/*

 * Copyright (c) 2016, Alliance for Open Media. All rights reserved

 *

 * This source code is subject to the terms of the BSD 2 Clause License and

 * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License

 * was not distributed with this source code in the LICENSE file, you can

 * obtain it at www.aomedia.org/license/software. If the Alliance for Open

 * Media Patent License 1.0 was not distributed with this source code in the

 * PATENTS file, you can obtain it at www.aomedia.org/license/patent.

 */

#include <assert.h>

#include <limits.h>

#include <math.h>

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

#include "aom_dsp/aom_dsp_common.h"

#include "aom_mem/aom_mem.h"

#include "aom_ports/mem.h"

#include "av1/common/alloccommon.h"

#include "av1/encoder/aq_cyclicrefresh.h"

#include "av1/common/common.h"

#include "av1/common/entropymode.h"

#include "av1/common/quant_common.h"

#include "av1/common/seg_common.h"

#include "av1/encoder/encodemv.h"

#include "av1/encoder/encode_strategy.h"

#include "av1/encoder/gop_structure.h"

#include "av1/encoder/random.h"

#include "av1/encoder/ratectrl.h"

#define USE_UNRESTRICTED_Q_IN_CQ_MODE 0

// Max rate target for 1080P and below encodes under normal circumstances

// (1920 * 1080 / (16 * 16)) * MAX_MB_RATE bits per MB

#define MAX_MB_RATE 250

#define MAXRATE_1080P 2025000

#define MIN_BPB_FACTOR 0.005

#define MAX_BPB_FACTOR 50

#define SUPERRES_QADJ_PER_DENOM_KEYFRAME_SOLO 0

#define SUPERRES_QADJ_PER_DENOM_KEYFRAME 2

#define SUPERRES_QADJ_PER_DENOM_ARFFRAME 0

#define FRAME_OVERHEAD_BITS 200

#define ASSIGN_MINQ_TABLE(bit_depth, name)                   \

  do {                                                       \

    switch (bit_depth) {                                     \

      case AOM_BITS_8: name = name##_8; break;               \

      case AOM_BITS_10: name = name##_10; break;             \

      case AOM_BITS_12: name = name##_12; break;             \

      default:                                               \

        assert(0 &&                                          \

               "bit_depth should be AOM_BITS_8, AOM_BITS_10" \

               " or AOM_BITS_12");                           \

        name = NULL;                                         \

    }                                                        \

  } while (0)

// Tables relating active max Q to active min Q

static int kf_low_motion_minq_8[QINDEX_RANGE];

static int kf_high_motion_minq_8[QINDEX_RANGE];

static int arfgf_low_motion_minq_8[QINDEX_RANGE];

static int arfgf_high_motion_minq_8[QINDEX_RANGE];

static int inter_minq_8[QINDEX_RANGE];

static int rtc_minq_8[QINDEX_RANGE];

static int kf_low_motion_minq_10[QINDEX_RANGE];

static int kf_high_motion_minq_10[QINDEX_RANGE];

static int arfgf_low_motion_minq_10[QINDEX_RANGE];

static int arfgf_high_motion_minq_10[QINDEX_RANGE];

static int inter_minq_10[QINDEX_RANGE];

static int rtc_minq_10[QINDEX_RANGE];

static int kf_low_motion_minq_12[QINDEX_RANGE];

static int kf_high_motion_minq_12[QINDEX_RANGE];

static int arfgf_low_motion_minq_12[QINDEX_RANGE];

static int arfgf_high_motion_minq_12[QINDEX_RANGE];

static int inter_minq_12[QINDEX_RANGE];

static int rtc_minq_12[QINDEX_RANGE];

static int gf_high = 2400;

static int gf_low = 300;

#ifdef STRICT_RC

static int kf_high = 3200;

#else

static int kf_high = 5000;

#endif

static int kf_low = 400;

// How many times less pixels there are to encode given the current scaling.

// Temporary replacement for rcf_mult and rate_thresh_mult.

static double resize_rate_factor(const FrameDimensionCfg *const frm_dim_cfg,

                                 int width, int height) {

  return (double)(frm_dim_cfg->width * frm_dim_cfg->height) / (width * height);

}

// Functions to compute the active minq lookup table entries based on a

// formulaic approach to facilitate easier adjustment of the Q tables.

// The formulae were derived from computing a 3rd order polynomial best

// fit to the original data (after plotting real maxq vs minq (not q index))

static int get_minq_index(double maxq, double x3, double x2, double x1,

                          aom_bit_depth_t bit_depth) {

  const double minqtarget = AOMMIN(((x3 * maxq + x2) * maxq + x1) * maxq, maxq);

  // Special case handling to deal with the step from q2.0

  // down to lossless mode represented by q 1.0.

  if (minqtarget <= 2.0) return 0;

  return av1_find_qindex(minqtarget, bit_depth, 0, QINDEX_RANGE - 1);

}

static void init_minq_luts(int *kf_low_m, int *kf_high_m, int *arfgf_low,

                           int *arfgf_high, int *inter, int *rtc,

                           aom_bit_depth_t bit_depth) {

  int i;

  for (i = 0; i < QINDEX_RANGE; i++) {

    const double maxq = av1_convert_qindex_to_q(i, bit_depth);

    kf_low_m[i] = get_minq_index(maxq, 0.000001, -0.0004, 0.150, bit_depth);

    kf_high_m[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.45, bit_depth);

    arfgf_low[i] = get_minq_index(maxq, 0.0000015, -0.0009, 0.30, bit_depth);

    arfgf_high[i] = get_minq_index(maxq, 0.0000021, -0.00125, 0.55, bit_depth);

    inter[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.90, bit_depth);

    rtc[i] = get_minq_index(maxq, 0.00000271, -0.00113, 0.70, bit_depth);

