Merge pull request #850 from trav90/add-av1-support

Add initial support for AV1 video.

1 files changed, 3999 insertions, 0 deletions

diff --git a/third_party/aom/av1/encoder/bitstream.c b/third_party/aom/av1/encoder/bitstream.c
new file mode 100644
index 000000000..2c4acdb02
--- /dev/null
+++ b/third_party/aom/av1/encoder/bitstream.c
@@ -0,0 +1,3999 @@
+/*
+ * Copyright (c) 2016, Alliance for Open Media. All rights reserved
+ *
+ * This source code is subject to the terms of the BSD 2 Clause License and
+ * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
+ * was not distributed with this source code in the LICENSE file, you can
+ * obtain it at www.aomedia.org/license/software. If the Alliance for Open
+ * Media Patent License 1.0 was not distributed with this source code in the
+ * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
+ */
+
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+
+#include "aom/aom_encoder.h"
+#include "aom_dsp/aom_dsp_common.h"
+#include "aom_dsp/binary_codes_writer.h"
+#include "aom_dsp/bitwriter_buffer.h"
+#include "aom_mem/aom_mem.h"
+#include "aom_ports/bitops.h"
+#include "aom_ports/mem_ops.h"
+#include "aom_ports/system_state.h"
+#if CONFIG_BITSTREAM_DEBUG
+#include "aom_util/debug_util.h"
+#endif  // CONFIG_BITSTREAM_DEBUG
+
+#include "av1/common/cdef.h"
+#include "av1/common/cfl.h"
+#include "av1/common/entropy.h"
+#include "av1/common/entropymode.h"
+#include "av1/common/entropymv.h"
+#include "av1/common/mvref_common.h"
+#include "av1/common/pred_common.h"
+#include "av1/common/reconinter.h"
+#include "av1/common/reconintra.h"
+#include "av1/common/seg_common.h"
+#include "av1/common/tile_common.h"
+
+#include "av1/encoder/bitstream.h"
+#include "av1/encoder/cost.h"
+#include "av1/encoder/encodemv.h"
+#include "av1/encoder/encodetxb.h"
+#include "av1/encoder/mcomp.h"
+#include "av1/encoder/palette.h"
+#include "av1/encoder/segmentation.h"
+#include "av1/encoder/tokenize.h"
+
+#define ENC_MISMATCH_DEBUG 0
+
+static INLINE void write_uniform(aom_writer *w, int n, int v) {
+  const int l = get_unsigned_bits(n);
+  const int m = (1 << l) - n;
+  if (l == 0) return;
+  if (v < m) {
+    aom_write_literal(w, v, l - 1);
+  } else {
+    aom_write_literal(w, m + ((v - m) >> 1), l - 1);
+    aom_write_literal(w, (v - m) & 1, 1);
+  }
+}
+
+static void loop_restoration_write_sb_coeffs(const AV1_COMMON *const cm,
+                                             MACROBLOCKD *xd,
+                                             const RestorationUnitInfo *rui,
+                                             aom_writer *const w, int plane,
+                                             FRAME_COUNTS *counts);
+
+static void write_intra_y_mode_kf(FRAME_CONTEXT *frame_ctx,
+                                  const MB_MODE_INFO *mi,
+                                  const MB_MODE_INFO *above_mi,
+                                  const MB_MODE_INFO *left_mi,
+                                  PREDICTION_MODE mode, aom_writer *w) {
+  assert(!is_intrabc_block(mi));
+  (void)mi;
+  aom_write_symbol(w, mode, get_y_mode_cdf(frame_ctx, above_mi, left_mi),
+                   INTRA_MODES);
+}
+
+static void write_inter_mode(aom_writer *w, PREDICTION_MODE mode,
+                             FRAME_CONTEXT *ec_ctx, const int16_t mode_ctx) {
+  const int16_t newmv_ctx = mode_ctx & NEWMV_CTX_MASK;
+
+  aom_write_symbol(w, mode != NEWMV, ec_ctx->newmv_cdf[newmv_ctx], 2);
+
+  if (mode != NEWMV) {
+    const int16_t zeromv_ctx =
+        (mode_ctx >> GLOBALMV_OFFSET) & GLOBALMV_CTX_MASK;
+    aom_write_symbol(w, mode != GLOBALMV, ec_ctx->zeromv_cdf[zeromv_ctx], 2);
+
+    if (mode != GLOBALMV) {
+      int16_t refmv_ctx = (mode_ctx >> REFMV_OFFSET) & REFMV_CTX_MASK;
+      aom_write_symbol(w, mode != NEARESTMV, ec_ctx->refmv_cdf[refmv_ctx], 2);
+    }
+  }
+}
+
+static void write_drl_idx(FRAME_CONTEXT *ec_ctx, const MB_MODE_INFO *mbmi,
+                          const MB_MODE_INFO_EXT *mbmi_ext, aom_writer *w) {
+  uint8_t ref_frame_type = av1_ref_frame_type(mbmi->ref_frame);
+
+  assert(mbmi->ref_mv_idx < 3);
+
+  const int new_mv = mbmi->mode == NEWMV || mbmi->mode == NEW_NEWMV;
+  if (new_mv) {
+    int idx;
+    for (idx = 0; idx < 2; ++idx) {
+      if (mbmi_ext->ref_mv_count[ref_frame_type] > idx + 1) {
+        uint8_t drl_ctx =
+            av1_drl_ctx(mbmi_ext->ref_mv_stack[ref_frame_type], idx);
+
+        aom_write_symbol(w, mbmi->ref_mv_idx != idx, ec_ctx->drl_cdf[drl_ctx],
+                         2);
+        if (mbmi->ref_mv_idx == idx) return;
+      }
+    }
+    return;
+  }
+
+  if (have_nearmv_in_inter_mode(mbmi->mode)) {
+    int idx;
+    // TODO(jingning): Temporary solution to compensate the NEARESTMV offset.
+    for (idx = 1; idx < 3; ++idx) {
+      if (mbmi_ext->ref_mv_count[ref_frame_type] > idx + 1) {
+        uint8_t drl_ctx =
+            av1_drl_ctx(mbmi_ext->ref_mv_stack[ref_frame_type], idx);
+        aom_write_symbol(w, mbmi->ref_mv_idx != (idx - 1),
+                         ec_ctx->drl_cdf[drl_ctx], 2);
+        if (mbmi->ref_mv_idx == (idx - 1)) return;
+      }
+    }
+    return;
+  }
+}
+
+static void write_inter_compound_mode(MACROBLOCKD *xd, aom_writer *w,
+                                      PREDICTION_MODE mode,
+                                      const int16_t mode_ctx) {
+  assert(is_inter_compound_mode(mode));
+  aom_write_symbol(w, INTER_COMPOUND_OFFSET(mode),
+                   xd->tile_ctx->inter_compound_mode_cdf[mode_ctx],
+                   INTER_COMPOUND_MODES);
+}
+
+static void write_tx_size_vartx(MACROBLOCKD *xd, const MB_MODE_INFO *mbmi,
+                                TX_SIZE tx_size, int depth, int blk_row,
+                                int blk_col, aom_writer *w) {
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  const int max_blocks_high = max_block_high(xd, mbmi->sb_type, 0);
+  const int max_blocks_wide = max_block_wide(xd, mbmi->sb_type, 0);
+
+  if (blk_row >= max_blocks_high || blk_col >= max_blocks_wide) return;
+
+  if (depth == MAX_VARTX_DEPTH) {
+    txfm_partition_update(xd->above_txfm_context + blk_col,
+                          xd->left_txfm_context + blk_row, tx_size, tx_size);
+    return;
+  }
+
+  const int ctx = txfm_partition_context(xd->above_txfm_context + blk_col,
+                                         xd->left_txfm_context + blk_row,
+                                         mbmi->sb_type, tx_size);
+  const int txb_size_index =
+      av1_get_txb_size_index(mbmi->sb_type, blk_row, blk_col);
+  const int write_txfm_partition =
+      tx_size == mbmi->inter_tx_size[txb_size_index];
+  if (write_txfm_partition) {
+    aom_write_symbol(w, 0, ec_ctx->txfm_partition_cdf[ctx], 2);
+
+    txfm_partition_update(xd->above_txfm_context + blk_col,
+                          xd->left_txfm_context + blk_row, tx_size, tx_size);
+    // TODO(yuec): set correct txfm partition update for qttx
+  } else {
+    const TX_SIZE sub_txs = sub_tx_size_map[tx_size];
+    const int bsw = tx_size_wide_unit[sub_txs];
+    const int bsh = tx_size_high_unit[sub_txs];
+
+    aom_write_symbol(w, 1, ec_ctx->txfm_partition_cdf[ctx], 2);
+
+    if (sub_txs == TX_4X4) {
+      txfm_partition_update(xd->above_txfm_context + blk_col,
+                            xd->left_txfm_context + blk_row, sub_txs, tx_size);
+      return;
+    }
+
+    assert(bsw > 0 && bsh > 0);
+    for (int row = 0; row < tx_size_high_unit[tx_size]; row += bsh)
+      for (int col = 0; col < tx_size_wide_unit[tx_size]; col += bsw) {
+        int offsetr = blk_row + row;
+        int offsetc = blk_col + col;
+        write_tx_size_vartx(xd, mbmi, sub_txs, depth + 1, offsetr, offsetc, w);
+      }
+  }
+}
+
+static void write_selected_tx_size(const MACROBLOCKD *xd, aom_writer *w) {
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  if (block_signals_txsize(bsize)) {
+    const TX_SIZE tx_size = mbmi->tx_size;
+    const int tx_size_ctx = get_tx_size_context(xd);
+    const int depth = tx_size_to_depth(tx_size, bsize);
+    const int max_depths = bsize_to_max_depth(bsize);
+    const int32_t tx_size_cat = bsize_to_tx_size_cat(bsize);
+
+    assert(depth >= 0 && depth <= max_depths);
+    assert(!is_inter_block(mbmi));
+    assert(IMPLIES(is_rect_tx(tx_size), is_rect_tx_allowed(xd, mbmi)));
+
+    aom_write_symbol(w, depth, ec_ctx->tx_size_cdf[tx_size_cat][tx_size_ctx],
+                     max_depths + 1);
+  }
+}
+
+static int write_skip(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                      int segment_id, const MB_MODE_INFO *mi, aom_writer *w) {
+  if (segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)) {
+    return 1;
+  } else {
+    const int skip = mi->skip;
+    const int ctx = av1_get_skip_context(xd);
+    FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+    aom_write_symbol(w, skip, ec_ctx->skip_cdfs[ctx], 2);
+    return skip;
+  }
+}
+
+static int write_skip_mode(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                           int segment_id, const MB_MODE_INFO *mi,
+                           aom_writer *w) {
+  if (!cm->skip_mode_flag) return 0;
+  if (segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP)) {
+    return 0;
+  }
+  const int skip_mode = mi->skip_mode;
+  if (!is_comp_ref_allowed(mi->sb_type)) {
+    assert(!skip_mode);
+    return 0;
+  }
+  if (segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME) ||
+      segfeature_active(&cm->seg, segment_id, SEG_LVL_GLOBALMV)) {
+    // These features imply single-reference mode, while skip mode implies
+    // compound reference. Hence, the two are mutually exclusive.
+    // In other words, skip_mode is implicitly 0 here.
+    assert(!skip_mode);
+    return 0;
+  }
+  const int ctx = av1_get_skip_mode_context(xd);
+  aom_write_symbol(w, skip_mode, xd->tile_ctx->skip_mode_cdfs[ctx], 2);
+  return skip_mode;
+}
+
+static void write_is_inter(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                           int segment_id, aom_writer *w, const int is_inter) {
+  if (!segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
+    if (segfeature_active(&cm->seg, segment_id, SEG_LVL_GLOBALMV)) {
+      assert(is_inter);
+      return;
+    }
+    const int ctx = av1_get_intra_inter_context(xd);
+    FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+    aom_write_symbol(w, is_inter, ec_ctx->intra_inter_cdf[ctx], 2);
+  }
+}
+
+static void write_motion_mode(const AV1_COMMON *cm, MACROBLOCKD *xd,
+                              const MB_MODE_INFO *mbmi, aom_writer *w) {
+  MOTION_MODE last_motion_mode_allowed =
+      cm->switchable_motion_mode
+          ? motion_mode_allowed(cm->global_motion, xd, mbmi,
+                                cm->allow_warped_motion)
+          : SIMPLE_TRANSLATION;
+  assert(mbmi->motion_mode <= last_motion_mode_allowed);
+  switch (last_motion_mode_allowed) {
+    case SIMPLE_TRANSLATION: break;
+    case OBMC_CAUSAL:
+      aom_write_symbol(w, mbmi->motion_mode == OBMC_CAUSAL,
+                       xd->tile_ctx->obmc_cdf[mbmi->sb_type], 2);
+      break;
+    default:
+      aom_write_symbol(w, mbmi->motion_mode,
+                       xd->tile_ctx->motion_mode_cdf[mbmi->sb_type],
+                       MOTION_MODES);
+  }
+}
+
+static void write_delta_qindex(const MACROBLOCKD *xd, int delta_qindex,
+                               aom_writer *w) {
+  int sign = delta_qindex < 0;
+  int abs = sign ? -delta_qindex : delta_qindex;
+  int rem_bits, thr;
+  int smallval = abs < DELTA_Q_SMALL ? 1 : 0;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+
+  aom_write_symbol(w, AOMMIN(abs, DELTA_Q_SMALL), ec_ctx->delta_q_cdf,
+                   DELTA_Q_PROBS + 1);
+
+  if (!smallval) {
+    rem_bits = get_msb(abs - 1);
+    thr = (1 << rem_bits) + 1;
+    aom_write_literal(w, rem_bits - 1, 3);
+    aom_write_literal(w, abs - thr, rem_bits);
+  }
+  if (abs > 0) {
+    aom_write_bit(w, sign);
+  }
+}
+
+static void write_delta_lflevel(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                                int lf_id, int delta_lflevel, aom_writer *w) {
+  int sign = delta_lflevel < 0;
+  int abs = sign ? -delta_lflevel : delta_lflevel;
+  int rem_bits, thr;
+  int smallval = abs < DELTA_LF_SMALL ? 1 : 0;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+
+  if (cm->delta_lf_multi) {
+    assert(lf_id >= 0 && lf_id < (av1_num_planes(cm) > 1 ? FRAME_LF_COUNT
+                                                         : FRAME_LF_COUNT - 2));
+    aom_write_symbol(w, AOMMIN(abs, DELTA_LF_SMALL),
+                     ec_ctx->delta_lf_multi_cdf[lf_id], DELTA_LF_PROBS + 1);
+  } else {
+    aom_write_symbol(w, AOMMIN(abs, DELTA_LF_SMALL), ec_ctx->delta_lf_cdf,
+                     DELTA_LF_PROBS + 1);
+  }
+
+  if (!smallval) {
+    rem_bits = get_msb(abs - 1);
+    thr = (1 << rem_bits) + 1;
+    aom_write_literal(w, rem_bits - 1, 3);
+    aom_write_literal(w, abs - thr, rem_bits);
+  }
+  if (abs > 0) {
+    aom_write_bit(w, sign);
+  }
+}
+
+static void pack_map_tokens(aom_writer *w, const TOKENEXTRA **tp, int n,
+                            int num) {
+  const TOKENEXTRA *p = *tp;
+  write_uniform(w, n, p->token);  // The first color index.
