS_STATS *frame) { | 
 |   double sr_diff = (frame->sr_coded_error - frame->coded_error); | 
 |   double sr_decay = 1.0; | 
 |   double modified_pct_inter; | 
 |   double modified_pcnt_intra; | 
 |  | 
 |   modified_pct_inter = frame->pcnt_inter; | 
 |   if ((frame->coded_error > LOW_CODED_ERR_PER_MB) && | 
 |       ((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)) { | 
 |     double sr_diff_part = ((sr_diff * 0.25) / frame->intra_error); | 
 |     sr_decay = 1.0 - sr_diff_part - (INTRA_PART * modified_pcnt_intra); | 
 |   } | 
 |   return AOMMAX(sr_decay, DEFAULT_DECAY_LIMIT); | 
 | } | 
 |  | 
 | // 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 FIRSTPASS_STATS *frame) { | 
 |   const double zero_motion_pct = frame->pcnt_inter - frame->pcnt_motion; | 
 |   double sr_decay = get_sr_decay_rate(frame); | 
 |   return AOMMIN(sr_decay, zero_motion_pct); | 
 | } | 
 |  | 
 | #define DEFAULT_ZM_FACTOR 0.5 | 
 | static double get_prediction_decay_rate(const FIRSTPASS_STATS *frame_stats) { | 
 |   const double sr_decay_rate = get_sr_decay_rate(frame_stats); | 
 |   double zero_motion_factor = | 
 |       DEFAULT_ZM_FACTOR * (frame_stats->pcnt_inter - frame_stats->pcnt_motion); | 
 |  | 
 |   // Clamp value to range 0.0 to 1.0 | 
 |   // This should happen anyway if input values are sensibly clamped but checked | 
 |   // here just in case. | 
 |   if (zero_motion_factor > 1.0) | 
 |     zero_motion_factor = 1.0; | 
 |   else if (zero_motion_factor < 0.0) | 
 |     zero_motion_factor = 0.0; | 
 |  | 
 |   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(const FIRSTPASS_INFO *firstpass_info, | 
 |                                       int next_stats_index, | 
 |                                       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 stats_left = | 
 |         av1_firstpass_info_future_count(firstpass_info, next_stats_index); | 
 |     if (stats_left >= still_interval) { | 
 |       int j; | 
 |       // Look ahead a few frames to see if static condition persists... | 
 |       for (j = 0; j < still_interval; ++j) { | 
 |         const FIRSTPASS_STATS *stats = | 
 |             av1_firstpass_info_peek(firstpass_info, next_stats_index + j); | 
 |         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 TWO_PASS_FRAME *twopass_frame, const int offset) { | 
 |   const FIRSTPASS_STATS *const next_frame = | 
 |       read_frame_stats(twopass, twopass_frame, 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, double f_w, | 
 |                                           double f_h) { | 
 |   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 * f_h ? mvr_ratio : stats->mvr_abs * f_h); | 
 |     gf_stats->mv_ratio_accumulator += | 
 |         pct * | 
 |         (mvc_ratio < stats->mvc_abs * f_w ? mvc_ratio : stats->mvc_abs * f_w); | 
 |   } | 
 | } | 
 |  | 
 | 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; | 
 | } | 
 |  | 
 | void av1_accumulate_next_frame_stats(const FIRSTPASS_STATS *stats, | 
 |                                      const int flash_detected, | 
 |                                      const int frames_since_key, | 
 |                                      const int cur_idx, | 
 |                                      GF_GROUP_STATS *gf_stats, int f_w, | 
 |                                      int f_h) { | 
 |   accumulate_frame_motion_stats(stats, gf_stats, f_w, f_h); | 
 |   // sum up the metric values of current gf group | 
 |   gf_stats->avg_sr_coded_error += stats->sr_coded_error; | 
 |   gf_stats->avg_pcnt_second_ref += stats->pcnt_second_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(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(stats)); | 
 |     } | 
 |   } | 
 | } | 
 |  | 
 | static void average_gf_stats(const int total_frame, GF_GROUP_STATS *gf_stats) { | 
 |   if (total_frame) { | 
 |     gf_stats->avg_sr_coded_error /= total_frame; | 
 |     gf_stats->avg_pcnt_second_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; | 
 | } | 
 |  | 
 | #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 PRIMARY_RATE_CONTROL *p_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(p_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); | 
 |  | 
 |   // Underlying boost factor is based on inter error ratio. | 
 |   frame_boost = AOMMAX(baseline_err_per_mb(frame_info) * active_area, | 
 |                        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 PRIMARY_RATE_CONTROL *p_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(p_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); | 
 |  | 
 |   // Underlying boost factor is based on inter error ratio. | 
 |   frame_boost = AOMMAX(baseline_err_per_mb(frame_info) * active_area, | 
 |                        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 TWO_PASS_FRAME *twopass_frame, | 
 |                        const PRIMARY_RATE_CONTROL *p_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, twopass_frame, i + offset); | 
 |     if (this_frame == NULL) break; | 
 |  | 
 |     // Update the motion related elements to the boost calculation. | 
 |     accumulate_frame_motion_stats(this_frame, &gf_stats, | 
 |                                   frame_info->frame_width, | 
 |                                   frame_info->frame_height); | 
 |  | 
 |     // 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, twopass_frame, i + offset) || | 
 |                      detect_flash(twopass, twopass_frame, i + offset + 1); | 
 |  | 
 |     // Accumulate the effect of prediction quality decay. | 
 |     if (!flash_detected) { | 
 |       gf_stats.decay_accumulator *= get_prediction_decay_rate(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(p_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, twopass_frame, i + offset); | 
 |     if (this_frame == NULL) break; | 
 |  | 
 |     // Update the motion related elements to the boost calculation. | 
 |     accumulate_frame_motion_stats(this_frame, &gf_stats, | 
 |                                   frame_info->frame_width, | 
 |                                   frame_info->frame_height); | 
 |  | 
 |     // 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, twopass_frame, i + offset) || | 
 |                      detect_flash(twopass, twopass_frame, i + offset + 1); | 
 |  | 
 |     // Cumulative effect of prediction quality decay. | 
 |     if (!flash_detected) { | 
 |       gf_stats.decay_accumulator *= get_prediction_decay_rate(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(p_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) { | 
 |   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. | 
 |  | 
 |     // TODO(angiebird): This is a temporary change, we will avoid using | 
 |     // twopass_frame.stats_in in the follow-up CL | 
 |     int index = (int)(cpi->twopass_frame.stats_in - | 
 |                       twopass->stats_buf_ctx->stats_in_start); | 
 |     if (detect_transition_to_still(&twopass->firstpass_info, index, | 
 |                                    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) { | 
 |   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; | 
 |  | 
 |   av1_tpl_preload_rc_estimate(cpi, frame_params); | 
 |  | 
 |   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); | 
