/*
 * 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 <stdlib.h>  // qsort()

#include "./aom_config.h"
#include "./aom_dsp_rtcd.h"
#include "./aom_scale_rtcd.h"
#include "./av1_rtcd.h"

#include "aom/aom_codec.h"
#include "aom_dsp/aom_dsp_common.h"
#include "aom_dsp/bitreader.h"
#include "aom_dsp/bitreader_buffer.h"
#include "aom_mem/aom_mem.h"
#include "aom_ports/mem.h"
#include "aom_ports/mem_ops.h"
#include "aom_scale/aom_scale.h"
#include "aom_util/aom_thread.h"

#include "av1/common/alloccommon.h"
#if CONFIG_CLPF
#include "av1/common/clpf.h"
#endif
#include "av1/common/common.h"
#if CONFIG_DERING
#include "av1/common/dering.h"
#endif  // CONFIG_DERING
#include "av1/common/entropy.h"
#include "av1/common/entropymode.h"
#include "av1/common/idct.h"
#include "av1/common/pred_common.h"
#include "av1/common/quant_common.h"
#include "av1/common/reconinter.h"
#include "av1/common/reconintra.h"
#include "av1/common/seg_common.h"
#include "av1/common/thread_common.h"
#include "av1/common/tile_common.h"

#include "av1/decoder/decodeframe.h"
#include "av1/decoder/decodemv.h"
#include "av1/decoder/decoder.h"
#include "av1/decoder/detokenize.h"
#include "av1/decoder/dsubexp.h"

#define MAX_AV1_HEADER_SIZE 80
#define ACCT_STR __func__

static int is_compound_reference_allowed(const AV1_COMMON *cm) {
  int i;
  if (frame_is_intra_only(cm)) return 0;
  for (i = 1; i < REFS_PER_FRAME; ++i)
    if (cm->ref_frame_sign_bias[i + 1] != cm->ref_frame_sign_bias[1]) return 1;

  return 0;
}

static void setup_compound_reference_mode(AV1_COMMON *cm) {
#if CONFIG_EXT_REFS
  cm->comp_fwd_ref[0] = LAST_FRAME;
  cm->comp_fwd_ref[1] = LAST2_FRAME;
  cm->comp_fwd_ref[2] = LAST3_FRAME;
  cm->comp_fwd_ref[3] = GOLDEN_FRAME;
  cm->comp_bwd_ref[0] = BWDREF_FRAME;
  cm->comp_bwd_ref[1] = ALTREF_FRAME;
#else
  if (cm->ref_frame_sign_bias[LAST_FRAME] ==
      cm->ref_frame_sign_bias[GOLDEN_FRAME]) {
    cm->comp_fixed_ref = ALTREF_FRAME;
    cm->comp_var_ref[0] = LAST_FRAME;
    cm->comp_var_ref[1] = GOLDEN_FRAME;
  } else if (cm->ref_frame_sign_bias[LAST_FRAME] ==
             cm->ref_frame_sign_bias[ALTREF_FRAME]) {
    cm->comp_fixed_ref = GOLDEN_FRAME;
    cm->comp_var_ref[0] = LAST_FRAME;
    cm->comp_var_ref[1] = ALTREF_FRAME;
  } else {
    cm->comp_fixed_ref = LAST_FRAME;
    cm->comp_var_ref[0] = GOLDEN_FRAME;
    cm->comp_var_ref[1] = ALTREF_FRAME;
  }
#endif  // CONFIG_EXT_REFS
}

static int read_is_valid(const uint8_t *start, size_t len, const uint8_t *end) {
  return len != 0 && len <= (size_t)(end - start);
}

static int decode_unsigned_max(struct aom_read_bit_buffer *rb, int max) {
  const int data = aom_rb_read_literal(rb, get_unsigned_bits(max));
  return data > max ? max : data;
}

#if CONFIG_MISC_FIXES
static TX_MODE read_tx_mode(struct aom_read_bit_buffer *rb) {
  return aom_rb_read_bit(rb) ? TX_MODE_SELECT : aom_rb_read_literal(rb, 2);
}
#else
static TX_MODE read_tx_mode(aom_reader *r) {
  TX_MODE tx_mode = aom_read_literal(r, 2, ACCT_STR);
  if (tx_mode == ALLOW_32X32) tx_mode += aom_read_bit(r, ACCT_STR);
  return tx_mode;
}
#endif

static void read_tx_mode_probs(struct tx_probs *tx_probs, aom_reader *r) {
  int i, j;

  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
    for (j = TX_4X4; j < TX_SIZES - 3; ++j)
      av1_diff_update_prob(r, &tx_probs->p8x8[i][j], ACCT_STR);

  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
    for (j = TX_4X4; j < TX_SIZES - 2; ++j)
      av1_diff_update_prob(r, &tx_probs->p16x16[i][j], ACCT_STR);

  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
    for (j = TX_4X4; j < TX_SIZES - 1; ++j)
      av1_diff_update_prob(r, &tx_probs->p32x32[i][j], ACCT_STR);
}

static void read_switchable_interp_probs(FRAME_CONTEXT *fc, aom_reader *r) {
  int i, j;
  for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j) {
    for (i = 0; i < SWITCHABLE_FILTERS - 1; ++i)
      av1_diff_update_prob(r, &fc->switchable_interp_prob[j][i], ACCT_STR);
#if CONFIG_DAALA_EC
    av1_tree_to_cdf(av1_switchable_interp_tree, fc->switchable_interp_prob[j],
                    fc->switchable_interp_cdf[j]);
#endif
  }
}

static void read_inter_mode_probs(FRAME_CONTEXT *fc, aom_reader *r) {
  int i;
#if CONFIG_REF_MV
  for (i = 0; i < NEWMV_MODE_CONTEXTS; ++i)
    av1_diff_update_prob(r, &fc->newmv_prob[i], ACCT_STR);
  for (i = 0; i < ZEROMV_MODE_CONTEXTS; ++i)
    av1_diff_update_prob(r, &fc->zeromv_prob[i], ACCT_STR);
  for (i = 0; i < REFMV_MODE_CONTEXTS; ++i)
    av1_diff_update_prob(r, &fc->refmv_prob[i], ACCT_STR);
  for (i = 0; i < DRL_MODE_CONTEXTS; ++i)
    av1_diff_update_prob(r, &fc->drl_prob[i], ACCT_STR);
#else
  int j;
  for (i = 0; i < INTER_MODE_CONTEXTS; ++i)
    for (j = 0; j < INTER_MODES - 1; ++j)
      av1_diff_update_prob(r, &fc->inter_mode_probs[i][j], ACCT_STR);
#endif
}

#if CONFIG_MISC_FIXES
static REFERENCE_MODE read_frame_reference_mode(
    const AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  if (is_compound_reference_allowed(cm)) {
    return aom_rb_read_bit(rb)
               ? REFERENCE_MODE_SELECT
               : (aom_rb_read_bit(rb) ? COMPOUND_REFERENCE : SINGLE_REFERENCE);
  } else {
    return SINGLE_REFERENCE;
  }
}
#else
static REFERENCE_MODE read_frame_reference_mode(const AV1_COMMON *cm,
                                                aom_reader *r) {
  if (is_compound_reference_allowed(cm)) {
    return aom_read_bit(r, ACCT_STR)
               ? (aom_read_bit(r, ACCT_STR) ? REFERENCE_MODE_SELECT
                                            : COMPOUND_REFERENCE)
               : SINGLE_REFERENCE;
  } else {
    return SINGLE_REFERENCE;
  }
}
#endif

static void read_frame_reference_mode_probs(AV1_COMMON *cm, aom_reader *r) {
  FRAME_CONTEXT *const fc = cm->fc;
  int i, j;

  if (cm->reference_mode == REFERENCE_MODE_SELECT)
    for (i = 0; i < COMP_INTER_CONTEXTS; ++i)
      av1_diff_update_prob(r, &fc->comp_inter_prob[i], ACCT_STR);

  if (cm->reference_mode != COMPOUND_REFERENCE)
    for (i = 0; i < REF_CONTEXTS; ++i)
      for (j = 0; j < (SINGLE_REFS - 1); ++j)
        av1_diff_update_prob(r, &fc->single_ref_prob[i][j], ACCT_STR);

  if (cm->reference_mode != SINGLE_REFERENCE)
#if CONFIG_EXT_REFS
    for (i = 0; i < REF_CONTEXTS; ++i) {
      for (j = 0; j < (FWD_REFS - 1); ++j)
        av1_diff_update_prob(r, &fc->comp_fwdref_prob[i][j], ACCT_STR);
      for (j = 0; j < (BWD_REFS - 1); ++j) (r, &fc->comp_bwdref_prob[i][j]);
    }
#else
    for (i = 0; i < REF_CONTEXTS; ++i)
      av1_diff_update_prob(r, &fc->comp_ref_prob[i], ACCT_STR);
#endif  // CONFIG_EXT_REFS
}

static void update_mv_probs(aom_prob *p, int n, aom_reader *r) {
  int i;
  for (i = 0; i < n; ++i)
#if CONFIG_MISC_FIXES
    av1_diff_update_prob(r, &p[i], ACCT_STR);
#else
    if (aom_read(r, MV_UPDATE_PROB, ACCT_STR))
      p[i] = (aom_read_literal(r, 7, ACCT_STR) << 1) | 1;
#endif
}

static void read_mv_probs(nmv_context *ctx, int allow_hp, aom_reader *r) {
  int i, j;

  update_mv_probs(ctx->joints, MV_JOINTS - 1, r);

  for (i = 0; i < 2; ++i) {
    nmv_component *const comp_ctx = &ctx->comps[i];
    update_mv_probs(&comp_ctx->sign, 1, r);
    update_mv_probs(comp_ctx->classes, MV_CLASSES - 1, r);
    update_mv_probs(comp_ctx->class0, CLASS0_SIZE - 1, r);
    update_mv_probs(comp_ctx->bits, MV_OFFSET_BITS, r);
  }

  for (i = 0; i < 2; ++i) {
    nmv_component *const comp_ctx = &ctx->comps[i];
    for (j = 0; j < CLASS0_SIZE; ++j)
      update_mv_probs(comp_ctx->class0_fp[j], MV_FP_SIZE - 1, r);
    update_mv_probs(comp_ctx->fp, 3, r);
  }

  if (allow_hp) {
    for (i = 0; i < 2; ++i) {
      nmv_component *const comp_ctx = &ctx->comps[i];
      update_mv_probs(&comp_ctx->class0_hp, 1, r);
      update_mv_probs(&comp_ctx->hp, 1, r);
    }
  }
}

static void inverse_transform_block_inter(MACROBLOCKD *xd, int plane,
                                          const TX_SIZE tx_size, uint8_t *dst,
                                          int stride, int eob, int block) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  TX_TYPE tx_type = get_tx_type(pd->plane_type, xd, block);
  const int seg_id = xd->mi[0]->mbmi.segment_id;
  if (eob > 0) {
    tran_low_t *const dqcoeff = pd->dqcoeff;
#if CONFIG_AOM_HIGHBITDEPTH
    if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
      switch (tx_size) {
        case TX_4X4:
          av1_highbd_inv_txfm_add_4x4(dqcoeff, dst, stride, eob, xd->bd,
                                      tx_type, xd->lossless[seg_id]);
          break;
        case TX_8X8:
          av1_highbd_inv_txfm_add_8x8(dqcoeff, dst, stride, eob, xd->bd,
                                      tx_type);
          break;
        case TX_16X16:
          av1_highbd_inv_txfm_add_16x16(dqcoeff, dst, stride, eob, xd->bd,
                                        tx_type);
          break;
        case TX_32X32:
          av1_highbd_inv_txfm_add_32x32(dqcoeff, dst, stride, eob, xd->bd,
                                        tx_type);
          break;
        default: assert(0 && "Invalid transform size"); return;
      }
    } else {
#endif  // CONFIG_AOM_HIGHBITDEPTH
      switch (tx_size) {
        case TX_4X4:
          av1_inv_txfm_add_4x4(dqcoeff, dst, stride, eob, tx_type,
                               xd->lossless[seg_id]);
          break;
        case TX_8X8:
          av1_inv_txfm_add_8x8(dqcoeff, dst, stride, eob, tx_type);
          break;
        case TX_16X16:
          av1_inv_txfm_add_16x16(dqcoeff, dst, stride, eob, tx_type);
          break;
        case TX_32X32:
          av1_inv_txfm_add_32x32(dqcoeff, dst, stride, eob, tx_type);
          break;
        default: assert(0 && "Invalid transform size"); return;
      }
#if CONFIG_AOM_HIGHBITDEPTH
    }
#endif  // CONFIG_AOM_HIGHBITDEPTH