  }

}

void av1_rc_init_minq_luts(void) {

  init_minq_luts(kf_low_motion_minq_8, kf_high_motion_minq_8,

                 arfgf_low_motion_minq_8, arfgf_high_motion_minq_8,

                 inter_minq_8, rtc_minq_8, AOM_BITS_8);

  init_minq_luts(kf_low_motion_minq_10, kf_high_motion_minq_10,

                 arfgf_low_motion_minq_10, arfgf_high_motion_minq_10,

                 inter_minq_10, rtc_minq_10, AOM_BITS_10);

  init_minq_luts(kf_low_motion_minq_12, kf_high_motion_minq_12,

                 arfgf_low_motion_minq_12, arfgf_high_motion_minq_12,

                 inter_minq_12, rtc_minq_12, AOM_BITS_12);

}

// These functions use formulaic calculations to make playing with the

// quantizer tables easier. If necessary they can be replaced by lookup

// tables if and when things settle down in the experimental bitstream

double av1_convert_qindex_to_q(int qindex, aom_bit_depth_t bit_depth) {

  // Convert the index to a real Q value (scaled down to match old Q values)

  switch (bit_depth) {

    case AOM_BITS_8: return av1_ac_quant_QTX(qindex, 0, bit_depth) / 4.0;

    case AOM_BITS_10: return av1_ac_quant_QTX(qindex, 0, bit_depth) / 16.0;

    case AOM_BITS_12: return av1_ac_quant_QTX(qindex, 0, bit_depth) / 64.0;

    default:

      assert(0 && "bit_depth should be AOM_BITS_8, AOM_BITS_10 or AOM_BITS_12");

      return -1.0;

  }

}

int av1_rc_bits_per_mb(FRAME_TYPE frame_type, int qindex,

                       double correction_factor, aom_bit_depth_t bit_depth,

                       const int is_screen_content_type) {

  const double q = av1_convert_qindex_to_q(qindex, bit_depth);

  int enumerator = frame_type == KEY_FRAME ? 2000000 : 1500000;

  if (is_screen_content_type) {

    enumerator = frame_type == KEY_FRAME ? 1000000 : 750000;

  }

  assert(correction_factor <= MAX_BPB_FACTOR &&

         correction_factor >= MIN_BPB_FACTOR);

  // q based adjustment to baseline enumerator

  return (int)(enumerator * correction_factor / q);

}

int av1_estimate_bits_at_q(FRAME_TYPE frame_type, int q, int mbs,

                           double correction_factor, aom_bit_depth_t bit_depth,

                           const int is_screen_content_type) {

  const int bpm = (int)(av1_rc_bits_per_mb(frame_type, q, correction_factor,

                                           bit_depth, is_screen_content_type));

  return AOMMAX(FRAME_OVERHEAD_BITS,

                (int)((uint64_t)bpm * mbs) >> BPER_MB_NORMBITS);

}

int av1_rc_clamp_pframe_target_size(const AV1_COMP *const cpi, int target,

                                    FRAME_UPDATE_TYPE frame_update_type) {

  const RATE_CONTROL *rc = &cpi->rc;

  const AV1EncoderConfig *oxcf = &cpi->oxcf;

  const int min_frame_target =

      AOMMAX(rc->min_frame_bandwidth, rc->avg_frame_bandwidth >> 5);

  // Clip the frame target to the minimum setup value.

  if (frame_update_type == OVERLAY_UPDATE ||

      frame_update_type == INTNL_OVERLAY_UPDATE) {

    // If there is an active ARF at this location use the minimum

    // bits on this frame even if it is a constructed arf.

    // The active maximum quantizer insures that an appropriate

    // number of bits will be spent if needed for constructed ARFs.

    target = min_frame_target;

  } else if (target < min_frame_target) {

    target = min_frame_target;

  }

  // Clip the frame target to the maximum allowed value.

  if (target > rc->max_frame_bandwidth) target = rc->max_frame_bandwidth;

  if (oxcf->rc_cfg.max_inter_bitrate_pct) {

    const int max_rate =

        rc->avg_frame_bandwidth * oxcf->rc_cfg.max_inter_bitrate_pct / 100;

    target = AOMMIN(target, max_rate);

  }

  return target;

}

int av1_rc_clamp_iframe_target_size(const AV1_COMP *const cpi, int target) {

  const RATE_CONTROL *rc = &cpi->rc;

  const RateControlCfg *const rc_cfg = &cpi->oxcf.rc_cfg;

  if (rc_cfg->max_intra_bitrate_pct) {

    const int max_rate =

        rc->avg_frame_bandwidth * rc_cfg->max_intra_bitrate_pct / 100;

    target = AOMMIN(target, max_rate);

  }

  if (target > rc->max_frame_bandwidth) target = rc->max_frame_bandwidth;

  return target;

}

// Update the buffer level for higher temporal layers, given the encoded current

// temporal layer.

static void update_layer_buffer_level(SVC *svc, int encoded_frame_size) {

  const int current_temporal_layer = svc->temporal_layer_id;

  for (int i = current_temporal_layer + 1; i < svc->number_temporal_layers;

       ++i) {

    const int layer =

        LAYER_IDS_TO_IDX(svc->spatial_layer_id, i, svc->number_temporal_layers);

    LAYER_CONTEXT *lc = &svc->layer_context[layer];

    PRIMARY_RATE_CONTROL *lp_rc = &lc->p_rc;

    lp_rc->bits_off_target +=

        (int)round(lc->target_bandwidth / lc->framerate) - encoded_frame_size;

