/*

 * Copyright (c) 2019, Alliance for Open Media. All rights reserved.

 *

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

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

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

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

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

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

 */

#include <stdint.h>

#include "av1/common/blockd.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"

// This function sets gf_group->frame_parallel_level for LF_UPDATE frames based

// on the value of parallel_frame_count.

static void set_frame_parallel_level(int *frame_parallel_level,

                                     int *parallel_frame_count,

                                     int max_parallel_frames) {

  assert(*parallel_frame_count > 0);

  // parallel_frame_count > 1 indicates subsequent frame(s) in the current

  // parallel encode set.

  *frame_parallel_level = 1 + (*parallel_frame_count > 1);

  // Update the count of no. of parallel frames.

  (*parallel_frame_count)++;

  if (*parallel_frame_count > max_parallel_frames) *parallel_frame_count = 1;

}

// This function sets gf_group->src_offset based on frame_parallel_level.

// Outputs are gf_group->src_offset and first_frame_index

static void set_src_offset(GF_GROUP *const gf_group, int *first_frame_index,

                           int cur_frame_idx, int frame_ind) {

  if (gf_group->frame_parallel_level[frame_ind] > 0) {

    if (gf_group->frame_parallel_level[frame_ind] == 1) {

      *first_frame_index = cur_frame_idx;

    }

    // Obtain the offset of the frame at frame_ind in the lookahead queue by

    // subtracting the display order hints of the current frame from the display

    // order hint of the first frame in parallel encoding set (at

    // first_frame_index).

    gf_group->src_offset[frame_ind] =

        (cur_frame_idx + gf_group->arf_src_offset[frame_ind]) -

        *first_frame_index;

  }

}

// Sets the GF_GROUP params for LF_UPDATE frames.

static inline void set_params_for_leaf_frames(

    const TWO_PASS *twopass, const TWO_PASS_FRAME *twopass_frame,

    const PRIMARY_RATE_CONTROL *p_rc, FRAME_INFO *frame_info,

    GF_GROUP *const gf_group, int *cur_frame_idx, int *frame_ind,

    int *parallel_frame_count, int max_parallel_frames,

    int do_frame_parallel_encode, int *first_frame_index, int *cur_disp_index,

    int layer_depth, int start, int end) {

  gf_group->update_type[*frame_ind] = LF_UPDATE;

  gf_group->arf_src_offset[*frame_ind] = 0;

  gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

  gf_group->layer_depth[*frame_ind] = MAX_ARF_LAYERS;

  gf_group->frame_type[*frame_ind] = INTER_FRAME;

  gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

  gf_group->max_layer_depth = AOMMAX(gf_group->max_layer_depth, layer_depth);

  gf_group->display_idx[*frame_ind] = (*cur_disp_index);

  gf_group->arf_boost[*frame_ind] =

      av1_calc_arf_boost(twopass, twopass_frame, p_rc, frame_info, start,

                         end - start, 0, NULL, NULL, 0);

  ++(*cur_disp_index);

  // Set the level of parallelism for the LF_UPDATE frame.

  if (do_frame_parallel_encode) {

    set_frame_parallel_level(&gf_group->frame_parallel_level[*frame_ind],

                             parallel_frame_count, max_parallel_frames);

    // Set LF_UPDATE frames as non-reference frames.

    gf_group->is_frame_non_ref[*frame_ind] = true;

  }

  set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

  ++(*frame_ind);

  ++(*cur_frame_idx);

}

// Sets the GF_GROUP params for INTNL_OVERLAY_UPDATE frames.

static inline void set_params_for_intnl_overlay_frames(

    GF_GROUP *const gf_group, int *cur_frame_idx, int *frame_ind,

    int *first_frame_index, int *cur_disp_index, int layer_depth) {

  gf_group->update_type[*frame_ind] = INTNL_OVERLAY_UPDATE;

  gf_group->arf_src_offset[*frame_ind] = 0;

  gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

  gf_group->layer_depth[*frame_ind] = layer_depth;

  gf_group->frame_type[*frame_ind] = INTER_FRAME;

  gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

  gf_group->display_idx[*frame_ind] = (*cur_disp_index);

  ++(*cur_disp_index);

  set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

  ++(*frame_ind);

  ++(*cur_frame_idx);

}

// Sets the GF_GROUP params for INTNL_ARF_UPDATE frames.

static inline void set_params_for_internal_arfs(

    const TWO_PASS *twopass, const TWO_PASS_FRAME *twopass_frame,

    const PRIMARY_RATE_CONTROL *p_rc, FRAME_INFO *frame_info,

    GF_GROUP *const gf_group, int *cur_frame_idx, int *frame_ind,

    int *parallel_frame_count, int max_parallel_frames,

    int do_frame_parallel_encode, int *first_frame_index, int depth_thr,

    int *cur_disp_idx, int layer_depth, int arf_src_offset, int offset,

    int f_frames, int b_frames) {

  gf_group->update_type[*frame_ind] = INTNL_ARF_UPDATE;

  gf_group->arf_src_offset[*frame_ind] = arf_src_offset;

  gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

  gf_group->layer_depth[*frame_ind] = layer_depth;

  gf_group->frame_type[*frame_ind] = INTER_FRAME;

  gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

  gf_group->display_idx[*frame_ind] =

      (*cur_disp_idx) + gf_group->arf_src_offset[*frame_ind];

  gf_group->arf_boost[*frame_ind] =

      av1_calc_arf_boost(twopass, twopass_frame, p_rc, frame_info, offset,

                         f_frames, b_frames, NULL, NULL, 0);

  if (do_frame_parallel_encode) {

    if (depth_thr != INT_MAX) {

      assert(depth_thr == 3 || depth_thr == 4);

      assert(IMPLIES(depth_thr == 3, layer_depth == 4));

      assert(IMPLIES(depth_thr == 4, layer_depth == 5));