 |   } 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 (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); | 
 |  | 
 |       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); | 
 |       // 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->skip_tpl_setup_stats = 1; | 
 | #if CONFIG_BITRATE_ACCURACY && !CONFIG_THREE_PASS | 
 |         assert(cpi->gf_frame_index == 0); | 
 |         av1_vbr_rc_update_q_index_list(&cpi->vbr_rc_info, &cpi->ppi->tpl_data, | 
 |                                        gf_group, | 
 |                                        cpi->common.seq_params->bit_depth); | 
 | #endif  // CONFIG_BITRATE_ACCURACY | 
 |       } | 
 |     } | 
 |   } | 
 |   return shorten_gf_interval; | 
 | } | 
 |  | 
 | #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); | 
 | } | 
 |  | 
 | void av1_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 = | 
 |       (REGIONS *)aom_malloc(total_frames * sizeof(temp_regions[0])); | 
 |   av1_zero_array(temp_regions, total_frames); | 
 |   // buffers for filtered stats | 
 |   double *filt_intra_err = | 
 |       (double *)aom_calloc(total_frames, sizeof(*filt_intra_err)); | 
 |   double *filt_coded_err = | 
 |       (double *)aom_calloc(total_frames, sizeof(*filt_coded_err)); | 
 |   double *grad_coded = (double *)aom_calloc(total_frames, sizeof(*grad_coded)); | 
 |  | 
 |   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; | 
 |   } | 
 |  | 
 |   aom_free(temp_regions); | 
 |   aom_free(filt_coded_err); | 
 |   aom_free(filt_intra_err); | 
 |   aom_free(grad_coded); | 
 | } | 
 |  | 
 | 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 | 
 |  * | 
 |  * \remark 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 = cpi->twopass_frame.stats_in; | 
 |   const FIRSTPASS_STATS *const stats = start_pos - (rc->frames_since_key == 0); | 
 |  | 
 |   const int f_w = cpi->common.width; | 
 |   const int f_h = cpi->common.height; | 
 |   int i; | 
 |  | 
 |   int flash_detected; | 
 |  | 
 |   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) { | 
 |       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, &cpi->twopass_frame, &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, &cpi->twopass_frame, 0); | 
 |       // TODO(bohanli): remove redundant accumulations here, or unify | 
 |       // this and the ones in define_gf_group | 
 |       av1_accumulate_next_frame_stats(&next_frame, flash_detected, | 
 |                                       rc->frames_since_key, i, &gf_stats, f_w, | 
 |                                       f_h); | 
 |  | 
 |       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; | 
 |  | 
 |       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 shrunken location | 
 |       cpi->twopass_frame.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; | 
 |   cpi->twopass_frame.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 != AOM_RC_ONE_PASS && 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 | 
 |  * | 
 |  * \remark 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(PRIMARY_RATE_CONTROL *p_rc, | 
 |                                             int arf_position) { | 
 |   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_pcnt_second_ref = 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; | 
 | } | 
 |  | 
 | static void accumulate_gop_stats(AV1_COMP *cpi, int is_intra_only, int f_w, | 
 |                                  int f_h, FIRSTPASS_STATS *next_frame, | 
 |                                  const FIRSTPASS_STATS *start_pos, | 
 |                                  GF_GROUP_STATS *gf_stats, int *idx) { | 
 |   int i, flash_detected; | 
 |   TWO_PASS *const twopass = &cpi->ppi->twopass; | 
 |   PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc; | 
 |   RATE_CONTROL *const rc = &cpi->rc; | 
 |   FRAME_INFO *frame_info = &cpi->frame_info; | 
 |   const AV1EncoderConfig *const oxcf = &cpi->oxcf; | 
 |  | 
 |   init_gf_stats(gf_stats); | 
 |   av1_zero(*next_frame); | 
 |  | 
 |   // 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. | 
 |   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, &cpi->twopass_frame, next_frame)) break; | 
 |     // Accumulate error score of frames in this gf group. | 
 |     double 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); | 
 |     ++i; | 
 |   } | 
 |  | 
 |   reset_fpf_position(&cpi->twopass_frame, start_pos); | 
 |  | 
 |   i = is_intra_only; | 
 |   input_stats(twopass, &cpi->twopass_frame, next_frame); | 
 |   while (i < p_rc->gf_intervals[p_rc->cur_gf_index]) { | 
 |     // read in the next frame | 
 |     if (EOF == input_stats(twopass, &cpi->twopass_frame, 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, &cpi->twopass_frame, 0); | 
 |  | 
 |     // accumulate stats for next frame | 
 |     av1_accumulate_next_frame_stats(next_frame, flash_detected, | 
 |                                     rc->frames_since_key, i, gf_stats, f_w, | 
 |                                     f_h); | 
 |  | 
 |     ++i; | 
 |   } | 
 |  | 
 |   i = p_rc->gf_intervals[p_rc->cur_gf_index]; | 
 |   average_gf_stats(i, gf_stats); | 
 |  | 
 |   *idx = i; | 
 | } | 
 |  | 
 | static void update_gop_length(RATE_CONTROL *rc, PRIMARY_RATE_CONTROL *p_rc, | 
 |                               int idx, int is_final_pass) { | 
 |   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 = (idx >= rc->frames_to_key) ? 1 : 0; | 
 |  | 
 |   set_baseline_gf_interval(p_rc, idx); | 
 |   rc->frames_till_gf_update_due = p_rc->baseline_gf_interval; | 
 | } | 
 |  | 
 | #define MAX_GF_BOOST 5400 | 
 | #define REDUCE_GF_LENGTH_THRESH 4 | 
 | #define REDUCE_GF_LENGTH_TO_KEY_THRESH 9 | 
 | #define REDUCE_GF_LENGTH_BY 1 | 
 | static void set_gop_bits_boost(AV1_COMP *cpi, int i, int is_intra_only, | 
 |                                int is_final_pass, int use_alt_ref, | 
 |                                int alt_offset, const FIRSTPASS_STATS *start_pos, | 
 |                                GF_GROUP_STATS *gf_stats) { | 
 |   // Should we use the alternate reference frame. | 
 |   AV1_COMMON *const cm = &cpi->common; | 
 |   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 *gf_group = &cpi->ppi->gf_group; | 
 |   FRAME_INFO *frame_info = &cpi->frame_info; | 
 |   const AV1EncoderConfig *const oxcf = &cpi->oxcf; | 
 |   const RateControlCfg *const rc_cfg = &oxcf->rc_cfg; | 
 |  | 
 |   int ext_len = i - is_intra_only; | 
 |   if (use_alt_ref) { | 
 |     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, &cpi->twopass_frame, p_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(&cpi->twopass_frame, start_pos); | 
 |     p_rc->gfu_boost = AOMMIN( | 
 |         MAX_GF_BOOST, | 
 |         av1_calc_arf_boost( | 
 |             twopass, &cpi->twopass_frame, p_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; | 
 |     } | 
 |   } | 
 |  | 
 |   // Reset the file position. | 
 |   reset_fpf_position(&cpi->twopass_frame, 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 | 
 |   p_rc->gf_group_bits = | 
 |       calculate_total_gf_group_bits(cpi, gf_stats->gf_group_err); | 
 |  | 
 | #if GROUP_ADAPTIVE_MAXQ | 
 |   // Calculate an estimate of the maxq needed for the group. | 