    // Clip buffer level to maximum buffer size for the layer.

    lp_rc->bits_off_target =

        AOMMIN(lp_rc->bits_off_target, lp_rc->maximum_buffer_size);

    lp_rc->buffer_level = lp_rc->bits_off_target;

  }

}

// Update the buffer level: leaky bucket model.

static void update_buffer_level(AV1_COMP *cpi, int encoded_frame_size) {

  const AV1_COMMON *const cm = &cpi->common;

  RATE_CONTROL *const rc = &cpi->rc;

  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

  // Non-viewable frames are a special case and are treated as pure overhead.

  if (!cm->show_frame)

    p_rc->bits_off_target -= encoded_frame_size;

  else

    p_rc->bits_off_target += rc->avg_frame_bandwidth - encoded_frame_size;

  // Clip the buffer level to the maximum specified buffer size.

  p_rc->bits_off_target =

      AOMMIN(p_rc->bits_off_target, p_rc->maximum_buffer_size);

  p_rc->buffer_level = p_rc->bits_off_target;

  if (cpi->ppi->use_svc)

    update_layer_buffer_level(&cpi->svc, encoded_frame_size);

#if CONFIG_FRAME_PARALLEL_ENCODE && CONFIG_FPMT_TEST

  /* The variable temp_buffer_level is introduced 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. */

  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 &&

      cpi->ppi->fpmt_unit_test_cfg == PARALLEL_SIMULATION_ENCODE) {

    p_rc->temp_buffer_level = p_rc->buffer_level;

  }

#endif

}

int av1_rc_get_default_min_gf_interval(int width, int height,

                                       double framerate) {

  // Assume we do not need any constraint lower than 4K 20 fps

  static const double factor_safe = 3840 * 2160 * 20.0;

  const double factor = width * height * framerate;

  const int default_interval =

      clamp((int)(framerate * 0.125), MIN_GF_INTERVAL, MAX_GF_INTERVAL);

  if (factor <= factor_safe)

    return default_interval;

  else

    return AOMMAX(default_interval,

                  (int)(MIN_GF_INTERVAL * factor / factor_safe + 0.5));

  // Note this logic makes:

  // 4K24: 5

  // 4K30: 6

  // 4K60: 12

}

int av1_rc_get_default_max_gf_interval(double framerate, int min_gf_interval) {

  int interval = AOMMIN(MAX_GF_INTERVAL, (int)(framerate * 0.75));

  interval += (interval & 0x01);  // Round to even value

  interval = AOMMAX(MAX_GF_INTERVAL, interval);

  return AOMMAX(interval, min_gf_interval);

}

void av1_primary_rc_init(const AV1EncoderConfig *oxcf,

                         PRIMARY_RATE_CONTROL *p_rc) {

  const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;

  int worst_allowed_q = rc_cfg->worst_allowed_q;

  int min_gf_interval = oxcf->gf_cfg.min_gf_interval;

  int max_gf_interval = oxcf->gf_cfg.max_gf_interval;

  if (min_gf_interval == 0)

    min_gf_interval = av1_rc_get_default_min_gf_interval(

        oxcf->frm_dim_cfg.width, oxcf->frm_dim_cfg.height,

        oxcf->input_cfg.init_framerate);

  if (max_gf_interval == 0)

    max_gf_interval = av1_rc_get_default_max_gf_interval(

        oxcf->input_cfg.init_framerate, min_gf_interval);

  p_rc->baseline_gf_interval = (min_gf_interval + max_gf_interval) / 2;

  p_rc->this_key_frame_forced = 0;

  p_rc->next_key_frame_forced = 0;

  p_rc->ni_frames = 0;

  p_rc->tot_q = 0.0;

  p_rc->total_actual_bits = 0;

  p_rc->total_target_bits = 0;

  p_rc->buffer_level = p_rc->starting_buffer_level;

  if (oxcf->target_seq_level_idx[0] < SEQ_LEVELS) {

    worst_allowed_q = 255;

  }

  if (oxcf->pass == AOM_RC_ONE_PASS && rc_cfg->mode == AOM_CBR) {

    p_rc->avg_frame_qindex[KEY_FRAME] = worst_allowed_q;

    p_rc->avg_frame_qindex[INTER_FRAME] = worst_allowed_q;

  } else {

    p_rc->avg_frame_qindex[KEY_FRAME] =

        (worst_allowed_q + rc_cfg->best_allowed_q) / 2;

    p_rc->avg_frame_qindex[INTER_FRAME] =

        (worst_allowed_q + rc_cfg->best_allowed_q) / 2;

  }

  p_rc->avg_q = av1_convert_qindex_to_q(rc_cfg->worst_allowed_q,

                                        oxcf->tool_cfg.bit_depth);

  p_rc->last_q[KEY_FRAME] = rc_cfg->best_allowed_q;

  p_rc->last_q[INTER_FRAME] = rc_cfg->worst_allowed_q;

  for (int i = 0; i < RATE_FACTOR_LEVELS; ++i) {

    p_rc->rate_correction_factors[i] = 0.7;

  }

  p_rc->rate_correction_factors[KF_STD] = 1.0;

  p_rc->bits_off_target = p_rc->starting_buffer_level;

  p_rc->rolling_target_bits =

      (int)(oxcf->rc_cfg.target_bandwidth / oxcf->input_cfg.init_framerate);

  p_rc->rolling_actual_bits =

      (int)(oxcf->rc_cfg.target_bandwidth / oxcf->input_cfg.init_framerate);

}

void av1_rc_init(const AV1EncoderConfig *oxcf, RATE_CONTROL *rc) {

  const RateControlCfg *const rc_cfg = &oxcf->rc_cfg;

  rc->frames_since_key = 8;  // Sensible default for first frame.