+  ++p;
+  --num;
+  for (int i = 0; i < num; ++i) {
+    aom_write_symbol(w, p->token, p->color_map_cdf, n);
+    ++p;
+  }
+  *tp = p;
+}
+
+static void pack_txb_tokens(aom_writer *w, AV1_COMMON *cm, MACROBLOCK *const x,
+                            const TOKENEXTRA **tp,
+                            const TOKENEXTRA *const tok_end, MACROBLOCKD *xd,
+                            MB_MODE_INFO *mbmi, int plane,
+                            BLOCK_SIZE plane_bsize, aom_bit_depth_t bit_depth,
+                            int block, int blk_row, int blk_col,
+                            TX_SIZE tx_size, TOKEN_STATS *token_stats) {
+  const int max_blocks_high = max_block_high(xd, plane_bsize, plane);
+  const int max_blocks_wide = max_block_wide(xd, plane_bsize, plane);
+
+  if (blk_row >= max_blocks_high || blk_col >= max_blocks_wide) return;
+
+  const struct macroblockd_plane *const pd = &xd->plane[plane];
+  const TX_SIZE plane_tx_size =
+      plane ? av1_get_max_uv_txsize(mbmi->sb_type, pd->subsampling_x,
+                                    pd->subsampling_y)
+            : mbmi->inter_tx_size[av1_get_txb_size_index(plane_bsize, blk_row,
+                                                         blk_col)];
+
+  if (tx_size == plane_tx_size || plane) {
+    tran_low_t *tcoeff = BLOCK_OFFSET(x->mbmi_ext->tcoeff[plane], block);
+    const uint16_t eob = x->mbmi_ext->eobs[plane][block];
+    TXB_CTX txb_ctx = { x->mbmi_ext->txb_skip_ctx[plane][block],
+                        x->mbmi_ext->dc_sign_ctx[plane][block] };
+    av1_write_coeffs_txb(cm, xd, w, blk_row, blk_col, plane, tx_size, tcoeff,
+                         eob, &txb_ctx);
+#if CONFIG_RD_DEBUG
+    TOKEN_STATS tmp_token_stats;
+    init_token_stats(&tmp_token_stats);
+    token_stats->txb_coeff_cost_map[blk_row][blk_col] = tmp_token_stats.cost;
+    token_stats->cost += tmp_token_stats.cost;
+#endif
+  } else {
+    const TX_SIZE sub_txs = sub_tx_size_map[tx_size];
+    const int bsw = tx_size_wide_unit[sub_txs];
+    const int bsh = tx_size_high_unit[sub_txs];
+    const int step = bsh * bsw;
+
+    assert(bsw > 0 && bsh > 0);
+
+    for (int r = 0; r < tx_size_high_unit[tx_size]; r += bsh) {
+      for (int c = 0; c < tx_size_wide_unit[tx_size]; c += bsw) {
+        const int offsetr = blk_row + r;
+        const int offsetc = blk_col + c;
+        if (offsetr >= max_blocks_high || offsetc >= max_blocks_wide) continue;
+        pack_txb_tokens(w, cm, x, tp, tok_end, xd, mbmi, plane, plane_bsize,
+                        bit_depth, block, offsetr, offsetc, sub_txs,
+                        token_stats);
+        block += step;
+      }
+    }
+  }
+}
+
+static INLINE void set_spatial_segment_id(const AV1_COMMON *const cm,
+                                          uint8_t *segment_ids,
+                                          BLOCK_SIZE bsize, int mi_row,
+                                          int mi_col, int segment_id) {
+  const int mi_offset = mi_row * cm->mi_cols + mi_col;
+  const int bw = mi_size_wide[bsize];
+  const int bh = mi_size_high[bsize];
+  const int xmis = AOMMIN(cm->mi_cols - mi_col, bw);
+  const int ymis = AOMMIN(cm->mi_rows - mi_row, bh);
+  int x, y;
+
+  for (y = 0; y < ymis; ++y)
+    for (x = 0; x < xmis; ++x)
+      segment_ids[mi_offset + y * cm->mi_cols + x] = segment_id;
+}
+
+int av1_neg_interleave(int x, int ref, int max) {
+  assert(x < max);
+  const int diff = x - ref;
+  if (!ref) return x;
+  if (ref >= (max - 1)) return -x + max - 1;
+  if (2 * ref < max) {
+    if (abs(diff) <= ref) {
+      if (diff > 0)
+        return (diff << 1) - 1;
+      else
+        return ((-diff) << 1);
+    }
+    return x;
+  } else {
+    if (abs(diff) < (max - ref)) {
+      if (diff > 0)
+        return (diff << 1) - 1;
+      else
+        return ((-diff) << 1);
+    }
+    return (max - x) - 1;
+  }
+}
+
+static void write_segment_id(AV1_COMP *cpi, const MB_MODE_INFO *const mbmi,
+                             aom_writer *w, const struct segmentation *seg,
+                             struct segmentation_probs *segp, int mi_row,
+                             int mi_col, int skip) {
+  if (!seg->enabled || !seg->update_map) return;
+
+  AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  int cdf_num;
+  const int pred = av1_get_spatial_seg_pred(cm, xd, mi_row, mi_col, &cdf_num);
+
+  if (skip) {
+    // Still need to transmit tx size for intra blocks even if skip is
+    // true. Changing segment_id may make the tx size become invalid, e.g
+    // changing from lossless to lossy.
+    assert(is_inter_block(mbmi) || !cpi->has_lossless_segment);
+
+    set_spatial_segment_id(cm, cm->current_frame_seg_map, mbmi->sb_type, mi_row,
+                           mi_col, pred);
+    set_spatial_segment_id(cm, cpi->segmentation_map, mbmi->sb_type, mi_row,
+                           mi_col, pred);
+    /* mbmi is read only but we need to update segment_id */
+    ((MB_MODE_INFO *)mbmi)->segment_id = pred;
+    return;
+  }
+
+  const int coded_id =
+      av1_neg_interleave(mbmi->segment_id, pred, seg->last_active_segid + 1);
+  aom_cdf_prob *pred_cdf = segp->spatial_pred_seg_cdf[cdf_num];
+  aom_write_symbol(w, coded_id, pred_cdf, MAX_SEGMENTS);
+  set_spatial_segment_id(cm, cm->current_frame_seg_map, mbmi->sb_type, mi_row,
+                         mi_col, mbmi->segment_id);
+}
+
+#define WRITE_REF_BIT(bname, pname) \
+  aom_write_symbol(w, bname, av1_get_pred_cdf_##pname(xd), 2)
+
+// This function encodes the reference frame
+static void write_ref_frames(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                             aom_writer *w) {
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  const int is_compound = has_second_ref(mbmi);
+  const int segment_id = mbmi->segment_id;
+
+  // If segment level coding of this signal is disabled...
+  // or the segment allows multiple reference frame options
+  if (segfeature_active(&cm->seg, segment_id, SEG_LVL_REF_FRAME)) {
+    assert(!is_compound);
+    assert(mbmi->ref_frame[0] ==
+           get_segdata(&cm->seg, segment_id, SEG_LVL_REF_FRAME));
+  } else if (segfeature_active(&cm->seg, segment_id, SEG_LVL_SKIP) ||
+             segfeature_active(&cm->seg, segment_id, SEG_LVL_GLOBALMV)) {
+    assert(!is_compound);
+    assert(mbmi->ref_frame[0] == LAST_FRAME);
+  } else {
+    // does the feature use compound prediction or not
+    // (if not specified at the frame/segment level)
+    if (cm->reference_mode == REFERENCE_MODE_SELECT) {
+      if (is_comp_ref_allowed(mbmi->sb_type))
+        aom_write_symbol(w, is_compound, av1_get_reference_mode_cdf(xd), 2);
+    } else {
+      assert((!is_compound) == (cm->reference_mode == SINGLE_REFERENCE));
+    }
+
+    if (is_compound) {
+      const COMP_REFERENCE_TYPE comp_ref_type = has_uni_comp_refs(mbmi)
+                                                    ? UNIDIR_COMP_REFERENCE
+                                                    : BIDIR_COMP_REFERENCE;
+      aom_write_symbol(w, comp_ref_type, av1_get_comp_reference_type_cdf(xd),
+                       2);
+
+      if (comp_ref_type == UNIDIR_COMP_REFERENCE) {
+        const int bit = mbmi->ref_frame[0] == BWDREF_FRAME;
+        WRITE_REF_BIT(bit, uni_comp_ref_p);
+
+        if (!bit) {
+          assert(mbmi->ref_frame[0] == LAST_FRAME);
+          const int bit1 = mbmi->ref_frame[1] == LAST3_FRAME ||
+                           mbmi->ref_frame[1] == GOLDEN_FRAME;
+          WRITE_REF_BIT(bit1, uni_comp_ref_p1);
+          if (bit1) {
+            const int bit2 = mbmi->ref_frame[1] == GOLDEN_FRAME;
+            WRITE_REF_BIT(bit2, uni_comp_ref_p2);
+          }
+        } else {
+          assert(mbmi->ref_frame[1] == ALTREF_FRAME);
+        }
+
+        return;
+      }
+
+      assert(comp_ref_type == BIDIR_COMP_REFERENCE);
+
+      const int bit = (mbmi->ref_frame[0] == GOLDEN_FRAME ||
+                       mbmi->ref_frame[0] == LAST3_FRAME);
+      WRITE_REF_BIT(bit, comp_ref_p);
+
+      if (!bit) {
+        const int bit1 = mbmi->ref_frame[0] == LAST2_FRAME;
+        WRITE_REF_BIT(bit1, comp_ref_p1);
+      } else {
+        const int bit2 = mbmi->ref_frame[0] == GOLDEN_FRAME;
+        WRITE_REF_BIT(bit2, comp_ref_p2);
+      }
+
+      const int bit_bwd = mbmi->ref_frame[1] == ALTREF_FRAME;
+      WRITE_REF_BIT(bit_bwd, comp_bwdref_p);
+
+      if (!bit_bwd) {
+        WRITE_REF_BIT(mbmi->ref_frame[1] == ALTREF2_FRAME, comp_bwdref_p1);
+      }
+
+    } else {
+      const int bit0 = (mbmi->ref_frame[0] <= ALTREF_FRAME &&
+                        mbmi->ref_frame[0] >= BWDREF_FRAME);
+      WRITE_REF_BIT(bit0, single_ref_p1);
+
+      if (bit0) {
+        const int bit1 = mbmi->ref_frame[0] == ALTREF_FRAME;
+        WRITE_REF_BIT(bit1, single_ref_p2);
+
+        if (!bit1) {
+          WRITE_REF_BIT(mbmi->ref_frame[0] == ALTREF2_FRAME, single_ref_p6);
+        }
+      } else {
+        const int bit2 = (mbmi->ref_frame[0] == LAST3_FRAME ||
+                          mbmi->ref_frame[0] == GOLDEN_FRAME);
+        WRITE_REF_BIT(bit2, single_ref_p3);
+
+        if (!bit2) {
+          const int bit3 = mbmi->ref_frame[0] != LAST_FRAME;
+          WRITE_REF_BIT(bit3, single_ref_p4);
+        } else {
+          const int bit4 = mbmi->ref_frame[0] != LAST3_FRAME;
+          WRITE_REF_BIT(bit4, single_ref_p5);
+        }
+      }
+    }
+  }
+}
+
+static void write_filter_intra_mode_info(const AV1_COMMON *cm,
+                                         const MACROBLOCKD *xd,
+                                         const MB_MODE_INFO *const mbmi,
+                                         aom_writer *w) {
+  if (av1_filter_intra_allowed(cm, mbmi)) {
+    aom_write_symbol(w, mbmi->filter_intra_mode_info.use_filter_intra,
+                     xd->tile_ctx->filter_intra_cdfs[mbmi->sb_type], 2);
+    if (mbmi->filter_intra_mode_info.use_filter_intra) {
+      const FILTER_INTRA_MODE mode =
+          mbmi->filter_intra_mode_info.filter_intra_mode;
+      aom_write_symbol(w, mode, xd->tile_ctx->filter_intra_mode_cdf,
+                       FILTER_INTRA_MODES);
+    }
+  }
+}
+
+static void write_angle_delta(aom_writer *w, int angle_delta,
+                              aom_cdf_prob *cdf) {
+  aom_write_symbol(w, angle_delta + MAX_ANGLE_DELTA, cdf,
+                   2 * MAX_ANGLE_DELTA + 1);
+}
+
+static void write_mb_interp_filter(AV1_COMP *cpi, const MACROBLOCKD *xd,
+                                   aom_writer *w) {
+  AV1_COMMON *const cm = &cpi->common;
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+
+  if (!av1_is_interp_needed(xd)) {
+    assert(mbmi->interp_filters ==
+           av1_broadcast_interp_filter(
+               av1_unswitchable_filter(cm->interp_filter)));
+    return;
+  }
+  if (cm->interp_filter == SWITCHABLE) {
+    int dir;
+    for (dir = 0; dir < 2; ++dir) {
+      const int ctx = av1_get_pred_context_switchable_interp(xd, dir);
+      InterpFilter filter =
+          av1_extract_interp_filter(mbmi->interp_filters, dir);
+      aom_write_symbol(w, filter, ec_ctx->switchable_interp_cdf[ctx],
+                       SWITCHABLE_FILTERS);
+      ++cpi->interp_filter_selected[0][filter];
+      if (cm->seq_params.enable_dual_filter == 0) return;
+    }
+  }
+}
+
+// Transmit color values with delta encoding. Write the first value as
+// literal, and the deltas between each value and the previous one. "min_val" is
+// the smallest possible value of the deltas.
+static void delta_encode_palette_colors(const int *colors, int num,
+                                        int bit_depth, int min_val,
+                                        aom_writer *w) {
+  if (num <= 0) return;
+  assert(colors[0] < (1 << bit_depth));
+  aom_write_literal(w, colors[0], bit_depth);
+  if (num == 1) return;
+  int max_delta = 0;
+  int deltas[PALETTE_MAX_SIZE];
+  memset(deltas, 0, sizeof(deltas));
+  for (int i = 1; i < num; ++i) {
+    assert(colors[i] < (1 << bit_depth));
+    const int delta = colors[i] - colors[i - 1];
+    deltas[i - 1] = delta;
+    assert(delta >= min_val);
+    if (delta > max_delta) max_delta = delta;
+  }
+  const int min_bits = bit_depth - 3;
+  int bits = AOMMAX(av1_ceil_log2(max_delta + 1 - min_val), min_bits);
+  assert(bits <= bit_depth);
+  int range = (1 << bit_depth) - colors[0] - min_val;
+  aom_write_literal(w, bits - min_bits, 2);
+  for (int i = 0; i < num - 1; ++i) {
+    aom_write_literal(w, deltas[i] - min_val, bits);
+    range -= deltas[i];
+    bits = AOMMIN(bits, av1_ceil_log2(range));
+  }
+}
+
+// Transmit luma palette color values. First signal if each color in the color
+// cache is used. Those colors that are not in the cache are transmitted with
+// delta encoding.
+static void write_palette_colors_y(const MACROBLOCKD *const xd,
+                                   const PALETTE_MODE_INFO *const pmi,
+                                   int bit_depth, aom_writer *w) {
+  const int n = pmi->palette_size[0];
+  uint16_t color_cache[2 * PALETTE_MAX_SIZE];
+  const int n_cache = av1_get_palette_cache(xd, 0, color_cache);
+  int out_cache_colors[PALETTE_MAX_SIZE];
+  uint8_t cache_color_found[2 * PALETTE_MAX_SIZE];
+  const int n_out_cache =
+      av1_index_color_cache(color_cache, n_cache, pmi->palette_colors, n,
+                            cache_color_found, out_cache_colors);
+  int n_in_cache = 0;
+  for (int i = 0; i < n_cache && n_in_cache < n; ++i) {
+    const int found = cache_color_found[i];
+    aom_write_bit(w, found);
+    n_in_cache += found;
+  }
+  assert(n_in_cache + n_out_cache == n);
+  delta_encode_palette_colors(out_cache_colors, n_out_cache, bit_depth, 1, w);
+}
+
+// Write chroma palette color values. U channel is handled similarly to the luma
+// channel. For v channel, either use delta encoding or transmit raw values
+// directly, whichever costs less.
+static void write_palette_colors_uv(const MACROBLOCKD *const xd,
+                                    const PALETTE_MODE_INFO *const pmi,
+                                    int bit_depth, aom_writer *w) {
+  const int n = pmi->palette_size[1];
+  const uint16_t *colors_u = pmi->palette_colors + PALETTE_MAX_SIZE;
+  const uint16_t *colors_v = pmi->palette_colors + 2 * PALETTE_MAX_SIZE;
+  // U channel colors.
+  uint16_t color_cache[2 * PALETTE_MAX_SIZE];
+  const int n_cache = av1_get_palette_cache(xd, 1, color_cache);
+  int out_cache_colors[PALETTE_MAX_SIZE];
+  uint8_t cache_color_found[2 * PALETTE_MAX_SIZE];
+  const int n_out_cache = av1_index_color_cache(
+      color_cache, n_cache, colors_u, n, cache_color_found, out_cache_colors);
+  int n_in_cache = 0;
+  for (int i = 0; i < n_cache && n_in_cache < n; ++i) {
+    const int found = cache_color_found[i];
+    aom_write_bit(w, found);
+    n_in_cache += found;
+  }
+  delta_encode_palette_colors(out_cache_colors, n_out_cache, bit_depth, 0, w);
+
+  // V channel colors. Don't use color cache as the colors are not sorted.
+  const int max_val = 1 << bit_depth;
+  int zero_count = 0, min_bits_v = 0;
+  int bits_v =
+      av1_get_palette_delta_bits_v(pmi, bit_depth, &zero_count, &min_bits_v);
+  const int rate_using_delta =
+      2 + bit_depth + (bits_v + 1) * (n - 1) - zero_count;
+  const int rate_using_raw = bit_depth * n;
+  if (rate_using_delta < rate_using_raw) {  // delta encoding
+    assert(colors_v[0] < (1 << bit_depth));
+    aom_write_bit(w, 1);
+    aom_write_literal(w, bits_v - min_bits_v, 2);
+    aom_write_literal(w, colors_v[0], bit_depth);
+    for (int i = 1; i < n; ++i) {
+      assert(colors_v[i] < (1 << bit_depth));
+      if (colors_v[i] == colors_v[i - 1]) {  // No need to signal sign bit.
+        aom_write_literal(w, 0, bits_v);
+        continue;
+      }
+      const int delta = abs((int)colors_v[i] - colors_v[i - 1]);
+      const int sign_bit = colors_v[i] < colors_v[i - 1];
+      if (delta <= max_val - delta) {
+        aom_write_literal(w, delta, bits_v);
+        aom_write_bit(w, sign_bit);
+      } else {
+        aom_write_literal(w, max_val - delta, bits_v);
+        aom_write_bit(w, !sign_bit);
+      }
+    }
+  } else {  // Transmit raw values.