 |   // We are more aggressive 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)(p_rc->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 -= gf_stats->gf_group_err; | 
 |  | 
 |   // Reset the file position. | 
 |   reset_fpf_position(&cpi->twopass_frame, 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, p_rc->gf_group_bits); | 
 |  | 
 |   // 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; | 
 |   } | 
 | #if CONFIG_BITRATE_ACCURACY | 
 |   if (is_final_pass) { | 
 |     av1_vbr_rc_set_gop_bit_budget(&cpi->vbr_rc_info, | 
 |                                   p_rc->baseline_gf_interval); | 
 |   } | 
 | #endif | 
 | } | 
 |  | 
 | /*!\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]    frame_params    Structure with frame parameters | 
 |  * \param[in]    is_final_pass   Whether this is the final pass for the | 
 |  *                               GF group, or a trial (non-zero) | 
 |  * | 
 |  * \remark Nothing is returned. Instead, cpi->ppi->gf_group is changed. | 
 |  */ | 
 | static void define_gf_group(AV1_COMP *cpi, EncodeFrameParams *frame_params, | 
 |                             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 = cpi->twopass_frame.stats_in; | 
 |   GF_GROUP *gf_group = &cpi->ppi->gf_group; | 
 |   const GFConfig *const gf_cfg = &oxcf->gf_cfg; | 
 |   const RateControlCfg *const rc_cfg = &oxcf->rc_cfg; | 
 |   const int f_w = cm->width; | 
 |   const int f_h = cm->height; | 
 |   int i; | 
 |   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; | 
 |   } | 
 |  | 
 |   if (has_no_stats_stage(cpi)) { | 
 |     define_gf_group_pass0(cpi); | 
 |     return; | 
 |   } | 
 |  | 
 |   if (cpi->third_pass_ctx && oxcf->pass == AOM_RC_THIRD_PASS) { | 
 |     int ret = define_gf_group_pass3(cpi, frame_params, is_final_pass); | 
 |     if (ret == 0) return; | 
 |  | 
 |     av1_free_thirdpass_ctx(cpi->third_pass_ctx); | 
 |     cpi->third_pass_ctx = NULL; | 
 |   } | 
 |  | 
 |   // correct frames_to_key when lookahead queue is emptying | 
 |   if (cpi->ppi->lap_enabled) { | 
 |     correct_frames_to_key(cpi); | 
 |   } | 
 |  | 
 |   GF_GROUP_STATS gf_stats; | 
 |   accumulate_gop_stats(cpi, is_intra_only, f_w, f_h, &next_frame, start_pos, | 
 |                        &gf_stats, &i); | 
 |  | 
 |   const int can_disable_arf = !gf_cfg->gf_min_pyr_height; | 
 |  | 
 |   // 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. | 
 |   const int active_min_gf_interval = rc->min_gf_interval; | 
 |  | 
 |   // 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 < 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); | 
 |   } else { | 
 |     use_alt_ref = p_rc->use_arf_in_this_kf_group && | 
 |                   (i < gf_cfg->lag_in_frames) && (i > 2); | 
 |   } | 
 |   if (use_alt_ref) { | 
 |     gf_group->max_layer_depth_allowed = gf_cfg->gf_max_pyr_height; | 
 |   } else { | 
 |     gf_group->max_layer_depth_allowed = 0; | 
 |   } | 
 |  | 
 |   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; | 
 |         p_rc->gf_intervals[p_rc->cur_gf_index] -= roll_back; | 
 |         reset_fpf_position(&cpi->twopass_frame, start_pos); | 
 |         accumulate_gop_stats(cpi, is_intra_only, f_w, f_h, &next_frame, | 
 |                              start_pos, &gf_stats, &i); | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 |   update_gop_length(rc, p_rc, i, is_final_pass); | 
 |  | 
 |   // Set up the structure of this Group-Of-Pictures (same as GF_GROUP) | 
 |   av1_gop_setup_structure(cpi); | 
 |  | 
 |   set_gop_bits_boost(cpi, i, is_intra_only, is_final_pass, use_alt_ref, | 
 |                      alt_offset, start_pos, &gf_stats); | 
 |  | 
 |   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); | 
 | } | 
 |  | 
 | /*!\brief Define a GF group for the third apss. | 
 |  * | 
 |  * \ingroup gf_group_algo | 
 |  * This function defines the structure of a GF group for the third pass, along | 
 |  * with various parameters regarding bit-allocation and quality setup based on | 
 |  * the two-pass bitstream. | 
 |  * Much of the function still uses the strategies used for the second pass and | 
 |  * relies on first pass statistics. It is expected that over time these portions | 
 |  * would be replaced with strategies specific to the third pass. | 
 |  * | 
 |  * \param[in]    cpi             Top-level encoder structure | 
 |  * \param[in]    frame_params    Structure with frame parameters | 
 |  * \param[in]    is_final_pass   Whether this is the final pass for the | 
 |  *                               GF group, or a trial (non-zero) | 
 |  * | 
 |  * \return       0: Success; | 
 |  *              -1: There are conflicts between the bitstream and current config | 
 |  *               The values in cpi->ppi->gf_group are also changed. | 
 |  */ | 
 | static int define_gf_group_pass3(AV1_COMP *cpi, EncodeFrameParams *frame_params, | 
 |                                  int is_final_pass) { | 
 |   if (!cpi->third_pass_ctx) return -1; | 
 |   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; | 
 |   FIRSTPASS_STATS next_frame; | 
 |   const FIRSTPASS_STATS *const start_pos = cpi->twopass_frame.stats_in; | 
 |   GF_GROUP *gf_group = &cpi->ppi->gf_group; | 
 |   const GFConfig *const gf_cfg = &oxcf->gf_cfg; | 
 |   const int f_w = cm->width; | 
 |   const int f_h = cm->height; | 
 |   int i; | 
 |   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; | 
 |   } | 
 |  | 
 |   GF_GROUP_STATS gf_stats; | 
 |   accumulate_gop_stats(cpi, is_intra_only, f_w, f_h, &next_frame, start_pos, | 
 |                        &gf_stats, &i); | 
 |  | 
 |   const int can_disable_arf = !gf_cfg->gf_min_pyr_height; | 
 |  | 
 |   // TODO(any): set cpi->ppi->internal_altref_allowed accordingly; | 
 |  | 
 |   int use_alt_ref = av1_check_use_arf(cpi->third_pass_ctx); | 
 |   if (use_alt_ref == 0 && !can_disable_arf) return -1; | 
 |   if (use_alt_ref) { | 
 |     gf_group->max_layer_depth_allowed = gf_cfg->gf_max_pyr_height; | 
 |   } else { | 
 |     gf_group->max_layer_depth_allowed = 0; | 
 |   } | 
 |  | 
 |   update_gop_length(rc, p_rc, i, is_final_pass); | 
 |  | 
 |   // Set up the structure of this Group-Of-Pictures (same as GF_GROUP) | 
 |   av1_gop_setup_structure(cpi); | 
 |  | 
 |   set_gop_bits_boost(cpi, i, is_intra_only, is_final_pass, use_alt_ref, 0, | 
 |                      start_pos, &gf_stats); | 
 |  | 
 |   frame_params->frame_type = cpi->third_pass_ctx->frame_info[0].frame_type; | 
 |   frame_params->show_frame = cpi->third_pass_ctx->frame_info[0].is_show_frame; | 
 |   return 0; | 
 | } | 
 |  | 
 | // #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(const FIRSTPASS_INFO *firstpass_info, | 
 |                              int this_stats_index, int frame_count_so_far, | 
 |                              enum aom_rc_mode rc_mode, int scenecut_mode, | 
 |                              int num_mbs) { | 
 |   const FIRSTPASS_STATS *last_stats = | 
 |       av1_firstpass_info_peek(firstpass_info, this_stats_index - 1); | 
 |   const FIRSTPASS_STATS *this_stats = | 
 |       av1_firstpass_info_peek(firstpass_info, this_stats_index); | 
 |   const FIRSTPASS_STATS *next_stats = | 
 |       av1_firstpass_info_peek(firstpass_info, this_stats_index + 1); | 
 |   if (last_stats == NULL || this_stats == NULL || next_stats == NULL) { | 
