/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

static int FUNC(frame_sync_code)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  int err;

  fixed(8, frame_sync_byte_0, VP9_FRAME_SYNC_0);
  fixed(8, frame_sync_byte_1, VP9_FRAME_SYNC_1);
  fixed(8, frame_sync_byte_2, VP9_FRAME_SYNC_2);

  return 0;
}

static int FUNC(color_config)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current, int profile) {
  CodedBitstreamVP9Context *vp9 = ctx->priv_data;
  int err;

  if(profile >= 2) {
    f(1, ten_or_twelve_bit);
    vp9->bit_depth = current->ten_or_twelve_bit ? 12 : 10;
  }
  else
    vp9->bit_depth = 8;

  f(3, color_space);

  if(current->color_space != VP9_CS_RGB) {
    f(1, color_range);
    if(profile == 1 || profile == 3) {
      f(1, subsampling_x);
      f(1, subsampling_y);
      fixed(1, reserved_zero, 0);
    }
    else {
      infer(subsampling_x, 1);
      infer(subsampling_y, 1);
    }
  }
  else {
    infer(color_range, 1);
    if(profile == 1 || profile == 3) {
      infer(subsampling_x, 0);
      infer(subsampling_y, 0);
      fixed(1, reserved_zero, 0);
    }
  }

  vp9->subsampling_x = current->subsampling_x;
  vp9->subsampling_y = current->subsampling_y;

  return 0;
}

static int FUNC(frame_size)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  CodedBitstreamVP9Context *vp9 = ctx->priv_data;
  int err;

  f(16, frame_width_minus_1);
  f(16, frame_height_minus_1);

  vp9->frame_width  = current->frame_width_minus_1 + 1;
  vp9->frame_height = current->frame_height_minus_1 + 1;

  vp9->mi_cols   = (vp9->frame_width + 7) >> 3;
  vp9->mi_rows   = (vp9->frame_height + 7) >> 3;
  vp9->sb64_cols = (vp9->mi_cols + 7) >> 3;
  vp9->sb64_rows = (vp9->mi_rows + 7) >> 3;

  return 0;
}

static int FUNC(render_size)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  int err;

  f(1, render_and_frame_size_different);

  if(current->render_and_frame_size_different) {
    f(16, render_width_minus_1);
    f(16, render_height_minus_1);
  }

  return 0;
}

static int FUNC(frame_size_with_refs)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  CodedBitstreamVP9Context *vp9 = ctx->priv_data;
  int err, i;

  for(i = 0; i < VP9_REFS_PER_FRAME; i++) {
    fs(1, found_ref[i], 1, i);
    if(current->found_ref[i]) {
      VP9ReferenceFrameState *ref =
        &vp9->ref[current->ref_frame_idx[i]];

      vp9->frame_width  = ref->frame_width;
      vp9->frame_height = ref->frame_height;

      vp9->subsampling_x = ref->subsampling_x;
      vp9->subsampling_y = ref->subsampling_y;
      vp9->bit_depth     = ref->bit_depth;

      break;
    }
  }
  if(i >= VP9_REFS_PER_FRAME)
    CHECK(FUNC(frame_size)(ctx, rw, current));
  else {
    vp9->mi_cols   = (vp9->frame_width + 7) >> 3;
    vp9->mi_rows   = (vp9->frame_height + 7) >> 3;
    vp9->sb64_cols = (vp9->mi_cols + 7) >> 3;
    vp9->sb64_rows = (vp9->mi_rows + 7) >> 3;
  }
  CHECK(FUNC(render_size)(ctx, rw, current));

  return 0;
}

static int FUNC(interpolation_filter)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  int err;

  f(1, is_filter_switchable);
  if(!current->is_filter_switchable)
    f(2, raw_interpolation_filter_type);

  return 0;
}

static int FUNC(loop_filter_params)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  int err, i;

  f(6, loop_filter_level);
  f(3, loop_filter_sharpness);