+    aom_write_bit(w, 0);
+    for (int i = 0; i < n; ++i) {
+      assert(colors_v[i] < (1 << bit_depth));
+      aom_write_literal(w, colors_v[i], bit_depth);
+    }
+  }
+}
+
+static void write_palette_mode_info(const AV1_COMMON *cm, const MACROBLOCKD *xd,
+                                    const MB_MODE_INFO *const mbmi, int mi_row,
+                                    int mi_col, aom_writer *w) {
+  const int num_planes = av1_num_planes(cm);
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+  assert(av1_allow_palette(cm->allow_screen_content_tools, bsize));
+  const PALETTE_MODE_INFO *const pmi = &mbmi->palette_mode_info;
+  const int bsize_ctx = av1_get_palette_bsize_ctx(bsize);
+
+  if (mbmi->mode == DC_PRED) {
+    const int n = pmi->palette_size[0];
+    const int palette_y_mode_ctx = av1_get_palette_mode_ctx(xd);
+    aom_write_symbol(
+        w, n > 0,
+        xd->tile_ctx->palette_y_mode_cdf[bsize_ctx][palette_y_mode_ctx], 2);
+    if (n > 0) {
+      aom_write_symbol(w, n - PALETTE_MIN_SIZE,
+                       xd->tile_ctx->palette_y_size_cdf[bsize_ctx],
+                       PALETTE_SIZES);
+      write_palette_colors_y(xd, pmi, cm->seq_params.bit_depth, w);
+    }
+  }
+
+  const int uv_dc_pred =
+      num_planes > 1 && mbmi->uv_mode == UV_DC_PRED &&
+      is_chroma_reference(mi_row, mi_col, bsize, xd->plane[1].subsampling_x,
+                          xd->plane[1].subsampling_y);
+  if (uv_dc_pred) {
+    const int n = pmi->palette_size[1];
+    const int palette_uv_mode_ctx = (pmi->palette_size[0] > 0);
+    aom_write_symbol(w, n > 0,
+                     xd->tile_ctx->palette_uv_mode_cdf[palette_uv_mode_ctx], 2);
+    if (n > 0) {
+      aom_write_symbol(w, n - PALETTE_MIN_SIZE,
+                       xd->tile_ctx->palette_uv_size_cdf[bsize_ctx],
+                       PALETTE_SIZES);
+      write_palette_colors_uv(xd, pmi, cm->seq_params.bit_depth, w);
+    }
+  }
+}
+
+void av1_write_tx_type(const AV1_COMMON *const cm, const MACROBLOCKD *xd,
+                       int blk_row, int blk_col, int plane, TX_SIZE tx_size,
+                       aom_writer *w) {
+  MB_MODE_INFO *mbmi = xd->mi[0];
+  const int is_inter = is_inter_block(mbmi);
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+
+  // Only y plane's tx_type is transmitted
+  if (plane > 0) return;
+  PLANE_TYPE plane_type = get_plane_type(plane);
+  TX_TYPE tx_type = av1_get_tx_type(plane_type, xd, blk_row, blk_col, tx_size,
+                                    cm->reduced_tx_set_used);
+
+  const TX_SIZE square_tx_size = txsize_sqr_map[tx_size];
+  if (get_ext_tx_types(tx_size, is_inter, cm->reduced_tx_set_used) > 1 &&
+      ((!cm->seg.enabled && cm->base_qindex > 0) ||
+       (cm->seg.enabled && xd->qindex[mbmi->segment_id] > 0)) &&
+      !mbmi->skip &&
+      !segfeature_active(&cm->seg, mbmi->segment_id, SEG_LVL_SKIP)) {
+    const TxSetType tx_set_type =
+        av1_get_ext_tx_set_type(tx_size, is_inter, cm->reduced_tx_set_used);
+    const int eset = get_ext_tx_set(tx_size, is_inter, cm->reduced_tx_set_used);
+    // eset == 0 should correspond to a set with only DCT_DCT and there
+    // is no need to send the tx_type
+    assert(eset > 0);
+    assert(av1_ext_tx_used[tx_set_type][tx_type]);
+    if (is_inter) {
+      aom_write_symbol(w, av1_ext_tx_ind[tx_set_type][tx_type],
+                       ec_ctx->inter_ext_tx_cdf[eset][square_tx_size],
+                       av1_num_ext_tx_set[tx_set_type]);
+    } else {
+      PREDICTION_MODE intra_dir;
+      if (mbmi->filter_intra_mode_info.use_filter_intra)
+        intra_dir =
+            fimode_to_intradir[mbmi->filter_intra_mode_info.filter_intra_mode];
+      else
+        intra_dir = mbmi->mode;
+      aom_write_symbol(
+          w, av1_ext_tx_ind[tx_set_type][tx_type],
+          ec_ctx->intra_ext_tx_cdf[eset][square_tx_size][intra_dir],
+          av1_num_ext_tx_set[tx_set_type]);
+    }
+  }
+}
+
+static void write_intra_y_mode_nonkf(FRAME_CONTEXT *frame_ctx, BLOCK_SIZE bsize,
+                                     PREDICTION_MODE mode, aom_writer *w) {
+  aom_write_symbol(w, mode, frame_ctx->y_mode_cdf[size_group_lookup[bsize]],
+                   INTRA_MODES);
+}
+
+static void write_intra_uv_mode(FRAME_CONTEXT *frame_ctx,
+                                UV_PREDICTION_MODE uv_mode,
+                                PREDICTION_MODE y_mode,
+                                CFL_ALLOWED_TYPE cfl_allowed, aom_writer *w) {
+  aom_write_symbol(w, uv_mode, frame_ctx->uv_mode_cdf[cfl_allowed][y_mode],
+                   UV_INTRA_MODES - !cfl_allowed);
+}
+
+static void write_cfl_alphas(FRAME_CONTEXT *const ec_ctx, int idx,
+                             int joint_sign, aom_writer *w) {
+  aom_write_symbol(w, joint_sign, ec_ctx->cfl_sign_cdf, CFL_JOINT_SIGNS);
+  // Magnitudes are only signaled for nonzero codes.
+  if (CFL_SIGN_U(joint_sign) != CFL_SIGN_ZERO) {
+    aom_cdf_prob *cdf_u = ec_ctx->cfl_alpha_cdf[CFL_CONTEXT_U(joint_sign)];
+    aom_write_symbol(w, CFL_IDX_U(idx), cdf_u, CFL_ALPHABET_SIZE);
+  }
+  if (CFL_SIGN_V(joint_sign) != CFL_SIGN_ZERO) {
+    aom_cdf_prob *cdf_v = ec_ctx->cfl_alpha_cdf[CFL_CONTEXT_V(joint_sign)];
+    aom_write_symbol(w, CFL_IDX_V(idx), cdf_v, CFL_ALPHABET_SIZE);
+  }
+}
+
+static void write_cdef(AV1_COMMON *cm, MACROBLOCKD *const xd, aom_writer *w,
+                       int skip, int mi_col, int mi_row) {
+  if (cm->coded_lossless || cm->allow_intrabc) {
+    // Initialize to indicate no CDEF for safety.
+    cm->cdef_bits = 0;
+    cm->cdef_strengths[0] = 0;
+    cm->nb_cdef_strengths = 1;
+    cm->cdef_uv_strengths[0] = 0;
+    return;
+  }
+
+  const int m = ~((1 << (6 - MI_SIZE_LOG2)) - 1);
+  const MB_MODE_INFO *mbmi =
+      cm->mi_grid_visible[(mi_row & m) * cm->mi_stride + (mi_col & m)];
+  // Initialise when at top left part of the superblock
+  if (!(mi_row & (cm->seq_params.mib_size - 1)) &&
+      !(mi_col & (cm->seq_params.mib_size - 1))) {  // Top left?
+    xd->cdef_preset[0] = xd->cdef_preset[1] = xd->cdef_preset[2] =
+        xd->cdef_preset[3] = -1;
+  }
+
+  // Emit CDEF param at first non-skip coding block
+  const int mask = 1 << (6 - MI_SIZE_LOG2);
+  const int index = cm->seq_params.sb_size == BLOCK_128X128
+                        ? !!(mi_col & mask) + 2 * !!(mi_row & mask)
+                        : 0;
+  if (xd->cdef_preset[index] == -1 && !skip) {
+    aom_write_literal(w, mbmi->cdef_strength, cm->cdef_bits);
+    xd->cdef_preset[index] = mbmi->cdef_strength;
+  }
+}
+
+static void write_inter_segment_id(AV1_COMP *cpi, aom_writer *w,
+                                   const struct segmentation *const seg,
+                                   struct segmentation_probs *const segp,
+                                   int mi_row, int mi_col, int skip,
+                                   int preskip) {
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  AV1_COMMON *const cm = &cpi->common;
+
+  if (seg->update_map) {
+    if (preskip) {
+      if (!seg->segid_preskip) return;
+    } else {
+      if (seg->segid_preskip) return;
+      if (skip) {
+        write_segment_id(cpi, mbmi, w, seg, segp, mi_row, mi_col, 1);
+        if (seg->temporal_update) ((MB_MODE_INFO *)mbmi)->seg_id_predicted = 0;
+        return;
+      }
+    }
+    if (seg->temporal_update) {
+      const int pred_flag = mbmi->seg_id_predicted;
+      aom_cdf_prob *pred_cdf = av1_get_pred_cdf_seg_id(segp, xd);
+      aom_write_symbol(w, pred_flag, pred_cdf, 2);
+      if (!pred_flag) {
+        write_segment_id(cpi, mbmi, w, seg, segp, mi_row, mi_col, 0);
+      }
+      if (pred_flag) {
+        set_spatial_segment_id(cm, cm->current_frame_seg_map, mbmi->sb_type,
+                               mi_row, mi_col, mbmi->segment_id);
+      }
+    } else {
+      write_segment_id(cpi, mbmi, w, seg, segp, mi_row, mi_col, 0);
+    }
+  }
+}
+
+// If delta q is present, writes delta_q index.
+// Also writes delta_q loop filter levels, if present.
+static void write_delta_q_params(AV1_COMP *cpi, const int mi_row,
+                                 const int mi_col, int skip, aom_writer *w) {
+  AV1_COMMON *const cm = &cpi->common;
+  if (cm->delta_q_present_flag) {
+    MACROBLOCK *const x = &cpi->td.mb;
+    MACROBLOCKD *const xd = &x->e_mbd;
+    const MB_MODE_INFO *const mbmi = xd->mi[0];
+    const BLOCK_SIZE bsize = mbmi->sb_type;
+    const int super_block_upper_left =
+        ((mi_row & (cm->seq_params.mib_size - 1)) == 0) &&
+        ((mi_col & (cm->seq_params.mib_size - 1)) == 0);
+
+    if ((bsize != cm->seq_params.sb_size || skip == 0) &&
+        super_block_upper_left) {
+      assert(mbmi->current_qindex > 0);
+      const int reduced_delta_qindex =
+          (mbmi->current_qindex - xd->current_qindex) / cm->delta_q_res;
+      write_delta_qindex(xd, reduced_delta_qindex, w);
+      xd->current_qindex = mbmi->current_qindex;
+      if (cm->delta_lf_present_flag) {
+        if (cm->delta_lf_multi) {
+          const int frame_lf_count =
+              av1_num_planes(cm) > 1 ? FRAME_LF_COUNT : FRAME_LF_COUNT - 2;
+          for (int lf_id = 0; lf_id < frame_lf_count; ++lf_id) {
+            int reduced_delta_lflevel =
+                (mbmi->delta_lf[lf_id] - xd->delta_lf[lf_id]) /
+                cm->delta_lf_res;
+            write_delta_lflevel(cm, xd, lf_id, reduced_delta_lflevel, w);
+            xd->delta_lf[lf_id] = mbmi->delta_lf[lf_id];
+          }
+        } else {
+          int reduced_delta_lflevel =
+              (mbmi->delta_lf_from_base - xd->delta_lf_from_base) /
+              cm->delta_lf_res;
+          write_delta_lflevel(cm, xd, -1, reduced_delta_lflevel, w);
+          xd->delta_lf_from_base = mbmi->delta_lf_from_base;
+        }
+      }
+    }
+  }
+}
+
+static void write_intra_prediction_modes(AV1_COMP *cpi, const int mi_row,
+                                         const int mi_col, int is_keyframe,
+                                         aom_writer *w) {
+  const AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCK *const x = &cpi->td.mb;
+  MACROBLOCKD *const xd = &x->e_mbd;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  const PREDICTION_MODE mode = mbmi->mode;
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+
+  // Y mode.
+  if (is_keyframe) {
+    const MB_MODE_INFO *const above_mi = xd->above_mbmi;
+    const MB_MODE_INFO *const left_mi = xd->left_mbmi;
+    write_intra_y_mode_kf(ec_ctx, mbmi, above_mi, left_mi, mode, w);
+  } else {
+    write_intra_y_mode_nonkf(ec_ctx, bsize, mode, w);
+  }
+
+  // Y angle delta.
+  const int use_angle_delta = av1_use_angle_delta(bsize);
+  if (use_angle_delta && av1_is_directional_mode(mode)) {
+    write_angle_delta(w, mbmi->angle_delta[PLANE_TYPE_Y],
+                      ec_ctx->angle_delta_cdf[mode - V_PRED]);
+  }
+
+  // UV mode and UV angle delta.
+  if (!cm->seq_params.monochrome &&
+      is_chroma_reference(mi_row, mi_col, bsize, xd->plane[1].subsampling_x,
+                          xd->plane[1].subsampling_y)) {
+    const UV_PREDICTION_MODE uv_mode = mbmi->uv_mode;
+    write_intra_uv_mode(ec_ctx, uv_mode, mode, is_cfl_allowed(xd), w);
+    if (uv_mode == UV_CFL_PRED)
+      write_cfl_alphas(ec_ctx, mbmi->cfl_alpha_idx, mbmi->cfl_alpha_signs, w);
+    if (use_angle_delta && av1_is_directional_mode(get_uv_mode(uv_mode))) {
+      write_angle_delta(w, mbmi->angle_delta[PLANE_TYPE_UV],
+                        ec_ctx->angle_delta_cdf[uv_mode - V_PRED]);
+    }
+  }
+
+  // Palette.
+  if (av1_allow_palette(cm->allow_screen_content_tools, bsize)) {
+    write_palette_mode_info(cm, xd, mbmi, mi_row, mi_col, w);
+  }
+
+  // Filter intra.
+  write_filter_intra_mode_info(cm, xd, mbmi, w);
+}
+
+static void pack_inter_mode_mvs(AV1_COMP *cpi, const int mi_row,
+                                const int mi_col, aom_writer *w) {
+  AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCK *const x = &cpi->td.mb;
+  MACROBLOCKD *const xd = &x->e_mbd;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  const struct segmentation *const seg = &cm->seg;
+  struct segmentation_probs *const segp = &ec_ctx->seg;
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  const MB_MODE_INFO_EXT *const mbmi_ext = x->mbmi_ext;
+  const PREDICTION_MODE mode = mbmi->mode;
+  const int segment_id = mbmi->segment_id;
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+  const int allow_hp = cm->allow_high_precision_mv;
+  const int is_inter = is_inter_block(mbmi);
+  const int is_compound = has_second_ref(mbmi);
+  int ref;
+
+  write_inter_segment_id(cpi, w, seg, segp, mi_row, mi_col, 0, 1);
+
+  write_skip_mode(cm, xd, segment_id, mbmi, w);
+
+  assert(IMPLIES(mbmi->skip_mode, mbmi->skip));
+  const int skip =
+      mbmi->skip_mode ? 1 : write_skip(cm, xd, segment_id, mbmi, w);
+
+  write_inter_segment_id(cpi, w, seg, segp, mi_row, mi_col, skip, 0);
+
+  write_cdef(cm, xd, w, skip, mi_col, mi_row);
+
+  write_delta_q_params(cpi, mi_row, mi_col, skip, w);
+
+  if (!mbmi->skip_mode) write_is_inter(cm, xd, mbmi->segment_id, w, is_inter);
+
+  if (mbmi->skip_mode) return;
+
+  if (!is_inter) {
+    write_intra_prediction_modes(cpi, mi_row, mi_col, 0, w);
+  } else {
+    int16_t mode_ctx;
+
+    av1_collect_neighbors_ref_counts(xd);
+
+    write_ref_frames(cm, xd, w);
+
+    mode_ctx =
+        av1_mode_context_analyzer(mbmi_ext->mode_context, mbmi->ref_frame);
+
+    // If segment skip is not enabled code the mode.