      // Set frame_parallel_level of the first frame in the given layer to 1.

      if (gf_group->layer_depth[(*frame_ind) - 1] != layer_depth) {

        gf_group->frame_parallel_level[*frame_ind] = 1;

      } else {

        // Set frame_parallel_level of the consecutive frame in the same given

        // layer to 2.

        assert(gf_group->frame_parallel_level[(*frame_ind) - 1] == 1);

        gf_group->frame_parallel_level[*frame_ind] = 2;

        // Store the display order hints of the past 2 INTNL_ARF_UPDATE

        // frames which would not have been displayed at the time of the encode

        // of current frame.

        gf_group->skip_frame_refresh[*frame_ind][0] =

            gf_group->display_idx[(*frame_ind) - 1];

        gf_group->skip_frame_refresh[*frame_ind][1] =

            gf_group->display_idx[(*frame_ind) - 2];

        // Set the display_idx of frame_parallel_level 1 frame in

        // gf_group->skip_frame_as_ref.

        gf_group->skip_frame_as_ref[*frame_ind] =

            gf_group->display_idx[(*frame_ind) - 1];

      }

    }

    // If max_parallel_frames is not exceeded and if the frame will not be

    // temporally filtered, encode the next internal ARF frame in parallel.

    if (*parallel_frame_count > 1 &&

        *parallel_frame_count <= max_parallel_frames) {

      if (gf_group->arf_src_offset[*frame_ind] < TF_LOOKAHEAD_IDX_THR)

        gf_group->frame_parallel_level[*frame_ind] = 2;

      *parallel_frame_count = 1;

    }

  }

  set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

  ++(*frame_ind);

}

// Set parameters for frames between 'start' and 'end' (excluding both).

static void set_multi_layer_params_for_fp(

    const TWO_PASS *twopass, const TWO_PASS_FRAME *twopass_frame,

    GF_GROUP *const gf_group, const PRIMARY_RATE_CONTROL *p_rc,

    RATE_CONTROL *rc, FRAME_INFO *frame_info, int start, int end,

    int *cur_frame_idx, int *frame_ind, int *parallel_frame_count,

    int max_parallel_frames, int do_frame_parallel_encode,

    int *first_frame_index, int depth_thr, int *cur_disp_idx, int layer_depth) {

  const int num_frames_to_process = end - start;

  // Either we are at the last level of the pyramid, or we don't have enough

  // frames between 'l' and 'r' to create one more level.

  if (layer_depth > gf_group->max_layer_depth_allowed ||

      num_frames_to_process < 3) {

    // Leaf nodes.

    while (start < end) {

      set_params_for_leaf_frames(twopass, twopass_frame, p_rc, frame_info,

                                 gf_group, cur_frame_idx, frame_ind,

                                 parallel_frame_count, max_parallel_frames,

                                 do_frame_parallel_encode, first_frame_index,

                                 cur_disp_idx, layer_depth, start, end);

      ++start;

    }

  } else {

    const int m = (start + end - 1) / 2;

    // Internal ARF.

    int arf_src_offset = m - start;

    set_params_for_internal_arfs(

        twopass, twopass_frame, p_rc, frame_info, gf_group, cur_frame_idx,

        frame_ind, parallel_frame_count, max_parallel_frames,

        do_frame_parallel_encode, first_frame_index, INT_MAX, cur_disp_idx,

        layer_depth, arf_src_offset, m, end - m, m - start);

    // If encode reordering is enabled, configure the multi-layers accordingly

    // and return. For e.g., the encode order for gf-interval 16 after

    // reordering would be 0-> 16-> 8-> 4-> 2-> 6-> 1-> 3-> 5-> 7-> 12-> 10->

    // 14-> 9-> 11-> 13-> 15.

    if (layer_depth >= depth_thr) {

      int m1 = (m + start - 1) / 2;

      int m2 = (m + 1 + end) / 2;

      int arf_src_offsets[2] = { m1 - start, m2 - start };

      // Parameters to compute arf_boost.

      int offset[2] = { m1, m2 };

      int f_frames[2] = { m - m1, end - m2 };

      int b_frames[2] = { m1 - start, m2 - (m + 1) };

      // Set GF_GROUP params for INTNL_ARF_UPDATE frames which are reordered.

      for (int i = 0; i < 2; i++) {

        set_params_for_internal_arfs(

            twopass, twopass_frame, p_rc, frame_info, gf_group, cur_frame_idx,

            frame_ind, parallel_frame_count, max_parallel_frames,

            do_frame_parallel_encode, first_frame_index, depth_thr,

            cur_disp_idx, layer_depth + 1, arf_src_offsets[i], offset[i],

            f_frames[i], b_frames[i]);

      }

      // Initialize the start and end indices to configure LF_UPDATE frames.