  rc->frames_till_gf_update_due = 0;

  rc->ni_av_qi = rc_cfg->worst_allowed_q;

  rc->ni_tot_qi = 0;

  rc->min_gf_interval = oxcf->gf_cfg.min_gf_interval;

  rc->max_gf_interval = oxcf->gf_cfg.max_gf_interval;

  if (rc->min_gf_interval == 0)

    rc->min_gf_interval = av1_rc_get_default_min_gf_interval(

        oxcf->frm_dim_cfg.width, oxcf->frm_dim_cfg.height,

        oxcf->input_cfg.init_framerate);

  if (rc->max_gf_interval == 0)

    rc->max_gf_interval = av1_rc_get_default_max_gf_interval(

        oxcf->input_cfg.init_framerate, rc->min_gf_interval);

  rc->avg_frame_low_motion = 0;

  rc->resize_state = ORIG;

  rc->resize_avg_qp = 0;

  rc->resize_buffer_underflow = 0;

  rc->resize_count = 0;

  rc->rtc_external_ratectrl = 0;

#if CONFIG_FRAME_PARALLEL_ENCODE

  rc->frame_level_fast_extra_bits = 0;

#endif

}

int av1_rc_drop_frame(AV1_COMP *cpi) {

  const AV1EncoderConfig *oxcf = &cpi->oxcf;

  RATE_CONTROL *const rc = &cpi->rc;

  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

#if CONFIG_FRAME_PARALLEL_ENCODE && CONFIG_FPMT_TEST

  const int simulate_parallel_frame =

      cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0 &&

      cpi->ppi->fpmt_unit_test_cfg == PARALLEL_SIMULATION_ENCODE;

  int64_t buffer_level =

      simulate_parallel_frame ? p_rc->temp_buffer_level : p_rc->buffer_level;

#else

  int64_t buffer_level = p_rc->buffer_level;

#endif

  if (!oxcf->rc_cfg.drop_frames_water_mark) {

    return 0;

  } else {

    if (buffer_level < 0) {

      // Always drop if buffer is below 0.

      return 1;

    } else {

      // If buffer is below drop_mark, for now just drop every other frame

      // (starting with the next frame) until it increases back over drop_mark.

      int drop_mark = (int)(oxcf->rc_cfg.drop_frames_water_mark *

                            p_rc->optimal_buffer_level / 100);

      if ((buffer_level > drop_mark) && (rc->decimation_factor > 0)) {

        --rc->decimation_factor;

      } else if (buffer_level <= drop_mark && rc->decimation_factor == 0) {

        rc->decimation_factor = 1;

      }

      if (rc->decimation_factor > 0) {

        if (rc->decimation_count > 0) {

          --rc->decimation_count;

          return 1;

        } else {

          rc->decimation_count = rc->decimation_factor;

          return 0;

        }

      } else {

        rc->decimation_count = 0;

        return 0;

      }

    }

  }

}

static int adjust_q_cbr(const AV1_COMP *cpi, int q, int active_worst_quality) {

  const RATE_CONTROL *const rc = &cpi->rc;

  const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

  const AV1_COMMON *const cm = &cpi->common;

  const RefreshFrameInfo *const refresh_frame = &cpi->refresh_frame;

  const int max_delta_down = 16;

  const int max_delta_up = 20;

  const int change_avg_frame_bandwidth =

      abs(rc->avg_frame_bandwidth - rc->prev_avg_frame_bandwidth) >

      0.1 * (rc->avg_frame_bandwidth);

  // If resolution changes or avg_frame_bandwidth significantly changed,

  // then set this flag to indicate change in target bits per macroblock.

  const int change_target_bits_mb =

      cm->prev_frame &&

      (cm->width != cm->prev_frame->width ||

       cm->height != cm->prev_frame->height || change_avg_frame_bandwidth);

  // Apply some control/clamp to QP under certain conditions.

  if (cm->current_frame.frame_type != KEY_FRAME && !cpi->ppi->use_svc &&

      rc->frames_since_key > 1 && !change_target_bits_mb &&

      (!cpi->oxcf.rc_cfg.gf_cbr_boost_pct ||

       !(refresh_frame->alt_ref_frame || refresh_frame->golden_frame))) {

    // Make sure q is between oscillating Qs to prevent resonance.

    if (rc->rc_1_frame * rc->rc_2_frame == -1 &&

        rc->q_1_frame != rc->q_2_frame) {

      int qclamp = clamp(q, AOMMIN(rc->q_1_frame, rc->q_2_frame),

                         AOMMAX(rc->q_1_frame, rc->q_2_frame));

      // If the previous frame had overshoot and the current q needs to

      // increase above the clamped value, reduce the clamp for faster reaction

      // to overshoot.

      if (cpi->rc.rc_1_frame == -1 && q > qclamp && rc->frames_since_key > 10)

        q = (q + qclamp) >> 1;

      else

        q = qclamp;

    }

    // Adjust Q base on source content change from scene detection.

    if (cpi->sf.rt_sf.check_scene_detection && rc->prev_avg_source_sad > 0 &&

        rc->frames_since_key > 10 && !cpi->ppi->use_svc) {

      const int bit_depth = cm->seq_params->bit_depth;

      double delta =

          (double)rc->avg_source_sad / (double)rc->prev_avg_source_sad - 1.0;

      // Push Q downwards if content change is decreasing and buffer level

      // is stable (at least 1/4-optimal level), so not overshooting. Do so

      // only for high Q to avoid excess overshoot.