+    if (!segfeature_active(seg, segment_id, SEG_LVL_SKIP)) {
+      if (is_inter_compound_mode(mode))
+        write_inter_compound_mode(xd, w, mode, mode_ctx);
+      else if (is_inter_singleref_mode(mode))
+        write_inter_mode(w, mode, ec_ctx, mode_ctx);
+
+      if (mode == NEWMV || mode == NEW_NEWMV || have_nearmv_in_inter_mode(mode))
+        write_drl_idx(ec_ctx, mbmi, mbmi_ext, w);
+      else
+        assert(mbmi->ref_mv_idx == 0);
+    }
+
+    if (mode == NEWMV || mode == NEW_NEWMV) {
+      for (ref = 0; ref < 1 + is_compound; ++ref) {
+        nmv_context *nmvc = &ec_ctx->nmvc;
+        const int_mv ref_mv = av1_get_ref_mv(x, ref);
+        av1_encode_mv(cpi, w, &mbmi->mv[ref].as_mv, &ref_mv.as_mv, nmvc,
+                      allow_hp);
+      }
+    } else if (mode == NEAREST_NEWMV || mode == NEAR_NEWMV) {
+      nmv_context *nmvc = &ec_ctx->nmvc;
+      const int_mv ref_mv = av1_get_ref_mv(x, 1);
+      av1_encode_mv(cpi, w, &mbmi->mv[1].as_mv, &ref_mv.as_mv, nmvc, allow_hp);
+    } else if (mode == NEW_NEARESTMV || mode == NEW_NEARMV) {
+      nmv_context *nmvc = &ec_ctx->nmvc;
+      const int_mv ref_mv = av1_get_ref_mv(x, 0);
+      av1_encode_mv(cpi, w, &mbmi->mv[0].as_mv, &ref_mv.as_mv, nmvc, allow_hp);
+    }
+
+    if (cpi->common.reference_mode != COMPOUND_REFERENCE &&
+        cpi->common.seq_params.enable_interintra_compound &&
+        is_interintra_allowed(mbmi)) {
+      const int interintra = mbmi->ref_frame[1] == INTRA_FRAME;
+      const int bsize_group = size_group_lookup[bsize];
+      aom_write_symbol(w, interintra, ec_ctx->interintra_cdf[bsize_group], 2);
+      if (interintra) {
+        aom_write_symbol(w, mbmi->interintra_mode,
+                         ec_ctx->interintra_mode_cdf[bsize_group],
+                         INTERINTRA_MODES);
+        if (is_interintra_wedge_used(bsize)) {
+          aom_write_symbol(w, mbmi->use_wedge_interintra,
+                           ec_ctx->wedge_interintra_cdf[bsize], 2);
+          if (mbmi->use_wedge_interintra) {
+            aom_write_symbol(w, mbmi->interintra_wedge_index,
+                             ec_ctx->wedge_idx_cdf[bsize], 16);
+            assert(mbmi->interintra_wedge_sign == 0);
+          }
+        }
+      }
+    }
+
+    if (mbmi->ref_frame[1] != INTRA_FRAME) write_motion_mode(cm, xd, mbmi, w);
+
+    // First write idx to indicate current compound inter prediction mode group
+    // Group A (0): jnt_comp, compound_average
+    // Group B (1): interintra, compound_diffwtd, wedge
+    if (has_second_ref(mbmi)) {
+      const int masked_compound_used = is_any_masked_compound_used(bsize) &&
+                                       cm->seq_params.enable_masked_compound;
+
+      if (masked_compound_used) {
+        const int ctx_comp_group_idx = get_comp_group_idx_context(xd);
+        aom_write_symbol(w, mbmi->comp_group_idx,
+                         ec_ctx->comp_group_idx_cdf[ctx_comp_group_idx], 2);
+      } else {
+        assert(mbmi->comp_group_idx == 0);
+      }
+
+      if (mbmi->comp_group_idx == 0) {
+        if (mbmi->compound_idx)
+          assert(mbmi->interinter_comp.type == COMPOUND_AVERAGE);
+
+        if (cm->seq_params.enable_jnt_comp) {
+          const int comp_index_ctx = get_comp_index_context(cm, xd);
+          aom_write_symbol(w, mbmi->compound_idx,
+                           ec_ctx->compound_index_cdf[comp_index_ctx], 2);
+        } else {
+          assert(mbmi->compound_idx == 1);
+        }
+      } else {
+        assert(cpi->common.reference_mode != SINGLE_REFERENCE &&
+               is_inter_compound_mode(mbmi->mode) &&
+               mbmi->motion_mode == SIMPLE_TRANSLATION);
+        assert(masked_compound_used);
+        // compound_diffwtd, wedge
+        assert(mbmi->interinter_comp.type == COMPOUND_WEDGE ||
+               mbmi->interinter_comp.type == COMPOUND_DIFFWTD);
+
+        if (is_interinter_compound_used(COMPOUND_WEDGE, bsize))
+          aom_write_symbol(w, mbmi->interinter_comp.type - 1,
+                           ec_ctx->compound_type_cdf[bsize],
+                           COMPOUND_TYPES - 1);
+
+        if (mbmi->interinter_comp.type == COMPOUND_WEDGE) {
+          assert(is_interinter_compound_used(COMPOUND_WEDGE, bsize));
+          aom_write_symbol(w, mbmi->interinter_comp.wedge_index,
+                           ec_ctx->wedge_idx_cdf[bsize], 16);
+          aom_write_bit(w, mbmi->interinter_comp.wedge_sign);
+        } else {
+          assert(mbmi->interinter_comp.type == COMPOUND_DIFFWTD);
+          aom_write_literal(w, mbmi->interinter_comp.mask_type,
+                            MAX_DIFFWTD_MASK_BITS);
+        }
+      }
+    }
+
+    write_mb_interp_filter(cpi, xd, w);
+  }
+}
+
+static void write_intrabc_info(MACROBLOCKD *xd,
+                               const MB_MODE_INFO_EXT *mbmi_ext,
+                               aom_writer *w) {
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+  int use_intrabc = is_intrabc_block(mbmi);
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  aom_write_symbol(w, use_intrabc, ec_ctx->intrabc_cdf, 2);
+  if (use_intrabc) {
+    assert(mbmi->mode == DC_PRED);
+    assert(mbmi->uv_mode == UV_DC_PRED);
+    assert(mbmi->motion_mode == SIMPLE_TRANSLATION);
+    int_mv dv_ref = mbmi_ext->ref_mv_stack[INTRA_FRAME][0].this_mv;
+    av1_encode_dv(w, &mbmi->mv[0].as_mv, &dv_ref.as_mv, &ec_ctx->ndvc);
+  }
+}
+
+static void write_mb_modes_kf(AV1_COMP *cpi, MACROBLOCKD *xd,
+                              const MB_MODE_INFO_EXT *mbmi_ext,
+                              const int mi_row, const int mi_col,
+                              aom_writer *w) {
+  AV1_COMMON *const cm = &cpi->common;
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+  const struct segmentation *const seg = &cm->seg;
+  struct segmentation_probs *const segp = &ec_ctx->seg;
+  const MB_MODE_INFO *const mbmi = xd->mi[0];
+
+  if (seg->segid_preskip && seg->update_map)
+    write_segment_id(cpi, mbmi, w, seg, segp, mi_row, mi_col, 0);
+
+  const int skip = write_skip(cm, xd, mbmi->segment_id, mbmi, w);
+
+  if (!seg->segid_preskip && seg->update_map)
+    write_segment_id(cpi, mbmi, w, seg, segp, mi_row, mi_col, skip);
+
+  write_cdef(cm, xd, w, skip, mi_col, mi_row);
+
+  write_delta_q_params(cpi, mi_row, mi_col, skip, w);
+
+  if (av1_allow_intrabc(cm)) {
+    write_intrabc_info(xd, mbmi_ext, w);
+    if (is_intrabc_block(mbmi)) return;
+  }
+
+  write_intra_prediction_modes(cpi, mi_row, mi_col, 1, w);
+}
+
+#if CONFIG_RD_DEBUG
+static void dump_mode_info(MODE_INFO *mi) {
+  printf("\nmi->mi_row == %d\n", mi->mi_row);
+  printf("&& mi->mi_col == %d\n", mi->mi_col);
+  printf("&& mi->sb_type == %d\n", mi->sb_type);
+  printf("&& mi->tx_size == %d\n", mi->tx_size);
+  printf("&& mi->mode == %d\n", mi->mode);
+}
+static int rd_token_stats_mismatch(RD_STATS *rd_stats, TOKEN_STATS *token_stats,
+                                   int plane) {
+  if (rd_stats->txb_coeff_cost[plane] != token_stats->cost) {
+    int r, c;
+    printf("\nplane %d rd_stats->txb_coeff_cost %d token_stats->cost %d\n",
+           plane, rd_stats->txb_coeff_cost[plane], token_stats->cost);
+    printf("rd txb_coeff_cost_map\n");
+    for (r = 0; r < TXB_COEFF_COST_MAP_SIZE; ++r) {
+      for (c = 0; c < TXB_COEFF_COST_MAP_SIZE; ++c) {
+        printf("%d ", rd_stats->txb_coeff_cost_map[plane][r][c]);
+      }
+      printf("\n");
+    }
+
+    printf("pack txb_coeff_cost_map\n");
+    for (r = 0; r < TXB_COEFF_COST_MAP_SIZE; ++r) {
+      for (c = 0; c < TXB_COEFF_COST_MAP_SIZE; ++c) {
+        printf("%d ", token_stats->txb_coeff_cost_map[r][c]);
+      }
+      printf("\n");
+    }
+    return 1;
+  }
+  return 0;
+}
+#endif
+
+#if ENC_MISMATCH_DEBUG
+static void enc_dump_logs(AV1_COMP *cpi, int mi_row, int mi_col) {
+  AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  xd->mi = cm->mi_grid_visible + (mi_row * cm->mi_stride + mi_col);
+  const MB_MODE_INFO *const *mbmi = xd->mi[0];
+  if (is_inter_block(mbmi)) {
+#define FRAME_TO_CHECK 11
+    if (cm->current_video_frame == FRAME_TO_CHECK && cm->show_frame == 1) {
+      const BLOCK_SIZE bsize = mbmi->sb_type;
+
+      int_mv mv[2];
+      int is_comp_ref = has_second_ref(mbmi);
+      int ref;
+
+      for (ref = 0; ref < 1 + is_comp_ref; ++ref)
+        mv[ref].as_mv = mbmi->mv[ref].as_mv;
+
+      if (!is_comp_ref) {
+        mv[1].as_int = 0;
+      }
+
+      MACROBLOCK *const x = &cpi->td.mb;
+      const MB_MODE_INFO_EXT *const mbmi_ext = x->mbmi_ext;
+      const int16_t mode_ctx =
+          is_comp_ref ? mbmi_ext->compound_mode_context[mbmi->ref_frame[0]]
+                      : av1_mode_context_analyzer(mbmi_ext->mode_context,
+                                                  mbmi->ref_frame);
+
+      const int16_t newmv_ctx = mode_ctx & NEWMV_CTX_MASK;
+      int16_t zeromv_ctx = -1;
+      int16_t refmv_ctx = -1;
+
+      if (mbmi->mode != NEWMV) {
+        zeromv_ctx = (mode_ctx >> GLOBALMV_OFFSET) & GLOBALMV_CTX_MASK;
+        if (mbmi->mode != GLOBALMV)
+          refmv_ctx = (mode_ctx >> REFMV_OFFSET) & REFMV_CTX_MASK;
+      }
+
+      printf(
+          "=== ENCODER ===: "
+          "Frame=%d, (mi_row,mi_col)=(%d,%d), skip_mode=%d, mode=%d, bsize=%d, "
+          "show_frame=%d, mv[0]=(%d,%d), mv[1]=(%d,%d), ref[0]=%d, "
+          "ref[1]=%d, motion_mode=%d, mode_ctx=%d, "
+          "newmv_ctx=%d, zeromv_ctx=%d, refmv_ctx=%d, tx_size=%d\n",
+          cm->current_video_frame, mi_row, mi_col, mbmi->skip_mode, mbmi->mode,
+          bsize, cm->show_frame, mv[0].as_mv.row, mv[0].as_mv.col,
+          mv[1].as_mv.row, mv[1].as_mv.col, mbmi->ref_frame[0],
+          mbmi->ref_frame[1], mbmi->motion_mode, mode_ctx, newmv_ctx,
+          zeromv_ctx, refmv_ctx, mbmi->tx_size);
+    }
+  }
+}
+#endif  // ENC_MISMATCH_DEBUG
+
+static void write_mbmi_b(AV1_COMP *cpi, const TileInfo *const tile,
+                         aom_writer *w, int mi_row, int mi_col) {
+  AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  int bh, bw;
+  xd->mi = cm->mi_grid_visible + (mi_row * cm->mi_stride + mi_col);
+  MB_MODE_INFO *m = xd->mi[0];
+
+  assert(m->sb_type <= cm->seq_params.sb_size ||
+         (m->sb_type >= BLOCK_SIZES && m->sb_type < BLOCK_SIZES_ALL));
+
+  bh = mi_size_high[m->sb_type];
+  bw = mi_size_wide[m->sb_type];
+
+  cpi->td.mb.mbmi_ext = cpi->mbmi_ext_base + (mi_row * cm->mi_cols + mi_col);
+
+  set_mi_row_col(xd, tile, mi_row, bh, mi_col, bw, cm->mi_rows, cm->mi_cols);
+
+  xd->above_txfm_context = cm->above_txfm_context[tile->tile_row] + mi_col;
+  xd->left_txfm_context =
+      xd->left_txfm_context_buffer + (mi_row & MAX_MIB_MASK);
+
+  if (frame_is_intra_only(cm)) {
+    write_mb_modes_kf(cpi, xd, cpi->td.mb.mbmi_ext, mi_row, mi_col, w);
+  } else {
+    // has_subpel_mv_component needs the ref frame buffers set up to look
+    // up if they are scaled. has_subpel_mv_component is in turn needed by
+    // write_switchable_interp_filter, which is called by pack_inter_mode_mvs.
+    set_ref_ptrs(cm, xd, m->ref_frame[0], m->ref_frame[1]);
+
+#if ENC_MISMATCH_DEBUG
+    enc_dump_logs(cpi, mi_row, mi_col);
+#endif  // ENC_MISMATCH_DEBUG
+
+    pack_inter_mode_mvs(cpi, mi_row, mi_col, w);
+  }
+}
+
+static void write_inter_txb_coeff(AV1_COMMON *const cm, MACROBLOCK *const x,
+                                  MB_MODE_INFO *const mbmi, aom_writer *w,
+                                  const TOKENEXTRA **tok,
+                                  const TOKENEXTRA *const tok_end,
+                                  TOKEN_STATS *token_stats, const int row,
+                                  const int col, int *block, const int plane) {
+  MACROBLOCKD *const xd = &x->e_mbd;
+  const struct macroblockd_plane *const pd = &xd->plane[plane];
+  const BLOCK_SIZE bsize = mbmi->sb_type;
+  const BLOCK_SIZE bsizec =
+      scale_chroma_bsize(bsize, pd->subsampling_x, pd->subsampling_y);
+
+  const BLOCK_SIZE plane_bsize =
+      get_plane_block_size(bsizec, pd->subsampling_x, pd->subsampling_y);
+
+  const TX_SIZE max_tx_size = get_vartx_max_txsize(xd, plane_bsize, plane);
+  const int step =
+      tx_size_wide_unit[max_tx_size] * tx_size_high_unit[max_tx_size];
+  const int bkw = tx_size_wide_unit[max_tx_size];
+  const int bkh = tx_size_high_unit[max_tx_size];
+
+  const BLOCK_SIZE max_unit_bsize =
+      get_plane_block_size(BLOCK_64X64, pd->subsampling_x, pd->subsampling_y);
+  int mu_blocks_wide = block_size_wide[max_unit_bsize] >> tx_size_wide_log2[0];
+  int mu_blocks_high = block_size_high[max_unit_bsize] >> tx_size_high_log2[0];
+
+  int blk_row, blk_col;
+
+  const int num_4x4_w = block_size_wide[plane_bsize] >> tx_size_wide_log2[0];
+  const int num_4x4_h = block_size_high[plane_bsize] >> tx_size_high_log2[0];
+
+  const int unit_height =
+      AOMMIN(mu_blocks_high + (row >> pd->subsampling_y), num_4x4_h);
+  const int unit_width =
+      AOMMIN(mu_blocks_wide + (col >> pd->subsampling_x), num_4x4_w);
+  for (blk_row = row >> pd->subsampling_y; blk_row < unit_height;
+       blk_row += bkh) {
+    for (blk_col = col >> pd->subsampling_x; blk_col < unit_width;
+         blk_col += bkw) {
+      pack_txb_tokens(w, cm, x, tok, tok_end, xd, mbmi, plane, plane_bsize,
+                      cm->seq_params.bit_depth, *block, blk_row, blk_col,
+                      max_tx_size, token_stats);
+      *block += step;
+    }
+  }
+}
+
+static void write_tokens_b(AV1_COMP *cpi, const TileInfo *const tile,
+                           aom_writer *w, const TOKENEXTRA **tok,
+                           const TOKENEXTRA *const tok_end, int mi_row,
+                           int mi_col) {
+  AV1_COMMON *const cm = &cpi->common;
+  const int num_planes = av1_num_planes(cm);
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  const int mi_offset = mi_row * cm->mi_stride + mi_col;
+  MB_MODE_INFO *const mbmi = *(cm->mi_grid_visible + mi_offset);
+  int plane;
+  int bh, bw;
+  MACROBLOCK *const x = &cpi->td.mb;
+  (void)tok;
+  (void)tok_end;
+  xd->mi = cm->mi_grid_visible + mi_offset;
+
+  assert(mbmi->sb_type <= cm->seq_params.sb_size ||
+         (mbmi->sb_type >= BLOCK_SIZES && mbmi->sb_type < BLOCK_SIZES_ALL));
+
+  bh = mi_size_high[mbmi->sb_type];
+  bw = mi_size_wide[mbmi->sb_type];
+  cpi->td.mb.mbmi_ext = cpi->mbmi_ext_base + (mi_row * cm->mi_cols + mi_col);
+
+  set_mi_row_col(xd, tile, mi_row, bh, mi_col, bw, cm->mi_rows, cm->mi_cols);
+
+  if (!mbmi->skip) {
+    if (!is_inter_block(mbmi))
+      av1_write_coeffs_mb(cm, x, mi_row, mi_col, w, mbmi->sb_type);
+
+    if (is_inter_block(mbmi)) {
+      int block[MAX_MB_PLANE] = { 0 };
+      const BLOCK_SIZE plane_bsize = mbmi->sb_type;
+      assert(plane_bsize == get_plane_block_size(mbmi->sb_type,
+                                                 xd->plane[0].subsampling_x,
+                                                 xd->plane[0].subsampling_y));
+      const int num_4x4_w =
+          block_size_wide[plane_bsize] >> tx_size_wide_log2[0];
+      const int num_4x4_h =
+          block_size_high[plane_bsize] >> tx_size_high_log2[0];
+      int row, col;
+      TOKEN_STATS token_stats;
+      init_token_stats(&token_stats);
+
+      const BLOCK_SIZE max_unit_bsize = BLOCK_64X64;
+      assert(max_unit_bsize ==
+             get_plane_block_size(BLOCK_64X64, xd->plane[0].subsampling_x,
+                                  xd->plane[0].subsampling_y));
+      int mu_blocks_wide =
+          block_size_wide[max_unit_bsize] >> tx_size_wide_log2[0];
+      int mu_blocks_high =
+          block_size_high[max_unit_bsize] >> tx_size_high_log2[0];
+
+      mu_blocks_wide = AOMMIN(num_4x4_w, mu_blocks_wide);
+      mu_blocks_high = AOMMIN(num_4x4_h, mu_blocks_high);
+
+      for (row = 0; row < num_4x4_h; row += mu_blocks_high) {
+        for (col = 0; col < num_4x4_w; col += mu_blocks_wide) {
+          for (plane = 0; plane < num_planes && is_inter_block(mbmi); ++plane) {
+            const struct macroblockd_plane *const pd = &xd->plane[plane];
+            if (!is_chroma_reference(mi_row, mi_col, mbmi->sb_type,
+                                     pd->subsampling_x, pd->subsampling_y)) {
+              continue;
+            }
+            write_inter_txb_coeff(cm, x, mbmi, w, tok, tok_end, &token_stats,
+                                  row, col, &block[plane], plane);
+          }
+        }
+#if CONFIG_RD_DEBUG
+        if (mbmi->sb_type >= BLOCK_8X8 &&
+            rd_token_stats_mismatch(&mbmi->rd_stats, &token_stats, plane)) {
+          dump_mode_info(m);
+          assert(0);
+        }
+#endif  // CONFIG_RD_DEBUG
+      }
+    }
+  }
+}
+
+static void write_modes_b(AV1_COMP *cpi, const TileInfo *const tile,
+                          aom_writer *w, const TOKENEXTRA **tok,
+                          const TOKENEXTRA *const tok_end, int mi_row,
+                          int mi_col) {
+  write_mbmi_b(cpi, tile, w, mi_row, mi_col);
+
+  AV1_COMMON *cm = &cpi->common;
+  MACROBLOCKD *xd = &cpi->td.mb.e_mbd;
+  MB_MODE_INFO *mbmi = xd->mi[0];
+  for (int plane = 0; plane < AOMMIN(2, av1_num_planes(cm)); ++plane) {
+    const uint8_t palette_size_plane =
+        mbmi->palette_mode_info.palette_size[plane];
+    assert(!mbmi->skip_mode || !palette_size_plane);
+    if (palette_size_plane > 0) {
+      assert(mbmi->use_intrabc == 0);
+      assert(av1_allow_palette(cm->allow_screen_content_tools, mbmi->sb_type));
+      int rows, cols;
+      av1_get_block_dimensions(mbmi->sb_type, plane, xd, NULL, NULL, &rows,
+                               &cols);
+      assert(*tok < tok_end);
+      pack_map_tokens(w, tok, palette_size_plane, rows * cols);
+    }
+  }
+
+  BLOCK_SIZE bsize = mbmi->sb_type;
+  int is_inter_tx = is_inter_block(mbmi) || is_intrabc_block(mbmi);
+  int skip = mbmi->skip;
+  int segment_id = mbmi->segment_id;
+  if (cm->tx_mode == TX_MODE_SELECT && block_signals_txsize(bsize) &&
+      !(is_inter_tx && skip) && !xd->lossless[segment_id]) {
+    if (is_inter_tx) {  // This implies skip flag is 0.