    if (eob == 1) {
      dqcoeff[0] = 0;
    } else {
      if (tx_type == DCT_DCT && tx_size <= TX_16X16 && eob <= 10)
        memset(dqcoeff, 0, 4 * tx_size_1d[tx_size] * sizeof(dqcoeff[0]));
      else if (tx_size == TX_32X32 && eob <= 34)
        memset(dqcoeff, 0, 256 * sizeof(dqcoeff[0]));
      else
        memset(dqcoeff, 0,
               (1 << (tx_size_1d_log2[tx_size] * 2)) * sizeof(dqcoeff[0]));
    }
  }
}

static void inverse_transform_block_intra(MACROBLOCKD *xd, int plane,
                                          const TX_TYPE tx_type,
                                          const TX_SIZE tx_size, uint8_t *dst,
                                          int stride, int eob) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  const int seg_id = xd->mi[0]->mbmi.segment_id;
  if (eob > 0) {
    tran_low_t *const dqcoeff = pd->dqcoeff;
#if CONFIG_AOM_HIGHBITDEPTH
    if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
      switch (tx_size) {
        case TX_4X4:
          av1_highbd_inv_txfm_add_4x4(dqcoeff, dst, stride, eob, xd->bd,
                                      tx_type, xd->lossless[seg_id]);
          break;
        case TX_8X8:
          av1_highbd_inv_txfm_add_8x8(dqcoeff, dst, stride, eob, xd->bd,
                                      tx_type);
          break;
        case TX_16X16:
          av1_highbd_inv_txfm_add_16x16(dqcoeff, dst, stride, eob, xd->bd,
                                        tx_type);
          break;
        case TX_32X32:
          av1_highbd_inv_txfm_add_32x32(dqcoeff, dst, stride, eob, xd->bd,
                                        tx_type);
          break;
        default: assert(0 && "Invalid transform size"); return;
      }
    } else {
#endif  // CONFIG_AOM_HIGHBITDEPTH
      switch (tx_size) {
        case TX_4X4:
          av1_inv_txfm_add_4x4(dqcoeff, dst, stride, eob, tx_type,
                               xd->lossless[seg_id]);
          break;
        case TX_8X8:
          av1_inv_txfm_add_8x8(dqcoeff, dst, stride, eob, tx_type);
          break;
        case TX_16X16:
          av1_inv_txfm_add_16x16(dqcoeff, dst, stride, eob, tx_type);
          break;
        case TX_32X32:
          av1_inv_txfm_add_32x32(dqcoeff, dst, stride, eob, tx_type);
          break;
        default: assert(0 && "Invalid transform size"); return;
      }
#if CONFIG_AOM_HIGHBITDEPTH
    }
#endif  // CONFIG_AOM_HIGHBITDEPTH

    if (eob == 1) {
      dqcoeff[0] = 0;
    } else {
      if (tx_type == DCT_DCT && tx_size <= TX_16X16 && eob <= 10)
        memset(dqcoeff, 0, 4 * tx_size_1d[tx_size] * sizeof(dqcoeff[0]));
      else if (tx_size == TX_32X32 && eob <= 34)
        memset(dqcoeff, 0, 256 * sizeof(dqcoeff[0]));
      else
        memset(dqcoeff, 0,
               (1 << (tx_size_1d_log2[tx_size] * 2)) * sizeof(dqcoeff[0]));
    }
  }
}

static void predict_and_reconstruct_intra_block(MACROBLOCKD *const xd,
                                                aom_reader *r,
                                                MB_MODE_INFO *const mbmi,
                                                int plane, int row, int col,
                                                TX_SIZE tx_size) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  PREDICTION_MODE mode = (plane == 0) ? mbmi->mode : mbmi->uv_mode;
  PLANE_TYPE plane_type = (plane == 0) ? PLANE_TYPE_Y : PLANE_TYPE_UV;
  uint8_t *dst;
  int block_idx = (row << 1) + col;
  dst = &pd->dst.buf[4 * row * pd->dst.stride + 4 * col];

  if (mbmi->sb_type < BLOCK_8X8)
    if (plane == 0) mode = xd->mi[0]->bmi[(row << 1) + col].as_mode;

  av1_predict_intra_block(xd, pd->n4_wl, pd->n4_hl, tx_size, mode, dst,
                          pd->dst.stride, dst, pd->dst.stride, col, row, plane);

  if (!mbmi->skip) {
    TX_TYPE tx_type = get_tx_type(plane_type, xd, block_idx);
    const SCAN_ORDER *scan_order = get_scan(tx_size, tx_type);
    const int eob = av1_decode_block_tokens(xd, plane, scan_order, col, row,
                                            tx_size, r, mbmi->segment_id);
    inverse_transform_block_intra(xd, plane, tx_type, tx_size, dst,
                                  pd->dst.stride, eob);
  }
}

static int reconstruct_inter_block(MACROBLOCKD *const xd, aom_reader *r,
                                   MB_MODE_INFO *const mbmi, int plane, int row,
                                   int col, TX_SIZE tx_size) {
  struct macroblockd_plane *const pd = &xd->plane[plane];
  PLANE_TYPE plane_type = (plane == 0) ? PLANE_TYPE_Y : PLANE_TYPE_UV;
  int block_idx = (row << 1) + col;
  TX_TYPE tx_type = get_tx_type(plane_type, xd, block_idx);
  const SCAN_ORDER *scan_order = get_scan(tx_size, tx_type);
  const int eob = av1_decode_block_tokens(xd, plane, scan_order, col, row,
                                          tx_size, r, mbmi->segment_id);

  inverse_transform_block_inter(
      xd, plane, tx_size, &pd->dst.buf[4 * row * pd->dst.stride + 4 * col],
      pd->dst.stride, eob, block_idx);
  return eob;
}

static INLINE void dec_reset_skip_context(MACROBLOCKD *xd) {
  int i;
  for (i = 0; i < MAX_MB_PLANE; i++) {
    struct macroblockd_plane *const pd = &xd->plane[i];
    memset(pd->above_context, 0, sizeof(ENTROPY_CONTEXT) * pd->n4_w);
    memset(pd->left_context, 0, sizeof(ENTROPY_CONTEXT) * pd->n4_h);
  }
}

static MB_MODE_INFO *set_offsets(AV1_COMMON *const cm, MACROBLOCKD *const xd,
                                 BLOCK_SIZE bsize, int mi_row, int mi_col,
                                 int bw, int bh, int x_mis, int y_mis, int bwl,
                                 int bhl) {
  const int offset = mi_row * cm->mi_stride + mi_col;
  int x, y;
  const TileInfo *const tile = &xd->tile;

  xd->mi = cm->mi_grid_visible + offset;
  xd->mi[0] = &cm->mi[offset];
  // TODO(slavarnway): Generate sb_type based on bwl and bhl, instead of
  // passing bsize from decode_partition().
  xd->mi[0]->mbmi.sb_type = bsize;
  for (y = 0; y < y_mis; ++y)
    for (x = !y; x < x_mis; ++x) xd->mi[y * cm->mi_stride + x] = xd->mi[0];

  set_plane_n4(xd, bw, bh, bwl, bhl);
  set_skip_context(xd, mi_row, mi_col);

  // Distance of Mb to the various image edges. These are specified to 8th pel
  // as they are always compared to values that are in 1/8th pel units
  set_mi_row_col(xd, tile, mi_row, bh, mi_col, bw, cm->mi_rows, cm->mi_cols);

  av1_setup_dst_planes(xd->plane, get_frame_new_buffer(cm), mi_row, mi_col);
  return &xd->mi[0]->mbmi;
}

static void decode_block(AV1Decoder *const pbi, MACROBLOCKD *const xd,
                         int mi_row, int mi_col, aom_reader *r,
                         BLOCK_SIZE bsize, int bwl, int bhl) {
  AV1_COMMON *const cm = &pbi->common;
  const int less8x8 = bsize < BLOCK_8X8;
  const int bw = 1 << (bwl - 1);
  const int bh = 1 << (bhl - 1);
  const int x_mis = AOMMIN(bw, cm->mi_cols - mi_col);
  const int y_mis = AOMMIN(bh, cm->mi_rows - mi_row);

#if CONFIG_ACCOUNTING
  aom_accounting_set_context(&pbi->accounting, mi_col, mi_row);
#endif
  MB_MODE_INFO *mbmi = set_offsets(cm, xd, bsize, mi_row, mi_col, bw, bh, x_mis,
                                   y_mis, bwl, bhl);

  if (bsize >= BLOCK_8X8 && (cm->subsampling_x || cm->subsampling_y)) {
    const BLOCK_SIZE uv_subsize =
        ss_size_lookup[bsize][cm->subsampling_x][cm->subsampling_y];
    if (uv_subsize == BLOCK_INVALID)
      aom_internal_error(xd->error_info, AOM_CODEC_CORRUPT_FRAME,
                         "Invalid block size.");
  }

  av1_read_mode_info(pbi, xd, mi_row, mi_col, r, x_mis, y_mis);

  if (mbmi->skip) {
    dec_reset_skip_context(xd);
  }

  if (!is_inter_block(mbmi)) {
    int plane;
#if CONFIG_PALETTE
    for (plane = 0; plane <= 1; ++plane) {
      if (mbmi->palette_mode_info.palette_size[plane])
        av1_decode_palette_tokens(xd, plane, r);
    }
#endif  // CONFIG_PALETTE
    for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
      const struct macroblockd_plane *const pd = &xd->plane[plane];
      const TX_SIZE tx_size = plane ? get_uv_tx_size(mbmi, pd) : mbmi->tx_size;
      const int num_4x4_w = pd->n4_w;
      const int num_4x4_h = pd->n4_h;
      const int step = tx_size_1d_in_unit[tx_size];
      int row, col;
      const int max_blocks_wide =
          num_4x4_w + (xd->mb_to_right_edge >= 0
                           ? 0
                           : xd->mb_to_right_edge >> (5 + pd->subsampling_x));
      const int max_blocks_high =
          num_4x4_h + (xd->mb_to_bottom_edge >= 0
                           ? 0
                           : xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));

      for (row = 0; row < max_blocks_high; row += step)
        for (col = 0; col < max_blocks_wide; col += step)
          predict_and_reconstruct_intra_block(xd, r, mbmi, plane, row, col,
                                              tx_size);
    }
  } else {
    // Prediction
    av1_build_inter_predictors_sb(xd, mi_row, mi_col, AOMMAX(bsize, BLOCK_8X8));
#if CONFIG_MOTION_VAR
    if (mbmi->motion_mode == OBMC_CAUSAL)
      av1_build_obmc_inter_predictors_sb(cm, xd, mi_row, mi_col);
#endif  // CONFIG_MOTION_VAR
    // Reconstruction
    if (!mbmi->skip) {
      int eobtotal = 0;
      int plane;

      for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
        const struct macroblockd_plane *const pd = &xd->plane[plane];
        const TX_SIZE tx_size =
            plane ? get_uv_tx_size(mbmi, pd) : mbmi->tx_size;
        const int num_4x4_w = pd->n4_w;
        const int num_4x4_h = pd->n4_h;
        const int step = tx_size_1d_in_unit[tx_size];
        int row, col;
        const int max_blocks_wide =
            num_4x4_w + (xd->mb_to_right_edge >= 0
                             ? 0
                             : xd->mb_to_right_edge >> (5 + pd->subsampling_x));
        const int max_blocks_high =
            num_4x4_h +
            (xd->mb_to_bottom_edge >= 0 ? 0 : xd->mb_to_bottom_edge >>
                                                  (5 + pd->subsampling_y));

        for (row = 0; row < max_blocks_high; row += step)
          for (col = 0; col < max_blocks_wide; col += step)
            eobtotal +=
                reconstruct_inter_block(xd, r, mbmi, plane, row, col, tx_size);
      }

      if (!less8x8 && eobtotal == 0)
#if CONFIG_MISC_FIXES
        mbmi->has_no_coeffs = 1;  // skip loopfilter
#else
        mbmi->skip = 1;  // skip loopfilter
#endif
    }
  }

  xd->corrupted |= aom_reader_has_error(r);
}

static INLINE int dec_partition_plane_context(const MACROBLOCKD *xd, int mi_row,
                                              int mi_col, int bsl) {
  const PARTITION_CONTEXT *above_ctx = xd->above_seg_context + mi_col;
  const PARTITION_CONTEXT *left_ctx =
      xd->left_seg_context + (mi_row & MAX_MIB_MASK);
  int above = (*above_ctx >> bsl) & 1, left = (*left_ctx >> bsl) & 1;

  //  assert(bsl >= 0);

  return (left * 2 + above) + bsl * PARTITION_PLOFFSET;
}

static INLINE void dec_update_partition_context(MACROBLOCKD *xd, int mi_row,
                                                int mi_col, BLOCK_SIZE subsize,
                                                int bw) {
  PARTITION_CONTEXT *const above_ctx = xd->above_seg_context + mi_col;
  PARTITION_CONTEXT *const left_ctx =
      xd->left_seg_context + (mi_row & MAX_MIB_MASK);