      // Else reduce decrease in Q from previous frame if content change is

      // increasing and buffer is below max (so not undershooting).

      if (delta < 0.0 &&

          p_rc->buffer_level > (p_rc->optimal_buffer_level >> 2) &&

          q > (rc->worst_quality >> 1)) {

        double q_adj_factor = 1.0 + 0.5 * tanh(4.0 * delta);

        double q_val = av1_convert_qindex_to_q(q, bit_depth);

        q += av1_compute_qdelta(rc, q_val, q_val * q_adj_factor, bit_depth);

      } else if (rc->q_1_frame - q > 0 && delta > 0.1 &&

                 p_rc->buffer_level < AOMMIN(p_rc->maximum_buffer_size,

                                             p_rc->optimal_buffer_level << 1)) {

        q = (3 * q + rc->q_1_frame) >> 2;

      }

    }

    // Limit the decrease in Q from previous frame.

    if (rc->q_1_frame - q > max_delta_down) q = rc->q_1_frame - max_delta_down;

    // Limit the increase in Q from previous frame.

    else if (q - rc->q_1_frame > max_delta_up)

      q = rc->q_1_frame + max_delta_up;

  }

  // For single spatial layer: if resolution has increased push q closer

  // to the active_worst to avoid excess overshoot.

  if (cpi->svc.number_spatial_layers <= 1 && cm->prev_frame &&

      (cm->width * cm->height >

       1.5 * cm->prev_frame->width * cm->prev_frame->height))

    q = (q + active_worst_quality) >> 1;

  return AOMMAX(AOMMIN(q, cpi->rc.worst_quality), cpi->rc.best_quality);

}

static const RATE_FACTOR_LEVEL rate_factor_levels[FRAME_UPDATE_TYPES] = {

  KF_STD,        // KF_UPDATE

  INTER_NORMAL,  // LF_UPDATE

  GF_ARF_STD,    // GF_UPDATE

  GF_ARF_STD,    // ARF_UPDATE

  INTER_NORMAL,  // OVERLAY_UPDATE

  INTER_NORMAL,  // INTNL_OVERLAY_UPDATE

  GF_ARF_LOW,    // INTNL_ARF_UPDATE

};

static RATE_FACTOR_LEVEL get_rate_factor_level(const GF_GROUP *const gf_group,

                                               int gf_frame_index) {

  const FRAME_UPDATE_TYPE update_type = gf_group->update_type[gf_frame_index];

  assert(update_type < FRAME_UPDATE_TYPES);

  return rate_factor_levels[update_type];

}

/*!\brief Gets a rate vs Q correction factor

 *

 * This function returns the current value of a correction factor used to

 * dynamilcally adjust the relationship between Q and the expected number

 * of bits for the frame.

 *

 * \ingroup rate_control

 * \param[in]   cpi                   Top level encoder instance structure

 * \param[in]   width                 Frame width

 * \param[in]   height                Frame height

 *

 * \return Returns a correction factor for the current frame

 */

static double get_rate_correction_factor(const AV1_COMP *cpi, int width,

                                         int height) {

  const RATE_CONTROL *const rc = &cpi->rc;

  const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

  const RefreshFrameInfo *const refresh_frame = &cpi->refresh_frame;

  double rcf;

  double rate_correction_factors_kfstd;

  double rate_correction_factors_gfarfstd;

  double rate_correction_factors_internormal;

#if CONFIG_FRAME_PARALLEL_ENCODE

  rate_correction_factors_kfstd =

      (cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0)

          ? rc->frame_level_rate_correction_factors[KF_STD]

          : p_rc->rate_correction_factors[KF_STD];

  rate_correction_factors_gfarfstd =

      (cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0)

          ? rc->frame_level_rate_correction_factors[GF_ARF_STD]

          : p_rc->rate_correction_factors[GF_ARF_STD];

  rate_correction_factors_internormal =

      (cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0)

          ? rc->frame_level_rate_correction_factors[INTER_NORMAL]

          : p_rc->rate_correction_factors[INTER_NORMAL];

#else

  rate_correction_factors_kfstd = p_rc->rate_correction_factors[KF_STD];

  rate_correction_factors_gfarfstd = p_rc->rate_correction_factors[GF_ARF_STD];

  rate_correction_factors_internormal =

      p_rc->rate_correction_factors[INTER_NORMAL];

#endif

  if (cpi->common.current_frame.frame_type == KEY_FRAME) {

    rcf = rate_correction_factors_kfstd;

  } else if (is_stat_consumption_stage(cpi)) {

    const RATE_FACTOR_LEVEL rf_lvl =

        get_rate_factor_level(&cpi->ppi->gf_group, cpi->gf_frame_index);

    double rate_correction_factors_rflvl;

#if CONFIG_FRAME_PARALLEL_ENCODE

    rate_correction_factors_rflvl =

        (cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0)

            ? rc->frame_level_rate_correction_factors[rf_lvl]

            : p_rc->rate_correction_factors[rf_lvl];

#else

    rate_correction_factors_rflvl = p_rc->rate_correction_factors[rf_lvl];

#endif

    rcf = rate_correction_factors_rflvl;

  } else {

    if ((refresh_frame->alt_ref_frame || refresh_frame->golden_frame) &&

        !rc->is_src_frame_alt_ref && !cpi->ppi->use_svc &&

        (cpi->oxcf.rc_cfg.mode != AOM_CBR ||

         cpi->oxcf.rc_cfg.gf_cbr_boost_pct > 20))

      rcf = rate_correction_factors_gfarfstd;

    else

      rcf = rate_correction_factors_internormal;

  }

  rcf *= resize_rate_factor(&cpi->oxcf.frm_dim_cfg, width, height);

  return fclamp(rcf, MIN_BPB_FACTOR, MAX_BPB_FACTOR);

}

/*!\brief Sets a rate vs Q correction factor

 *

 * This function updates the current value of a correction factor used to

 * dynamilcally adjust the relationship between Q and the expected number

 * of bits for the frame.