      int start_idx[4] = { start, m1 + 1, m + 1, end - 1 };

      int end_idx[4] = { m1, m, m2, end };

      int layer_depth_for_intnl_overlay[4] = { layer_depth + 1, layer_depth,

                                               layer_depth + 1, INVALID_IDX };

      // Set GF_GROUP params for the rest of LF_UPDATE and INTNL_OVERLAY_UPDATE

      // frames after reordering.

      for (int i = 0; i < 4; i++) {

        set_multi_layer_params_for_fp(

            twopass, twopass_frame, gf_group, p_rc, rc, frame_info,

            start_idx[i], end_idx[i], cur_frame_idx, frame_ind,

            parallel_frame_count, max_parallel_frames, do_frame_parallel_encode,

            first_frame_index, depth_thr, cur_disp_idx, layer_depth + 2);

        if (layer_depth_for_intnl_overlay[i] != INVALID_IDX)

          set_params_for_intnl_overlay_frames(

              gf_group, cur_frame_idx, frame_ind, first_frame_index,

              cur_disp_idx, layer_depth_for_intnl_overlay[i]);

      }

      return;

    }

    // Frames displayed before this internal ARF.

    set_multi_layer_params_for_fp(

        twopass, twopass_frame, gf_group, p_rc, rc, frame_info, start, m,

        cur_frame_idx, frame_ind, parallel_frame_count, max_parallel_frames,

        do_frame_parallel_encode, first_frame_index, depth_thr, cur_disp_idx,

        layer_depth + 1);

    // Overlay for internal ARF.

    set_params_for_intnl_overlay_frames(gf_group, cur_frame_idx, frame_ind,

                                        first_frame_index, cur_disp_idx,

                                        layer_depth);

    // Frames displayed after this internal ARF.

    set_multi_layer_params_for_fp(

        twopass, twopass_frame, gf_group, p_rc, rc, frame_info, m + 1, end,

        cur_frame_idx, frame_ind, parallel_frame_count, max_parallel_frames,

        do_frame_parallel_encode, first_frame_index, depth_thr, cur_disp_idx,

        layer_depth + 1);

  }

}

// Structure for bookkeeping start, end and display indices to configure

// INTNL_ARF_UPDATE frames.

typedef struct {

  int start;

  int end;

  int display_index;

} FRAME_REORDER_INFO;

// Updates the stats required to configure the GF_GROUP.

static inline void fill_arf_frame_stats(FRAME_REORDER_INFO *arf_frame_stats,

                                        int arf_frame_index, int display_idx,

                                        int start, int end) {

  arf_frame_stats[arf_frame_index].start = start;

  arf_frame_stats[arf_frame_index].end = end;

  arf_frame_stats[arf_frame_index].display_index = display_idx;

}

// Sets GF_GROUP params for INTNL_ARF_UPDATE frames. Also populates

// doh_gf_index_map and arf_frame_stats.

static inline void set_params_for_internal_arfs_in_gf14(

    GF_GROUP *const gf_group, FRAME_REORDER_INFO *arf_frame_stats,

    int *cur_frame_idx, int *cur_disp_idx, int *frame_ind,

    int *count_arf_frames, int *doh_gf_index_map, int start, int end,

    int layer_depth, int layer_with_parallel_encodes) {

  int index = (start + end - 1) / 2;

  gf_group->update_type[*frame_ind] = INTNL_ARF_UPDATE;

  gf_group->arf_src_offset[*frame_ind] = index - 1;

  gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

  gf_group->layer_depth[*frame_ind] = layer_depth;

  gf_group->frame_type[*frame_ind] = INTER_FRAME;

  gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

  gf_group->display_idx[*frame_ind] =

      (*cur_disp_idx) + gf_group->arf_src_offset[*frame_ind];

  // Update the display index of the current frame with its gf index.

  doh_gf_index_map[index] = *frame_ind;

  if (layer_with_parallel_encodes) {

    assert(layer_depth == 4);

    // Set frame_parallel_level of the first frame in the given layer depth

    // to 1.

    if (gf_group->layer_depth[(*frame_ind) - 1] != layer_depth) {

      gf_group->frame_parallel_level[*frame_ind] = 1;

    } else {

      // Set frame_parallel_level of the consecutive frame in the same given

      // layer depth to 2.

      assert(gf_group->frame_parallel_level[(*frame_ind) - 1] == 1);

      gf_group->frame_parallel_level[*frame_ind] = 2;

      // Set the display_idx of frame_parallel_level 1 frame in

      // gf_group->skip_frame_as_ref.

      gf_group->skip_frame_as_ref[*frame_ind] =

          gf_group->display_idx[(*frame_ind) - 1];

    }

  }

  ++(*frame_ind);

  // Update arf_frame_stats.

  fill_arf_frame_stats(arf_frame_stats, *count_arf_frames, index, start, end);

  ++(*count_arf_frames);

}

// Sets GF_GROUP params for all INTNL_ARF_UPDATE frames in the given layer

// dpeth.

static inline void set_params_for_cur_layer_frames(

    GF_GROUP *const gf_group, FRAME_REORDER_INFO *arf_frame_stats,

    int *cur_frame_idx, int *cur_disp_idx, int *frame_ind,

    int *count_arf_frames, int *doh_gf_index_map, int num_dir, int node_start,

    int node_end, int layer_depth) {

  assert(num_dir < 3);

  int start, end;