  // update the partition context at the end notes. set partition bits
  // of block sizes larger than the current one to be one, and partition
  // bits of smaller block sizes to be zero.
  memset(above_ctx, partition_context_lookup[subsize].above, bw);
  memset(left_ctx, partition_context_lookup[subsize].left, bw);
}

static PARTITION_TYPE read_partition(AV1_COMMON *cm, MACROBLOCKD *xd,
                                     int mi_row, int mi_col, aom_reader *r,
                                     int has_rows, int has_cols, int bsl) {
  const int ctx = dec_partition_plane_context(xd, mi_row, mi_col, bsl);
  const aom_prob *const probs = cm->fc->partition_prob[ctx];
  FRAME_COUNTS *counts = xd->counts;
  PARTITION_TYPE p;

  if (has_rows && has_cols)
#if CONFIG_DAALA_EC
    p = (PARTITION_TYPE)aom_read_symbol(r, cm->fc->partition_cdf[ctx],
                                        PARTITION_TYPES, ACCT_STR);
#else
    p = (PARTITION_TYPE)aom_read_tree(r, av1_partition_tree, probs, ACCT_STR);
#endif
  else if (!has_rows && has_cols)
    p = aom_read(r, probs[1], ACCT_STR) ? PARTITION_SPLIT : PARTITION_HORZ;
  else if (has_rows && !has_cols)
    p = aom_read(r, probs[2], ACCT_STR) ? PARTITION_SPLIT : PARTITION_VERT;
  else
    p = PARTITION_SPLIT;

  if (counts) ++counts->partition[ctx][p];

  return p;
}

// TODO(slavarnway): eliminate bsize and subsize in future commits
static void decode_partition(AV1Decoder *const pbi, MACROBLOCKD *const xd,
                             int mi_row, int mi_col, aom_reader *r,
                             BLOCK_SIZE bsize, int n4x4_l2) {
  AV1_COMMON *const cm = &pbi->common;
  const int n8x8_l2 = n4x4_l2 - 1;
  const int num_8x8_wh = 1 << n8x8_l2;
  const int hbs = num_8x8_wh >> 1;
  PARTITION_TYPE partition;
  BLOCK_SIZE subsize;
  const int has_rows = (mi_row + hbs) < cm->mi_rows;
  const int has_cols = (mi_col + hbs) < cm->mi_cols;

  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols) return;

  partition =
      read_partition(cm, xd, mi_row, mi_col, r, has_rows, has_cols, n8x8_l2);
  subsize = subsize_lookup[partition][bsize];  // get_subsize(bsize, partition);
  if (!hbs) {
    // calculate bmode block dimensions (log 2)
    xd->bmode_blocks_wl = 1 >> !!(partition & PARTITION_VERT);
    xd->bmode_blocks_hl = 1 >> !!(partition & PARTITION_HORZ);
    decode_block(pbi, xd, mi_row, mi_col, r, subsize, 1, 1);
  } else {
    switch (partition) {
      case PARTITION_NONE:
        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n4x4_l2, n4x4_l2);
        break;
      case PARTITION_HORZ:
        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n4x4_l2, n8x8_l2);
        if (has_rows)
          decode_block(pbi, xd, mi_row + hbs, mi_col, r, subsize, n4x4_l2,
                       n8x8_l2);
        break;
      case PARTITION_VERT:
        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n8x8_l2, n4x4_l2);
        if (has_cols)
          decode_block(pbi, xd, mi_row, mi_col + hbs, r, subsize, n8x8_l2,
                       n4x4_l2);
        break;
      case PARTITION_SPLIT:
        decode_partition(pbi, xd, mi_row, mi_col, r, subsize, n8x8_l2);
        decode_partition(pbi, xd, mi_row, mi_col + hbs, r, subsize, n8x8_l2);
        decode_partition(pbi, xd, mi_row + hbs, mi_col, r, subsize, n8x8_l2);
        decode_partition(pbi, xd, mi_row + hbs, mi_col + hbs, r, subsize,
                         n8x8_l2);
        break;
      default: assert(0 && "Invalid partition type");
    }
  }

  // update partition context
  if (bsize >= BLOCK_8X8 &&
      (bsize == BLOCK_8X8 || partition != PARTITION_SPLIT))
    dec_update_partition_context(xd, mi_row, mi_col, subsize, num_8x8_wh);

#if CONFIG_DERING
  if (bsize == BLOCK_64X64) {
    if (cm->dering_level != 0 && !sb_all_skip(cm, mi_row, mi_col)) {
      cm->mi_grid_visible[mi_row * cm->mi_stride + mi_col]->mbmi.dering_gain =
          aom_read_literal(r, DERING_REFINEMENT_BITS);
    } else {
      cm->mi_grid_visible[mi_row * cm->mi_stride + mi_col]->mbmi.dering_gain =
          0;
    }
  }
#endif
}

static void setup_token_decoder(const uint8_t *data, const uint8_t *data_end,
                                size_t read_size,
                                struct aom_internal_error_info *error_info,
                                aom_reader *r, aom_decrypt_cb decrypt_cb,
                                void *decrypt_state) {
  // Validate the calculated partition length. If the buffer
  // described by the partition can't be fully read, then restrict
  // it to the portion that can be (for EC mode) or throw an error.
  if (!read_is_valid(data, read_size, data_end))
    aom_internal_error(error_info, AOM_CODEC_CORRUPT_FRAME,
                       "Truncated packet or corrupt tile length");

  if (aom_reader_init(r, data, read_size, decrypt_cb, decrypt_state))
    aom_internal_error(error_info, AOM_CODEC_MEM_ERROR,
                       "Failed to allocate bool decoder %d", 1);
}

static void read_coef_probs_common(av1_coeff_probs_model *coef_probs,
                                   aom_reader *r) {
  int i, j, k, l, m;

  if (aom_read_bit(r, ACCT_STR))
    for (i = 0; i < PLANE_TYPES; ++i)
      for (j = 0; j < REF_TYPES; ++j)
        for (k = 0; k < COEF_BANDS; ++k)
          for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l)
            for (m = 0; m < UNCONSTRAINED_NODES; ++m)
              av1_diff_update_prob(r, &coef_probs[i][j][k][l][m], ACCT_STR);
}

static void read_coef_probs(FRAME_CONTEXT *fc, TX_MODE tx_mode, aom_reader *r) {
  const TX_SIZE max_tx_size = tx_mode_to_biggest_tx_size[tx_mode];
  TX_SIZE tx_size;
  for (tx_size = 0; tx_size <= max_tx_size; ++tx_size)
    read_coef_probs_common(fc->coef_probs[tx_size], r);
#if CONFIG_RANS || CONFIG_DAALA_EC
  av1_coef_pareto_cdfs(fc);
#endif  // CONFIG_RANS
}

static void setup_segmentation(AV1_COMMON *const cm,
                               struct aom_read_bit_buffer *rb) {
  struct segmentation *const seg = &cm->seg;
#if !CONFIG_MISC_FIXES
  struct segmentation_probs *const segp = &cm->segp;
#endif
  int i, j;

  seg->update_map = 0;
  seg->update_data = 0;

  seg->enabled = aom_rb_read_bit(rb);
  if (!seg->enabled) return;

  // Segmentation map update
  if (frame_is_intra_only(cm) || cm->error_resilient_mode) {
    seg->update_map = 1;
  } else {
    seg->update_map = aom_rb_read_bit(rb);
  }
  if (seg->update_map) {
#if !CONFIG_MISC_FIXES
    for (i = 0; i < SEG_TREE_PROBS; i++) {
      segp->tree_probs[i] =
          aom_rb_read_bit(rb) ? aom_rb_read_literal(rb, 8) : MAX_PROB;
    }
#if CONFIG_DAALA_EC
    av1_tree_to_cdf(av1_segment_tree, segp->tree_probs, segp->tree_cdf);
#endif
#endif
    if (frame_is_intra_only(cm) || cm->error_resilient_mode) {
      seg->temporal_update = 0;
    } else {
      seg->temporal_update = aom_rb_read_bit(rb);
    }
#if !CONFIG_MISC_FIXES
    if (seg->temporal_update) {
      for (i = 0; i < PREDICTION_PROBS; i++)
        segp->pred_probs[i] =
            aom_rb_read_bit(rb) ? aom_rb_read_literal(rb, 8) : MAX_PROB;
    } else {
      for (i = 0; i < PREDICTION_PROBS; i++) segp->pred_probs[i] = MAX_PROB;
    }
#endif
  }

  // Segmentation data update
  seg->update_data = aom_rb_read_bit(rb);
  if (seg->update_data) {
    seg->abs_delta = aom_rb_read_bit(rb);

    av1_clearall_segfeatures(seg);

    for (i = 0; i < MAX_SEGMENTS; i++) {
      for (j = 0; j < SEG_LVL_MAX; j++) {
        int data = 0;
        const int feature_enabled = aom_rb_read_bit(rb);
        if (feature_enabled) {
          av1_enable_segfeature(seg, i, j);
          data = decode_unsigned_max(rb, av1_seg_feature_data_max(j));
          if (av1_is_segfeature_signed(j))
            data = aom_rb_read_bit(rb) ? -data : data;
        }
        av1_set_segdata(seg, i, j, data);
      }
    }
  }
}

static void setup_loopfilter(struct loopfilter *lf,
                             struct aom_read_bit_buffer *rb) {
  lf->filter_level = aom_rb_read_literal(rb, 6);
  lf->sharpness_level = aom_rb_read_literal(rb, 3);

  // Read in loop filter deltas applied at the MB level based on mode or ref
  // frame.
  lf->mode_ref_delta_update = 0;

  lf->mode_ref_delta_enabled = aom_rb_read_bit(rb);
  if (lf->mode_ref_delta_enabled) {
    lf->mode_ref_delta_update = aom_rb_read_bit(rb);
    if (lf->mode_ref_delta_update) {
      int i;

      for (i = 0; i < MAX_REF_FRAMES; i++)
        if (aom_rb_read_bit(rb))
          lf->ref_deltas[i] = aom_rb_read_inv_signed_literal(rb, 6);

      for (i = 0; i < MAX_MODE_LF_DELTAS; i++)
        if (aom_rb_read_bit(rb))
          lf->mode_deltas[i] = aom_rb_read_inv_signed_literal(rb, 6);
    }
  }
}

#if CONFIG_CLPF
static void setup_clpf(AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  cm->clpf_blocks = 0;
  cm->clpf_strength = aom_rb_read_literal(rb, 2);
  if (cm->clpf_strength) {
    cm->clpf_size = aom_rb_read_literal(rb, 2);
    if (cm->clpf_size) {
      int i;
      cm->clpf_numblocks = aom_rb_read_literal(rb, av1_clpf_maxbits(cm));
      CHECK_MEM_ERROR(cm, cm->clpf_blocks, aom_malloc(cm->clpf_numblocks));
      for (i = 0; i < cm->clpf_numblocks; i++) {
        cm->clpf_blocks[i] = aom_rb_read_literal(rb, 1);
      }
    }
  }
}

static int clpf_bit(UNUSED int k, UNUSED int l,
                    UNUSED const YV12_BUFFER_CONFIG *rec,
                    UNUSED const YV12_BUFFER_CONFIG *org,
                    UNUSED const AV1_COMMON *cm, UNUSED int block_size,
                    UNUSED int w, UNUSED int h, UNUSED unsigned int strength,
                    UNUSED unsigned int fb_size_log2, uint8_t *bit) {
  return *bit;
}
#endif