 *

 * \ingroup rate_control

 * \param[in]   cpi                   Top level encoder instance structure

 * \param[in]   factor                New correction factor

 * \param[in]   width                 Frame width

 * \param[in]   height                Frame height

 *

 * \return None but updates the rate correction factor for the

 *         current frame type in cpi->rc.

 */

static void set_rate_correction_factor(AV1_COMP *cpi,

#if CONFIG_FRAME_PARALLEL_ENCODE

                                       int is_encode_stage,

#endif  // CONFIG_FRAME_PARALLEL_ENCODE

                                       double factor, int width, int height) {

  RATE_CONTROL *const rc = &cpi->rc;

  PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

  const RefreshFrameInfo *const refresh_frame = &cpi->refresh_frame;

  int update_default_rcf = 1;

  // Normalize RCF to account for the size-dependent scaling factor.

  factor /= resize_rate_factor(&cpi->oxcf.frm_dim_cfg, width, height);

  factor = fclamp(factor, MIN_BPB_FACTOR, MAX_BPB_FACTOR);

  if (cpi->common.current_frame.frame_type == KEY_FRAME) {

    p_rc->rate_correction_factors[KF_STD] = factor;

  } else if (is_stat_consumption_stage(cpi)) {

    const RATE_FACTOR_LEVEL rf_lvl =

        get_rate_factor_level(&cpi->ppi->gf_group, cpi->gf_frame_index);

#if CONFIG_FRAME_PARALLEL_ENCODE

    if (is_encode_stage &&

        cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) {

      rc->frame_level_rate_correction_factors[rf_lvl] = factor;

      update_default_rcf = 0;

    }

#endif

    if (update_default_rcf) p_rc->rate_correction_factors[rf_lvl] = factor;

  } else {

    if ((refresh_frame->alt_ref_frame || refresh_frame->golden_frame) &&

        !rc->is_src_frame_alt_ref && !cpi->ppi->use_svc &&

        (cpi->oxcf.rc_cfg.mode != AOM_CBR ||

         cpi->oxcf.rc_cfg.gf_cbr_boost_pct > 20)) {

      p_rc->rate_correction_factors[GF_ARF_STD] = factor;

    } else {

#if CONFIG_FRAME_PARALLEL_ENCODE

      if (is_encode_stage &&

          cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0) {

        rc->frame_level_rate_correction_factors[INTER_NORMAL] = factor;

        update_default_rcf = 0;

      }

#endif

      if (update_default_rcf)

        p_rc->rate_correction_factors[INTER_NORMAL] = factor;

    }

  }

}

void av1_rc_update_rate_correction_factors(AV1_COMP *cpi,

#if CONFIG_FRAME_PARALLEL_ENCODE

                                           int is_encode_stage,

#endif

                                           int width, int height) {

  const AV1_COMMON *const cm = &cpi->common;

  int correction_factor = 100;

  double rate_correction_factor =

      get_rate_correction_factor(cpi, width, height);

  double adjustment_limit;

  const int MBs = av1_get_MBs(width, height);

  int projected_size_based_on_q = 0;

  // Do not update the rate factors for arf overlay frames.

  if (cpi->rc.is_src_frame_alt_ref) return;

  // Clear down mmx registers to allow floating point in what follows

  // Work out how big we would have expected the frame to be at this Q given

  // the current correction factor.

  // Stay in double to avoid int overflow when values are large

  if (cpi->oxcf.q_cfg.aq_mode == CYCLIC_REFRESH_AQ && cpi->common.seg.enabled) {

    projected_size_based_on_q =

        av1_cyclic_refresh_estimate_bits_at_q(cpi, rate_correction_factor);

  } else {

    projected_size_based_on_q = av1_estimate_bits_at_q(

        cm->current_frame.frame_type, cm->quant_params.base_qindex, MBs,

        rate_correction_factor, cm->seq_params->bit_depth,

        cpi->is_screen_content_type);

  }

  // Work out a size correction factor.

  if (projected_size_based_on_q > FRAME_OVERHEAD_BITS)

    correction_factor = (int)((100 * (int64_t)cpi->rc.projected_frame_size) /

                              projected_size_based_on_q);

  // More heavily damped adjustment used if we have been oscillating either side

  // of target.

  if (correction_factor > 0) {

    adjustment_limit =

        0.25 + 0.5 * AOMMIN(1, fabs(log10(0.01 * correction_factor)));

  } else {

    adjustment_limit = 0.75;

  }

  cpi->rc.q_2_frame = cpi->rc.q_1_frame;

  cpi->rc.q_1_frame = cm->quant_params.base_qindex;

  cpi->rc.rc_2_frame = cpi->rc.rc_1_frame;

  if (correction_factor > 110)

    cpi->rc.rc_1_frame = -1;

  else if (correction_factor < 90)

    cpi->rc.rc_1_frame = 1;

  else

    cpi->rc.rc_1_frame = 0;

  if (correction_factor > 102) {

    // We are not already at the worst allowable quality

    correction_factor =

        (int)(100 + ((correction_factor - 100) * adjustment_limit));

    rate_correction_factor = (rate_correction_factor * correction_factor) / 100;

    // Keep rate_correction_factor within limits

    if (rate_correction_factor > MAX_BPB_FACTOR)

      rate_correction_factor = MAX_BPB_FACTOR;

  } else if (correction_factor < 99) {

    // We are not already at the best allowable quality

    correction_factor =

        (int)(100 - ((100 - correction_factor) * adjustment_limit));

    rate_correction_factor = (rate_correction_factor * correction_factor) / 100;