 |     return 0; | 
 |   } | 
 |  | 
 |   int is_viable_kf = 0; | 
 |   double pcnt_intra = 1.0 - this_stats->pcnt_inter; | 
 |   double modified_pcnt_inter = | 
 |       this_stats->pcnt_inter - this_stats->pcnt_neutral; | 
 |   const double second_ref_usage_thresh = | 
 |       get_second_ref_usage_thresh(frame_count_so_far); | 
 |   int frames_to_test_after_candidate_key = SCENE_CUT_KEY_TEST_INTERVAL; | 
 |   int count_for_tolerable_prediction = 3; | 
 |  | 
 |   // We do "-1" because the candidate key is not counted. | 
 |   int stats_after_this_stats = | 
 |       av1_firstpass_info_future_count(firstpass_info, this_stats_index) - 1; | 
 |  | 
 |   if (scenecut_mode == ENABLE_SCENECUT_MODE_1) { | 
 |     if (stats_after_this_stats < 3) { | 
 |       return 0; | 
 |     } else { | 
 |       frames_to_test_after_candidate_key = 3; | 
 |       count_for_tolerable_prediction = 1; | 
 |     } | 
 |   } | 
 |   // Make sure we have enough stats after the candidate key. | 
 |   frames_to_test_after_candidate_key = | 
 |       AOMMIN(frames_to_test_after_candidate_key, stats_after_this_stats); | 
 |  | 
 |   // 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_stats->pcnt_second_ref < second_ref_usage_thresh) && | 
 |       (next_stats->pcnt_second_ref < second_ref_usage_thresh) && | 
 |       ((this_stats->pcnt_inter < VERY_LOW_INTER_THRESH) || | 
 |        slide_transition(this_stats, last_stats, next_stats) || | 
 |        ((pcnt_intra > MIN_INTRA_LEVEL) && | 
 |         (pcnt_intra > (INTRA_VS_INTER_THRESH * modified_pcnt_inter)) && | 
 |         ((this_stats->intra_error / | 
 |           DOUBLE_DIVIDE_CHECK(this_stats->coded_error)) < | 
 |          KF_II_ERR_THRESHOLD) && | 
 |         ((fabs(last_stats->coded_error - this_stats->coded_error) / | 
 |               DOUBLE_DIVIDE_CHECK(this_stats->coded_error) > | 
 |           ERR_CHANGE_THRESHOLD) || | 
 |          (fabs(last_stats->intra_error - this_stats->intra_error) / | 
 |               DOUBLE_DIVIDE_CHECK(this_stats->intra_error) > | 
 |           ERR_CHANGE_THRESHOLD) || | 
 |          ((next_stats->intra_error / | 
 |            DOUBLE_DIVIDE_CHECK(next_stats->coded_error)) > | 
 |           II_IMPROVEMENT_THRESHOLD))))) { | 
 |     int i; | 
 |     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 = 1; i <= frames_to_test_after_candidate_key; ++i) { | 
 |       // Get the next frame details | 
 |       const FIRSTPASS_STATS *local_next_frame = | 
 |           av1_firstpass_info_peek(firstpass_info, this_stats_index + 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. | 
 |       // TODO(any): Test of intra error should be normalized to an MB. | 
 |       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 < (200.0 / (double)num_mbs))) { | 
 |         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; | 
 |     } | 
 |   } | 
 |   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) { | 
 |   int num_frames_to_app_forced_key = is_forced_keyframe_pending( | 
 |       cpi->ppi->lookahead, cpi->ppi->lookahead->max_sz, cpi->compressor_stage); | 
 |   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]    firstpass_info   struct for firstpass info | 
 |  * \param[in]    num_frames_to_detect_scenecut Maximum lookahead frames. | 
 |  * \param[in]    search_start_idx   the start index for searching key frame. | 
 |  *                                  Set it to one if we already know the | 
 |  *                                  current frame is key frame. Otherwise, | 
 |  *                                  set it to zero. | 
 |  * | 
 |  * \return       Number of frames to the next key including the current frame. | 
 |  */ | 
 | static int define_kf_interval(AV1_COMP *cpi, | 
 |                               const FIRSTPASS_INFO *firstpass_info, | 
 |                               int num_frames_to_detect_scenecut, | 
 |                               int search_start_idx) { | 
 |   const TWO_PASS *const twopass = &cpi->ppi->twopass; | 
 |   const 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]; | 
 |   double decay_accumulator = 1.0; | 
 |   int i = 0, j; | 
 |   int frames_to_key = search_start_idx; | 
 |   int frames_since_key = rc->frames_since_key + 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; | 
 |   const int num_mbs = (oxcf->resize_cfg.resize_mode != RESIZE_NONE) | 
 |                           ? cpi->initial_mbs | 
 |                           : cpi->common.mi_params.MBs; | 
 |   const int future_stats_count = | 
 |       av1_firstpass_info_future_count(firstpass_info, 0); | 
 |   while (frames_to_key < future_stats_count && | 
 |          frames_to_key < num_frames_to_detect_scenecut) { | 
 |     // Provided that we are not at the end of the file... | 
 |     if ((cpi->ppi->p_rc.enable_scenecut_detection > 0) && kf_cfg->auto_key && | 
 |         frames_to_key + 1 < future_stats_count) { | 
 |       double loop_decay_rate; | 
 |  | 
 |       // Check for a scene cut. | 
 |       if (frames_since_key >= kf_cfg->key_freq_min) { | 
 |         scenecut_detected = test_candidate_kf( | 
 |             &twopass->firstpass_info, frames_to_key, frames_since_key, | 
 |             oxcf->rc_cfg.mode, cpi->ppi->p_rc.enable_scenecut_detection, | 
 |             num_mbs); | 
 |         if (scenecut_detected) { | 
 |           break; | 
 |         } | 
 |       } | 
 |  | 
 |       // How fast is the prediction quality decaying? | 
 |       const FIRSTPASS_STATS *next_stats = | 
 |           av1_firstpass_info_peek(firstpass_info, frames_to_key + 1); | 
 |       loop_decay_rate = get_prediction_decay_rate(next_stats); | 
 |  | 
 |       // 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) { | 
 |         scenecut_detected = detect_transition_to_still( | 
 |             firstpass_info, frames_to_key + 1, rc->min_gf_interval, i, | 
 |             kf_cfg->key_freq_max - i, loop_decay_rate, decay_accumulator); | 
 |         if (scenecut_detected) { | 
 |           // 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 (cpi->ppi->lap_enabled && !scenecut_detected) | 
 |     frames_to_key = num_frames_to_next_key; | 
 |  | 
 |   return frames_to_key; | 
 | } | 
 |  | 
 | static double get_kf_group_avg_error(TWO_PASS *twopass, | 
 |                                      TWO_PASS_FRAME *twopass_frame, | 
 |                                      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_frame, start_position); | 
 |  | 
 |   for (i = 0; i < frames_to_key; ++i) { | 
 |     kf_group_avg_error += cur_frame.coded_error; | 
 |     if (EOF == input_stats(twopass, twopass_frame, &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) { | 
 |       double vbr_corpus_complexity_lap = | 
 |           cpi->oxcf.rc_cfg.vbr_corpus_complexity_lap / 10.0; | 
 |       /* Get the average corpus complexity of the frame */ | 
 |       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, &cpi->twopass_frame, &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, &cpi->twopass_frame, &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_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(&cpi->ppi->p_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 | 
 |  */ | 
 | 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; | 