  // Iterate through the nodes in the previous layer depth.

  for (int i = node_start; i < node_end; i++) {

    // For each node, check if a frame can be coded as INTNL_ARF_UPDATE frame on

    // either direction.

    for (int dir = 0; dir < num_dir; dir++) {

      // Checks for a frame to the left of current node.

      if (dir == 0) {

        start = arf_frame_stats[i].start;

        end = arf_frame_stats[i].display_index;

      } else {

        // Checks for a frame to the right of current node.

        start = arf_frame_stats[i].display_index + 1;

        end = arf_frame_stats[i].end;

      }

      const int num_frames_to_process = end - start;

      // Checks if a frame can be coded as INTNL_ARF_UPDATE frame. If

      // num_frames_to_process is less than 3, then there are not enough frames

      // between 'start' and 'end' to create another level.

      if (num_frames_to_process >= 3) {

        // Flag to indicate the lower layer depths for which parallel encoding

        // is enabled. Currently enabled for layer 4 frames.

        int layer_with_parallel_encodes = layer_depth == 4;

        set_params_for_internal_arfs_in_gf14(

            gf_group, arf_frame_stats, cur_frame_idx, cur_disp_idx, frame_ind,

            count_arf_frames, doh_gf_index_map, start, end, layer_depth,

            layer_with_parallel_encodes);

      }

    }

  }

}

// Configures multi-layers of the GF_GROUP when consecutive encode of frames in

// the same layer depth is enbaled.

static inline void set_multi_layer_params_for_gf14(

    const TWO_PASS *twopass, const TWO_PASS_FRAME *twopass_frame,

    const PRIMARY_RATE_CONTROL *p_rc, FRAME_INFO *frame_info,

    GF_GROUP *const gf_group, FRAME_REORDER_INFO *arf_frame_stats,

    int *cur_frame_idx, int *frame_ind, int *count_arf_frames,

    int *doh_gf_index_map, int *parallel_frame_count, int *first_frame_index,

    int *cur_disp_index, int gf_interval, int layer_depth,

    int max_parallel_frames) {

  assert(layer_depth == 2);

  assert(gf_group->max_layer_depth_allowed >= 4);

  int layer, node_start, node_end = 0;

  // Maximum layer depth excluding LF_UPDATE frames is 4 since applicable only

  // for gf-interval 14.

  const int max_layer_depth = 4;

  // Iterate through each layer depth starting from 2 till 'max_layer_depth'.

  for (layer = layer_depth; layer <= max_layer_depth; layer++) {

    // 'node_start' and 'node_end' indicate the number of nodes from the

    // previous layer depth to be considered. It also corresponds to the indices

    // of arf_frame_stats.

    node_start = node_end;

    node_end = (*count_arf_frames);

    // 'num_dir' indicates the number of directions to traverse w.r.t. a given

    // node in order to choose an INTNL_ARF_UPDATE frame. Layer depth 2 would

    // have only one frame and hence needs to traverse only in the left

    // direction w.r.t the node in the previous layer.

    int num_dir = layer == 2 ? 1 : 2;

    set_params_for_cur_layer_frames(gf_group, arf_frame_stats, cur_frame_idx,

                                    cur_disp_index, frame_ind, count_arf_frames,

                                    doh_gf_index_map, num_dir, node_start,

                                    node_end, layer);

  }

  for (int i = 1; i < gf_interval; i++) {

    // Since doh_gf_index_map is already populated for all INTNL_ARF_UPDATE

    // frames in the GF_GROUP, any frame with INVALID_IDX would correspond to an

    // LF_UPDATE frame.

    if (doh_gf_index_map[i] == INVALID_IDX) {

      // LF_UPDATE frames.

      // TODO(Remya): Correct start and end parameters passed to

      // set_params_for_leaf_frames() once encode reordering for gf-interval 14

      // is enbaled for parallel encode of lower layer frames.

      set_params_for_leaf_frames(

          twopass, twopass_frame, p_rc, frame_info, gf_group, cur_frame_idx,

          frame_ind, parallel_frame_count, max_parallel_frames, 1,

          first_frame_index, cur_disp_index, layer, 0, 0);

    } else {

      // In order to obtain the layer depths of INTNL_OVERLAY_UPDATE frames, get

      // the gf index of corresponding INTNL_ARF_UPDATE frames.

      int intnl_arf_index = doh_gf_index_map[i];

      int ld = gf_group->layer_depth[intnl_arf_index];

      set_params_for_intnl_overlay_frames(gf_group, cur_frame_idx, frame_ind,

                                          first_frame_index, cur_disp_index,

                                          ld);

    }

  }

}

// Set parameters for frames between 'start' and 'end' (excluding both).

static void set_multi_layer_params(

    const TWO_PASS *twopass, const TWO_PASS_FRAME *twopass_frame,

    GF_GROUP *const gf_group, const PRIMARY_RATE_CONTROL *p_rc,

    RATE_CONTROL *rc, FRAME_INFO *frame_info, int start, int end,

    int *cur_frame_idx, int *frame_ind, int *parallel_frame_count,

    int max_parallel_frames, int do_frame_parallel_encode,

    int *first_frame_index, int *cur_disp_idx, int layer_depth) {

  const int num_frames_to_process = end - start;