    // Keep rate_correction_factor within limits

    if (rate_correction_factor < MIN_BPB_FACTOR)

      rate_correction_factor = MIN_BPB_FACTOR;

  }

  set_rate_correction_factor(cpi,

#if CONFIG_FRAME_PARALLEL_ENCODE

                             is_encode_stage,

#endif

                             rate_correction_factor, width, height);

}

// Calculate rate for the given 'q'.

static int get_bits_per_mb(const AV1_COMP *cpi, int use_cyclic_refresh,

                           double correction_factor, int q) {

  const AV1_COMMON *const cm = &cpi->common;

  return use_cyclic_refresh

             ? av1_cyclic_refresh_rc_bits_per_mb(cpi, q, correction_factor)

             : av1_rc_bits_per_mb(cm->current_frame.frame_type, q,

                                  correction_factor, cm->seq_params->bit_depth,

                                  cpi->is_screen_content_type);

}

/*!\brief Searches for a Q index value predicted to give an average macro

 * block rate closest to the target value.

 *

 * Similar to find_qindex_by_rate() function, but returns a q index with a

 * rate just above or below the desired rate, depending on which of the two

 * rates is closer to the desired rate.

 * Also, respects the selected aq_mode when computing the rate.

 *

 * \ingroup rate_control

 * \param[in]   desired_bits_per_mb   Target bits per mb

 * \param[in]   cpi                   Top level encoder instance structure

 * \param[in]   correction_factor     Current Q to rate correction factor

 * \param[in]   best_qindex           Min allowed Q value.

 * \param[in]   worst_qindex          Max allowed Q value.

 *

 * \return Returns a correction factor for the current frame

 */

static int find_closest_qindex_by_rate(int desired_bits_per_mb,

                                       const AV1_COMP *cpi,

                                       double correction_factor,

                                       int best_qindex, int worst_qindex) {

  const int use_cyclic_refresh = cpi->oxcf.q_cfg.aq_mode == CYCLIC_REFRESH_AQ &&

                                 cpi->cyclic_refresh->apply_cyclic_refresh;

  // Find 'qindex' based on 'desired_bits_per_mb'.

  assert(best_qindex <= worst_qindex);

  int low = best_qindex;

  int high = worst_qindex;

  while (low < high) {

    const int mid = (low + high) >> 1;

    const int mid_bits_per_mb =

        get_bits_per_mb(cpi, use_cyclic_refresh, correction_factor, mid);

    if (mid_bits_per_mb > desired_bits_per_mb) {

      low = mid + 1;

    } else {

      high = mid;

    }

  }

  assert(low == high);

  // Calculate rate difference of this q index from the desired rate.

  const int curr_q = low;

  const int curr_bits_per_mb =

      get_bits_per_mb(cpi, use_cyclic_refresh, correction_factor, curr_q);

  const int curr_bit_diff = (curr_bits_per_mb <= desired_bits_per_mb)

                                ? desired_bits_per_mb - curr_bits_per_mb

                                : INT_MAX;

  assert((curr_bit_diff != INT_MAX && curr_bit_diff >= 0) ||

         curr_q == worst_qindex);

  // Calculate rate difference for previous q index too.

  const int prev_q = curr_q - 1;

  int prev_bit_diff;

  if (curr_bit_diff == INT_MAX || curr_q == best_qindex) {

    prev_bit_diff = INT_MAX;

  } else {

    const int prev_bits_per_mb =

        get_bits_per_mb(cpi, use_cyclic_refresh, correction_factor, prev_q);

    assert(prev_bits_per_mb > desired_bits_per_mb);

    prev_bit_diff = prev_bits_per_mb - desired_bits_per_mb;

  }

  // Pick one of the two q indices, depending on which one has rate closer to

  // the desired rate.

  return (curr_bit_diff <= prev_bit_diff) ? curr_q : prev_q;

}

int av1_rc_regulate_q(const AV1_COMP *cpi, int target_bits_per_frame,

                      int active_best_quality, int active_worst_quality,

                      int width, int height) {

  const int MBs = av1_get_MBs(width, height);

  const double correction_factor =

      get_rate_correction_factor(cpi, width, height);

  const int target_bits_per_mb =

      (int)(((uint64_t)target_bits_per_frame << BPER_MB_NORMBITS) / MBs);

  int q =

      find_closest_qindex_by_rate(target_bits_per_mb, cpi, correction_factor,

                                  active_best_quality, active_worst_quality);

  if (cpi->oxcf.rc_cfg.mode == AOM_CBR && has_no_stats_stage(cpi))

    return adjust_q_cbr(cpi, q, active_worst_quality);

  return q;

}

static int get_active_quality(int q, int gfu_boost, int low, int high,

                              int *low_motion_minq, int *high_motion_minq) {

  if (gfu_boost > high) {

    return low_motion_minq[q];

  } else if (gfu_boost < low) {

    return high_motion_minq[q];

  } else {

    const int gap = high - low;

    const int offset = high - gfu_boost;

    const int qdiff = high_motion_minq[q] - low_motion_minq[q];

    const int adjustment = ((offset * qdiff) + (gap >> 1)) / gap;

    return low_motion_minq[q] + adjustment;

  }

}

static int get_kf_active_quality(const PRIMARY_RATE_CONTROL *const p_rc, int q,

                                 aom_bit_depth_t bit_depth) {

  int *kf_low_motion_minq;

  int *kf_high_motion_minq;

  ASSIGN_MINQ_TABLE(bit_depth, kf_low_motion_minq);