  f(1, loop_filter_delta_enabled);
  if(current->loop_filter_delta_enabled) {
    f(1, loop_filter_delta_update);
    if(current->loop_filter_delta_update) {
      for(i = 0; i < VP9_MAX_REF_FRAMES; i++) {
        fs(1, update_ref_delta[i], 1, i);
        if(current->update_ref_delta[i])
          ss(6, loop_filter_ref_deltas[i], 1, i);
      }
      for(i = 0; i < 2; i++) {
        fs(1, update_mode_delta[i], 1, i);
        if(current->update_mode_delta[i])
          ss(6, loop_filter_mode_deltas[i], 1, i);
      }
    }
  }

  return 0;
}

static int FUNC(quantization_params)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  int err;

  f(8, base_q_idx);

  delta_q(delta_q_y_dc);
  delta_q(delta_q_uv_dc);
  delta_q(delta_q_uv_ac);

  return 0;
}

static int FUNC(segmentation_params)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  static const uint8_t segmentation_feature_bits[VP9_SEG_LVL_MAX]   = { 8, 6, 2, 0 };
  static const uint8_t segmentation_feature_signed[VP9_SEG_LVL_MAX] = { 1, 1, 0, 0 };

  int err, i, j;

  f(1, segmentation_enabled);

  if(current->segmentation_enabled) {
    f(1, segmentation_update_map);
    if(current->segmentation_update_map) {
      for(i = 0; i < 7; i++)
        prob(segmentation_tree_probs[i], 1, i);
      f(1, segmentation_temporal_update);
      for(i = 0; i < 3; i++) {
        if(current->segmentation_temporal_update)
          prob(segmentation_pred_prob[i], 1, i);
        else
          infer(segmentation_pred_prob[i], 255);
      }
    }

    f(1, segmentation_update_data);
    if(current->segmentation_update_data) {
      f(1, segmentation_abs_or_delta_update);
      for(i = 0; i < VP9_MAX_SEGMENTS; i++) {
        for(j = 0; j < VP9_SEG_LVL_MAX; j++) {
          fs(1, feature_enabled[i][j], 2, i, j);
          if(current->feature_enabled[i][j] &&
             segmentation_feature_bits[j]) {
            fs(segmentation_feature_bits[j],
              feature_value[i][j], 2, i, j);
            if(segmentation_feature_signed[j])
              fs(1, feature_sign[i][j], 2, i, j);
            else
              infer(feature_sign[i][j], 0);
          }
          else {
            infer(feature_value[i][j], 0);
            infer(feature_sign[i][j], 0);
          }
        }
      }
    }
  }

  return 0;
}

static int FUNC(tile_info)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  CodedBitstreamVP9Context *vp9 = ctx->priv_data;
  int min_log2_tile_cols, max_log2_tile_cols;
  int err;

  min_log2_tile_cols = 0;
  while((VP9_MAX_TILE_WIDTH_B64 << min_log2_tile_cols) < vp9->sb64_cols)
    ++min_log2_tile_cols;
  max_log2_tile_cols = 0;
  while((vp9->sb64_cols >> (max_log2_tile_cols + 1)) >= VP9_MIN_TILE_WIDTH_B64)
    ++max_log2_tile_cols;

  increment(tile_cols_log2, min_log2_tile_cols, max_log2_tile_cols);

  increment(tile_rows_log2, 0, 2);

  return 0;
}

static int FUNC(uncompressed_header)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrameHeader *current) {
  CodedBitstreamVP9Context *vp9 = ctx->priv_data;
  int err, i;

  f(2, frame_marker);

  f(1, profile_low_bit);
  f(1, profile_high_bit);
  vp9->profile = (current->profile_high_bit << 1) + current->profile_low_bit;
  if(vp9->profile == 3)
    fixed(1, reserved_zero, 0);

  f(1, show_existing_frame);
  if(current->show_existing_frame) {
    f(3, frame_to_show_map_idx);
    infer(header_size_in_bytes, 0);
    infer(refresh_frame_flags, 0x00);
    infer(loop_filter_level, 0);
    return 0;
  }

  f(1, frame_type);
  f(1, show_frame);
  f(1, error_resilient_mode);

  if(current->frame_type == VP9_KEY_FRAME) {
    CHECK(FUNC(frame_sync_code)(ctx, rw, current));
    CHECK(FUNC(color_config)(ctx, rw, current, vp9->profile));
    CHECK(FUNC(frame_size)(ctx, rw, current));
    CHECK(FUNC(render_size)(ctx, rw, current));