+      const TX_SIZE max_tx_size = get_vartx_max_txsize(xd, bsize, 0);
+      const int txbh = tx_size_high_unit[max_tx_size];
+      const int txbw = tx_size_wide_unit[max_tx_size];
+      const int width = block_size_wide[bsize] >> tx_size_wide_log2[0];
+      const int height = block_size_high[bsize] >> tx_size_high_log2[0];
+      int idx, idy;
+      for (idy = 0; idy < height; idy += txbh)
+        for (idx = 0; idx < width; idx += txbw)
+          write_tx_size_vartx(xd, mbmi, max_tx_size, 0, idy, idx, w);
+    } else {
+      write_selected_tx_size(xd, w);
+      set_txfm_ctxs(mbmi->tx_size, xd->n4_w, xd->n4_h, 0, xd);
+    }
+  } else {
+    set_txfm_ctxs(mbmi->tx_size, xd->n4_w, xd->n4_h,
+                  skip && is_inter_block(mbmi), xd);
+  }
+
+  write_tokens_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+}
+
+static void write_partition(const AV1_COMMON *const cm,
+                            const MACROBLOCKD *const xd, int hbs, int mi_row,
+                            int mi_col, PARTITION_TYPE p, BLOCK_SIZE bsize,
+                            aom_writer *w) {
+  const int is_partition_point = bsize >= BLOCK_8X8;
+
+  if (!is_partition_point) return;
+
+  const int has_rows = (mi_row + hbs) < cm->mi_rows;
+  const int has_cols = (mi_col + hbs) < cm->mi_cols;
+  const int ctx = partition_plane_context(xd, mi_row, mi_col, bsize);
+  FRAME_CONTEXT *ec_ctx = xd->tile_ctx;
+
+  if (!has_rows && !has_cols) {
+    assert(p == PARTITION_SPLIT);
+    return;
+  }
+
+  if (has_rows && has_cols) {
+    aom_write_symbol(w, p, ec_ctx->partition_cdf[ctx],
+                     partition_cdf_length(bsize));
+  } else if (!has_rows && has_cols) {
+    assert(p == PARTITION_SPLIT || p == PARTITION_HORZ);
+    assert(bsize > BLOCK_8X8);
+    aom_cdf_prob cdf[2];
+    partition_gather_vert_alike(cdf, ec_ctx->partition_cdf[ctx], bsize);
+    aom_write_cdf(w, p == PARTITION_SPLIT, cdf, 2);
+  } else {
+    assert(has_rows && !has_cols);
+    assert(p == PARTITION_SPLIT || p == PARTITION_VERT);
+    assert(bsize > BLOCK_8X8);
+    aom_cdf_prob cdf[2];
+    partition_gather_horz_alike(cdf, ec_ctx->partition_cdf[ctx], bsize);
+    aom_write_cdf(w, p == PARTITION_SPLIT, cdf, 2);
+  }
+}
+
+static void write_modes_sb(AV1_COMP *const cpi, const TileInfo *const tile,
+                           aom_writer *const w, const TOKENEXTRA **tok,
+                           const TOKENEXTRA *const tok_end, int mi_row,
+                           int mi_col, BLOCK_SIZE bsize) {
+  const AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  const int hbs = mi_size_wide[bsize] / 2;
+  const int quarter_step = mi_size_wide[bsize] / 4;
+  int i;
+  const PARTITION_TYPE partition = get_partition(cm, mi_row, mi_col, bsize);
+  const BLOCK_SIZE subsize = get_partition_subsize(bsize, partition);
+
+  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols) return;
+
+  const int num_planes = av1_num_planes(cm);
+  for (int plane = 0; plane < num_planes; ++plane) {
+    int rcol0, rcol1, rrow0, rrow1;
+    if (av1_loop_restoration_corners_in_sb(cm, plane, mi_row, mi_col, bsize,
+                                           &rcol0, &rcol1, &rrow0, &rrow1)) {
+      const int rstride = cm->rst_info[plane].horz_units_per_tile;
+      for (int rrow = rrow0; rrow < rrow1; ++rrow) {
+        for (int rcol = rcol0; rcol < rcol1; ++rcol) {
+          const int runit_idx = rcol + rrow * rstride;
+          const RestorationUnitInfo *rui =
+              &cm->rst_info[plane].unit_info[runit_idx];
+          loop_restoration_write_sb_coeffs(cm, xd, rui, w, plane,
+                                           cpi->td.counts);
+        }
+      }
+    }
+  }
+
+  write_partition(cm, xd, hbs, mi_row, mi_col, partition, bsize, w);
+  switch (partition) {
+    case PARTITION_NONE:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      break;
+    case PARTITION_HORZ:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      if (mi_row + hbs < cm->mi_rows)
+        write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col);
+      break;
+    case PARTITION_VERT:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      if (mi_col + hbs < cm->mi_cols)
+        write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col + hbs);
+      break;
+    case PARTITION_SPLIT:
+      write_modes_sb(cpi, tile, w, tok, tok_end, mi_row, mi_col, subsize);
+      write_modes_sb(cpi, tile, w, tok, tok_end, mi_row, mi_col + hbs, subsize);
+      write_modes_sb(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col, subsize);
+      write_modes_sb(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col + hbs,
+                     subsize);
+      break;
+    case PARTITION_HORZ_A:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col + hbs);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col);
+      break;
+    case PARTITION_HORZ_B:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col + hbs);
+      break;
+    case PARTITION_VERT_A:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col + hbs);
+      break;
+    case PARTITION_VERT_B:
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row, mi_col + hbs);
+      write_modes_b(cpi, tile, w, tok, tok_end, mi_row + hbs, mi_col + hbs);
+      break;
+    case PARTITION_HORZ_4:
+      for (i = 0; i < 4; ++i) {
+        int this_mi_row = mi_row + i * quarter_step;
+        if (i > 0 && this_mi_row >= cm->mi_rows) break;
+
+        write_modes_b(cpi, tile, w, tok, tok_end, this_mi_row, mi_col);
+      }
+      break;
+    case PARTITION_VERT_4:
+      for (i = 0; i < 4; ++i) {
+        int this_mi_col = mi_col + i * quarter_step;
+        if (i > 0 && this_mi_col >= cm->mi_cols) break;
+
+        write_modes_b(cpi, tile, w, tok, tok_end, mi_row, this_mi_col);
+      }
+      break;
+    default: assert(0);
+  }
+
+  // update partition context
+  update_ext_partition_context(xd, mi_row, mi_col, subsize, bsize, partition);
+}
+
+static void write_modes(AV1_COMP *const cpi, const TileInfo *const tile,
+                        aom_writer *const w, int tile_row, int tile_col) {
+  AV1_COMMON *const cm = &cpi->common;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+  const int mi_row_start = tile->mi_row_start;
+  const int mi_row_end = tile->mi_row_end;
+  const int mi_col_start = tile->mi_col_start;
+  const int mi_col_end = tile->mi_col_end;
+  int mi_row, mi_col, sb_row_in_tile;
+
+  av1_zero_above_context(cm, xd, mi_col_start, mi_col_end, tile->tile_row);
+  av1_init_above_context(cm, xd, tile->tile_row);
+
+  if (cpi->common.delta_q_present_flag) {
+    xd->current_qindex = cpi->common.base_qindex;
+    if (cpi->common.delta_lf_present_flag) {
+      av1_reset_loop_filter_delta(xd, av1_num_planes(cm));
+    }
+  }
+
+  for (mi_row = mi_row_start; mi_row < mi_row_end;
+       mi_row += cm->seq_params.mib_size) {
+    sb_row_in_tile =
+        (mi_row - tile->mi_row_start) >> cm->seq_params.mib_size_log2;
+    const TOKENEXTRA *tok =
+        cpi->tplist[tile_row][tile_col][sb_row_in_tile].start;
+    const TOKENEXTRA *tok_end =
+        tok + cpi->tplist[tile_row][tile_col][sb_row_in_tile].count;
+
+    av1_zero_left_context(xd);
+
+    for (mi_col = mi_col_start; mi_col < mi_col_end;
+         mi_col += cm->seq_params.mib_size) {
+      write_modes_sb(cpi, tile, w, &tok, tok_end, mi_row, mi_col,
+                     cm->seq_params.sb_size);
+    }
+    assert(tok == cpi->tplist[tile_row][tile_col][sb_row_in_tile].stop);
+  }
+}
+
+static void encode_restoration_mode(AV1_COMMON *cm,
+                                    struct aom_write_bit_buffer *wb) {
+  assert(!cm->all_lossless);
+  if (!cm->seq_params.enable_restoration) return;
+  if (cm->allow_intrabc) return;
+  const int num_planes = av1_num_planes(cm);
+  int all_none = 1, chroma_none = 1;
+  for (int p = 0; p < num_planes; ++p) {
+    RestorationInfo *rsi = &cm->rst_info[p];
+    if (rsi->frame_restoration_type != RESTORE_NONE) {
+      all_none = 0;
+      chroma_none &= p == 0;
+    }
+    switch (rsi->frame_restoration_type) {
+      case RESTORE_NONE:
+        aom_wb_write_bit(wb, 0);
+        aom_wb_write_bit(wb, 0);
+        break;
+      case RESTORE_WIENER:
+        aom_wb_write_bit(wb, 1);
+        aom_wb_write_bit(wb, 0);
+        break;
+      case RESTORE_SGRPROJ:
+        aom_wb_write_bit(wb, 1);
+        aom_wb_write_bit(wb, 1);
+        break;
+      case RESTORE_SWITCHABLE:
+        aom_wb_write_bit(wb, 0);
+        aom_wb_write_bit(wb, 1);
+        break;
+      default: assert(0);
+    }
+  }
+  if (!all_none) {
+    assert(cm->seq_params.sb_size == BLOCK_64X64 ||
+           cm->seq_params.sb_size == BLOCK_128X128);
+    const int sb_size = cm->seq_params.sb_size == BLOCK_128X128 ? 128 : 64;
+
+    RestorationInfo *rsi = &cm->rst_info[0];
+
+    assert(rsi->restoration_unit_size >= sb_size);
+    assert(RESTORATION_UNITSIZE_MAX == 256);
+
+    if (sb_size == 64) {
+      aom_wb_write_bit(wb, rsi->restoration_unit_size > 64);
+    }
+    if (rsi->restoration_unit_size > 64) {
+      aom_wb_write_bit(wb, rsi->restoration_unit_size > 128);
+    }
+  }
+
+  if (num_planes > 1) {
+    int s = AOMMIN(cm->seq_params.subsampling_x, cm->seq_params.subsampling_y);
+    if (s && !chroma_none) {
+      aom_wb_write_bit(wb, cm->rst_info[1].restoration_unit_size !=
+                               cm->rst_info[0].restoration_unit_size);
+      assert(cm->rst_info[1].restoration_unit_size ==
+                 cm->rst_info[0].restoration_unit_size ||
+             cm->rst_info[1].restoration_unit_size ==
+                 (cm->rst_info[0].restoration_unit_size >> s));
+      assert(cm->rst_info[2].restoration_unit_size ==
+             cm->rst_info[1].restoration_unit_size);
+    } else if (!s) {
+      assert(cm->rst_info[1].restoration_unit_size ==
+             cm->rst_info[0].restoration_unit_size);
+      assert(cm->rst_info[2].restoration_unit_size ==
+             cm->rst_info[1].restoration_unit_size);
+    }
+  }
+}
+
+static void write_wiener_filter(int wiener_win, const WienerInfo *wiener_info,
+                                WienerInfo *ref_wiener_info, aom_writer *wb) {
+  if (wiener_win == WIENER_WIN)
+    aom_write_primitive_refsubexpfin(
+        wb, WIENER_FILT_TAP0_MAXV - WIENER_FILT_TAP0_MINV + 1,
+        WIENER_FILT_TAP0_SUBEXP_K,
+        ref_wiener_info->vfilter[0] - WIENER_FILT_TAP0_MINV,
+        wiener_info->vfilter[0] - WIENER_FILT_TAP0_MINV);
+  else
+    assert(wiener_info->vfilter[0] == 0 &&
+           wiener_info->vfilter[WIENER_WIN - 1] == 0);
+  aom_write_primitive_refsubexpfin(
+      wb, WIENER_FILT_TAP1_MAXV - WIENER_FILT_TAP1_MINV + 1,
+      WIENER_FILT_TAP1_SUBEXP_K,
+      ref_wiener_info->vfilter[1] - WIENER_FILT_TAP1_MINV,
+      wiener_info->vfilter[1] - WIENER_FILT_TAP1_MINV);
+  aom_write_primitive_refsubexpfin(
+      wb, WIENER_FILT_TAP2_MAXV - WIENER_FILT_TAP2_MINV + 1,
+      WIENER_FILT_TAP2_SUBEXP_K,
+      ref_wiener_info->vfilter[2] - WIENER_FILT_TAP2_MINV,
+      wiener_info->vfilter[2] - WIENER_FILT_TAP2_MINV);
+  if (wiener_win == WIENER_WIN)
+    aom_write_primitive_refsubexpfin(
+        wb, WIENER_FILT_TAP0_MAXV - WIENER_FILT_TAP0_MINV + 1,
+        WIENER_FILT_TAP0_SUBEXP_K,
+        ref_wiener_info->hfilter[0] - WIENER_FILT_TAP0_MINV,
+        wiener_info->hfilter[0] - WIENER_FILT_TAP0_MINV);
+  else
+    assert(wiener_info->hfilter[0] == 0 &&
+           wiener_info->hfilter[WIENER_WIN - 1] == 0);
+  aom_write_primitive_refsubexpfin(
+      wb, WIENER_FILT_TAP1_MAXV - WIENER_FILT_TAP1_MINV + 1,
+      WIENER_FILT_TAP1_SUBEXP_K,
+      ref_wiener_info->hfilter[1] - WIENER_FILT_TAP1_MINV,
+      wiener_info->hfilter[1] - WIENER_FILT_TAP1_MINV);
+  aom_write_primitive_refsubexpfin(
+      wb, WIENER_FILT_TAP2_MAXV - WIENER_FILT_TAP2_MINV + 1,
+      WIENER_FILT_TAP2_SUBEXP_K,
+      ref_wiener_info->hfilter[2] - WIENER_FILT_TAP2_MINV,
+      wiener_info->hfilter[2] - WIENER_FILT_TAP2_MINV);
+  memcpy(ref_wiener_info, wiener_info, sizeof(*wiener_info));
+}
+
+static void write_sgrproj_filter(const SgrprojInfo *sgrproj_info,
+                                 SgrprojInfo *ref_sgrproj_info,
+                                 aom_writer *wb) {
+  aom_write_literal(wb, sgrproj_info->ep, SGRPROJ_PARAMS_BITS);
+  const sgr_params_type *params = &sgr_params[sgrproj_info->ep];
+
+  if (params->r[0] == 0) {
+    assert(sgrproj_info->xqd[0] == 0);
+    aom_write_primitive_refsubexpfin(
+        wb, SGRPROJ_PRJ_MAX1 - SGRPROJ_PRJ_MIN1 + 1, SGRPROJ_PRJ_SUBEXP_K,
+        ref_sgrproj_info->xqd[1] - SGRPROJ_PRJ_MIN1,
+        sgrproj_info->xqd[1] - SGRPROJ_PRJ_MIN1);
+  } else if (params->r[1] == 0) {
+    aom_write_primitive_refsubexpfin(
+        wb, SGRPROJ_PRJ_MAX0 - SGRPROJ_PRJ_MIN0 + 1, SGRPROJ_PRJ_SUBEXP_K,