#if CONFIG_DERING
static void setup_dering(AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  cm->dering_level = aom_rb_read_literal(rb, DERING_LEVEL_BITS);
}
#endif  // CONFIG_DERING

static INLINE int read_delta_q(struct aom_read_bit_buffer *rb) {
  return aom_rb_read_bit(rb)
             ? aom_rb_read_inv_signed_literal(rb, CONFIG_MISC_FIXES ? 6 : 4)
             : 0;
}

static void setup_quantization(AV1_COMMON *const cm,
                               struct aom_read_bit_buffer *rb) {
  cm->base_qindex = aom_rb_read_literal(rb, QINDEX_BITS);
  cm->y_dc_delta_q = read_delta_q(rb);
  cm->uv_dc_delta_q = read_delta_q(rb);
  cm->uv_ac_delta_q = read_delta_q(rb);
  cm->dequant_bit_depth = cm->bit_depth;
#if CONFIG_AOM_QM
  cm->using_qmatrix = aom_rb_read_bit(rb);
  if (cm->using_qmatrix) {
    cm->min_qmlevel = aom_rb_read_literal(rb, QM_LEVEL_BITS);
    cm->max_qmlevel = aom_rb_read_literal(rb, QM_LEVEL_BITS);
  } else {
    cm->min_qmlevel = 0;
    cm->max_qmlevel = 0;
  }
#endif
}

static void setup_segmentation_dequant(AV1_COMMON *const cm) {
  // Build y/uv dequant values based on segmentation.
  int i = 0;
#if CONFIG_AOM_QM
  int lossless;
  int j = 0;
  int qmlevel;
  int using_qm = cm->using_qmatrix;
  int minqm = cm->min_qmlevel;
  int maxqm = cm->max_qmlevel;
#endif
  if (cm->seg.enabled) {
    for (i = 0; i < MAX_SEGMENTS; ++i) {
      const int qindex = av1_get_qindex(&cm->seg, i, cm->base_qindex);
      cm->y_dequant[i][0] =
          av1_dc_quant(qindex, cm->y_dc_delta_q, cm->bit_depth);
      cm->y_dequant[i][1] = av1_ac_quant(qindex, 0, cm->bit_depth);
      cm->uv_dequant[i][0] =
          av1_dc_quant(qindex, cm->uv_dc_delta_q, cm->bit_depth);
      cm->uv_dequant[i][1] =
          av1_ac_quant(qindex, cm->uv_ac_delta_q, cm->bit_depth);
#if CONFIG_AOM_QM
      lossless = qindex == 0 && cm->y_dc_delta_q == 0 &&
                 cm->uv_dc_delta_q == 0 && cm->uv_ac_delta_q == 0;
      // NB: depends on base index so there is only 1 set per frame
      // No quant weighting when lossless or signalled not using QM
      qmlevel = (lossless || using_qm == 0)
                    ? NUM_QM_LEVELS - 1
                    : aom_get_qmlevel(cm->base_qindex, minqm, maxqm);
      for (j = 0; j < TX_SIZES; ++j) {
        cm->y_iqmatrix[i][1][j] = aom_iqmatrix(cm, qmlevel, 0, j, 1);
        cm->y_iqmatrix[i][0][j] = aom_iqmatrix(cm, qmlevel, 0, j, 0);
        cm->uv_iqmatrix[i][1][j] = aom_iqmatrix(cm, qmlevel, 1, j, 1);
        cm->uv_iqmatrix[i][0][j] = aom_iqmatrix(cm, qmlevel, 1, j, 0);
      }
#endif
    }
  } else {
    const int qindex = cm->base_qindex;
    // When segmentation is disabled, only the first value is used.  The
    // remaining are don't cares.
    cm->y_dequant[0][0] = av1_dc_quant(qindex, cm->y_dc_delta_q, cm->bit_depth);
    cm->y_dequant[0][1] = av1_ac_quant(qindex, 0, cm->bit_depth);
    cm->uv_dequant[0][0] =
        av1_dc_quant(qindex, cm->uv_dc_delta_q, cm->bit_depth);
    cm->uv_dequant[0][1] =
        av1_ac_quant(qindex, cm->uv_ac_delta_q, cm->bit_depth);
#if CONFIG_AOM_QM
    lossless = qindex == 0 && cm->y_dc_delta_q == 0 && cm->uv_dc_delta_q == 0 &&
               cm->uv_ac_delta_q == 0;
    // No quant weighting when lossless or signalled not using QM
    qmlevel = (lossless || using_qm == 0)
                  ? NUM_QM_LEVELS - 1
                  : aom_get_qmlevel(cm->base_qindex, minqm, maxqm);
    for (j = 0; j < TX_SIZES; ++j) {
      cm->y_iqmatrix[i][1][j] = aom_iqmatrix(cm, qmlevel, 0, j, 1);
      cm->y_iqmatrix[i][0][j] = aom_iqmatrix(cm, qmlevel, 0, j, 0);
      cm->uv_iqmatrix[i][1][j] = aom_iqmatrix(cm, qmlevel, 1, j, 1);
      cm->uv_iqmatrix[i][0][j] = aom_iqmatrix(cm, qmlevel, 1, j, 0);
    }
#endif
  }
}

static InterpFilter read_interp_filter(struct aom_read_bit_buffer *rb) {
  return aom_rb_read_bit(rb) ? SWITCHABLE
                             : aom_rb_read_literal(rb, LOG_SWITCHABLE_FILTERS);
}

static void setup_render_size(AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  cm->render_width = cm->width;
  cm->render_height = cm->height;
  if (aom_rb_read_bit(rb))
    av1_read_frame_size(rb, &cm->render_width, &cm->render_height);
}

static void resize_mv_buffer(AV1_COMMON *cm) {
  aom_free(cm->cur_frame->mvs);
  cm->cur_frame->mi_rows = cm->mi_rows;
  cm->cur_frame->mi_cols = cm->mi_cols;
  cm->cur_frame->mvs = (MV_REF *)aom_calloc(cm->mi_rows * cm->mi_cols,
                                            sizeof(*cm->cur_frame->mvs));
}

static void resize_context_buffers(AV1_COMMON *cm, int width, int height) {
#if CONFIG_SIZE_LIMIT
  if (width > DECODE_WIDTH_LIMIT || height > DECODE_HEIGHT_LIMIT)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Dimensions of %dx%d beyond allowed size of %dx%d.",
                       width, height, DECODE_WIDTH_LIMIT, DECODE_HEIGHT_LIMIT);
#endif
  if (cm->width != width || cm->height != height) {
    const int new_mi_rows =
        ALIGN_POWER_OF_TWO(height, MI_SIZE_LOG2) >> MI_SIZE_LOG2;
    const int new_mi_cols =
        ALIGN_POWER_OF_TWO(width, MI_SIZE_LOG2) >> MI_SIZE_LOG2;

    // Allocations in av1_alloc_context_buffers() depend on individual
    // dimensions as well as the overall size.
    if (new_mi_cols > cm->mi_cols || new_mi_rows > cm->mi_rows) {
      if (av1_alloc_context_buffers(cm, width, height))
        aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
                           "Failed to allocate context buffers");
    } else {
      av1_set_mb_mi(cm, width, height);
    }
    av1_init_context_buffers(cm);
    cm->width = width;
    cm->height = height;
  }
  if (cm->cur_frame->mvs == NULL || cm->mi_rows > cm->cur_frame->mi_rows ||
      cm->mi_cols > cm->cur_frame->mi_cols) {
    resize_mv_buffer(cm);
  }
}

static void setup_frame_size(AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  int width, height;
  BufferPool *const pool = cm->buffer_pool;
  av1_read_frame_size(rb, &width, &height);
  resize_context_buffers(cm, width, height);
  setup_render_size(cm, rb);

  lock_buffer_pool(pool);
  if (aom_realloc_frame_buffer(
          get_frame_new_buffer(cm), cm->width, cm->height, cm->subsampling_x,
          cm->subsampling_y,
#if CONFIG_AOM_HIGHBITDEPTH
          cm->use_highbitdepth,
#endif
          AOM_BORDER_IN_PIXELS, cm->byte_alignment,
          &pool->frame_bufs[cm->new_fb_idx].raw_frame_buffer, pool->get_fb_cb,
          pool->cb_priv)) {
    unlock_buffer_pool(pool);
    aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
                       "Failed to allocate frame buffer");
  }
  unlock_buffer_pool(pool);

  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_x = cm->subsampling_x;
  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_y = cm->subsampling_y;
  pool->frame_bufs[cm->new_fb_idx].buf.bit_depth = (unsigned int)cm->bit_depth;
  pool->frame_bufs[cm->new_fb_idx].buf.color_space = cm->color_space;
  pool->frame_bufs[cm->new_fb_idx].buf.color_range = cm->color_range;
  pool->frame_bufs[cm->new_fb_idx].buf.render_width = cm->render_width;
  pool->frame_bufs[cm->new_fb_idx].buf.render_height = cm->render_height;
}

static INLINE int valid_ref_frame_img_fmt(aom_bit_depth_t ref_bit_depth,
                                          int ref_xss, int ref_yss,
                                          aom_bit_depth_t this_bit_depth,
                                          int this_xss, int this_yss) {
  return ref_bit_depth == this_bit_depth && ref_xss == this_xss &&
         ref_yss == this_yss;
}

static void setup_frame_size_with_refs(AV1_COMMON *cm,
                                       struct aom_read_bit_buffer *rb) {
  int width, height;
  int found = 0, i;
  int has_valid_ref_frame = 0;
  BufferPool *const pool = cm->buffer_pool;
  for (i = 0; i < REFS_PER_FRAME; ++i) {
    if (aom_rb_read_bit(rb)) {
      YV12_BUFFER_CONFIG *const buf = cm->frame_refs[i].buf;
      width = buf->y_crop_width;
      height = buf->y_crop_height;
#if CONFIG_MISC_FIXES
      cm->render_width = buf->render_width;
      cm->render_height = buf->render_height;
#endif
      found = 1;
      break;
    }
  }

  if (!found) {
    av1_read_frame_size(rb, &width, &height);
#if CONFIG_MISC_FIXES
    setup_render_size(cm, rb);
#endif
  }

  if (width <= 0 || height <= 0)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Invalid frame size");

  // Check to make sure at least one of frames that this frame references
  // has valid dimensions.
  for (i = 0; i < REFS_PER_FRAME; ++i) {
    RefBuffer *const ref_frame = &cm->frame_refs[i];
    has_valid_ref_frame |=
        valid_ref_frame_size(ref_frame->buf->y_crop_width,
                             ref_frame->buf->y_crop_height, width, height);
  }
  if (!has_valid_ref_frame)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Referenced frame has invalid size");
  for (i = 0; i < REFS_PER_FRAME; ++i) {
    RefBuffer *const ref_frame = &cm->frame_refs[i];
    if (!valid_ref_frame_img_fmt(ref_frame->buf->bit_depth,
                                 ref_frame->buf->subsampling_x,
                                 ref_frame->buf->subsampling_y, cm->bit_depth,
                                 cm->subsampling_x, cm->subsampling_y))
      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                         "Referenced frame has incompatible color format");
  }

  resize_context_buffers(cm, width, height);
#if !CONFIG_MISC_FIXES
  setup_render_size(cm, rb);
#endif

  lock_buffer_pool(pool);
  if (aom_realloc_frame_buffer(
          get_frame_new_buffer(cm), cm->width, cm->height, cm->subsampling_x,
          cm->subsampling_y,
#if CONFIG_AOM_HIGHBITDEPTH
          cm->use_highbitdepth,
#endif
          AOM_BORDER_IN_PIXELS, cm->byte_alignment,
          &pool->frame_bufs[cm->new_fb_idx].raw_frame_buffer, pool->get_fb_cb,
          pool->cb_priv)) {
    unlock_buffer_pool(pool);
    aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
                       "Failed to allocate frame buffer");
  }
  unlock_buffer_pool(pool);

  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_x = cm->subsampling_x;
  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_y = cm->subsampling_y;
  pool->frame_bufs[cm->new_fb_idx].buf.bit_depth = (unsigned int)cm->bit_depth;
  pool->frame_bufs[cm->new_fb_idx].buf.color_space = cm->color_space;
  pool->frame_bufs[cm->new_fb_idx].buf.color_range = cm->color_range;
  pool->frame_bufs[cm->new_fb_idx].buf.render_width = cm->render_width;
  pool->frame_bufs[cm->new_fb_idx].buf.render_height = cm->render_height;
}

static void setup_tile_info(AV1_COMMON *cm, struct aom_read_bit_buffer *rb) {
  int min_log2_tile_cols, max_log2_tile_cols, max_ones;
  av1_get_tile_n_bits(cm->mi_cols, &min_log2_tile_cols, &max_log2_tile_cols);

  // columns
  max_ones = max_log2_tile_cols - min_log2_tile_cols;
  cm->log2_tile_cols = min_log2_tile_cols;
  while (max_ones-- && aom_rb_read_bit(rb)) cm->log2_tile_cols++;

  if (cm->log2_tile_cols > 6)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Invalid number of tile columns");

  // rows
  cm->log2_tile_rows = aom_rb_read_bit(rb);
  if (cm->log2_tile_rows) cm->log2_tile_rows += aom_rb_read_bit(rb);