 |   const FIRSTPASS_INFO *firstpass_info = &twopass->firstpass_info; | 
 |   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 = cpi->twopass_frame.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 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); | 
 |  | 
 |   // We assume the current frame is a key frame and we are looking for the next | 
 |   // key frame. Therefore search_start_idx = 1 | 
 |   frames_to_key = define_kf_interval(cpi, firstpass_info, kf_cfg->key_freq_max, | 
 |                                      /*search_start_idx=*/1); | 
 |  | 
 |   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(&cpi->twopass_frame, start_position); | 
 |     // Rescan to get the correct error data for the forced kf group. | 
 |     for (i = 0; i < rc->frames_to_key; ++i) { | 
 |       if (EOF == input_stats(twopass, &cpi->twopass_frame, &tmp_frame)) break; | 
 |     } | 
 |     p_rc->next_key_frame_forced = 1; | 
 |   } else if ((cpi->twopass_frame.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; | 
 |   } | 
 |  | 
 |   double kf_group_err = 0; | 
 |   for (i = 0; i < rc->frames_to_key; ++i) { | 
 |     const FIRSTPASS_STATS *this_stats = | 
 |         av1_firstpass_info_peek(&twopass->firstpass_info, i); | 
 |     if (this_stats != NULL) { | 
 |       // Accumulate kf group error. | 
 |       kf_group_err += calculate_modified_err_new( | 
 |           frame_info, &firstpass_info->total_stats, this_stats, | 
 |           oxcf->rc_cfg.vbrbias, twopass->modified_error_min, | 
 |           twopass->modified_error_max); | 
 |       ++p_rc->num_stats_used_for_kf_boost; | 
 |     } | 
 |   } | 
 |  | 
 |   // 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, &cpi->twopass_frame, &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(&cpi->twopass_frame, 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(&cpi->twopass_frame, 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(&cpi->twopass_frame, 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 = (double)(rc->frames_to_key - 1); | 
 |   else | 
 |     twopass->kf_group_error_left = 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; | 
 | } | 
 |  | 
 | #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 INLINE void set_twopass_params_based_on_fp_stats( | 
 |     AV1_COMP *cpi, const FIRSTPASS_STATS *this_frame_ptr) { | 
 |   if (this_frame_ptr == NULL) return; | 
 |  | 
 |   TWO_PASS_FRAME *twopass_frame = &cpi->twopass_frame; | 
 |   // The multiplication by 256 reverses a scaling factor of (>> 8) | 
 |   // applied when combining MB error values for the frame. | 
 |   twopass_frame->mb_av_energy = log((this_frame_ptr->intra_error) + 1.0); | 
 |  | 
 |   const FIRSTPASS_STATS *const total_stats = | 
 |       cpi->ppi->twopass.stats_buf_ctx->total_stats; | 
 |   if (is_fp_wavelet_energy_invalid(total_stats) == 0) { | 
 |     twopass_frame->frame_avg_haar_energy = | 
 |         log((this_frame_ptr->frame_avg_wavelet_energy) + 1.0); | 
 |   } | 
 |  | 
 |   // Set the frame content type flag. | 
 |   if (this_frame_ptr->intra_skip_pct >= FC_ANIMATION_THRESH) | 
 |     twopass_frame->fr_content_type = FC_GRAPHICS_ANIMATION; | 
 |   else | 
 |     twopass_frame->fr_content_type = FC_NORMAL; | 
 | } | 
 |  | 
 | 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; | 
 |   PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc; | 
 |   TWO_PASS *const twopass = &cpi->ppi->twopass; | 
 |   FIRSTPASS_STATS *total_stats = twopass->stats_buf_ctx->total_stats; | 
 |  | 
 |   if (cpi->oxcf.rc_cfg.mode != AOM_Q && current_frame->frame_number == 0 && | 
 |       cpi->gf_frame_index == 0 && total_stats && | 
 |       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. | 
 |        */ | 
 |       *twopass->stats_buf_ctx->total_left_stats = *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; | 
 |     p_rc->last_q[INTER_FRAME] = tmp_q; | 
 |     p_rc->avg_q = av1_convert_qindex_to_q(tmp_q, cm->seq_params->bit_depth); | 
 |     p_rc->avg_frame_qindex[INTER_FRAME] = tmp_q; | 
 |     p_rc->last_q[KEY_FRAME] = (tmp_q + cpi->oxcf.rc_cfg.best_allowed_q) / 2; | 
 |     p_rc->avg_frame_qindex[KEY_FRAME] = p_rc->last_q[KEY_FRAME]; | 
 |   } | 
 |  | 
 |   if (cpi->twopass_frame.stats_in < twopass->stats_buf_ctx->stats_in_end) { | 
 |     *this_frame = *cpi->twopass_frame.stats_in; | 
 |     ++cpi->twopass_frame.stats_in; | 
 |   } | 
 |   set_twopass_params_based_on_fp_stats(cpi, this_frame); | 
 | } | 
 |  | 
 | 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; | 
 | } | 
 |  | 
 | void av1_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 | 
 | void av1_estimate_noise(FIRSTPASS_STATS *first_stats, | 
 |                         FIRSTPASS_STATS *last_stats) { | 
 |   FIRSTPASS_STATS *this_stats, *next_stats; | 
 |   double C1, C2, C3, noise; | 
 |   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; | 
 |   } | 
 |  | 
 |   // 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. | 
 | void av1_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, | 
 |                                 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; | 
 |  | 
 |   if (cpi->use_ducky_encode && | 
 |       cpi->ducky_encode_info.frame_info.gop_mode == DUCKY_ENCODE_GOP_MODE_RCL) { | 
 |     frame_params->frame_type = gf_group->frame_type[cpi->gf_frame_index]; | 
 |     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); | 
 |     return; | 
 |   } | 
 |  | 
 |   const FIRSTPASS_STATS *const start_pos = cpi->twopass_frame.stats_in; | 
 |   int update_total_stats = 0; | 
 |  | 
 |   if (is_stat_consumption_stage(cpi) && !cpi->twopass_frame.stats_in) return; | 
 |  | 
 |   // Check forced key frames. | 
 |   const int frames_to_next_forced_key = detect_app_forced_key(cpi); | 
 |   if (frames_to_next_forced_key == 0) { | 
 |     rc->frames_to_key = 0; | 
 |     frame_flags &= FRAMEFLAGS_KEY; | 
 |   } else if (frames_to_next_forced_key > 0 && | 
 |              frames_to_next_forced_key < rc->frames_to_key) { | 
 |     rc->frames_to_key = frames_to_next_forced_key; | 
 |   } | 
 |  | 
 |   assert(cpi->twopass_frame.stats_in != NULL); | 
 |   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) { | 
 |       const FIRSTPASS_STATS *const this_frame_ptr = | 
 |           read_frame_stats(twopass, &cpi->twopass_frame, | 
 |                            gf_group->arf_src_offset[cpi->gf_frame_index]); | 
 |       set_twopass_params_based_on_fp_stats(cpi, this_frame_ptr); | 
 |       return; | 
 |     } | 
 |   } | 
 |  | 
 |   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); | 
 |       update_total_stats = 1; | 
 |     } | 
 |   } else { | 
 |     rc->active_worst_quality = oxcf->rc_cfg.cq_level; | 
 |   } | 
 |  | 
 |   if (cpi->gf_frame_index == gf_group->size) { | 
 |     if (cpi->ppi->lap_enabled && cpi->ppi->p_rc.enable_scenecut_detection) { | 
 |       const int num_frames_to_detect_scenecut = MAX_GF_LENGTH_LAP + 1; | 
 |       const int frames_to_key = define_kf_interval( | 
 |           cpi, &twopass->firstpass_info, num_frames_to_detect_scenecut, | 
 |           /*search_start_idx=*/0); | 
 |       if (frames_to_key != -1) | 
 |         rc->frames_to_key = AOMMIN(rc->frames_to_key, frames_to_key); | 
 |     } | 
 |   } | 
 |  | 
 |   // Keyframe and section processing. | 