+        ref_sgrproj_info->xqd[0] - SGRPROJ_PRJ_MIN0,
+        sgrproj_info->xqd[0] - SGRPROJ_PRJ_MIN0);
+  } else {
+    aom_write_primitive_refsubexpfin(
+        wb, SGRPROJ_PRJ_MAX0 - SGRPROJ_PRJ_MIN0 + 1, SGRPROJ_PRJ_SUBEXP_K,
+        ref_sgrproj_info->xqd[0] - SGRPROJ_PRJ_MIN0,
+        sgrproj_info->xqd[0] - SGRPROJ_PRJ_MIN0);
+    aom_write_primitive_refsubexpfin(
+        wb, SGRPROJ_PRJ_MAX1 - SGRPROJ_PRJ_MIN1 + 1, SGRPROJ_PRJ_SUBEXP_K,
+        ref_sgrproj_info->xqd[1] - SGRPROJ_PRJ_MIN1,
+        sgrproj_info->xqd[1] - SGRPROJ_PRJ_MIN1);
+  }
+
+  memcpy(ref_sgrproj_info, sgrproj_info, sizeof(*sgrproj_info));
+}
+
+static void loop_restoration_write_sb_coeffs(const AV1_COMMON *const cm,
+                                             MACROBLOCKD *xd,
+                                             const RestorationUnitInfo *rui,
+                                             aom_writer *const w, int plane,
+                                             FRAME_COUNTS *counts) {
+  const RestorationInfo *rsi = cm->rst_info + plane;
+  RestorationType frame_rtype = rsi->frame_restoration_type;
+  if (frame_rtype == RESTORE_NONE) return;
+
+  (void)counts;
+  assert(!cm->all_lossless);
+
+  const int wiener_win = (plane > 0) ? WIENER_WIN_CHROMA : WIENER_WIN;
+  WienerInfo *wiener_info = xd->wiener_info + plane;
+  SgrprojInfo *sgrproj_info = xd->sgrproj_info + plane;
+  RestorationType unit_rtype = rui->restoration_type;
+
+  if (frame_rtype == RESTORE_SWITCHABLE) {
+    aom_write_symbol(w, unit_rtype, xd->tile_ctx->switchable_restore_cdf,
+                     RESTORE_SWITCHABLE_TYPES);
+#if CONFIG_ENTROPY_STATS
+    ++counts->switchable_restore[unit_rtype];
+#endif
+    switch (unit_rtype) {
+      case RESTORE_WIENER:
+        write_wiener_filter(wiener_win, &rui->wiener_info, wiener_info, w);
+        break;
+      case RESTORE_SGRPROJ:
+        write_sgrproj_filter(&rui->sgrproj_info, sgrproj_info, w);
+        break;
+      default: assert(unit_rtype == RESTORE_NONE); break;
+    }
+  } else if (frame_rtype == RESTORE_WIENER) {
+    aom_write_symbol(w, unit_rtype != RESTORE_NONE,
+                     xd->tile_ctx->wiener_restore_cdf, 2);
+#if CONFIG_ENTROPY_STATS
+    ++counts->wiener_restore[unit_rtype != RESTORE_NONE];
+#endif
+    if (unit_rtype != RESTORE_NONE) {
+      write_wiener_filter(wiener_win, &rui->wiener_info, wiener_info, w);
+    }
+  } else if (frame_rtype == RESTORE_SGRPROJ) {
+    aom_write_symbol(w, unit_rtype != RESTORE_NONE,
+                     xd->tile_ctx->sgrproj_restore_cdf, 2);
+#if CONFIG_ENTROPY_STATS
+    ++counts->sgrproj_restore[unit_rtype != RESTORE_NONE];
+#endif
+    if (unit_rtype != RESTORE_NONE) {
+      write_sgrproj_filter(&rui->sgrproj_info, sgrproj_info, w);
+    }
+  }
+}
+
+static void encode_loopfilter(AV1_COMMON *cm, struct aom_write_bit_buffer *wb) {
+  assert(!cm->coded_lossless);
+  if (cm->allow_intrabc) return;
+  const int num_planes = av1_num_planes(cm);
+  int i;
+  struct loopfilter *lf = &cm->lf;
+
+  // Encode the loop filter level and type
+  aom_wb_write_literal(wb, lf->filter_level[0], 6);
+  aom_wb_write_literal(wb, lf->filter_level[1], 6);
+  if (num_planes > 1) {
+    if (lf->filter_level[0] || lf->filter_level[1]) {
+      aom_wb_write_literal(wb, lf->filter_level_u, 6);
+      aom_wb_write_literal(wb, lf->filter_level_v, 6);
+    }
+  }
+  aom_wb_write_literal(wb, lf->sharpness_level, 3);
+
+  // Write out loop filter deltas applied at the MB level based on mode or
+  // ref frame (if they are enabled).
+  aom_wb_write_bit(wb, lf->mode_ref_delta_enabled);
+
+  if (lf->mode_ref_delta_enabled) {
+    aom_wb_write_bit(wb, lf->mode_ref_delta_update);
+
+    if (lf->mode_ref_delta_update) {
+      const int prime_idx = cm->primary_ref_frame;
+      const int buf_idx =
+          prime_idx == PRIMARY_REF_NONE ? -1 : cm->frame_refs[prime_idx].idx;
+      int8_t last_ref_deltas[REF_FRAMES];
+      if (prime_idx == PRIMARY_REF_NONE || buf_idx < 0) {
+        av1_set_default_ref_deltas(last_ref_deltas);
+      } else {
+        memcpy(last_ref_deltas, cm->buffer_pool->frame_bufs[buf_idx].ref_deltas,
+               REF_FRAMES);
+      }
+      for (i = 0; i < REF_FRAMES; i++) {
+        const int delta = lf->ref_deltas[i];
+        const int changed = delta != last_ref_deltas[i];
+        aom_wb_write_bit(wb, changed);
+        if (changed) aom_wb_write_inv_signed_literal(wb, delta, 6);
+      }
+
+      int8_t last_mode_deltas[MAX_MODE_LF_DELTAS];
+      if (prime_idx == PRIMARY_REF_NONE || buf_idx < 0) {
+        av1_set_default_mode_deltas(last_mode_deltas);
+      } else {
+        memcpy(last_mode_deltas,
+               cm->buffer_pool->frame_bufs[buf_idx].mode_deltas,
+               MAX_MODE_LF_DELTAS);
+      }
+      for (i = 0; i < MAX_MODE_LF_DELTAS; i++) {
+        const int delta = lf->mode_deltas[i];
+        const int changed = delta != last_mode_deltas[i];
+        aom_wb_write_bit(wb, changed);
+        if (changed) aom_wb_write_inv_signed_literal(wb, delta, 6);
+      }
+    }
+  }
+}
+
+static void encode_cdef(const AV1_COMMON *cm, struct aom_write_bit_buffer *wb) {
+  assert(!cm->coded_lossless);
+  if (!cm->seq_params.enable_cdef) return;
+  if (cm->allow_intrabc) return;
+  const int num_planes = av1_num_planes(cm);
+  int i;
+  aom_wb_write_literal(wb, cm->cdef_pri_damping - 3, 2);
+  assert(cm->cdef_pri_damping == cm->cdef_sec_damping);
+  aom_wb_write_literal(wb, cm->cdef_bits, 2);
+  for (i = 0; i < cm->nb_cdef_strengths; i++) {
+    aom_wb_write_literal(wb, cm->cdef_strengths[i], CDEF_STRENGTH_BITS);
+    if (num_planes > 1)
+      aom_wb_write_literal(wb, cm->cdef_uv_strengths[i], CDEF_STRENGTH_BITS);
+  }
+}
+
+static void write_delta_q(struct aom_write_bit_buffer *wb, int delta_q) {
+  if (delta_q != 0) {
+    aom_wb_write_bit(wb, 1);
+    aom_wb_write_inv_signed_literal(wb, delta_q, 6);
+  } else {
+    aom_wb_write_bit(wb, 0);
+  }
+}
+
+static void encode_quantization(const AV1_COMMON *const cm,
+                                struct aom_write_bit_buffer *wb) {
+  const int num_planes = av1_num_planes(cm);
+
+  aom_wb_write_literal(wb, cm->base_qindex, QINDEX_BITS);
+  write_delta_q(wb, cm->y_dc_delta_q);
+  if (num_planes > 1) {
+    int diff_uv_delta = (cm->u_dc_delta_q != cm->v_dc_delta_q) ||
+                        (cm->u_ac_delta_q != cm->v_ac_delta_q);
+    if (cm->seq_params.separate_uv_delta_q) aom_wb_write_bit(wb, diff_uv_delta);
+    write_delta_q(wb, cm->u_dc_delta_q);
+    write_delta_q(wb, cm->u_ac_delta_q);
+    if (diff_uv_delta) {
+      write_delta_q(wb, cm->v_dc_delta_q);
+      write_delta_q(wb, cm->v_ac_delta_q);
+    }
+  }
+  aom_wb_write_bit(wb, cm->using_qmatrix);
+  if (cm->using_qmatrix) {
+    aom_wb_write_literal(wb, cm->qm_y, QM_LEVEL_BITS);
+    aom_wb_write_literal(wb, cm->qm_u, QM_LEVEL_BITS);
+    if (!cm->seq_params.separate_uv_delta_q)
+      assert(cm->qm_u == cm->qm_v);
+    else
+      aom_wb_write_literal(wb, cm->qm_v, QM_LEVEL_BITS);
+  }
+}
+
+static void encode_segmentation(AV1_COMMON *cm, MACROBLOCKD *xd,
+                                struct aom_write_bit_buffer *wb) {
+  int i, j;
+  struct segmentation *seg = &cm->seg;
+
+  aom_wb_write_bit(wb, seg->enabled);
+  if (!seg->enabled) return;
+
+  // Write update flags
+  if (cm->primary_ref_frame == PRIMARY_REF_NONE) {
+    assert(seg->update_map == 1);
+    seg->temporal_update = 0;
+    assert(seg->update_data == 1);
+  } else {
+    aom_wb_write_bit(wb, seg->update_map);
+    if (seg->update_map) {
+      // Select the coding strategy (temporal or spatial)
+      av1_choose_segmap_coding_method(cm, xd);
+      aom_wb_write_bit(wb, seg->temporal_update);
+    }
+    aom_wb_write_bit(wb, seg->update_data);
+  }
+
+  // Segmentation data
+  if (seg->update_data) {
+    for (i = 0; i < MAX_SEGMENTS; i++) {
+      for (j = 0; j < SEG_LVL_MAX; j++) {
+        const int active = segfeature_active(seg, i, j);
+        aom_wb_write_bit(wb, active);
+        if (active) {
+          const int data_max = av1_seg_feature_data_max(j);
+          const int data_min = -data_max;
+          const int ubits = get_unsigned_bits(data_max);
+          const int data = clamp(get_segdata(seg, i, j), data_min, data_max);
+
+          if (av1_is_segfeature_signed(j)) {
+            aom_wb_write_inv_signed_literal(wb, data, ubits);
+          } else {
+            aom_wb_write_literal(wb, data, ubits);
+          }
+        }
+      }
+    }
+  }
+}
+
+static void write_tx_mode(AV1_COMMON *cm, TX_MODE *mode,
+                          struct aom_write_bit_buffer *wb) {
+  if (cm->coded_lossless) {
+    *mode = ONLY_4X4;
+    return;
+  }
+  aom_wb_write_bit(wb, *mode == TX_MODE_SELECT);
+}
+
+static void write_frame_interp_filter(InterpFilter filter,
+                                      struct aom_write_bit_buffer *wb) {
+  aom_wb_write_bit(wb, filter == SWITCHABLE);
+  if (filter != SWITCHABLE)
+    aom_wb_write_literal(wb, filter, LOG_SWITCHABLE_FILTERS);
+}
+
+static void fix_interp_filter(AV1_COMMON *cm, FRAME_COUNTS *counts) {
+  if (cm->interp_filter == SWITCHABLE) {
+    // Check to see if only one of the filters is actually used
+    int count[SWITCHABLE_FILTERS];
+    int i, j, c = 0;
+    for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
+      count[i] = 0;
+      for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
+        count[i] += counts->switchable_interp[j][i];
+      c += (count[i] > 0);
+    }
+    if (c == 1) {
+      // Only one filter is used. So set the filter at frame level
+      for (i = 0; i < SWITCHABLE_FILTERS; ++i) {
+        if (count[i]) {
+          if (i == EIGHTTAP_REGULAR) cm->interp_filter = i;
+          break;
+        }
+      }
+    }
+  }
+}
+
+// Same function as write_uniform but writing to uncompresses header wb
+static void wb_write_uniform(struct aom_write_bit_buffer *wb, int n, int v) {
+  const int l = get_unsigned_bits(n);
+  const int m = (1 << l) - n;
+  if (l == 0) return;
+  if (v < m) {
+    aom_wb_write_literal(wb, v, l - 1);
+  } else {
+    aom_wb_write_literal(wb, m + ((v - m) >> 1), l - 1);
+    aom_wb_write_literal(wb, (v - m) & 1, 1);
+  }
+}
+
+static void write_tile_info_max_tile(const AV1_COMMON *const cm,
+                                     struct aom_write_bit_buffer *wb) {
+  int width_mi = ALIGN_POWER_OF_TWO(cm->mi_cols, cm->seq_params.mib_size_log2);
+  int height_mi = ALIGN_POWER_OF_TWO(cm->mi_rows, cm->seq_params.mib_size_log2);
+  int width_sb = width_mi >> cm->seq_params.mib_size_log2;
+  int height_sb = height_mi >> cm->seq_params.mib_size_log2;
+  int size_sb, i;
+
+  aom_wb_write_bit(wb, cm->uniform_tile_spacing_flag);
+
+  if (cm->uniform_tile_spacing_flag) {
+    // Uniform spaced tiles with power-of-two number of rows and columns
+    // tile columns
+    int ones = cm->log2_tile_cols - cm->min_log2_tile_cols;
+    while (ones--) {
+      aom_wb_write_bit(wb, 1);
+    }
+    if (cm->log2_tile_cols < cm->max_log2_tile_cols) {
+      aom_wb_write_bit(wb, 0);
+    }
+
+    // rows
+    ones = cm->log2_tile_rows - cm->min_log2_tile_rows;
+    while (ones--) {
+      aom_wb_write_bit(wb, 1);
+    }
+    if (cm->log2_tile_rows < cm->max_log2_tile_rows) {
+      aom_wb_write_bit(wb, 0);
+    }
+  } else {
+    // Explicit tiles with configurable tile widths and heights
+    // columns
+    for (i = 0; i < cm->tile_cols; i++) {
+      size_sb = cm->tile_col_start_sb[i + 1] - cm->tile_col_start_sb[i];
+      wb_write_uniform(wb, AOMMIN(width_sb, cm->max_tile_width_sb),
+                       size_sb - 1);
+      width_sb -= size_sb;
+    }
+    assert(width_sb == 0);
+
+    // rows
+    for (i = 0; i < cm->tile_rows; i++) {
+      size_sb = cm->tile_row_start_sb[i + 1] - cm->tile_row_start_sb[i];
+      wb_write_uniform(wb, AOMMIN(height_sb, cm->max_tile_height_sb),
+                       size_sb - 1);
+      height_sb -= size_sb;
+    }
+    assert(height_sb == 0);
+  }
+}
+
+static void write_tile_info(const AV1_COMMON *const cm,
+                            struct aom_write_bit_buffer *saved_wb,
+                            struct aom_write_bit_buffer *wb) {
+  write_tile_info_max_tile(cm, wb);
+
+  *saved_wb = *wb;
+  if (cm->tile_rows * cm->tile_cols > 1) {
+    // tile id used for cdf update
+    aom_wb_write_literal(wb, 0, cm->log2_tile_cols + cm->log2_tile_rows);
+    // Number of bytes in tile size - 1
+    aom_wb_write_literal(wb, 3, 2);
+  }
+}
+
+static void write_ext_tile_info(const AV1_COMMON *const cm,
+                                struct aom_write_bit_buffer *saved_wb,
+                                struct aom_write_bit_buffer *wb) {
+  // This information is stored as a separate byte.