  // Either we are at the last level of the pyramid, or we don't have enough

  // frames between 'l' and 'r' to create one more level.

  if (layer_depth > gf_group->max_layer_depth_allowed ||

      num_frames_to_process < 3) {

    // Leaf nodes.

    while (start < end) {

      gf_group->update_type[*frame_ind] = LF_UPDATE;

      gf_group->arf_src_offset[*frame_ind] = 0;

      gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

      gf_group->display_idx[*frame_ind] = *cur_disp_idx;

      gf_group->layer_depth[*frame_ind] = MAX_ARF_LAYERS;

      gf_group->arf_boost[*frame_ind] =

          av1_calc_arf_boost(twopass, twopass_frame, p_rc, frame_info, start,

                             end - start, 0, NULL, NULL, 0);

      gf_group->frame_type[*frame_ind] = INTER_FRAME;

      gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

      gf_group->max_layer_depth =

          AOMMAX(gf_group->max_layer_depth, layer_depth);

      // Set the level of parallelism for the LF_UPDATE frame.

      if (do_frame_parallel_encode) {

        set_frame_parallel_level(&gf_group->frame_parallel_level[*frame_ind],

                                 parallel_frame_count, max_parallel_frames);

        // Set LF_UPDATE frames as non-reference frames.

        gf_group->is_frame_non_ref[*frame_ind] = true;

      }

      set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

      ++(*frame_ind);

      ++(*cur_frame_idx);

      ++(*cur_disp_idx);

      ++start;

    }

  } else {

    const int m = (start + end - 1) / 2;

    // Internal ARF.

    gf_group->update_type[*frame_ind] = INTNL_ARF_UPDATE;

    gf_group->arf_src_offset[*frame_ind] = m - start;

    gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

    gf_group->display_idx[*frame_ind] =

        *cur_disp_idx + gf_group->arf_src_offset[*frame_ind];

    gf_group->layer_depth[*frame_ind] = layer_depth;

    gf_group->frame_type[*frame_ind] = INTER_FRAME;

    gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

    if (do_frame_parallel_encode) {

      // If max_parallel_frames is not exceeded and if the frame will not be

      // temporally filtered, encode the next internal ARF frame in parallel.

      if (*parallel_frame_count > 1 &&

          *parallel_frame_count <= max_parallel_frames) {

        if (gf_group->arf_src_offset[*frame_ind] < TF_LOOKAHEAD_IDX_THR)

          gf_group->frame_parallel_level[*frame_ind] = 2;

        *parallel_frame_count = 1;

      }

    }

    set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

    // Get the boost factor for intermediate ARF frames.

    gf_group->arf_boost[*frame_ind] =

        av1_calc_arf_boost(twopass, twopass_frame, p_rc, frame_info, m, end - m,

                           m - start, NULL, NULL, 0);

    ++(*frame_ind);

    // Frames displayed before this internal ARF.

    set_multi_layer_params(twopass, twopass_frame, gf_group, p_rc, rc,

                           frame_info, start, m, cur_frame_idx, frame_ind,

                           parallel_frame_count, max_parallel_frames,

                           do_frame_parallel_encode, first_frame_index,

                           cur_disp_idx, layer_depth + 1);

    // Overlay for internal ARF.

    gf_group->update_type[*frame_ind] = INTNL_OVERLAY_UPDATE;

    gf_group->arf_src_offset[*frame_ind] = 0;

    gf_group->cur_frame_idx[*frame_ind] = *cur_frame_idx;

    gf_group->display_idx[*frame_ind] = *cur_disp_idx;

    gf_group->arf_boost[*frame_ind] = 0;

    gf_group->layer_depth[*frame_ind] = layer_depth;

    gf_group->frame_type[*frame_ind] = INTER_FRAME;

    gf_group->refbuf_state[*frame_ind] = REFBUF_UPDATE;

    set_src_offset(gf_group, first_frame_index, *cur_frame_idx, *frame_ind);

    ++(*frame_ind);

    ++(*cur_frame_idx);

    ++(*cur_disp_idx);

    // Frames displayed after this internal ARF.

    set_multi_layer_params(twopass, twopass_frame, gf_group, p_rc, rc,

                           frame_info, m + 1, end, cur_frame_idx, frame_ind,

                           parallel_frame_count, max_parallel_frames,

                           do_frame_parallel_encode, first_frame_index,

                           cur_disp_idx, layer_depth + 1);

  }

}

static int construct_multi_layer_gf_structure(

    AV1_COMP *cpi, TWO_PASS *twopass, GF_GROUP *const gf_group,

    RATE_CONTROL *rc, FRAME_INFO *const frame_info, int baseline_gf_interval,

    FRAME_UPDATE_TYPE first_frame_update_type) {

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

  // TODO(angiebird): Why do we need "-1" here?

  const int gf_interval = baseline_gf_interval - 1;

  int frame_index = 0;

  int cur_frame_index = 0;

  // Set the display order hint for the first frame in the GF_GROUP.

  int cur_disp_index = (first_frame_update_type == KF_UPDATE)

                           ? 0

                           : cpi->common.current_frame.frame_number;

  // Initialize gf_group->frame_parallel_level, gf_group->is_frame_non_ref,

  // gf_group->src_offset and gf_group->is_frame_dropped with 0.