#if CONFIG_MISC_FIXES
  // tile size magnitude
  if (cm->log2_tile_rows > 0 || cm->log2_tile_cols > 0) {
    cm->tile_sz_mag = aom_rb_read_literal(rb, 2);
  }
#else
  cm->tile_sz_mag = 3;
#endif
}

typedef struct TileBuffer {
  const uint8_t *data;
  size_t size;
  int col;  // only used with multi-threaded decoding
} TileBuffer;

static int mem_get_varsize(const uint8_t *data, const int mag) {
  switch (mag) {
    case 0: return data[0];
    case 1: return mem_get_le16(data);
    case 2: return mem_get_le24(data);
    case 3: return mem_get_le32(data);
  }

  assert("Invalid tile size marker value" && 0);

  return -1;
}

// Reads the next tile returning its size and adjusting '*data' accordingly
// based on 'is_last'.
static void get_tile_buffer(const uint8_t *const data_end,
                            const int tile_sz_mag, int is_last,
                            struct aom_internal_error_info *error_info,
                            const uint8_t **data, aom_decrypt_cb decrypt_cb,
                            void *decrypt_state, TileBuffer *buf) {
  size_t size;

  if (!is_last) {
    if (!read_is_valid(*data, 4, data_end))
      aom_internal_error(error_info, AOM_CODEC_CORRUPT_FRAME,
                         "Truncated packet or corrupt tile length");

    if (decrypt_cb) {
      uint8_t be_data[4];
      decrypt_cb(decrypt_state, *data, be_data, tile_sz_mag + 1);
      size = mem_get_varsize(be_data, tile_sz_mag) + CONFIG_MISC_FIXES;
    } else {
      size = mem_get_varsize(*data, tile_sz_mag) + CONFIG_MISC_FIXES;
    }
    *data += tile_sz_mag + 1;

    if (size > (size_t)(data_end - *data))
      aom_internal_error(error_info, AOM_CODEC_CORRUPT_FRAME,
                         "Truncated packet or corrupt tile size");
  } else {
    size = data_end - *data;
  }

  buf->data = *data;
  buf->size = size;

  *data += size;
}

static void get_tile_buffers(AV1Decoder *pbi, const uint8_t *data,
                             const uint8_t *data_end, int tile_cols,
                             int tile_rows,
                             TileBuffer (*tile_buffers)[1 << 6]) {
  int r, c;

  for (r = 0; r < tile_rows; ++r) {
    for (c = 0; c < tile_cols; ++c) {
      const int is_last = (r == tile_rows - 1) && (c == tile_cols - 1);
      TileBuffer *const buf = &tile_buffers[r][c];
      buf->col = c;
      get_tile_buffer(data_end, pbi->common.tile_sz_mag, is_last,
                      &pbi->common.error, &data, pbi->decrypt_cb,
                      pbi->decrypt_state, buf);
    }
  }
}

static const uint8_t *decode_tiles(AV1Decoder *pbi, const uint8_t *data,
                                   const uint8_t *data_end) {
  AV1_COMMON *const cm = &pbi->common;
  const AVxWorkerInterface *const winterface = aom_get_worker_interface();
  const int aligned_cols = mi_cols_aligned_to_sb(cm->mi_cols);
  const int tile_cols = 1 << cm->log2_tile_cols;
  const int tile_rows = 1 << cm->log2_tile_rows;
  TileBuffer tile_buffers[4][1 << 6];
  int tile_row, tile_col;
  int mi_row, mi_col;
  TileData *tile_data = NULL;

  if (cm->lf.filter_level && !cm->skip_loop_filter &&
      pbi->lf_worker.data1 == NULL) {
    CHECK_MEM_ERROR(cm, pbi->lf_worker.data1,
                    aom_memalign(32, sizeof(LFWorkerData)));
    pbi->lf_worker.hook = (AVxWorkerHook)av1_loop_filter_worker;
    if (pbi->max_threads > 1 && !winterface->reset(&pbi->lf_worker)) {
      aom_internal_error(&cm->error, AOM_CODEC_ERROR,
                         "Loop filter thread creation failed");
    }
  }

  if (cm->lf.filter_level && !cm->skip_loop_filter) {
    LFWorkerData *const lf_data = (LFWorkerData *)pbi->lf_worker.data1;
    // Be sure to sync as we might be resuming after a failed frame decode.
    winterface->sync(&pbi->lf_worker);
    av1_loop_filter_data_reset(lf_data, get_frame_new_buffer(cm), cm,
                               pbi->mb.plane);
  }

  assert(tile_rows <= 4);
  assert(tile_cols <= (1 << 6));

  // Note: this memset assumes above_context[0], [1] and [2]
  // are allocated as part of the same buffer.
  memset(cm->above_context, 0,
         sizeof(*cm->above_context) * MAX_MB_PLANE * 2 * aligned_cols);

  memset(cm->above_seg_context, 0,
         sizeof(*cm->above_seg_context) * aligned_cols);

  get_tile_buffers(pbi, data, data_end, tile_cols, tile_rows, tile_buffers);

  if (pbi->tile_data == NULL || (tile_cols * tile_rows) != pbi->total_tiles) {
    aom_free(pbi->tile_data);
    CHECK_MEM_ERROR(
        cm, pbi->tile_data,
        aom_memalign(32, tile_cols * tile_rows * (sizeof(*pbi->tile_data))));
    pbi->total_tiles = tile_rows * tile_cols;
  }
#if CONFIG_ACCOUNTING
  aom_accounting_reset(&pbi->accounting);
#endif
  // Load all tile information into tile_data.
  for (tile_row = 0; tile_row < tile_rows; ++tile_row) {
    for (tile_col = 0; tile_col < tile_cols; ++tile_col) {
      const TileBuffer *const buf = &tile_buffers[tile_row][tile_col];
      tile_data = pbi->tile_data + tile_cols * tile_row + tile_col;
      tile_data->cm = cm;
      tile_data->xd = pbi->mb;
      tile_data->xd.corrupted = 0;
      tile_data->xd.counts =
          cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_BACKWARD
              ? &cm->counts
              : NULL;
      av1_zero(tile_data->dqcoeff);
      av1_tile_init(&tile_data->xd.tile, tile_data->cm, tile_row, tile_col);
      setup_token_decoder(buf->data, data_end, buf->size, &cm->error,
                          &tile_data->bit_reader, pbi->decrypt_cb,
                          pbi->decrypt_state);
#if CONFIG_ACCOUNTING
      tile_data->bit_reader.accounting = &pbi->accounting;
#endif
      av1_init_macroblockd(cm, &tile_data->xd, tile_data->dqcoeff);
#if CONFIG_PALETTE
      tile_data->xd.plane[0].color_index_map = tile_data->color_index_map[0];
      tile_data->xd.plane[1].color_index_map = tile_data->color_index_map[1];
#endif  // CONFIG_PALETTE
    }
  }

  for (tile_row = 0; tile_row < tile_rows; ++tile_row) {
    TileInfo tile;
    av1_tile_set_row(&tile, cm, tile_row);
    for (mi_row = tile.mi_row_start; mi_row < tile.mi_row_end;
         mi_row += MAX_MIB_SIZE) {
      for (tile_col = 0; tile_col < tile_cols; ++tile_col) {
        const int col =
            pbi->inv_tile_order ? tile_cols - tile_col - 1 : tile_col;
        tile_data = pbi->tile_data + tile_cols * tile_row + col;
#if CONFIG_ACCOUNTING
        tile_data->bit_reader.accounting->last_tell_frac =
            aom_reader_tell_frac(&tile_data->bit_reader);
#endif
        av1_tile_set_col(&tile, tile_data->cm, col);
        av1_zero(tile_data->xd.left_context);
        av1_zero(tile_data->xd.left_seg_context);
        for (mi_col = tile.mi_col_start; mi_col < tile.mi_col_end;
             mi_col += MAX_MIB_SIZE) {
          decode_partition(pbi, &tile_data->xd, mi_row, mi_col,
                           &tile_data->bit_reader, BLOCK_64X64, 4);
        }
        pbi->mb.corrupted |= tile_data->xd.corrupted;
        if (pbi->mb.corrupted)
          aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                             "Failed to decode tile data");
      }
      // Loopfilter one row.
      if (cm->lf.filter_level && !cm->skip_loop_filter) {
        const int lf_start = mi_row - MAX_MIB_SIZE;
        LFWorkerData *const lf_data = (LFWorkerData *)pbi->lf_worker.data1;

        // delay the loopfilter by 1 macroblock row.
        if (lf_start < 0) continue;

        // decoding has completed: finish up the loop filter in this thread.
        if (mi_row + MAX_MIB_SIZE >= cm->mi_rows) continue;

        winterface->sync(&pbi->lf_worker);
        lf_data->start = lf_start;
        lf_data->stop = mi_row;
        if (pbi->max_threads > 1) {
          winterface->launch(&pbi->lf_worker);
        } else {
          winterface->execute(&pbi->lf_worker);
        }
      }
      // After loopfiltering, the last 7 row pixels in each superblock row may
      // still be changed by the longest loopfilter of the next superblock
      // row.
      if (cm->frame_parallel_decode)
        av1_frameworker_broadcast(pbi->cur_buf, mi_row << MAX_MIB_SIZE_LOG2);
    }
  }

#if CONFIG_ACCOUNTING
// aom_accounting_dump(&pbi->accounting);
#endif

  // Loopfilter remaining rows in the frame.
  if (cm->lf.filter_level && !cm->skip_loop_filter) {
    LFWorkerData *const lf_data = (LFWorkerData *)pbi->lf_worker.data1;
    winterface->sync(&pbi->lf_worker);
    lf_data->start = lf_data->stop;
    lf_data->stop = cm->mi_rows;
    winterface->execute(&pbi->lf_worker);
  }

  // Get last tile data.
  tile_data = pbi->tile_data + tile_cols * tile_rows - 1;

  if (cm->frame_parallel_decode)
    av1_frameworker_broadcast(pbi->cur_buf, INT_MAX);
#if CONFIG_ANS
  return data_end;
#else
  return aom_reader_find_end(&tile_data->bit_reader);
#endif
}

static int tile_worker_hook(TileWorkerData *const tile_data,
                            const TileInfo *const tile) {
  int mi_row, mi_col;

  if (setjmp(tile_data->error_info.jmp)) {
    tile_data->error_info.setjmp = 0;
    tile_data->xd.corrupted = 1;
    return 0;
  }

  tile_data->error_info.setjmp = 1;
  tile_data->xd.error_info = &tile_data->error_info;

  for (mi_row = tile->mi_row_start; mi_row < tile->mi_row_end;
       mi_row += MAX_MIB_SIZE) {
    av1_zero(tile_data->xd.left_context);
    av1_zero(tile_data->xd.left_seg_context);
    for (mi_col = tile->mi_col_start; mi_col < tile->mi_col_end;
         mi_col += MAX_MIB_SIZE) {
      decode_partition(tile_data->pbi, &tile_data->xd, mi_row, mi_col,
                       &tile_data->bit_reader, BLOCK_64X64, 4);
    }
  }
  return !tile_data->xd.corrupted;
}

// sorts in descending order
static int compare_tile_buffers(const void *a, const void *b) {
  const TileBuffer *const buf1 = (const TileBuffer *)a;
  const TileBuffer *const buf2 = (const TileBuffer *)b;
  return (int)(buf2->size - buf1->size);
}

static const uint8_t *decode_tiles_mt(AV1Decoder *pbi, const uint8_t *data,
                                      const uint8_t *data_end) {
  AV1_COMMON *const cm = &pbi->common;
  const AVxWorkerInterface *const winterface = aom_get_worker_interface();
  const uint8_t *bit_reader_end = NULL;
  const int aligned_mi_cols = mi_cols_aligned_to_sb(cm->mi_cols);
  const int tile_cols = 1 << cm->log2_tile_cols;
  const int tile_rows = 1 << cm->log2_tile_rows;
  const int num_workers = AOMMIN(pbi->max_threads & ~1, tile_cols);
  TileBuffer tile_buffers[1][1 << 6];
  int n;
  int final_worker = -1;

  assert(tile_cols <= (1 << 6));
  assert(tile_rows == 1);
  (void)tile_rows;

  // TODO(jzern): See if we can remove the restriction of passing in max
  // threads to the decoder.
  if (pbi->num_tile_workers == 0) {
    const int num_threads = pbi->max_threads & ~1;
    int i;
    CHECK_MEM_ERROR(cm, pbi->tile_workers,
                    aom_malloc(num_threads * sizeof(*pbi->tile_workers)));
    // Ensure tile data offsets will be properly aligned. This may fail on
    // platforms without DECLARE_ALIGNED().
    assert((sizeof(*pbi->tile_worker_data) % 16) == 0);
    CHECK_MEM_ERROR(
        cm, pbi->tile_worker_data,
        aom_memalign(32, num_threads * sizeof(*pbi->tile_worker_data)));
    CHECK_MEM_ERROR(cm, pbi->tile_worker_info,
                    aom_malloc(num_threads * sizeof(*pbi->tile_worker_info)));
    for (i = 0; i < num_threads; ++i) {
      AVxWorker *const worker = &pbi->tile_workers[i];
      ++pbi->num_tile_workers;

      winterface->init(worker);
      if (i < num_threads - 1 && !winterface->reset(worker)) {
        aom_internal_error(&cm->error, AOM_CODEC_ERROR,
                           "Tile decoder thread creation failed");
      }
    }
  }

  // Reset tile decoding hook
  for (n = 0; n < num_workers; ++n) {
    AVxWorker *const worker = &pbi->tile_workers[n];
    winterface->sync(worker);
    worker->hook = (AVxWorkerHook)tile_worker_hook;
    worker->data1 = &pbi->tile_worker_data[n];
    worker->data2 = &pbi->tile_worker_info[n];
  }