 |   FIRSTPASS_STATS this_frame_copy; | 
 |   this_frame_copy = this_frame; | 
 |   if (rc->frames_to_key <= 0) { | 
 |     assert(rc->frames_to_key == 0); | 
 |     // Define next KF group and assign bits to it. | 
 |     frame_params->frame_type = KEY_FRAME; | 
 |     find_next_key_frame(cpi, &this_frame); | 
 |     this_frame = this_frame_copy; | 
 |   } | 
 |  | 
 |   if (rc->frames_to_fwd_kf <= 0) | 
 |     rc->frames_to_fwd_kf = oxcf->kf_cfg.fwd_kf_dist; | 
 |  | 
 |   // Define a new GF/ARF group. (Should always enter here for key frames). | 
 |   if (cpi->gf_frame_index == gf_group->size) { | 
 |     av1_tf_info_reset(&cpi->ppi->tf_info); | 
 | #if CONFIG_BITRATE_ACCURACY && !CONFIG_THREE_PASS | 
 |     vbr_rc_reset_gop_data(&cpi->vbr_rc_info); | 
 | #endif  // CONFIG_BITRATE_ACCURACY | 
 |     int max_gop_length = | 
 |         (oxcf->gf_cfg.lag_in_frames >= 32) | 
 |             ? AOMMIN(MAX_GF_INTERVAL, oxcf->gf_cfg.lag_in_frames - | 
 |                                           oxcf->algo_cfg.arnr_max_frames / 2) | 
 |             : MAX_GF_LENGTH_LAP; | 
 |  | 
 |     // Handle forward key frame when enabled. | 
 |     if (oxcf->kf_cfg.fwd_kf_dist > 0) | 
 |       max_gop_length = AOMMIN(rc->frames_to_fwd_kf + 1, max_gop_length); | 
 |  | 
 |     // Use the provided gop size in low delay setting | 
 |     if (oxcf->gf_cfg.lag_in_frames == 0) max_gop_length = rc->max_gf_interval; | 
 |  | 
 |     // Limit the max gop length for the last gop in 1 pass setting. | 
 |     max_gop_length = AOMMIN(max_gop_length, rc->frames_to_key); | 
 |  | 
 |     // 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, MAX_FIRSTPASS_ANALYSIS_FRAMES); | 
 |       rest_frames = | 
 |           AOMMIN(rest_frames, (int)(twopass->stats_buf_ctx->stats_in_end - | 
 |                                     cpi->twopass_frame.stats_in + | 
 |                                     (rc->frames_since_key == 0))); | 
 |       p_rc->frames_till_regions_update = rest_frames; | 
 |  | 
 |       if (cpi->ppi->lap_enabled) { | 
 |         av1_mark_flashes(twopass->stats_buf_ctx->stats_in_start, | 
 |                          twopass->stats_buf_ctx->stats_in_end); | 
 |         av1_estimate_noise(twopass->stats_buf_ctx->stats_in_start, | 
 |                            twopass->stats_buf_ctx->stats_in_end); | 
 |         av1_estimate_coeff(twopass->stats_buf_ctx->stats_in_start, | 
 |                            twopass->stats_buf_ctx->stats_in_end); | 
 |         av1_identify_regions(cpi->twopass_frame.stats_in, rest_frames, | 
 |                              (rc->frames_since_key == 0), p_rc->regions, | 
 |                              &p_rc->num_regions); | 
 |       } else { | 
 |         av1_identify_regions( | 
 |             cpi->twopass_frame.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; | 
 |     } | 
 |  | 
 |     int need_gf_len = 1; | 
 |     if (cpi->third_pass_ctx && oxcf->pass == AOM_RC_THIRD_PASS) { | 
 |       // set up bitstream to read | 
 |       if (!cpi->third_pass_ctx->input_file_name && oxcf->two_pass_output) { | 
 |         cpi->third_pass_ctx->input_file_name = oxcf->two_pass_output; | 
 |       } | 
 |       av1_open_second_pass_log(cpi, 1); | 
 |       THIRD_PASS_GOP_INFO *gop_info = &cpi->third_pass_ctx->gop_info; | 
 |       // Read in GOP information from the second pass file. | 
 |       av1_read_second_pass_gop_info(cpi->second_pass_log_stream, gop_info, | 
 |                                     cpi->common.error); | 
 | #if CONFIG_BITRATE_ACCURACY | 
 |       TPL_INFO *tpl_info; | 
 |       AOM_CHECK_MEM_ERROR(cpi->common.error, tpl_info, | 
 |                           aom_malloc(sizeof(*tpl_info))); | 
 |       av1_read_tpl_info(tpl_info, cpi->second_pass_log_stream, | 
 |                         cpi->common.error); | 
 |       aom_free(tpl_info); | 
 | #if CONFIG_THREE_PASS | 
 |       // TODO(angiebird): Put this part into a func | 
 |       cpi->vbr_rc_info.cur_gop_idx++; | 
 | #endif  // CONFIG_THREE_PASS | 
 | #endif  // CONFIG_BITRATE_ACCURACY | 
 |       // Read in third_pass_info from the bitstream. | 
 |       av1_set_gop_third_pass(cpi->third_pass_ctx); | 
 |       // Read in per-frame info from second-pass encoding | 
 |       av1_read_second_pass_per_frame_info( | 
 |           cpi->second_pass_log_stream, cpi->third_pass_ctx->frame_info, | 
 |           gop_info->num_frames, cpi->common.error); | 
 |  | 
 |       p_rc->cur_gf_index = 0; | 
 |       p_rc->gf_intervals[0] = cpi->third_pass_ctx->gop_info.gf_length; | 
 |       need_gf_len = 0; | 
 |     } | 
 |  | 
 |     if (need_gf_len) { | 
 |       // If we cannot obtain GF group length from second_pass_file | 
 |       // TODO(jingning): Resolve 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 && | 
 |           oxcf->gf_cfg.lag_in_frames >= 32 && | 
 |           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); | 
 |         // TODO(angiebird): Figure out why this_region and next_region are -1 in | 
 |         // unit test like AltRefFramePresenceTestLarge (aomedia:3134) | 
 |         int is_last_scenecut = | 
 |             p_rc->gf_intervals[p_rc->cur_gf_index] >= rc->frames_to_key || | 
 |             (this_region != -1 && | 
 |              p_rc->regions[this_region].type == SCENECUT_REGION) || | 
 |             (next_region != -1 && | 
 |              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 && | 
 |             rc->min_gf_interval <= 16) { | 
 |           // The calculate_gf_length function is previously used with | 
 |           // max_gop_length = 32 with look-ahead gf intervals. | 
 |           define_gf_group(cpi, frame_params, 0); | 
 |           av1_tf_info_filtering(&cpi->ppi->tf_info, cpi, gf_group); | 
 |           this_frame = this_frame_copy; | 
 |  | 
 |           if (is_shorter_gf_interval_better(cpi, frame_params)) { | 
 |             // 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, frame_params, 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, frame_params, 1); | 
 |  | 
 |     // write gop info if needed for third pass. Per-frame info is written after | 
 |     // each frame is encoded. | 
 |     av1_write_second_pass_gop_info(cpi); | 
 |  | 
 |     av1_tf_info_filtering(&cpi->ppi->tf_info, cpi, gf_group); | 
 |  | 
 |     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(&cpi->twopass_frame, start_pos); | 
 |  | 
 |     const FIRSTPASS_STATS *const this_frame_ptr = | 
 |         read_frame_stats(twopass, &cpi->twopass_frame, | 
 |                          gf_group->arf_src_offset[cpi->gf_frame_index]); | 
 |     set_twopass_params_based_on_fp_stats(cpi, this_frame_ptr); | 
 |   } else { | 
 |     // Back up this frame's stats for updating total stats during post encode. | 
 |     cpi->twopass_frame.this_frame = update_total_stats ? start_pos : NULL; | 
 |   } | 
 |  | 
 |   frame_params->frame_type = gf_group->frame_type[cpi->gf_frame_index]; | 
 |   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; | 
 |  | 
 |   av1_mark_flashes(twopass->stats_buf_ctx->stats_in_start, | 
 |                    twopass->stats_buf_ctx->stats_in_end); | 
 |   av1_estimate_noise(twopass->stats_buf_ctx->stats_in_start, | 
 |                      twopass->stats_buf_ctx->stats_in_end); | 