  memset(gf_group->frame_parallel_level, 0,

         sizeof(gf_group->frame_parallel_level));

  memset(gf_group->is_frame_non_ref, 0, sizeof(gf_group->is_frame_non_ref));

  memset(gf_group->src_offset, 0, sizeof(gf_group->src_offset));

  memset(gf_group->is_frame_dropped, 0, sizeof(gf_group->is_frame_dropped));

  // Initialize gf_group->skip_frame_refresh and gf_group->skip_frame_as_ref

  // with INVALID_IDX.

  memset(gf_group->skip_frame_refresh, INVALID_IDX,

         sizeof(gf_group->skip_frame_refresh));

  memset(gf_group->skip_frame_as_ref, INVALID_IDX,

         sizeof(gf_group->skip_frame_as_ref));

  int kf_decomp = cpi->oxcf.kf_cfg.enable_keyframe_filtering > 1;

  // This is a patch that fixes https://crbug.com/aomedia/3163

  // enable_keyframe_filtering > 1 will introduce an extra overlay frame at

  // key frame location. However when

  // baseline_gf_interval == MAX_STATIC_GF_GROUP_LENGTH, we can't

  // afford to have an extra overlay frame. Otherwise, the gf_group->size will

  // become MAX_STATIC_GF_GROUP_LENGTH + 1, which causes memory error.

  // A cheap solution is to turn of kf_decomp here.

  // TODO(angiebird): Find a systematic way to solve this issue.

  if (baseline_gf_interval == MAX_STATIC_GF_GROUP_LENGTH) {

    kf_decomp = 0;

  }

  if (first_frame_update_type == KF_UPDATE) {

    gf_group->update_type[frame_index] = kf_decomp ? ARF_UPDATE : KF_UPDATE;

    gf_group->arf_src_offset[frame_index] = 0;

    gf_group->cur_frame_idx[frame_index] = cur_frame_index;

    gf_group->layer_depth[frame_index] = 0;

    gf_group->frame_type[frame_index] = KEY_FRAME;

    gf_group->refbuf_state[frame_index] = REFBUF_RESET;

    gf_group->max_layer_depth = 0;

    gf_group->display_idx[frame_index] = cur_disp_index;

    if (!kf_decomp) cur_disp_index++;

    ++frame_index;

    if (kf_decomp) {

      gf_group->update_type[frame_index] = OVERLAY_UPDATE;

      gf_group->arf_src_offset[frame_index] = 0;

      gf_group->cur_frame_idx[frame_index] = cur_frame_index;

      gf_group->layer_depth[frame_index] = 0;

      gf_group->frame_type[frame_index] = INTER_FRAME;

      gf_group->refbuf_state[frame_index] = REFBUF_UPDATE;

      gf_group->max_layer_depth = 0;

      gf_group->display_idx[frame_index] = cur_disp_index;

      cur_disp_index++;

      ++frame_index;

    }

    cur_frame_index++;

  }

  if (first_frame_update_type == GF_UPDATE) {

    gf_group->update_type[frame_index] = GF_UPDATE;

    gf_group->arf_src_offset[frame_index] = 0;

    gf_group->cur_frame_idx[frame_index] = cur_frame_index;

    gf_group->layer_depth[frame_index] = 0;

    gf_group->frame_type[frame_index] = INTER_FRAME;

    gf_group->refbuf_state[frame_index] = REFBUF_UPDATE;

    gf_group->max_layer_depth = 0;

    gf_group->display_idx[frame_index] = cur_disp_index;

    cur_disp_index++;

    ++frame_index;

    ++cur_frame_index;

  }

  // ALTREF.

  const int use_altref = gf_group->max_layer_depth_allowed > 0;

  int is_fwd_kf = rc->frames_to_fwd_kf == gf_interval;

  if (use_altref) {

    gf_group->update_type[frame_index] = ARF_UPDATE;

    gf_group->arf_src_offset[frame_index] = gf_interval - cur_frame_index;

    gf_group->cur_frame_idx[frame_index] = cur_frame_index;

    gf_group->layer_depth[frame_index] = 1;

    gf_group->arf_boost[frame_index] = cpi->ppi->p_rc.gfu_boost;

    gf_group->frame_type[frame_index] = is_fwd_kf ? KEY_FRAME : INTER_FRAME;

    gf_group->refbuf_state[frame_index] = REFBUF_UPDATE;

    gf_group->max_layer_depth = 1;

    gf_group->arf_index = frame_index;

    gf_group->display_idx[frame_index] =

        cur_disp_index + gf_group->arf_src_offset[frame_index];

    ++frame_index;

  } else {

    gf_group->arf_index = -1;

  }

  // Flag to indicate if multi-layer configuration is complete.

  int is_multi_layer_configured = 0;

  // Running count of no. of frames that is part of a given parallel

  // encode set in a gf_group. Value of 1 indicates no parallel encode.

  int parallel_frame_count = 1;

  // Enable parallel encode of frames if gf_group has a multi-layer pyramid

  // structure with minimum 4 layers.

  int do_frame_parallel_encode = (cpi->ppi->num_fp_contexts > 1 && use_altref &&

                                  gf_group->max_layer_depth_allowed >= 4);

  int first_frame_index = cur_frame_index;

  if (do_frame_parallel_encode) {

    // construct_multi_layer_gf_structure() takes the input parameter

    // 'gf_interval' as p_rc->baseline_gf_interval - 1 . Below code computes the

    // actual GF_GROUP length by compensating for this offset.

    int actual_gf_length = ((first_frame_update_type == KF_UPDATE) ||

                            (first_frame_update_type == GF_UPDATE))

                               ? gf_interval

                               : gf_interval + 1;

    // In order to facilitate parallel encoding of frames in lower layer depths,

    // encode reordering is done. Currently encode reordering is enabled only

    // for gf-intervals 16 and 32. NOTE: Since the buffer holding the

    // reference frames is of size 8 (ref_frame_map[REF_FRAMES]), there is a

    // limitation on the number of hidden frames possible at any given point and

    // hence the reordering is enabled only for gf-intervals 16 and 32.