  // Note: this memset assumes above_context[0], [1] and [2]
  // are allocated as part of the same buffer.
  memset(cm->above_context, 0,
         sizeof(*cm->above_context) * MAX_MB_PLANE * 2 * aligned_mi_cols);
  memset(cm->above_seg_context, 0,
         sizeof(*cm->above_seg_context) * aligned_mi_cols);

  // Load tile data into tile_buffers
  get_tile_buffers(pbi, data, data_end, tile_cols, tile_rows, tile_buffers);

  // Sort the buffers based on size in descending order.
  qsort(tile_buffers[0], tile_cols, sizeof(tile_buffers[0][0]),
        compare_tile_buffers);

  // Rearrange the tile buffers such that per-tile group the largest, and
  // presumably the most difficult, tile will be decoded in the main thread.
  // This should help minimize the number of instances where the main thread is
  // waiting for a worker to complete.
  {
    int group_start = 0;
    while (group_start < tile_cols) {
      const TileBuffer largest = tile_buffers[0][group_start];
      const int group_end = AOMMIN(group_start + num_workers, tile_cols) - 1;
      memmove(tile_buffers[0] + group_start, tile_buffers[0] + group_start + 1,
              (group_end - group_start) * sizeof(tile_buffers[0][0]));
      tile_buffers[0][group_end] = largest;
      group_start = group_end + 1;
    }
  }

  // Initialize thread frame counts.
  if (cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_BACKWARD) {
    int i;

    for (i = 0; i < num_workers; ++i) {
      TileWorkerData *const tile_data =
          (TileWorkerData *)pbi->tile_workers[i].data1;
      av1_zero(tile_data->counts);
    }
  }

  n = 0;
  while (n < tile_cols) {
    int i;
    for (i = 0; i < num_workers && n < tile_cols; ++i) {
      AVxWorker *const worker = &pbi->tile_workers[i];
      TileWorkerData *const tile_data = (TileWorkerData *)worker->data1;
      TileInfo *const tile = (TileInfo *)worker->data2;
      TileBuffer *const buf = &tile_buffers[0][n];

      tile_data->pbi = pbi;
      tile_data->xd = pbi->mb;
      tile_data->xd.corrupted = 0;
      tile_data->xd.counts =
          cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_BACKWARD
              ? &tile_data->counts
              : NULL;
      av1_zero(tile_data->dqcoeff);
      av1_tile_init(tile, cm, 0, buf->col);
      av1_tile_init(&tile_data->xd.tile, cm, 0, buf->col);
      setup_token_decoder(buf->data, data_end, buf->size, &cm->error,
                          &tile_data->bit_reader, pbi->decrypt_cb,
                          pbi->decrypt_state);
      av1_init_macroblockd(cm, &tile_data->xd, tile_data->dqcoeff);
#if CONFIG_PALETTE
      tile_data->xd.plane[0].color_index_map = tile_data->color_index_map[0];
      tile_data->xd.plane[1].color_index_map = tile_data->color_index_map[1];
#endif  // CONFIG_PALETTE

      worker->had_error = 0;
      if (i == num_workers - 1 || n == tile_cols - 1) {
        winterface->execute(worker);
      } else {
        winterface->launch(worker);
      }

      if (buf->col == tile_cols - 1) {
        final_worker = i;
      }

      ++n;
    }

    for (; i > 0; --i) {
      AVxWorker *const worker = &pbi->tile_workers[i - 1];
      // TODO(jzern): The tile may have specific error data associated with
      // its aom_internal_error_info which could be propagated to the main info
      // in cm. Additionally once the threads have been synced and an error is
      // detected, there's no point in continuing to decode tiles.
      pbi->mb.corrupted |= !winterface->sync(worker);
    }
    if (final_worker > -1) {
      TileWorkerData *const tile_data =
          (TileWorkerData *)pbi->tile_workers[final_worker].data1;
      bit_reader_end = aom_reader_find_end(&tile_data->bit_reader);
      final_worker = -1;
    }

    // Accumulate thread frame counts.
    if (n >= tile_cols &&
        cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_BACKWARD) {
      for (i = 0; i < num_workers; ++i) {
        TileWorkerData *const tile_data =
            (TileWorkerData *)pbi->tile_workers[i].data1;
        av1_accumulate_frame_counts(cm, &tile_data->counts, 1);
      }
    }
  }

  return bit_reader_end;
}

static void error_handler(void *data) {
  AV1_COMMON *const cm = (AV1_COMMON *)data;
  aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME, "Truncated packet");
}

static void read_bitdepth_colorspace_sampling(AV1_COMMON *cm,
                                              struct aom_read_bit_buffer *rb) {
  if (cm->profile >= PROFILE_2) {
    cm->bit_depth = aom_rb_read_bit(rb) ? AOM_BITS_12 : AOM_BITS_10;
#if CONFIG_AOM_HIGHBITDEPTH
    cm->use_highbitdepth = 1;
#endif
  } else {
    cm->bit_depth = AOM_BITS_8;
#if CONFIG_AOM_HIGHBITDEPTH
    cm->use_highbitdepth = 0;
#endif
  }
  cm->color_space = aom_rb_read_literal(rb, 3);
  if (cm->color_space != AOM_CS_SRGB) {
    // [16,235] (including xvycc) vs [0,255] range
    cm->color_range = aom_rb_read_bit(rb);
    if (cm->profile == PROFILE_1 || cm->profile == PROFILE_3) {
      cm->subsampling_x = aom_rb_read_bit(rb);
      cm->subsampling_y = aom_rb_read_bit(rb);
      if (cm->subsampling_x == 1 && cm->subsampling_y == 1)
        aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                           "4:2:0 color not supported in profile 1 or 3");
      if (aom_rb_read_bit(rb))
        aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                           "Reserved bit set");
    } else {
      cm->subsampling_y = cm->subsampling_x = 1;
    }
  } else {
    if (cm->profile == PROFILE_1 || cm->profile == PROFILE_3) {
      // Note if colorspace is SRGB then 4:4:4 chroma sampling is assumed.
      // 4:2:2 or 4:4:0 chroma sampling is not allowed.
      cm->subsampling_y = cm->subsampling_x = 0;
      if (aom_rb_read_bit(rb))
        aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                           "Reserved bit set");
    } else {
      aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                         "4:4:4 color not supported in profile 0 or 2");
    }
  }
}

static size_t read_uncompressed_header(AV1Decoder *pbi,
                                       struct aom_read_bit_buffer *rb) {
  AV1_COMMON *const cm = &pbi->common;
  MACROBLOCKD *const xd = &pbi->mb;
  BufferPool *const pool = cm->buffer_pool;
  RefCntBuffer *const frame_bufs = pool->frame_bufs;
  int i, mask, ref_index = 0;
  size_t sz;

  cm->last_frame_type = cm->frame_type;
  cm->last_intra_only = cm->intra_only;

#if CONFIG_EXT_REFS
  // NOTE: By default all coded frames to be used as a reference
  cm->is_reference_frame = 1;
#endif  // CONFIG_EXT_REFS

  if (aom_rb_read_literal(rb, 2) != AOM_FRAME_MARKER)
    aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                       "Invalid frame marker");

  cm->profile = av1_read_profile(rb);
#if CONFIG_AOM_HIGHBITDEPTH
  if (cm->profile >= MAX_PROFILES)
    aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                       "Unsupported bitstream profile");
#else
  if (cm->profile >= PROFILE_2)
    aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                       "Unsupported bitstream profile");
#endif

  cm->show_existing_frame = aom_rb_read_bit(rb);
  if (cm->show_existing_frame) {
    // Show an existing frame directly.
    const int frame_to_show = cm->ref_frame_map[aom_rb_read_literal(rb, 3)];
    lock_buffer_pool(pool);
    if (frame_to_show < 0 || frame_bufs[frame_to_show].ref_count < 1) {
      unlock_buffer_pool(pool);
      aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                         "Buffer %d does not contain a decoded frame",
                         frame_to_show);
    }

    ref_cnt_fb(frame_bufs, &cm->new_fb_idx, frame_to_show);
    unlock_buffer_pool(pool);
    cm->lf.filter_level = 0;
    cm->show_frame = 1;

#if CONFIG_EXT_REFS
    // NOTE: The existing frame to show is adopted as a reference frame.
    pbi->refresh_frame_flags = aom_rb_read_literal(rb, REF_FRAMES);

    for (i = 0; i < REFS_PER_FRAME; ++i) {
      const int ref = aom_rb_read_literal(rb, REF_FRAMES_LOG2);
      const int idx = cm->ref_frame_map[ref];
      RefBuffer *const ref_frame = &cm->frame_refs[i];
      ref_frame->idx = idx;
      ref_frame->buf = &frame_bufs[idx].buf;
      cm->ref_frame_sign_bias[LAST_FRAME + i] = aom_rb_read_bit(rb);
    }

    for (i = 0; i < REFS_PER_FRAME; ++i) {
      RefBuffer *const ref_buf = &cm->frame_refs[i];
#if CONFIG_AOM_HIGHBITDEPTH
      av1_setup_scale_factors_for_frame(
          &ref_buf->sf, ref_buf->buf->y_crop_width, ref_buf->buf->y_crop_height,
          cm->width, cm->height, cm->use_highbitdepth);
#else   // CONFIG_AOM_HIGHBITDEPTH
      av1_setup_scale_factors_for_frame(
          &ref_buf->sf, ref_buf->buf->y_crop_width, ref_buf->buf->y_crop_height,
          cm->width, cm->height);
#endif  // CONFIG_AOM_HIGHBITDEPTH
    }

    // Generate next_ref_frame_map.
    lock_buffer_pool(pool);
    for (mask = pbi->refresh_frame_flags; mask; mask >>= 1) {
      if (mask & 1) {
        cm->next_ref_frame_map[ref_index] = cm->new_fb_idx;
        ++frame_bufs[cm->new_fb_idx].ref_count;
      } else {
        cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
      }
      // Current thread holds the reference frame.
      if (cm->ref_frame_map[ref_index] >= 0)
        ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
      ++ref_index;
    }

    for (; ref_index < REF_FRAMES; ++ref_index) {
      cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
      // Current thread holds the reference frame.
      if (cm->ref_frame_map[ref_index] >= 0)
        ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
    }
    unlock_buffer_pool(pool);
    pbi->hold_ref_buf = 1;
#else
    pbi->refresh_frame_flags = 0;
    if (cm->frame_parallel_decode) {
      for (i = 0; i < REF_FRAMES; ++i)
        cm->next_ref_frame_map[i] = cm->ref_frame_map[i];
    }
#endif  // CONFIG_EXT_REFS
    return 0;
  }

  cm->frame_type = (FRAME_TYPE)aom_rb_read_bit(rb);
  cm->show_frame = aom_rb_read_bit(rb);
  cm->error_resilient_mode = aom_rb_read_bit(rb);

  if (cm->frame_type == KEY_FRAME) {
    if (!av1_read_sync_code(rb))
      aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                         "Invalid frame sync code");

    read_bitdepth_colorspace_sampling(cm, rb);
    pbi->refresh_frame_flags = (1 << REF_FRAMES) - 1;

    for (i = 0; i < REFS_PER_FRAME; ++i) {
      cm->frame_refs[i].idx = INVALID_IDX;
      cm->frame_refs[i].buf = NULL;
    }

    setup_frame_size(cm, rb);
    if (pbi->need_resync) {
      memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
      pbi->need_resync = 0;
    }
#if CONFIG_PALETTE
    if (frame_is_intra_only(cm))
      cm->allow_screen_content_tools = aom_rb_read_bit(rb);
#endif  // CONFIG_PALETTE
  } else {
    cm->intra_only = cm->show_frame ? 0 : aom_rb_read_bit(rb);

    if (cm->error_resilient_mode) {
      cm->reset_frame_context = RESET_FRAME_CONTEXT_ALL;
    } else {
#if CONFIG_MISC_FIXES
      if (cm->intra_only) {
        cm->reset_frame_context = aom_rb_read_bit(rb)
                                      ? RESET_FRAME_CONTEXT_ALL
                                      : RESET_FRAME_CONTEXT_CURRENT;
      } else {
        cm->reset_frame_context = aom_rb_read_bit(rb)
                                      ? RESET_FRAME_CONTEXT_CURRENT
                                      : RESET_FRAME_CONTEXT_NONE;
        if (cm->reset_frame_context == RESET_FRAME_CONTEXT_CURRENT)
          cm->reset_frame_context = aom_rb_read_bit(rb)
                                        ? RESET_FRAME_CONTEXT_ALL
                                        : RESET_FRAME_CONTEXT_CURRENT;
      }
#else
      static const RESET_FRAME_CONTEXT_MODE reset_frame_context_conv_tbl[4] = {
        RESET_FRAME_CONTEXT_NONE, RESET_FRAME_CONTEXT_NONE,
        RESET_FRAME_CONTEXT_CURRENT, RESET_FRAME_CONTEXT_ALL
      };

      cm->reset_frame_context =
          reset_frame_context_conv_tbl[aom_rb_read_literal(rb, 2)];
#endif
    }

    if (cm->intra_only) {
      if (!av1_read_sync_code(rb))
        aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
                           "Invalid frame sync code");
#if CONFIG_MISC_FIXES
      read_bitdepth_colorspace_sampling(cm, rb);
#else
      if (cm->profile > PROFILE_0) {
        read_bitdepth_colorspace_sampling(cm, rb);
      } else {
        // NOTE: The intra-only frame header does not include the specification
        // of either the color format or color sub-sampling in profile 0. AV1
        // specifies that the default color format should be YUV 4:2:0 in this
        // case (normative).
        cm->color_space = AOM_CS_BT_601;
        cm->color_range = 0;
        cm->subsampling_y = cm->subsampling_x = 1;
        cm->bit_depth = AOM_BITS_8;
#if CONFIG_AOM_HIGHBITDEPTH
        cm->use_highbitdepth = 0;
#endif
      }
#endif

      pbi->refresh_frame_flags = aom_rb_read_literal(rb, REF_FRAMES);
      setup_frame_size(cm, rb);
      if (pbi->need_resync) {
        memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
        pbi->need_resync = 0;
      }
    } else if (pbi->need_resync != 1) { /* Skip if need resync */
      pbi->refresh_frame_flags = aom_rb_read_literal(rb, REF_FRAMES);