    infer(refresh_frame_flags, 0xff);
  }
  else {
    if(current->show_frame == 0)
      f(1, intra_only);
    else
      infer(intra_only, 0);

    if(current->error_resilient_mode == 0)
      f(2, reset_frame_context);
    else
      infer(reset_frame_context, 0);

    if(current->intra_only == 1) {
      CHECK(FUNC(frame_sync_code)(ctx, rw, current));

      if(vp9->profile > 0) {
        CHECK(FUNC(color_config)(ctx, rw, current, vp9->profile));
      }
      else {
        infer(color_space, 1);
        infer(subsampling_x, 1);
        infer(subsampling_y, 1);
        vp9->bit_depth = 8;

        vp9->subsampling_x = current->subsampling_x;
        vp9->subsampling_y = current->subsampling_y;
      }

      f(8, refresh_frame_flags);

      CHECK(FUNC(frame_size)(ctx, rw, current));
      CHECK(FUNC(render_size)(ctx, rw, current));
    }
    else {
      f(8, refresh_frame_flags);

      for(i = 0; i < VP9_REFS_PER_FRAME; i++) {
        fs(3, ref_frame_idx[i], 1, i);
        fs(1, ref_frame_sign_bias[VP9_LAST_FRAME + i],
          1, VP9_LAST_FRAME + i);
      }

      CHECK(FUNC(frame_size_with_refs)(ctx, rw, current));
      f(1, allow_high_precision_mv);
      CHECK(FUNC(interpolation_filter)(ctx, rw, current));
    }
  }

  if(current->error_resilient_mode == 0) {
    f(1, refresh_frame_context);
    f(1, frame_parallel_decoding_mode);
  }
  else {
    infer(refresh_frame_context, 0);
    infer(frame_parallel_decoding_mode, 1);
  }

  f(2, frame_context_idx);

  CHECK(FUNC(loop_filter_params)(ctx, rw, current));
  CHECK(FUNC(quantization_params)(ctx, rw, current));
  CHECK(FUNC(segmentation_params)(ctx, rw, current));
  CHECK(FUNC(tile_info)(ctx, rw, current));

  f(16, header_size_in_bytes);

  for(i = 0; i < VP9_NUM_REF_FRAMES; i++) {
    if(current->refresh_frame_flags & (1 << i)) {
      vp9->ref[i] = (VP9ReferenceFrameState) {
        .frame_width   = vp9->frame_width,
        .frame_height  = vp9->frame_height,
        .subsampling_x = vp9->subsampling_x,
        .subsampling_y = vp9->subsampling_y,
        .bit_depth     = vp9->bit_depth,
      };
    }
  }

  av_log(ctx->log_ctx, AV_LOG_DEBUG, "Frame:  size %dx%d  "
                                     "subsample %dx%d  bit_depth %d  tiles %dx%d.\n",
    vp9->frame_width, vp9->frame_height,
    vp9->subsampling_x, vp9->subsampling_y,
    vp9->bit_depth, 1 << current->tile_cols_log2,
    1 << current->tile_rows_log2);

  return 0;
}

static int FUNC(trailing_bits)(CodedBitstreamContext *ctx, RWContext *rw) {
  int err;
  while(byte_alignment(rw) != 0)
    fixed(1, zero_bit, 0);

  return 0;
}

static int FUNC(frame)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawFrame *current) {
  int err;

  HEADER("Frame");

  CHECK(FUNC(uncompressed_header)(ctx, rw, &current->header));

  CHECK(FUNC(trailing_bits)(ctx, rw));

  return 0;
}

static int FUNC(superframe_index)(CodedBitstreamContext *ctx, RWContext *rw,
  VP9RawSuperframeIndex *current) {
  int err, i;

  HEADER("Superframe Index");

  f(3, superframe_marker);
  f(2, bytes_per_framesize_minus_1);
  f(3, frames_in_superframe_minus_1);

  for(i = 0; i <= current->frames_in_superframe_minus_1; i++) {
    // Surprise little-endian!
    fle(8 * (current->bytes_per_framesize_minus_1 + 1),
      frame_sizes[i], 1, i);
  }

  f(3, superframe_marker);
  f(2, bytes_per_framesize_minus_1);
  f(3, frames_in_superframe_minus_1);

  return 0;
}