    // Disabling encode reordering for gf-interval 14 since some cross-frame

    // dependencies related to temporal filtering for FPMT is currently not

    // handled.

    int disable_gf14_reorder = 1;

    if (actual_gf_length == 14 && !disable_gf14_reorder) {

      // This array holds the gf index of INTNL_ARF_UPDATE frames in the slot

      // corresponding to their display order hint. This is used while

      // configuring the LF_UPDATE frames and INTNL_OVERLAY_UPDATE frames.

      int doh_gf_index_map[FIXED_GF_INTERVAL];

      // Initialize doh_gf_index_map with INVALID_IDX.

      memset(&doh_gf_index_map[0], INVALID_IDX,

             (sizeof(doh_gf_index_map[0]) * FIXED_GF_INTERVAL));

      FRAME_REORDER_INFO arf_frame_stats[REF_FRAMES - 1];

      // Store the stats corresponding to layer 1 frame.

      fill_arf_frame_stats(arf_frame_stats, 0, actual_gf_length, 1,

                           actual_gf_length);

      int count_arf_frames = 1;

      // Sets multi-layer params for gf-interval 14 to consecutively encode

      // frames in the same layer depth, i.e., encode order would be 0-> 14->

      // 7-> 3-> 10-> 5-> 12-> 1-> 2-> 4-> 6-> 8-> 9-> 11-> 13.

      // TODO(Remya): Set GF_GROUP param 'arf_boost' for all frames.

      set_multi_layer_params_for_gf14(

          twopass, &cpi->twopass_frame, p_rc, frame_info, gf_group,

          arf_frame_stats, &cur_frame_index, &frame_index, &count_arf_frames,

          doh_gf_index_map, &parallel_frame_count, &first_frame_index,

          &cur_disp_index, actual_gf_length, use_altref + 1,

          cpi->ppi->num_fp_contexts);

      // Set gf_group->skip_frame_refresh.

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

        int count = 0;

        if (gf_group->update_type[i] == INTNL_ARF_UPDATE) {

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

            // Store the display order hint of the frames which would not

            // have been displayed at the encode call of frame 'i'.

            if ((gf_group->display_idx[j] < gf_group->display_idx[i]) &&

                gf_group->update_type[j] == INTNL_ARF_UPDATE) {

              gf_group->skip_frame_refresh[i][count++] =

                  gf_group->display_idx[j];

            }

          }

        }

      }

    } else {

      // Set layer depth threshold for reordering as per the gf length.

      int depth_thr = (actual_gf_length == 16)   ? 3

                      : (actual_gf_length == 32) ? 4

                                                 : INT_MAX;

      set_multi_layer_params_for_fp(

          twopass, &cpi->twopass_frame, gf_group, p_rc, rc, frame_info,

          cur_frame_index, gf_interval, &cur_frame_index, &frame_index,

          &parallel_frame_count, cpi->ppi->num_fp_contexts,

          do_frame_parallel_encode, &first_frame_index, depth_thr,

          &cur_disp_index, use_altref + 1);

    }

    is_multi_layer_configured = 1;

  }

  // Rest of the frames.

  if (!is_multi_layer_configured)

    set_multi_layer_params(twopass, &cpi->twopass_frame, gf_group, p_rc, rc,

                           frame_info, cur_frame_index, gf_interval,

                           &cur_frame_index, &frame_index,

                           &parallel_frame_count, cpi->ppi->num_fp_contexts,

                           do_frame_parallel_encode, &first_frame_index,

                           &cur_disp_index, use_altref + 1);

  if (use_altref) {

    gf_group->update_type[frame_index] = OVERLAY_UPDATE;

    gf_group->arf_src_offset[frame_index] = 0;

    gf_group->cur_frame_idx[frame_index] = cur_frame_index;

    gf_group->layer_depth[frame_index] = MAX_ARF_LAYERS;

    gf_group->arf_boost[frame_index] = NORMAL_BOOST;

    gf_group->frame_type[frame_index] = INTER_FRAME;

    gf_group->refbuf_state[frame_index] =

        is_fwd_kf ? REFBUF_RESET : REFBUF_UPDATE;

    gf_group->display_idx[frame_index] = cur_disp_index;

    ++frame_index;

  } else {

    for (; cur_frame_index <= gf_interval; ++cur_frame_index) {

      gf_group->update_type[frame_index] = LF_UPDATE;

      gf_group->arf_src_offset[frame_index] = 0;

      gf_group->cur_frame_idx[frame_index] = cur_frame_index;

      gf_group->layer_depth[frame_index] = MAX_ARF_LAYERS;

      gf_group->arf_boost[frame_index] = NORMAL_BOOST;

      gf_group->frame_type[frame_index] = INTER_FRAME;

      gf_group->refbuf_state[frame_index] = REFBUF_UPDATE;

      gf_group->max_layer_depth = AOMMAX(gf_group->max_layer_depth, 2);

      set_src_offset(gf_group, &first_frame_index, cur_frame_index,

                     frame_index);

      gf_group->display_idx[frame_index] = cur_disp_index;

      cur_disp_index++;