#if CONFIG_EXT_REFS
      if (!pbi->refresh_frame_flags) {
        // NOTE: "pbi->refresh_frame_flags == 0" indicates that the coded frame
        //       will not be used as a reference
        cm->is_reference_frame = 0;
      }
#endif  // CONFIG_EXT_REFS

      for (i = 0; i < REFS_PER_FRAME; ++i) {
        const int ref = aom_rb_read_literal(rb, REF_FRAMES_LOG2);
        const int idx = cm->ref_frame_map[ref];
        RefBuffer *const ref_frame = &cm->frame_refs[i];
        ref_frame->idx = idx;
        ref_frame->buf = &frame_bufs[idx].buf;
        cm->ref_frame_sign_bias[LAST_FRAME + i] = aom_rb_read_bit(rb);
      }

#if CONFIG_FRAME_SIZE
      if (cm->error_resilient_mode == 0) {
        setup_frame_size_with_refs(cm, rb);
      } else {
        setup_frame_size(cm, rb);
      }
#else
      setup_frame_size_with_refs(cm, rb);
#endif

      cm->allow_high_precision_mv = aom_rb_read_bit(rb);
      cm->interp_filter = read_interp_filter(rb);

      for (i = 0; i < REFS_PER_FRAME; ++i) {
        RefBuffer *const ref_buf = &cm->frame_refs[i];
#if CONFIG_AOM_HIGHBITDEPTH
        av1_setup_scale_factors_for_frame(
            &ref_buf->sf, ref_buf->buf->y_crop_width,
            ref_buf->buf->y_crop_height, cm->width, cm->height,
            cm->use_highbitdepth);
#else
        av1_setup_scale_factors_for_frame(
            &ref_buf->sf, ref_buf->buf->y_crop_width,
            ref_buf->buf->y_crop_height, cm->width, cm->height);
#endif
      }
    }
  }
#if CONFIG_AOM_HIGHBITDEPTH
  get_frame_new_buffer(cm)->bit_depth = cm->bit_depth;
#endif
  get_frame_new_buffer(cm)->color_space = cm->color_space;
  get_frame_new_buffer(cm)->color_range = cm->color_range;
  get_frame_new_buffer(cm)->render_width = cm->render_width;
  get_frame_new_buffer(cm)->render_height = cm->render_height;

  if (pbi->need_resync) {
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Keyframe / intra-only frame required to reset decoder"
                       " state");
  }

  if (!cm->error_resilient_mode) {
    cm->refresh_frame_context = aom_rb_read_bit(rb)
                                    ? REFRESH_FRAME_CONTEXT_FORWARD
                                    : REFRESH_FRAME_CONTEXT_OFF;
    if (cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_FORWARD) {
      cm->refresh_frame_context = aom_rb_read_bit(rb)
                                      ? REFRESH_FRAME_CONTEXT_FORWARD
                                      : REFRESH_FRAME_CONTEXT_BACKWARD;
#if !CONFIG_MISC_FIXES
    } else {
      aom_rb_read_bit(rb);  // parallel decoding mode flag
#endif
    }
  } else {
    cm->refresh_frame_context = REFRESH_FRAME_CONTEXT_OFF;
  }

  // This flag will be overridden by the call to av1_setup_past_independence
  // below, forcing the use of context 0 for those frame types.
  cm->frame_context_idx = aom_rb_read_literal(rb, FRAME_CONTEXTS_LOG2);

  // Generate next_ref_frame_map.
  lock_buffer_pool(pool);
  for (mask = pbi->refresh_frame_flags; mask; mask >>= 1) {
    if (mask & 1) {
      cm->next_ref_frame_map[ref_index] = cm->new_fb_idx;
      ++frame_bufs[cm->new_fb_idx].ref_count;
    } else {
      cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
    }
    // Current thread holds the reference frame.
    if (cm->ref_frame_map[ref_index] >= 0)
      ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
    ++ref_index;
  }

  for (; ref_index < REF_FRAMES; ++ref_index) {
    cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
    // Current thread holds the reference frame.
    if (cm->ref_frame_map[ref_index] >= 0)
      ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
  }
  unlock_buffer_pool(pool);
  pbi->hold_ref_buf = 1;

  if (frame_is_intra_only(cm) || cm->error_resilient_mode)
    av1_setup_past_independence(cm);

  setup_loopfilter(&cm->lf, rb);
#if CONFIG_CLPF
  setup_clpf(cm, rb);
#endif
#if CONFIG_DERING
  setup_dering(cm, rb);
#endif
  setup_quantization(cm, rb);
#if CONFIG_AOM_HIGHBITDEPTH
  xd->bd = (int)cm->bit_depth;
#endif

  setup_segmentation(cm, rb);

  for (i = 0; i < MAX_SEGMENTS; ++i) {
    const int qindex = CONFIG_MISC_FIXES && cm->seg.enabled
                           ? av1_get_qindex(&cm->seg, i, cm->base_qindex)
                           : cm->base_qindex;
    xd->lossless[i] = qindex == 0 && cm->y_dc_delta_q == 0 &&
                      cm->uv_dc_delta_q == 0 && cm->uv_ac_delta_q == 0;
  }

  setup_segmentation_dequant(cm);
#if CONFIG_MISC_FIXES
  cm->tx_mode =
      (!cm->seg.enabled && xd->lossless[0]) ? ONLY_4X4 : read_tx_mode(rb);
  cm->reference_mode = read_frame_reference_mode(cm, rb);
#endif

  setup_tile_info(cm, rb);
  sz = aom_rb_read_literal(rb, 16);

  if (sz == 0)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Invalid header size");

  return sz;
}

static void read_ext_tx_probs(FRAME_CONTEXT *fc, aom_reader *r) {
  int i, j, k;
  if (aom_read(r, GROUP_DIFF_UPDATE_PROB, ACCT_STR)) {
    for (i = TX_4X4; i < EXT_TX_SIZES; ++i) {
      for (j = 0; j < TX_TYPES; ++j) {
        for (k = 0; k < TX_TYPES - 1; ++k)
          av1_diff_update_prob(r, &fc->intra_ext_tx_prob[i][j][k], ACCT_STR);
#if CONFIG_DAALA_EC
        av1_tree_to_cdf(av1_ext_tx_tree, fc->intra_ext_tx_prob[i][j],
                        fc->intra_ext_tx_cdf[i][j]);
#endif
      }
    }
  }
  if (aom_read(r, GROUP_DIFF_UPDATE_PROB, ACCT_STR)) {
    for (i = TX_4X4; i < EXT_TX_SIZES; ++i) {
      for (k = 0; k < TX_TYPES - 1; ++k)
        av1_diff_update_prob(r, &fc->inter_ext_tx_prob[i][k], ACCT_STR);
#if CONFIG_DAALA_EC
      av1_tree_to_cdf(av1_ext_tx_tree, fc->inter_ext_tx_prob[i],
                      fc->inter_ext_tx_cdf[i]);
#endif
    }
  }
}

static int read_compressed_header(AV1Decoder *pbi, const uint8_t *data,
                                  size_t partition_size) {
  AV1_COMMON *const cm = &pbi->common;
#if !CONFIG_MISC_FIXES
  MACROBLOCKD *const xd = &pbi->mb;
#endif
  FRAME_CONTEXT *const fc = cm->fc;
  aom_reader r;
  int k, i, j;

  if (aom_reader_init(&r, data, partition_size, pbi->decrypt_cb,
                      pbi->decrypt_state))
    aom_internal_error(&cm->error, AOM_CODEC_MEM_ERROR,
                       "Failed to allocate bool decoder 0");

#if !CONFIG_MISC_FIXES
  cm->tx_mode = xd->lossless[0] ? ONLY_4X4 : read_tx_mode(&r);
#endif
  if (cm->tx_mode == TX_MODE_SELECT) read_tx_mode_probs(&fc->tx_probs, &r);
  read_coef_probs(fc, cm->tx_mode, &r);

  for (k = 0; k < SKIP_CONTEXTS; ++k)
    av1_diff_update_prob(&r, &fc->skip_probs[k], ACCT_STR);

#if CONFIG_MISC_FIXES
  if (cm->seg.enabled && cm->seg.update_map) {
    if (cm->seg.temporal_update) {
      for (k = 0; k < PREDICTION_PROBS; k++)
        av1_diff_update_prob(&r, &cm->fc->seg.pred_probs[k], ACCT_STR);
    }
    for (k = 0; k < MAX_SEGMENTS - 1; k++)
      av1_diff_update_prob(&r, &cm->fc->seg.tree_probs[k], ACCT_STR);
#if CONFIG_DAALA_EC
    av1_tree_to_cdf(av1_segment_tree, cm->fc->seg.tree_probs,
                    cm->fc->seg.tree_cdf);
#endif
  }

  for (j = 0; j < INTRA_MODES; j++)
    for (i = 0; i < INTRA_MODES - 1; ++i)
      av1_diff_update_prob(&r, &fc->uv_mode_prob[j][i], ACCT_STR);

  for (j = 0; j < PARTITION_CONTEXTS; ++j) {
    for (i = 0; i < PARTITION_TYPES - 1; ++i)
      av1_diff_update_prob(&r, &fc->partition_prob[j][i], ACCT_STR);
#if CONFIG_DAALA_EC
    av1_tree_to_cdf(av1_partition_tree, fc->partition_prob[j],
                    fc->partition_cdf[j]);
#endif
  }
#endif

  if (frame_is_intra_only(cm)) {
    av1_copy(cm->kf_y_prob, av1_kf_y_mode_prob);
#if CONFIG_MISC_FIXES
    for (k = 0; k < INTRA_MODES; k++)
      for (j = 0; j < INTRA_MODES; j++)
        for (i = 0; i < INTRA_MODES - 1; ++i)
          av1_diff_update_prob(&r, &cm->kf_y_prob[k][j][i], ACCT_STR);
#endif
  } else {
#if !CONFIG_REF_MV
    nmv_context *const nmvc = &fc->nmvc;
#endif
    read_inter_mode_probs(fc, &r);

#if CONFIG_MOTION_VAR
    for (j = 0; j < BLOCK_SIZES; ++j)
      if (is_motion_variation_allowed_bsize(j)) {
        for (i = 0; i < MOTION_MODES - 1; ++i)
          av1_diff_update_prob(&r, &fc->motion_mode_prob[j][i], ACCT_STR);
      }
#endif  // CONFIG_MOTION_VAR

    if (cm->interp_filter == SWITCHABLE) read_switchable_interp_probs(fc, &r);

    for (i = 0; i < INTRA_INTER_CONTEXTS; i++)
      av1_diff_update_prob(&r, &fc->intra_inter_prob[i], ACCT_STR);

#if !CONFIG_MISC_FIXES
    cm->reference_mode = read_frame_reference_mode(cm, &r);
#endif
    if (cm->reference_mode != SINGLE_REFERENCE)
      setup_compound_reference_mode(cm);
    read_frame_reference_mode_probs(cm, &r);

    for (j = 0; j < BLOCK_SIZE_GROUPS; j++)
      for (i = 0; i < INTRA_MODES - 1; ++i)
        av1_diff_update_prob(&r, &fc->y_mode_prob[j][i], ACCT_STR);