 |   av1_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); | 
 |  | 
 | #if CONFIG_BITRATE_ACCURACY | 
 |   av1_vbr_rc_init(&cpi->vbr_rc_info, twopass->bits_left, | 
 |                   (int)round(stats->count)); | 
 | #endif | 
 |  | 
 | #if CONFIG_RATECTRL_LOG | 
 |   rc_log_init(&cpi->rc_log); | 
 | #endif | 
 |  | 
 |   // 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 = cpi->twopass_frame.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->ppi->p_rc.vbr_bits_off_target = 0; | 
 |   cpi->ppi->p_rc.vbr_bits_off_target_fast = 0; | 
 |  | 
 |   cpi->ppi->p_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->ppi->p_rc.vbr_bits_off_target = 0; | 
 |   cpi->ppi->p_rc.vbr_bits_off_target_fast = 0; | 
 |  | 
 |   cpi->ppi->p_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; | 
 |   PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc; | 
 |   const RateControlCfg *const rc_cfg = &cpi->oxcf.rc_cfg; | 
 |  | 
 |   // Increment the stats_in pointer. | 
 |   if (is_stat_consumption_stage(cpi) && | 
 |       !(cpi->use_ducky_encode && cpi->ducky_encode_info.frame_info.gop_mode == | 
 |                                      DUCKY_ENCODE_GOP_MODE_RCL) && | 
 |       (cpi->gf_frame_index < cpi->ppi->gf_group.size || | 
 |        rc->frames_to_key == 0)) { | 
 |     const int update_type = cpi->ppi->gf_group.update_type[cpi->gf_frame_index]; | 
 |     if (update_type != ARF_UPDATE && update_type != INTNL_ARF_UPDATE) { | 
 |       FIRSTPASS_STATS this_frame; | 
 |       assert(cpi->twopass_frame.stats_in > | 
 |              twopass->stats_buf_ctx->stats_in_start); | 
 |       --cpi->twopass_frame.stats_in; | 
 |       if (cpi->ppi->lap_enabled) { | 
 |         input_stats_lap(twopass, &cpi->twopass_frame, &this_frame); | 
 |       } else { | 
 |         input_stats(twopass, &cpi->twopass_frame, &this_frame); | 
 |       } | 
 |     } else if (cpi->ppi->lap_enabled) { | 
 |       cpi->twopass_frame.stats_in = twopass->stats_buf_ctx->stats_in_start; | 
 |     } | 
 |   } | 
 |  | 
 |   // 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. | 
 |   p_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); | 
 |  | 
 |   if (cpi->do_update_vbr_bits_off_target_fast) { | 
 |     // Subtract current frame's fast_extra_bits. | 
 |     p_rc->vbr_bits_off_target_fast -= rc->frame_level_fast_extra_bits; | 
 |     rc->frame_level_fast_extra_bits = 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 (p_rc->total_actual_bits) { | 
 |     p_rc->rate_error_estimate = | 
 |         (int)((p_rc->vbr_bits_off_target * 100) / p_rc->total_actual_bits); | 
 |     p_rc->rate_error_estimate = clamp(p_rc->rate_error_estimate, -100, 100); | 
 |   } else { | 
 |     p_rc->rate_error_estimate = 0; | 
 |   } | 
 |  | 
 | #if CONFIG_FPMT_TEST | 
 |   /* The variables temp_vbr_bits_off_target, temp_bits_left, | 
 |    * temp_rolling_arf_group_target_bits, temp_rolling_arf_group_actual_bits | 
 |    * temp_rate_error_estimate are introduced for quality simulation purpose, | 
 |    * it retains the value previous to the parallel encode frames. The | 
 |    * variables are updated based on the update flag. | 
 |    * | 
 |    * If there exist show_existing_frames between parallel frames, then to | 
 |    * retain the temp state do not update it. */ | 
 |   const int simulate_parallel_frame = | 
 |       cpi->ppi->fpmt_unit_test_cfg == PARALLEL_SIMULATION_ENCODE; | 
 |   int show_existing_between_parallel_frames = | 
 |       (cpi->ppi->gf_group.update_type[cpi->gf_frame_index] == | 
 |            INTNL_OVERLAY_UPDATE && | 
 |        cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index + 1] == 2); | 
 |  | 
 |   if (cpi->do_frame_data_update && !show_existing_between_parallel_frames && | 
 |       simulate_parallel_frame) { | 
 |     cpi->ppi->p_rc.temp_vbr_bits_off_target = p_rc->vbr_bits_off_target; | 
 |     cpi->ppi->p_rc.temp_bits_left = twopass->bits_left; | 
 |     cpi->ppi->p_rc.temp_rolling_arf_group_target_bits = | 
 |         twopass->rolling_arf_group_target_bits; | 
 |     cpi->ppi->p_rc.temp_rolling_arf_group_actual_bits = | 
 |         twopass->rolling_arf_group_actual_bits; | 
 |     cpi->ppi->p_rc.temp_rate_error_estimate = p_rc->rate_error_estimate; | 
 |   } | 
 | #endif | 
 |   // 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) { | 
 |       p_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)) { | 
 |         p_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, p_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) { | 
 |     int maxq_adj_limit; | 
 |     int minq_adj_limit; | 
 |     maxq_adj_limit = rc->worst_quality - rc->active_worst_quality; | 
 |     minq_adj_limit = | 
 |         (rc_cfg->mode == AOM_CQ ? MINQ_ADJ_LIMIT_CQ : MINQ_ADJ_LIMIT); | 
 |     // Undershoot. | 
 |     if (p_rc->rate_error_estimate > rc_cfg->under_shoot_pct) { | 
 |       --twopass->extend_maxq; | 
 |       if (p_rc->rolling_target_bits >= p_rc->rolling_actual_bits) | 
 |         ++twopass->extend_minq; | 
 |       // Overshoot. | 
 |     } else if (p_rc->rate_error_estimate < -rc_cfg->over_shoot_pct) { | 
 |       --twopass->extend_minq; | 
 |       if (p_rc->rolling_target_bits < p_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 (p_rc->rolling_target_bits < p_rc->rolling_actual_bits) | 
 |         --twopass->extend_minq; | 
 |       else if (p_rc->rolling_target_bits > p_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) { | 
 |         p_rc->vbr_bits_off_target_fast += | 
 |             fast_extra_thresh - rc->projected_frame_size; | 
 |         p_rc->vbr_bits_off_target_fast = AOMMIN(p_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)(p_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 (p_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; | 
 |       } | 
 |     } | 
 |  | 
 | #if CONFIG_FPMT_TEST | 
 |     if (cpi->do_frame_data_update && !show_existing_between_parallel_frames && | 
 |         simulate_parallel_frame) { | 
 |       cpi->ppi->p_rc.temp_vbr_bits_off_target_fast = | 
 |           p_rc->vbr_bits_off_target_fast; | 
 |       cpi->ppi->p_rc.temp_extend_minq = twopass->extend_minq; | 
 |       cpi->ppi->p_rc.temp_extend_maxq = twopass->extend_maxq; | 
 |       cpi->ppi->p_rc.temp_extend_minq_fast = twopass->extend_minq_fast; | 
 |     } | 
 | #endif | 
 |   } | 
 |  | 
 |   // Update the frame probabilities obtained from parallel encode frames | 
 |   FrameProbInfo *const frame_probs = &cpi->ppi->frame_probs; | 
 | #if CONFIG_FPMT_TEST | 
 |   /* The variable temp_active_best_quality is introduced only for quality | 
 |    * simulation purpose, it retains the value previous to the parallel | 
 |    * encode frames. The variable is updated based on the update flag. | 
 |    * | 
 |    * If there exist show_existing_frames between parallel frames, then to | 
 |    * retain the temp state do not update it. */ | 
 |   if (cpi->do_frame_data_update && !show_existing_between_parallel_frames && | 
 |       simulate_parallel_frame) { | 
 |     int i; | 
 |     const int pyramid_level = | 
 |         cpi->ppi->gf_group.layer_depth[cpi->gf_frame_index]; | 
 |     if (!rc->is_src_frame_alt_ref) { | 
 |       for (i = pyramid_level; i <= MAX_ARF_LAYERS; ++i) | 