+  int mod = wb->bit_offset % CHAR_BIT;
+  if (mod > 0) aom_wb_write_literal(wb, 0, CHAR_BIT - mod);
+  assert(aom_wb_is_byte_aligned(wb));
+
+  *saved_wb = *wb;
+  if (cm->tile_rows * cm->tile_cols > 1) {
+    // Note that the last item in the uncompressed header is the data
+    // describing tile configuration.
+    // Number of bytes in tile column size - 1
+    aom_wb_write_literal(wb, 0, 2);
+    // Number of bytes in tile size - 1
+    aom_wb_write_literal(wb, 0, 2);
+  }
+}
+
+static int get_refresh_mask(AV1_COMP *cpi) {
+  if ((cpi->common.frame_type == KEY_FRAME && cpi->common.show_frame) ||
+      frame_is_sframe(&cpi->common))
+    return 0xFF;
+
+  int refresh_mask = 0;
+
+  // NOTE(zoeliu): When LAST_FRAME is to get refreshed, the decoder will be
+  // notified to get LAST3_FRAME refreshed and then the virtual indexes for all
+  // the 3 LAST reference frames will be updated accordingly, i.e.:
+  // (1) The original virtual index for LAST3_FRAME will become the new virtual
+  //     index for LAST_FRAME; and
+  // (2) The original virtual indexes for LAST_FRAME and LAST2_FRAME will be
+  //     shifted and become the new virtual indexes for LAST2_FRAME and
+  //     LAST3_FRAME.
+  refresh_mask |=
+      (cpi->refresh_last_frame << cpi->ref_fb_idx[LAST_REF_FRAMES - 1]);
+#if USE_SYMM_MULTI_LAYER
+  refresh_mask |=
+      (cpi->new_bwdref_update_rule == 1)
+          ? (cpi->refresh_bwd_ref_frame << cpi->ref_fb_idx[EXTREF_FRAME - 1])
+          : (cpi->refresh_bwd_ref_frame << cpi->ref_fb_idx[BWDREF_FRAME - 1]);
+#else
+  refresh_mask |=
+      (cpi->refresh_bwd_ref_frame << cpi->ref_fb_idx[BWDREF_FRAME - 1]);
+#endif
+  refresh_mask |=
+      (cpi->refresh_alt2_ref_frame << cpi->ref_fb_idx[ALTREF2_FRAME - 1]);
+
+  if (av1_preserve_existing_gf(cpi)) {
+    // We have decided to preserve the previously existing golden frame as our
+    // new ARF frame. However, in the short term we leave it in the GF slot and,
+    // if we're updating the GF with the current decoded frame, we save it
+    // instead to the ARF slot.
+    // Later, in the function av1_encoder.c:av1_update_reference_frames() we
+    // will swap gld_fb_idx and alt_fb_idx to achieve our objective. We do it
+    // there so that it can be done outside of the recode loop.
+    // Note: This is highly specific to the use of ARF as a forward reference,
+    // and this needs to be generalized as other uses are implemented
+    // (like RTC/temporal scalability).
+
+    if (cpi->preserve_arf_as_gld) {
+      return refresh_mask;
+    } else {
+      return refresh_mask |
+             (cpi->refresh_golden_frame << cpi->ref_fb_idx[ALTREF_FRAME - 1]);
+    }
+  } else {
+    const int arf_idx = cpi->ref_fb_idx[ALTREF_FRAME - 1];
+    return refresh_mask |
+           (cpi->refresh_golden_frame << cpi->ref_fb_idx[GOLDEN_FRAME - 1]) |
+           (cpi->refresh_alt_ref_frame << arf_idx);
+  }
+}
+
+static INLINE int find_identical_tile(
+    const int tile_row, const int tile_col,
+    TileBufferEnc (*const tile_buffers)[MAX_TILE_COLS]) {
+  const MV32 candidate_offset[1] = { { 1, 0 } };
+  const uint8_t *const cur_tile_data =
+      tile_buffers[tile_row][tile_col].data + 4;
+  const size_t cur_tile_size = tile_buffers[tile_row][tile_col].size;
+
+  int i;
+
+  if (tile_row == 0) return 0;
+
+  // (TODO: yunqingwang) For now, only above tile is checked and used.
+  // More candidates such as left tile can be added later.
+  for (i = 0; i < 1; i++) {
+    int row_offset = candidate_offset[0].row;
+    int col_offset = candidate_offset[0].col;
+    int row = tile_row - row_offset;
+    int col = tile_col - col_offset;
+    uint8_t tile_hdr;
+    const uint8_t *tile_data;
+    TileBufferEnc *candidate;
+
+    if (row < 0 || col < 0) continue;
+
+    tile_hdr = *(tile_buffers[row][col].data);
+
+    // Read out tcm bit
+    if ((tile_hdr >> 7) == 1) {
+      // The candidate is a copy tile itself
+      row_offset += tile_hdr & 0x7f;
+      row = tile_row - row_offset;
+    }
+
+    candidate = &tile_buffers[row][col];
+
+    if (row_offset >= 128 || candidate->size != cur_tile_size) continue;
+
+    tile_data = candidate->data + 4;
+
+    if (memcmp(tile_data, cur_tile_data, cur_tile_size) != 0) continue;
+
+    // Identical tile found
+    assert(row_offset > 0);
+    return row_offset;
+  }
+
+  // No identical tile found
+  return 0;
+}
+
+static void write_render_size(const AV1_COMMON *cm,
+                              struct aom_write_bit_buffer *wb) {
+  const int scaling_active = av1_resize_scaled(cm);
+  aom_wb_write_bit(wb, scaling_active);
+  if (scaling_active) {
+    aom_wb_write_literal(wb, cm->render_width - 1, 16);
+    aom_wb_write_literal(wb, cm->render_height - 1, 16);
+  }
+}
+
+static void write_superres_scale(const AV1_COMMON *const cm,
+                                 struct aom_write_bit_buffer *wb) {
+  const SequenceHeader *const seq_params = &cm->seq_params;
+  if (!seq_params->enable_superres) {
+    assert(cm->superres_scale_denominator == SCALE_NUMERATOR);
+    return;
+  }
+
+  // First bit is whether to to scale or not
+  if (cm->superres_scale_denominator == SCALE_NUMERATOR) {
+    aom_wb_write_bit(wb, 0);  // no scaling
+  } else {
+    aom_wb_write_bit(wb, 1);  // scaling, write scale factor
+    assert(cm->superres_scale_denominator >= SUPERRES_SCALE_DENOMINATOR_MIN);
+    assert(cm->superres_scale_denominator <
+           SUPERRES_SCALE_DENOMINATOR_MIN + (1 << SUPERRES_SCALE_BITS));
+    aom_wb_write_literal(
+        wb, cm->superres_scale_denominator - SUPERRES_SCALE_DENOMINATOR_MIN,
+        SUPERRES_SCALE_BITS);
+  }
+}
+
+static void write_frame_size(const AV1_COMMON *cm, int frame_size_override,
+                             struct aom_write_bit_buffer *wb) {
+  const int coded_width = cm->superres_upscaled_width - 1;
+  const int coded_height = cm->superres_upscaled_height - 1;
+
+  if (frame_size_override) {
+    const SequenceHeader *seq_params = &cm->seq_params;
+    int num_bits_width = seq_params->num_bits_width;
+    int num_bits_height = seq_params->num_bits_height;
+    aom_wb_write_literal(wb, coded_width, num_bits_width);
+    aom_wb_write_literal(wb, coded_height, num_bits_height);
+  }
+
+  write_superres_scale(cm, wb);
+  write_render_size(cm, wb);
+}
+
+static void write_frame_size_with_refs(AV1_COMP *cpi,
+                                       struct aom_write_bit_buffer *wb) {
+  AV1_COMMON *const cm = &cpi->common;
+  int found = 0;
+
+  MV_REFERENCE_FRAME ref_frame;
+  for (ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
+    YV12_BUFFER_CONFIG *cfg = get_ref_frame_buffer(cpi, ref_frame);
+
+    if (cfg != NULL) {
+      found = cm->superres_upscaled_width == cfg->y_crop_width &&
+              cm->superres_upscaled_height == cfg->y_crop_height;
+      found &= cm->render_width == cfg->render_width &&
+               cm->render_height == cfg->render_height;
+    }
+    aom_wb_write_bit(wb, found);
+    if (found) {
+      write_superres_scale(cm, wb);
+      break;
+    }
+  }
+
+  if (!found) {
+    int frame_size_override = 1;  // Always equal to 1 in this function
+    write_frame_size(cm, frame_size_override, wb);
+  }
+}
+
+static void write_profile(BITSTREAM_PROFILE profile,
+                          struct aom_write_bit_buffer *wb) {
+  assert(profile >= PROFILE_0 && profile < MAX_PROFILES);
+  aom_wb_write_literal(wb, profile, PROFILE_BITS);
+}
+
+static void write_bitdepth(const SequenceHeader *const seq_params,
+                           struct aom_write_bit_buffer *wb) {
+  // Profile 0/1: [0] for 8 bit, [1]  10-bit
+  // Profile   2: [0] for 8 bit, [10] 10-bit, [11] - 12-bit
+  aom_wb_write_bit(wb, seq_params->bit_depth == AOM_BITS_8 ? 0 : 1);
+  if (seq_params->profile == PROFILE_2 && seq_params->bit_depth != AOM_BITS_8) {
+    aom_wb_write_bit(wb, seq_params->bit_depth == AOM_BITS_10 ? 0 : 1);
+  }
+}
+
+static void write_color_config(const SequenceHeader *const seq_params,
+                               struct aom_write_bit_buffer *wb) {
+  write_bitdepth(seq_params, wb);
+  const int is_monochrome = seq_params->monochrome;
+  // monochrome bit
+  if (seq_params->profile != PROFILE_1)
+    aom_wb_write_bit(wb, is_monochrome);
+  else
+    assert(!is_monochrome);
+  if (seq_params->color_primaries == AOM_CICP_CP_UNSPECIFIED &&
+      seq_params->transfer_characteristics == AOM_CICP_TC_UNSPECIFIED &&
+      seq_params->matrix_coefficients == AOM_CICP_MC_UNSPECIFIED) {
+    aom_wb_write_bit(wb, 0);  // No color description present
+  } else {
+    aom_wb_write_bit(wb, 1);  // Color description present
+    aom_wb_write_literal(wb, seq_params->color_primaries, 8);
+    aom_wb_write_literal(wb, seq_params->transfer_characteristics, 8);
+    aom_wb_write_literal(wb, seq_params->matrix_coefficients, 8);
+  }
+  if (is_monochrome) {
+    // 0: [16, 235] (i.e. xvYCC), 1: [0, 255]
+    aom_wb_write_bit(wb, seq_params->color_range);
+    return;
+  }
+  if (seq_params->color_primaries == AOM_CICP_CP_BT_709 &&
+      seq_params->transfer_characteristics == AOM_CICP_TC_SRGB &&
+      seq_params->matrix_coefficients ==
+          AOM_CICP_MC_IDENTITY) {  // it would be better to remove this
+                                   // dependency too
+    assert(seq_params->subsampling_x == 0 && seq_params->subsampling_y == 0);
+    assert(seq_params->profile == PROFILE_1 ||
+           (seq_params->profile == PROFILE_2 &&
+            seq_params->bit_depth == AOM_BITS_12));
+  } else {
+    // 0: [16, 235] (i.e. xvYCC), 1: [0, 255]
+    aom_wb_write_bit(wb, seq_params->color_range);
+    if (seq_params->profile == PROFILE_0) {
+      // 420 only
+      assert(seq_params->subsampling_x == 1 && seq_params->subsampling_y == 1);
+    } else if (seq_params->profile == PROFILE_1) {
+      // 444 only
+      assert(seq_params->subsampling_x == 0 && seq_params->subsampling_y == 0);
+    } else if (seq_params->profile == PROFILE_2) {
+      if (seq_params->bit_depth == AOM_BITS_12) {
+        // 420, 444 or 422
+        aom_wb_write_bit(wb, seq_params->subsampling_x);
+        if (seq_params->subsampling_x == 0) {
+          assert(seq_params->subsampling_y == 0 &&
+                 "4:4:0 subsampling not allowed in AV1");
+        } else {
+          aom_wb_write_bit(wb, seq_params->subsampling_y);
+        }
+      } else {
+        // 422 only
+        assert(seq_params->subsampling_x == 1 &&
+               seq_params->subsampling_y == 0);
+      }
+    }
+    if (seq_params->matrix_coefficients == AOM_CICP_MC_IDENTITY) {
+      assert(seq_params->subsampling_x == 0 && seq_params->subsampling_y == 0);
+    }
+    if (seq_params->subsampling_x == 1 && seq_params->subsampling_y == 1) {
+      aom_wb_write_literal(wb, seq_params->chroma_sample_position, 2);
+    }
+  }
+  aom_wb_write_bit(wb, seq_params->separate_uv_delta_q);
+}
+
+static void write_timing_info_header(AV1_COMMON *const cm,
+                                     struct aom_write_bit_buffer *wb) {
+  aom_wb_write_unsigned_literal(wb, cm->timing_info.num_units_in_display_tick,
+                                32);  // Number of units in tick
+  aom_wb_write_unsigned_literal(wb, cm->timing_info.time_scale,
+                                32);  // Time scale
+  aom_wb_write_bit(
+      wb,
+      cm->timing_info.equal_picture_interval);  // Equal picture interval bit
+  if (cm->timing_info.equal_picture_interval) {
+    aom_wb_write_uvlc(
+        wb,
+        cm->timing_info.num_ticks_per_picture - 1);  // ticks per picture
+  }
+}
+
+static void write_decoder_model_info(AV1_COMMON *const cm,
+                                     struct aom_write_bit_buffer *wb) {
+  aom_wb_write_literal(
+      wb, cm->buffer_model.encoder_decoder_buffer_delay_length - 1, 5);
+  aom_wb_write_unsigned_literal(wb, cm->buffer_model.num_units_in_decoding_tick,
+                                32);  // Number of units in decoding tick
+  aom_wb_write_literal(wb, cm->buffer_model.buffer_removal_time_length - 1, 5);
+  aom_wb_write_literal(wb, cm->buffer_model.frame_presentation_time_length - 1,
+                       5);
+}
+
+static void write_dec_model_op_parameters(AV1_COMMON *const cm,
+                                          struct aom_write_bit_buffer *wb,
+                                          int op_num) {
+  if (op_num > MAX_NUM_OPERATING_POINTS)
+    aom_internal_error(
+        &cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+        "Encoder does not support %d decoder model operating points", op_num);
+
+  //  aom_wb_write_bit(wb, cm->op_params[op_num].has_parameters);
+  //  if (!cm->op_params[op_num].has_parameters) return;
+
+  aom_wb_write_unsigned_literal(
+      wb, cm->op_params[op_num].decoder_buffer_delay,
+      cm->buffer_model.encoder_decoder_buffer_delay_length);
+
+  aom_wb_write_unsigned_literal(
+      wb, cm->op_params[op_num].encoder_buffer_delay,
+      cm->buffer_model.encoder_decoder_buffer_delay_length);
+
+  aom_wb_write_bit(wb, cm->op_params[op_num].low_delay_mode_flag);
+
+  cm->op_frame_timing[op_num].buffer_removal_time =
+      0;  // reset the decoded frame counter
+}
+
+static void write_tu_pts_info(AV1_COMMON *const cm,
+                              struct aom_write_bit_buffer *wb) {
+  aom_wb_write_unsigned_literal(
+      wb, cm->frame_presentation_time,
+      cm->buffer_model.frame_presentation_time_length);
+}
+
+static void write_film_grain_params(AV1_COMP *cpi,
+                                    struct aom_write_bit_buffer *wb) {
+  AV1_COMMON *const cm = &cpi->common;
+  aom_film_grain_t *pars = &cm->film_grain_params;
+
+  cm->cur_frame->film_grain_params = *pars;
+
+  aom_wb_write_bit(wb, pars->apply_grain);
+  if (!pars->apply_grain) return;
+
+  aom_wb_write_literal(wb, pars->random_seed, 16);
+
+  pars->random_seed += 3381;  // Changing random seed for film grain
+  if (!pars->random_seed)     // Random seed should not be zero
+    pars->random_seed += 7391;
+  if (cm->frame_type == INTER_FRAME)
+    aom_wb_write_bit(wb, pars->update_parameters);
+  else
+    pars->update_parameters = 1;
+  if (!pars->update_parameters) {
+    RefCntBuffer *const frame_bufs = cm->buffer_pool->frame_bufs;
+    int ref_frame, ref_idx, buf_idx;
+    for (ref_frame = LAST_FRAME; ref_frame < REF_FRAMES; ref_frame++) {
+      ref_idx = get_ref_frame_map_idx(cpi, ref_frame);
+      assert(ref_idx != INVALID_IDX);
+      buf_idx = cm->ref_frame_map[ref_idx];
+      if (frame_bufs[buf_idx].film_grain_params_present &&
+          memcmp(pars, &frame_bufs[buf_idx].film_grain_params, sizeof(*pars))) {
+        break;
+      }
+    }
+    assert(ref_frame < REF_FRAMES);
+    aom_wb_write_literal(wb, ref_idx, 3);
+    return;
+  }
+
+  // Scaling functions parameters
+  aom_wb_write_literal(wb, pars->num_y_points, 4);  // max 14
+  for (int i = 0; i < pars->num_y_points; i++) {
+    aom_wb_write_literal(wb, pars->scaling_points_y[i][0], 8);