#if !CONFIG_MISC_FIXES
    for (j = 0; j < PARTITION_CONTEXTS; ++j) {
      for (i = 0; i < PARTITION_TYPES - 1; ++i)
        av1_diff_update_prob(&r, &fc->partition_prob[j][i], ACCT_STR);
#if CONFIG_DAALA_EC
      av1_tree_to_cdf(av1_partition_tree, fc->partition_prob[j],
                      fc->partition_cdf[j]);
#endif
    }
#endif

#if CONFIG_REF_MV
    for (i = 0; i < NMV_CONTEXTS; ++i)
      read_mv_probs(&fc->nmvc[i], cm->allow_high_precision_mv, &r);
#else
    read_mv_probs(nmvc, cm->allow_high_precision_mv, &r);
#endif
    read_ext_tx_probs(fc, &r);
  }

  return aom_reader_has_error(&r);
}

#ifdef NDEBUG
#define debug_check_frame_counts(cm) (void)0
#else  // !NDEBUG
// Counts should only be incremented when frame_parallel_decoding_mode and
// error_resilient_mode are disabled.
static void debug_check_frame_counts(const AV1_COMMON *const cm) {
  FRAME_COUNTS zero_counts;
  av1_zero(zero_counts);
  assert(cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_BACKWARD ||
         cm->error_resilient_mode);
  assert(!memcmp(cm->counts.y_mode, zero_counts.y_mode,
                 sizeof(cm->counts.y_mode)));
  assert(!memcmp(cm->counts.uv_mode, zero_counts.uv_mode,
                 sizeof(cm->counts.uv_mode)));
  assert(!memcmp(cm->counts.partition, zero_counts.partition,
                 sizeof(cm->counts.partition)));
  assert(!memcmp(cm->counts.coef, zero_counts.coef, sizeof(cm->counts.coef)));
  assert(!memcmp(cm->counts.eob_branch, zero_counts.eob_branch,
                 sizeof(cm->counts.eob_branch)));
  assert(!memcmp(cm->counts.switchable_interp, zero_counts.switchable_interp,
                 sizeof(cm->counts.switchable_interp)));
  assert(!memcmp(cm->counts.inter_mode, zero_counts.inter_mode,
                 sizeof(cm->counts.inter_mode)));
#if CONFIG_MOTION_VAR
  assert(!memcmp(cm->counts.motion_mode, zero_counts.motion_mode,
                 sizeof(cm->counts.motion_mode)));
#endif  // CONFIG_MOTION_VAR
  assert(!memcmp(cm->counts.intra_inter, zero_counts.intra_inter,
                 sizeof(cm->counts.intra_inter)));
  assert(!memcmp(cm->counts.comp_inter, zero_counts.comp_inter,
                 sizeof(cm->counts.comp_inter)));
  assert(!memcmp(cm->counts.single_ref, zero_counts.single_ref,
                 sizeof(cm->counts.single_ref)));
#if CONFIG_EXT_REFS
  assert(!memcmp(cm->counts.comp_fwdref, zero_counts.comp_fwdref,
                 sizeof(cm->counts.comp_fwdref)));
  assert(!memcmp(cm->counts.comp_bwdref, zero_counts.comp_bwdref,
                 sizeof(cm->counts.comp_bwdref)));
#else
  assert(!memcmp(cm->counts.comp_ref, zero_counts.comp_ref,
                 sizeof(cm->counts.comp_ref)));
#endif  // CONFIG_EXT_REFS
  assert(!memcmp(&cm->counts.tx, &zero_counts.tx, sizeof(cm->counts.tx)));
  assert(!memcmp(cm->counts.skip, zero_counts.skip, sizeof(cm->counts.skip)));
#if CONFIG_REF_MV
  assert(
      !memcmp(&cm->counts.mv[0], &zero_counts.mv[0], sizeof(cm->counts.mv[0])));
  assert(
      !memcmp(&cm->counts.mv[1], &zero_counts.mv[1], sizeof(cm->counts.mv[0])));
#else
  assert(!memcmp(&cm->counts.mv, &zero_counts.mv, sizeof(cm->counts.mv)));
#endif
  assert(!memcmp(cm->counts.intra_ext_tx, zero_counts.intra_ext_tx,
                 sizeof(cm->counts.intra_ext_tx)));
  assert(!memcmp(cm->counts.inter_ext_tx, zero_counts.inter_ext_tx,
                 sizeof(cm->counts.inter_ext_tx)));
}
#endif  // NDEBUG

static struct aom_read_bit_buffer *init_read_bit_buffer(
    AV1Decoder *pbi, struct aom_read_bit_buffer *rb, const uint8_t *data,
    const uint8_t *data_end, uint8_t clear_data[MAX_AV1_HEADER_SIZE]) {
  rb->bit_offset = 0;
  rb->error_handler = error_handler;
  rb->error_handler_data = &pbi->common;
  if (pbi->decrypt_cb) {
    const int n = (int)AOMMIN(MAX_AV1_HEADER_SIZE, data_end - data);
    pbi->decrypt_cb(pbi->decrypt_state, data, clear_data, n);
    rb->bit_buffer = clear_data;
    rb->bit_buffer_end = clear_data + n;
  } else {
    rb->bit_buffer = data;
    rb->bit_buffer_end = data_end;
  }
  return rb;
}

//------------------------------------------------------------------------------

int av1_read_sync_code(struct aom_read_bit_buffer *const rb) {
  return aom_rb_read_literal(rb, 8) == AV1_SYNC_CODE_0 &&
         aom_rb_read_literal(rb, 8) == AV1_SYNC_CODE_1 &&
         aom_rb_read_literal(rb, 8) == AV1_SYNC_CODE_2;
}

void av1_read_frame_size(struct aom_read_bit_buffer *rb, int *width,
                         int *height) {
  *width = aom_rb_read_literal(rb, 16) + 1;
  *height = aom_rb_read_literal(rb, 16) + 1;
}

BITSTREAM_PROFILE av1_read_profile(struct aom_read_bit_buffer *rb) {
  int profile = aom_rb_read_bit(rb);
  profile |= aom_rb_read_bit(rb) << 1;
  if (profile > 2) profile += aom_rb_read_bit(rb);
  return (BITSTREAM_PROFILE)profile;
}

void av1_decode_frame(AV1Decoder *pbi, const uint8_t *data,
                      const uint8_t *data_end, const uint8_t **p_data_end) {
  AV1_COMMON *const cm = &pbi->common;
  MACROBLOCKD *const xd = &pbi->mb;
  struct aom_read_bit_buffer rb;
  int context_updated = 0;
  uint8_t clear_data[MAX_AV1_HEADER_SIZE];
  const size_t first_partition_size = read_uncompressed_header(
      pbi, init_read_bit_buffer(pbi, &rb, data, data_end, clear_data));
  const int tile_rows = 1 << cm->log2_tile_rows;
  const int tile_cols = 1 << cm->log2_tile_cols;
  YV12_BUFFER_CONFIG *const new_fb = get_frame_new_buffer(cm);
  xd->cur_buf = new_fb;

  if (!first_partition_size) {
// showing a frame directly
#if CONFIG_EXT_REFS
    if (cm->show_existing_frame)
      *p_data_end = data + aom_rb_bytes_read(&rb);
    else
#endif  // CONFIG_EXT_REFS
      *p_data_end = data + (cm->profile <= PROFILE_2 ? 1 : 2);
    return;
  }

  data += aom_rb_bytes_read(&rb);
  if (!read_is_valid(data, first_partition_size, data_end))
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Truncated packet or corrupt header length");

  cm->use_prev_frame_mvs =
      !cm->error_resilient_mode && cm->width == cm->last_width &&
      cm->height == cm->last_height && !cm->last_intra_only &&
      cm->last_show_frame && (cm->last_frame_type != KEY_FRAME);
#if CONFIG_EXT_REFS
  // NOTE(zoeliu): As cm->prev_frame can take neither a frame of
  //               show_exisiting_frame=1, nor can it take a frame not used as
  //               a reference, it is probable that by the time it is being
  //               referred to, the frame buffer it originally points to may
  //               already get expired and have been reassigned to the current
  //               newly coded frame. Hence, we need to check whether this is
  //               the case, and if yes, we have 2 choices:
  //               (1) Simply disable the use of previous frame mvs; or
  //               (2) Have cm->prev_frame point to one reference frame buffer,
  //                   e.g. LAST_FRAME.
  if (cm->use_prev_frame_mvs && !dec_is_ref_frame_buf(pbi, cm->prev_frame)) {
    // Reassign the LAST_FRAME buffer to cm->prev_frame.
    RefBuffer *last_fb_ref_buf = &cm->frame_refs[LAST_FRAME - LAST_FRAME];
    cm->prev_frame = &cm->buffer_pool->frame_bufs[last_fb_ref_buf->idx];
  }
#endif  // CONFIG_EXT_REFS

  av1_setup_block_planes(xd, cm->subsampling_x, cm->subsampling_y);

  *cm->fc = cm->frame_contexts[cm->frame_context_idx];
  if (!cm->fc->initialized)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Uninitialized entropy context.");

  av1_zero(cm->counts);

  xd->corrupted = 0;
  new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
  if (new_fb->corrupted)
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Decode failed. Frame data header is corrupted.");

  if (cm->lf.filter_level && !cm->skip_loop_filter) {
    av1_loop_filter_frame_init(cm, cm->lf.filter_level);
  }

  // If encoded in frame parallel mode, frame context is ready after decoding
  // the frame header.
  if (cm->frame_parallel_decode &&
      cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_BACKWARD) {
    AVxWorker *const worker = pbi->frame_worker_owner;
    FrameWorkerData *const frame_worker_data = worker->data1;
    if (cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_FORWARD) {
      context_updated = 1;
      cm->frame_contexts[cm->frame_context_idx] = *cm->fc;
    }
    av1_frameworker_lock_stats(worker);
    pbi->cur_buf->row = -1;
    pbi->cur_buf->col = -1;
    frame_worker_data->frame_context_ready = 1;
    // Signal the main thread that context is ready.
    av1_frameworker_signal_stats(worker);
    av1_frameworker_unlock_stats(worker);
  }

  if (pbi->max_threads > 1 && tile_rows == 1 && tile_cols > 1) {
    // Multi-threaded tile decoder
    *p_data_end = decode_tiles_mt(pbi, data + first_partition_size, data_end);
    if (!xd->corrupted) {
      if (!cm->skip_loop_filter) {
        // If multiple threads are used to decode tiles, then we use those
        // threads to do parallel loopfiltering.
        av1_loop_filter_frame_mt(new_fb, cm, pbi->mb.plane, cm->lf.filter_level,
                                 0, 0, pbi->tile_workers, pbi->num_tile_workers,
                                 &pbi->lf_row_sync);
      }
    } else {
      aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                         "Decode failed. Frame data is corrupted.");
    }
  } else {
    *p_data_end = decode_tiles(pbi, data + first_partition_size, data_end);
  }

#if CONFIG_CLPF
  if (cm->clpf_strength && !cm->skip_loop_filter) {
    YV12_BUFFER_CONFIG dst;  // Buffer for the result

    dst = pbi->cur_buf->buf;
    CHECK_MEM_ERROR(cm, dst.y_buffer, aom_malloc(dst.y_stride * dst.y_height));

    av1_clpf_frame(&dst, &pbi->cur_buf->buf, 0, cm, !!cm->clpf_size,
                   cm->clpf_strength + (cm->clpf_strength == 3),
                   4 + cm->clpf_size, cm->clpf_blocks, clpf_bit);

    // Copy result
    memcpy(pbi->cur_buf->buf.y_buffer, dst.y_buffer,
           dst.y_height * dst.y_stride);
    aom_free(dst.y_buffer);
  }
  if (cm->clpf_blocks) aom_free(cm->clpf_blocks);
#endif
#if CONFIG_DERING
  if (cm->dering_level && !cm->skip_loop_filter) {
    av1_dering_frame(&pbi->cur_buf->buf, cm, &pbi->mb, cm->dering_level);
  }
#endif  // CONFIG_DERING

  if (!xd->corrupted) {
    if (cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_BACKWARD) {
      av1_adapt_coef_probs(cm);
#if CONFIG_MISC_FIXES
      av1_adapt_intra_frame_probs(cm);
#endif

      if (!frame_is_intra_only(cm)) {
#if !CONFIG_MISC_FIXES
        av1_adapt_intra_frame_probs(cm);
#endif
        av1_adapt_inter_frame_probs(cm);
        av1_adapt_mv_probs(cm, cm->allow_high_precision_mv);
      }
    } else {
      debug_check_frame_counts(cm);
    }
  } else {
    aom_internal_error(&cm->error, AOM_CODEC_CORRUPT_FRAME,
                       "Decode failed. Frame data is corrupted.");
  }

  // Non frame parallel update frame context here.
  if (cm->refresh_frame_context != REFRESH_FRAME_CONTEXT_OFF &&
      !context_updated)
    cm->frame_contexts[cm->frame_context_idx] = *cm->fc;
}