      ++frame_index;

    }

  }

  if (do_frame_parallel_encode) {

    // Iterate through the gf_group and reset frame_parallel_level to 0 in case

    // a frame is marked as frame_parallel_level 1 with no subsequent

    // frame_parallel_level 2 frame(s).

    int level1_frame_idx = INT_MAX;

    int level2_frame_count = 0;

    for (int frame_idx = 0; frame_idx < frame_index; frame_idx++) {

      if (gf_group->frame_parallel_level[frame_idx] == 1) {

        // Set frame_parallel_level to 0 if only one frame is present in a

        // parallel encode set.

        if (level1_frame_idx != INT_MAX && !level2_frame_count)

          gf_group->frame_parallel_level[level1_frame_idx] = 0;

        // Book-keep frame_idx of frame_parallel_level 1 frame and reset the

        // count of frame_parallel_level 2 frames in the corresponding parallel

        // encode set.

        level1_frame_idx = frame_idx;

        level2_frame_count = 0;

      }

      if (gf_group->frame_parallel_level[frame_idx] == 2) level2_frame_count++;

    }

    // If frame_parallel_level is set to 1 for the last LF_UPDATE

    // frame in the gf_group, reset it to zero since there are no subsequent

    // frames in the gf_group.

    if (gf_group->frame_parallel_level[frame_index - 2] == 1) {

      assert(gf_group->update_type[frame_index - 2] == LF_UPDATE);

      gf_group->frame_parallel_level[frame_index - 2] = 0;

    }

  }

  for (int gf_idx = frame_index; gf_idx < MAX_STATIC_GF_GROUP_LENGTH;

       ++gf_idx) {

    gf_group->update_type[gf_idx] = LF_UPDATE;

    gf_group->arf_src_offset[gf_idx] = 0;

    gf_group->cur_frame_idx[gf_idx] = gf_idx;

    gf_group->layer_depth[gf_idx] = MAX_ARF_LAYERS;

    gf_group->arf_boost[gf_idx] = NORMAL_BOOST;

    gf_group->frame_type[gf_idx] = INTER_FRAME;

    gf_group->refbuf_state[gf_idx] = REFBUF_UPDATE;

    gf_group->max_layer_depth = AOMMAX(gf_group->max_layer_depth, 2);

  }

  return frame_index;

}

static void set_ld_layer_depth(GF_GROUP *gf_group, int gop_length) {

  int log_gop_length = 0;

  while ((1 << log_gop_length) < gop_length) {

    ++log_gop_length;

  }

  for (int gf_index = 0; gf_index < gf_group->size; ++gf_index) {

    int count = 0;

    // Find the trailing zeros

    for (; count < MAX_ARF_LAYERS; ++count) {

      if ((gf_index >> count) & 0x01) break;

    }

    gf_group->layer_depth[gf_index] = AOMMAX(log_gop_length - count, 0);

  }

  gf_group->max_layer_depth = AOMMIN(log_gop_length, MAX_ARF_LAYERS);

}

void av1_gop_setup_structure(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;

  TWO_PASS *const twopass = &cpi->ppi->twopass;

  FRAME_INFO *const frame_info = &cpi->frame_info;

  const int key_frame = rc->frames_since_key == 0;

  FRAME_UPDATE_TYPE first_frame_update_type = ARF_UPDATE;

  if (key_frame) {

    first_frame_update_type = KF_UPDATE;

    if (cpi->oxcf.kf_max_pyr_height != -1) {

      gf_group->max_layer_depth_allowed = AOMMIN(

          cpi->oxcf.kf_max_pyr_height, gf_group->max_layer_depth_allowed);

    }

  } else if (!cpi->ppi->gf_state.arf_gf_boost_lst) {

    first_frame_update_type = GF_UPDATE;

  }

  gf_group->size = construct_multi_layer_gf_structure(

      cpi, twopass, gf_group, rc, frame_info, p_rc->baseline_gf_interval,

      first_frame_update_type);

  if (gf_group->max_layer_depth_allowed == 0)

    set_ld_layer_depth(gf_group, p_rc->baseline_gf_interval);

}

int av1_gop_check_forward_keyframe(const GF_GROUP *gf_group,

                                   int gf_frame_index) {

  return gf_group->frame_type[gf_frame_index] == KEY_FRAME &&

         gf_group->refbuf_state[gf_frame_index] == REFBUF_UPDATE;

}

int av1_gop_is_second_arf(const GF_GROUP *gf_group, int gf_frame_index) {

  const int arf_src_offset = gf_group->arf_src_offset[gf_frame_index];

  // TODO(angiebird): when gf_group->size == 32, it's possble to

  // have "two" second arf. Check if this is acceptable.

  if (gf_group->update_type[gf_frame_index] == INTNL_ARF_UPDATE &&

      arf_src_offset >= TF_LOOKAHEAD_IDX_THR) {

    return 1;

  }

  return 0;

}