 |         cpi->ppi->p_rc.temp_active_best_quality[i] = | 
 |             p_rc->active_best_quality[i]; | 
 |     } | 
 |   } | 
 |  | 
 |   // Update the frame probabilities obtained from parallel encode frames | 
 |   FrameProbInfo *const temp_frame_probs_simulation = | 
 |       simulate_parallel_frame ? &cpi->ppi->temp_frame_probs_simulation | 
 |                               : frame_probs; | 
 |   FrameProbInfo *const temp_frame_probs = | 
 |       simulate_parallel_frame ? &cpi->ppi->temp_frame_probs : NULL; | 
 | #endif | 
 |   int i, j, loop; | 
 |   // Sequentially do average on temp_frame_probs_simulation which holds | 
 |   // probabilities of last frame before parallel encode | 
 |   for (loop = 0; loop <= cpi->num_frame_recode; loop++) { | 
 |     // Sequentially update tx_type_probs | 
 |     if (cpi->do_update_frame_probs_txtype[loop] && | 
 |         (cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0)) { | 
 |       const FRAME_UPDATE_TYPE update_type = | 
 |           get_frame_update_type(&cpi->ppi->gf_group, cpi->gf_frame_index); | 
 |       for (i = 0; i < TX_SIZES_ALL; i++) { | 
 |         int left = 1024; | 
 |  | 
 |         for (j = TX_TYPES - 1; j >= 0; j--) { | 
 |           const int new_prob = | 
 |               cpi->frame_new_probs[loop].tx_type_probs[update_type][i][j]; | 
 | #if CONFIG_FPMT_TEST | 
 |           int prob = | 
 |               (temp_frame_probs_simulation->tx_type_probs[update_type][i][j] + | 
 |                new_prob) >> | 
 |               1; | 
 |           left -= prob; | 
 |           if (j == 0) prob += left; | 
 |           temp_frame_probs_simulation->tx_type_probs[update_type][i][j] = prob; | 
 | #else | 
 |           int prob = | 
 |               (frame_probs->tx_type_probs[update_type][i][j] + new_prob) >> 1; | 
 |           left -= prob; | 
 |           if (j == 0) prob += left; | 
 |           frame_probs->tx_type_probs[update_type][i][j] = prob; | 
 | #endif | 
 |         } | 
 |       } | 
 |     } | 
 |  | 
 |     // Sequentially update obmc_probs | 
 |     if (cpi->do_update_frame_probs_obmc[loop] && | 
 |         cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) { | 
 |       const FRAME_UPDATE_TYPE update_type = | 
 |           get_frame_update_type(&cpi->ppi->gf_group, cpi->gf_frame_index); | 
 |  | 
 |       for (i = 0; i < BLOCK_SIZES_ALL; i++) { | 
 |         const int new_prob = | 
 |             cpi->frame_new_probs[loop].obmc_probs[update_type][i]; | 
 | #if CONFIG_FPMT_TEST | 
 |         temp_frame_probs_simulation->obmc_probs[update_type][i] = | 
 |             (temp_frame_probs_simulation->obmc_probs[update_type][i] + | 
 |              new_prob) >> | 
 |             1; | 
 | #else | 
 |         frame_probs->obmc_probs[update_type][i] = | 
 |             (frame_probs->obmc_probs[update_type][i] + new_prob) >> 1; | 
 | #endif | 
 |       } | 
 |     } | 
 |  | 
 |     // Sequentially update warped_probs | 
 |     if (cpi->do_update_frame_probs_warp[loop] && | 
 |         cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) { | 
 |       const FRAME_UPDATE_TYPE update_type = | 
 |           get_frame_update_type(&cpi->ppi->gf_group, cpi->gf_frame_index); | 
 |       const int new_prob = cpi->frame_new_probs[loop].warped_probs[update_type]; | 
 | #if CONFIG_FPMT_TEST | 
 |       temp_frame_probs_simulation->warped_probs[update_type] = | 
 |           (temp_frame_probs_simulation->warped_probs[update_type] + new_prob) >> | 
 |           1; | 
 | #else | 
 |       frame_probs->warped_probs[update_type] = | 
 |           (frame_probs->warped_probs[update_type] + new_prob) >> 1; | 
 | #endif | 
 |     } | 
 |  | 
 |     // Sequentially update switchable_interp_probs | 
 |     if (cpi->do_update_frame_probs_interpfilter[loop] && | 
 |         cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) { | 
 |       const FRAME_UPDATE_TYPE update_type = | 
 |           get_frame_update_type(&cpi->ppi->gf_group, cpi->gf_frame_index); | 
 |  | 
 |       for (i = 0; i < SWITCHABLE_FILTER_CONTEXTS; i++) { | 
 |         int left = 1536; | 
 |  | 
 |         for (j = SWITCHABLE_FILTERS - 1; j >= 0; j--) { | 
 |           const int new_prob = cpi->frame_new_probs[loop] | 
 |                                    .switchable_interp_probs[update_type][i][j]; | 
 | #if CONFIG_FPMT_TEST | 
 |           int prob = (temp_frame_probs_simulation | 
 |                           ->switchable_interp_probs[update_type][i][j] + | 
 |                       new_prob) >> | 
 |                      1; | 
 |           left -= prob; | 
 |           if (j == 0) prob += left; | 
 |  | 
 |           temp_frame_probs_simulation | 
 |               ->switchable_interp_probs[update_type][i][j] = prob; | 
 | #else | 
 |           int prob = (frame_probs->switchable_interp_probs[update_type][i][j] + | 
 |                       new_prob) >> | 
 |                      1; | 
 |           left -= prob; | 
 |           if (j == 0) prob += left; | 
 |           frame_probs->switchable_interp_probs[update_type][i][j] = prob; | 
 | #endif | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 |  | 
 | #if CONFIG_FPMT_TEST | 
 |   // Copying temp_frame_probs_simulation to temp_frame_probs based on | 
 |   // the flag | 
 |   if (cpi->do_frame_data_update && | 
 |       cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0 && | 
 |       simulate_parallel_frame) { | 
 |     for (int update_type_idx = 0; update_type_idx < FRAME_UPDATE_TYPES; | 
 |          update_type_idx++) { | 
 |       for (i = 0; i < BLOCK_SIZES_ALL; i++) { | 
 |         temp_frame_probs->obmc_probs[update_type_idx][i] = | 
 |             temp_frame_probs_simulation->obmc_probs[update_type_idx][i]; | 
 |       } | 
 |       temp_frame_probs->warped_probs[update_type_idx] = | 
 |           temp_frame_probs_simulation->warped_probs[update_type_idx]; | 
 |       for (i = 0; i < TX_SIZES_ALL; i++) { | 
 |         for (j = 0; j < TX_TYPES; j++) { | 
 |           temp_frame_probs->tx_type_probs[update_type_idx][i][j] = | 
 |               temp_frame_probs_simulation->tx_type_probs[update_type_idx][i][j]; | 
 |         } | 
 |       } | 
 |       for (i = 0; i < SWITCHABLE_FILTER_CONTEXTS; i++) { | 
 |         for (j = 0; j < SWITCHABLE_FILTERS; j++) { | 
 |           temp_frame_probs->switchable_interp_probs[update_type_idx][i][j] = | 
 |               temp_frame_probs_simulation | 
 |                   ->switchable_interp_probs[update_type_idx][i][j]; | 
 |         } | 
 |       } | 
 |     } | 
 |   } | 
 | #endif | 
 |   // Update framerate obtained from parallel encode frames | 
 |   if (cpi->common.show_frame && | 
 |       cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) | 
 |     cpi->framerate = cpi->new_framerate; | 
 | #if CONFIG_FPMT_TEST | 
 |   // SIMULATION PURPOSE | 
 |   int show_existing_between_parallel_frames_cndn = | 
 |       (cpi->ppi->gf_group.update_type[cpi->gf_frame_index] == | 
 |            INTNL_OVERLAY_UPDATE && | 
 |        cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index + 1] == 2); | 
 |   if (cpi->common.show_frame && !show_existing_between_parallel_frames_cndn && | 
 |       cpi->do_frame_data_update && simulate_parallel_frame) | 
 |     cpi->temp_framerate = cpi->framerate; | 
 | #endif | 
 | } |