  ASSIGN_MINQ_TABLE(bit_depth, kf_high_motion_minq);

  return get_active_quality(q, p_rc->kf_boost, kf_low, kf_high,

                            kf_low_motion_minq, kf_high_motion_minq);

}

static int get_gf_active_quality_no_rc(int gfu_boost, int q,

                                       aom_bit_depth_t bit_depth) {

  int *arfgf_low_motion_minq;

  int *arfgf_high_motion_minq;

  ASSIGN_MINQ_TABLE(bit_depth, arfgf_low_motion_minq);

  ASSIGN_MINQ_TABLE(bit_depth, arfgf_high_motion_minq);

  return get_active_quality(q, gfu_boost, gf_low, gf_high,

                            arfgf_low_motion_minq, arfgf_high_motion_minq);

}

static int get_gf_active_quality(const PRIMARY_RATE_CONTROL *const p_rc, int q,

                                 aom_bit_depth_t bit_depth) {

  return get_gf_active_quality_no_rc(p_rc->gfu_boost, q, bit_depth);

}

static int get_gf_high_motion_quality(int q, aom_bit_depth_t bit_depth) {

  int *arfgf_high_motion_minq;

  ASSIGN_MINQ_TABLE(bit_depth, arfgf_high_motion_minq);

  return arfgf_high_motion_minq[q];

}

static int calc_active_worst_quality_no_stats_vbr(const AV1_COMP *cpi) {

  const RATE_CONTROL *const rc = &cpi->rc;

  const PRIMARY_RATE_CONTROL *const p_rc = &cpi->ppi->p_rc;

  const RefreshFrameInfo *const refresh_frame = &cpi->refresh_frame;

  const unsigned int curr_frame = cpi->common.current_frame.frame_number;

  int active_worst_quality;

  int last_q_key_frame;

  int last_q_inter_frame;

#if CONFIG_FRAME_PARALLEL_ENCODE && CONFIG_FPMT_TEST

  const int simulate_parallel_frame =

      cpi->ppi->gf_group.frame_parallel_level[cpi->gf_frame_index] > 0 &&

      cpi->ppi->fpmt_unit_test_cfg == PARALLEL_SIMULATION_ENCODE;

  last_q_key_frame = simulate_parallel_frame ? p_rc->temp_last_q[KEY_FRAME]

                                             : p_rc->last_q[KEY_FRAME];

  last_q_inter_frame = simulate_parallel_frame ? p_rc->temp_last_q[INTER_FRAME]

                                               : p_rc->last_q[INTER_FRAME];

#else

  last_q_key_frame = p_rc->last_q[KEY_FRAME];

  last_q_inter_frame = p_rc->last_q[INTER_FRAME];

#endif

  if (cpi->common.current_frame.frame_type == KEY_FRAME) {

    active_worst_quality =

        curr_frame == 0 ? rc->worst_quality : last_q_key_frame * 2;

  } else {

    if (!rc->is_src_frame_alt_ref &&

        (refresh_frame->golden_frame || refresh_frame->bwd_ref_frame ||

         refresh_frame->alt_ref_frame)) {

      active_worst_quality =

          curr_frame == 1 ? last_q_key_frame * 5 / 4 : last_q_inter_frame;

    } else {

      active_worst_quality =

          curr_frame == 1 ? last_q_key_frame * 2 : last_q_inter_frame * 2;

    }

  }

  return AOMMIN(active_worst_quality, rc->worst_quality);

}

// Adjust active_worst_quality level based on buffer level.

static int calc_active_worst_quality_no_stats_cbr(const AV1_COMP *cpi) {

  // Adjust active_worst_quality: If buffer is above the optimal/target level,

  // bring active_worst_quality down depending on fullness of buffer.

  // If buffer is below the optimal level, let the active_worst_quality go from

  // ambient Q (at buffer = optimal level) to worst_quality level

  // (at buffer = critical level).

  const AV1_COMMON *const cm = &cpi->common;

  const RATE_CONTROL *rc = &cpi->rc;

  const PRIMARY_RATE_CONTROL *p_rc = &cpi->ppi->p_rc;

  const SVC *const svc = &cpi->svc;

  unsigned int num_frames_weight_key = 5 * cpi->svc.number_temporal_layers;

  // Buffer level below which we push active_worst to worst_quality.

  int64_t critical_level = p_rc->optimal_buffer_level >> 3;

  int64_t buff_lvl_step = 0;

  int adjustment = 0;

  int active_worst_quality;

  int ambient_qp;

  if (cm->current_frame.frame_type == KEY_FRAME) return rc->worst_quality;

  // For ambient_qp we use minimum of avg_frame_qindex[KEY_FRAME/INTER_FRAME]

  // for the first few frames following key frame. These are both initialized

  // to worst_quality and updated with (3/4, 1/4) average in postencode_update.

  // So for first few frames following key, the qp of that key frame is weighted

  // into the active_worst_quality setting. For SVC the key frame should

  // correspond to layer (0, 0), so use that for layer context.

  int avg_qindex_key = p_rc->avg_frame_qindex[KEY_FRAME];

  if (svc->number_temporal_layers > 1) {

    int layer = LAYER_IDS_TO_IDX(0, 0, svc->number_temporal_layers);

    const LAYER_CONTEXT *lc = &svc->layer_context[layer];

    const PRIMARY_RATE_CONTROL *const lp_rc = &lc->p_rc;

    avg_qindex_key = lp_rc->avg_frame_qindex[KEY_FRAME];

    if (svc->temporal_layer_id == 0)

      avg_qindex_key =

          AOMMIN(lp_rc->avg_frame_qindex[KEY_FRAME], lp_rc->last_q[KEY_FRAME]);

  }

  ambient_qp = (cm->current_frame.frame_number < num_frames_weight_key)