+    aom_wb_write_literal(wb, pars->scaling_points_y[i][1], 8);
+  }
+
+  if (!cm->seq_params.monochrome)
+    aom_wb_write_bit(wb, pars->chroma_scaling_from_luma);
+  else
+    pars->chroma_scaling_from_luma = 0;  // for monochrome override to 0
+
+  if (cm->seq_params.monochrome || pars->chroma_scaling_from_luma ||
+      ((cm->seq_params.subsampling_x == 1) &&
+       (cm->seq_params.subsampling_y == 1) && (pars->num_y_points == 0))) {
+    pars->num_cb_points = 0;
+    pars->num_cr_points = 0;
+  } else {
+    aom_wb_write_literal(wb, pars->num_cb_points, 4);  // max 10
+    for (int i = 0; i < pars->num_cb_points; i++) {
+      aom_wb_write_literal(wb, pars->scaling_points_cb[i][0], 8);
+      aom_wb_write_literal(wb, pars->scaling_points_cb[i][1], 8);
+    }
+
+    aom_wb_write_literal(wb, pars->num_cr_points, 4);  // max 10
+    for (int i = 0; i < pars->num_cr_points; i++) {
+      aom_wb_write_literal(wb, pars->scaling_points_cr[i][0], 8);
+      aom_wb_write_literal(wb, pars->scaling_points_cr[i][1], 8);
+    }
+  }
+
+  aom_wb_write_literal(wb, pars->scaling_shift - 8, 2);  // 8 + value
+
+  // AR coefficients
+  // Only sent if the corresponsing scaling function has
+  // more than 0 points
+
+  aom_wb_write_literal(wb, pars->ar_coeff_lag, 2);
+
+  int num_pos_luma = 2 * pars->ar_coeff_lag * (pars->ar_coeff_lag + 1);
+  int num_pos_chroma = num_pos_luma;
+  if (pars->num_y_points > 0) ++num_pos_chroma;
+
+  if (pars->num_y_points)
+    for (int i = 0; i < num_pos_luma; i++)
+      aom_wb_write_literal(wb, pars->ar_coeffs_y[i] + 128, 8);
+
+  if (pars->num_cb_points || pars->chroma_scaling_from_luma)
+    for (int i = 0; i < num_pos_chroma; i++)
+      aom_wb_write_literal(wb, pars->ar_coeffs_cb[i] + 128, 8);
+
+  if (pars->num_cr_points || pars->chroma_scaling_from_luma)
+    for (int i = 0; i < num_pos_chroma; i++)
+      aom_wb_write_literal(wb, pars->ar_coeffs_cr[i] + 128, 8);
+
+  aom_wb_write_literal(wb, pars->ar_coeff_shift - 6, 2);  // 8 + value
+
+  aom_wb_write_literal(wb, pars->grain_scale_shift, 2);
+
+  if (pars->num_cb_points) {
+    aom_wb_write_literal(wb, pars->cb_mult, 8);
+    aom_wb_write_literal(wb, pars->cb_luma_mult, 8);
+    aom_wb_write_literal(wb, pars->cb_offset, 9);
+  }
+
+  if (pars->num_cr_points) {
+    aom_wb_write_literal(wb, pars->cr_mult, 8);
+    aom_wb_write_literal(wb, pars->cr_luma_mult, 8);
+    aom_wb_write_literal(wb, pars->cr_offset, 9);
+  }
+
+  aom_wb_write_bit(wb, pars->overlap_flag);
+
+  aom_wb_write_bit(wb, pars->clip_to_restricted_range);
+}
+
+static void write_sb_size(SequenceHeader *seq_params,
+                          struct aom_write_bit_buffer *wb) {
+  (void)seq_params;
+  (void)wb;
+  assert(seq_params->mib_size == mi_size_wide[seq_params->sb_size]);
+  assert(seq_params->mib_size == 1 << seq_params->mib_size_log2);
+  assert(seq_params->sb_size == BLOCK_128X128 ||
+         seq_params->sb_size == BLOCK_64X64);
+  aom_wb_write_bit(wb, seq_params->sb_size == BLOCK_128X128 ? 1 : 0);
+}
+
+static void write_sequence_header(AV1_COMP *cpi,
+                                  struct aom_write_bit_buffer *wb) {
+  AV1_COMMON *const cm = &cpi->common;
+  SequenceHeader *seq_params = &cm->seq_params;
+
+  int max_frame_width = cpi->oxcf.forced_max_frame_width
+                            ? cpi->oxcf.forced_max_frame_width
+                            : cpi->oxcf.width;
+  int max_frame_height = cpi->oxcf.forced_max_frame_height
+                             ? cpi->oxcf.forced_max_frame_height
+                             : cpi->oxcf.height;
+  // max((int)ceil(log2(max_frame_width)), 1)
+  const int num_bits_width =
+      (max_frame_width > 1) ? get_msb(max_frame_width - 1) + 1 : 1;
+  // max((int)ceil(log2(max_frame_height)), 1)
+  const int num_bits_height =
+      (max_frame_height > 1) ? get_msb(max_frame_height - 1) + 1 : 1;
+  assert(num_bits_width <= 16);
+  assert(num_bits_height <= 16);
+
+  seq_params->num_bits_width = num_bits_width;
+  seq_params->num_bits_height = num_bits_height;
+  seq_params->max_frame_width = max_frame_width;
+  seq_params->max_frame_height = max_frame_height;
+
+  aom_wb_write_literal(wb, num_bits_width - 1, 4);
+  aom_wb_write_literal(wb, num_bits_height - 1, 4);
+  aom_wb_write_literal(wb, max_frame_width - 1, num_bits_width);
+  aom_wb_write_literal(wb, max_frame_height - 1, num_bits_height);
+
+  /* Placeholder for actually writing to the bitstream */
+  if (!seq_params->reduced_still_picture_hdr) {
+    seq_params->frame_id_numbers_present_flag =
+        cm->large_scale_tile ? 0 : cm->error_resilient_mode;
+    seq_params->frame_id_length = FRAME_ID_LENGTH;
+    seq_params->delta_frame_id_length = DELTA_FRAME_ID_LENGTH;
+
+    aom_wb_write_bit(wb, seq_params->frame_id_numbers_present_flag);
+    if (seq_params->frame_id_numbers_present_flag) {
+      // We must always have delta_frame_id_length < frame_id_length,
+      // in order for a frame to be referenced with a unique delta.
+      // Avoid wasting bits by using a coding that enforces this restriction.
+      aom_wb_write_literal(wb, seq_params->delta_frame_id_length - 2, 4);
+      aom_wb_write_literal(
+          wb,
+          seq_params->frame_id_length - seq_params->delta_frame_id_length - 1,
+          3);
+    }
+  }
+
+  write_sb_size(seq_params, wb);
+
+  aom_wb_write_bit(wb, seq_params->enable_filter_intra);
+  aom_wb_write_bit(wb, seq_params->enable_intra_edge_filter);
+
+  if (!seq_params->reduced_still_picture_hdr) {
+    aom_wb_write_bit(wb, seq_params->enable_interintra_compound);
+    aom_wb_write_bit(wb, seq_params->enable_masked_compound);
+    aom_wb_write_bit(wb, seq_params->enable_warped_motion);
+    aom_wb_write_bit(wb, seq_params->enable_dual_filter);
+
+    aom_wb_write_bit(wb, seq_params->enable_order_hint);
+
+    if (seq_params->enable_order_hint) {
+      aom_wb_write_bit(wb, seq_params->enable_jnt_comp);
+      aom_wb_write_bit(wb, seq_params->enable_ref_frame_mvs);
+    }
+    if (seq_params->force_screen_content_tools == 2) {
+      aom_wb_write_bit(wb, 1);
+    } else {
+      aom_wb_write_bit(wb, 0);
+      aom_wb_write_bit(wb, seq_params->force_screen_content_tools);
+    }
+    if (seq_params->force_screen_content_tools > 0) {
+      if (seq_params->force_integer_mv == 2) {
+        aom_wb_write_bit(wb, 1);
+      } else {
+        aom_wb_write_bit(wb, 0);
+        aom_wb_write_bit(wb, seq_params->force_integer_mv);
+      }
+    } else {
+      assert(seq_params->force_integer_mv == 2);
+    }
+    if (seq_params->enable_order_hint)
+      aom_wb_write_literal(wb, seq_params->order_hint_bits_minus_1, 3);
+  }
+
+  aom_wb_write_bit(wb, seq_params->enable_superres);
+  aom_wb_write_bit(wb, seq_params->enable_cdef);
+  aom_wb_write_bit(wb, seq_params->enable_restoration);
+}
+
+static void write_global_motion_params(const WarpedMotionParams *params,
+                                       const WarpedMotionParams *ref_params,
+                                       struct aom_write_bit_buffer *wb,
+                                       int allow_hp) {
+  const TransformationType type = params->wmtype;
+
+  aom_wb_write_bit(wb, type != IDENTITY);
+  if (type != IDENTITY) {
+    aom_wb_write_bit(wb, type == ROTZOOM);
+    if (type != ROTZOOM) aom_wb_write_bit(wb, type == TRANSLATION);
+  }
+
+  if (type >= ROTZOOM) {
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, GM_ALPHA_MAX + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[2] >> GM_ALPHA_PREC_DIFF) -
+            (1 << GM_ALPHA_PREC_BITS),
+        (params->wmmat[2] >> GM_ALPHA_PREC_DIFF) - (1 << GM_ALPHA_PREC_BITS));
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, GM_ALPHA_MAX + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[3] >> GM_ALPHA_PREC_DIFF),
+        (params->wmmat[3] >> GM_ALPHA_PREC_DIFF));
+  }
+
+  if (type >= AFFINE) {
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, GM_ALPHA_MAX + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[4] >> GM_ALPHA_PREC_DIFF),
+        (params->wmmat[4] >> GM_ALPHA_PREC_DIFF));
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, GM_ALPHA_MAX + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[5] >> GM_ALPHA_PREC_DIFF) -
+            (1 << GM_ALPHA_PREC_BITS),
+        (params->wmmat[5] >> GM_ALPHA_PREC_DIFF) - (1 << GM_ALPHA_PREC_BITS));
+  }
+
+  if (type >= TRANSLATION) {
+    const int trans_bits = (type == TRANSLATION)
+                               ? GM_ABS_TRANS_ONLY_BITS - !allow_hp
+                               : GM_ABS_TRANS_BITS;
+    const int trans_prec_diff = (type == TRANSLATION)
+                                    ? GM_TRANS_ONLY_PREC_DIFF + !allow_hp
+                                    : GM_TRANS_PREC_DIFF;
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, (1 << trans_bits) + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[0] >> trans_prec_diff),
+        (params->wmmat[0] >> trans_prec_diff));
+    aom_wb_write_signed_primitive_refsubexpfin(
+        wb, (1 << trans_bits) + 1, SUBEXPFIN_K,
+        (ref_params->wmmat[1] >> trans_prec_diff),
+        (params->wmmat[1] >> trans_prec_diff));
+  }
+}
+
+static void write_global_motion(AV1_COMP *cpi,
+                                struct aom_write_bit_buffer *wb) {
+  AV1_COMMON *const cm = &cpi->common;
+  int frame;
+  for (frame = LAST_FRAME; frame <= ALTREF_FRAME; ++frame) {
+    const WarpedMotionParams *ref_params =
+        cm->prev_frame ? &cm->prev_frame->global_motion[frame]
+                       : &default_warp_params;
+    write_global_motion_params(&cm->global_motion[frame], ref_params, wb,
+                               cm->allow_high_precision_mv);
+    // TODO(sarahparker, debargha): The logic in the commented out code below
+    // does not work currently and causes mismatches when resize is on.
+    // Fix it before turning the optimization back on.
+    /*
+    YV12_BUFFER_CONFIG *ref_buf = get_ref_frame_buffer(cpi, frame);
+    if (cpi->source->y_crop_width == ref_buf->y_crop_width &&
+        cpi->source->y_crop_height == ref_buf->y_crop_height) {
+      write_global_motion_params(&cm->global_motion[frame],
+                                 &cm->prev_frame->global_motion[frame], wb,
+                                 cm->allow_high_precision_mv);
+    } else {
+      assert(cm->global_motion[frame].wmtype == IDENTITY &&
+             "Invalid warp type for frames of different resolutions");
+    }
+    */
+    /*
+    printf("Frame %d/%d: Enc Ref %d: %d %d %d %d\n",
+           cm->current_video_frame, cm->show_frame, frame,
+           cm->global_motion[frame].wmmat[0],
+           cm->global_motion[frame].wmmat[1], cm->global_motion[frame].wmmat[2],
+           cm->global_motion[frame].wmmat[3]);
+           */
+  }
+}
+
+static void check_frame_refs_short_signaling(AV1_COMP *const cpi) {
+  AV1_COMMON *const cm = &cpi->common;
+  if (!cm->frame_refs_short_signaling) return;
+
+  // Check whether all references are distinct frames.
+  int buf_markers[FRAME_BUFFERS] = { 0 };
+  for (int ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
+    const int buf_idx = get_ref_frame_buf_idx(cpi, ref_frame);
+    if (buf_idx != INVALID_IDX) {
+      assert(buf_idx >= 0 && buf_idx < FRAME_BUFFERS);
+      buf_markers[buf_idx] = 1;
+    }
+  }
+
+  int num_refs = 0;
+  for (int buf_idx = 0; buf_idx < FRAME_BUFFERS; ++buf_idx) {
+    num_refs += buf_markers[buf_idx];
+  }
+
+  // We only turn on frame_refs_short_signaling when all references are
+  // distinct.
+  if (num_refs < INTER_REFS_PER_FRAME) {
+    // It indicates that there exist more than one reference frame pointing to
+    // the same reference buffer, i.e. two or more references are duplicate.
+    cm->frame_refs_short_signaling = 0;
+    return;
+  }
+
+  // Check whether the encoder side ref frame choices are aligned with that to
+  // be derived at the decoder side.
+  RefBuffer frame_refs_copy[INTER_REFS_PER_FRAME];
+
+  // Backup the frame refs info
+  memcpy(frame_refs_copy, cm->frame_refs,
+         INTER_REFS_PER_FRAME * sizeof(RefBuffer));
+
+  const int lst_map_idx = get_ref_frame_map_idx(cpi, LAST_FRAME);
+  const int gld_map_idx = get_ref_frame_map_idx(cpi, GOLDEN_FRAME);
+
+  // Set up the frame refs mapping indexes according to the
+  // frame_refs_short_signaling policy.
+  av1_set_frame_refs(cm, lst_map_idx, gld_map_idx);
+
+  // We only turn on frame_refs_short_signaling when the encoder side decision
+  // on ref frames is identical to that at the decoder side.
+  for (int ref_idx = 0; ref_idx < INTER_REFS_PER_FRAME; ++ref_idx) {
+    // Compare the buffer index between two reference frames indexed
+    // respectively by the encoder and the decoder side decisions.
+    if (cm->frame_refs[ref_idx].idx != frame_refs_copy[ref_idx].idx) {
+      cm->frame_refs_short_signaling = 0;
+      break;
+    }
+  }
+
+#if 0   // For debug
+  printf("\nFrame=%d: \n", cm->current_video_frame);
+  printf("***frame_refs_short_signaling=%d\n", cm->frame_refs_short_signaling);
+  for (int ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
+    printf("enc_ref(map_idx=%d, buf_idx=%d)=%d, vs. "
+        "dec_ref(map_idx=%d, buf_idx=%d)=%d\n",
+        get_ref_frame_map_idx(cpi, ref_frame),
+        get_ref_frame_buf_idx(cpi, ref_frame), ref_frame,
+        cm->frame_refs[ref_frame - LAST_FRAME].map_idx,
+        cm->frame_refs[ref_frame - LAST_FRAME].idx, ref_frame);
+  }
+#endif  // 0
+
+  // Restore the frame refs info if frame_refs_short_signaling is off.
+  if (!cm->frame_refs_short_signaling)
+    memcpy(cm->frame_refs, frame_refs_copy,
+           INTER_REFS_PER_FRAME * sizeof(RefBuffer));
+}
+
+// New function based on HLS R18
+static void write_uncompressed_header_obu(AV1_COMP *cpi,
+                                          struct aom_write_bit_buffer *saved_wb,
+                                          struct aom_write_bit_buffer *wb) {
+  AV1_COMMON *const cm = &cpi->common;
+  const SequenceHeader *const seq_params = &cm->seq_params;
+  MACROBLOCKD *const xd = &cpi->td.mb.e_mbd;
+
+  // NOTE: By default all coded frames to be used as a reference
+  cm->is_reference_frame = 1;
+  cm->frame_type = cm->intra_only ? INTRA_ONLY_FRAME : cm->frame_type;
+
+  if (seq_params->still_picture) {
+    assert(cm->show_existing_frame == 0);
+    assert(cm->show_frame == 1);
+    assert(cm->frame_type == KEY_FRAME);
+  }
+  if (!seq_params->reduced_still_picture_hdr) {
+    if (encode_show_existing_frame(cm)) {
+      RefCntBuffer *const frame_bufs = cm->buffer_pool->frame_bufs;
+      const int frame_to_show = cm->ref_frame_map[cpi->existing_fb_idx_to_show];
+
+      if (frame_to_show < 0 || frame_bufs[frame_to_show].ref_count < 1) {
+        aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+                           "Buffer %d does not contain a reconstructed frame",
+                           frame_to_show);
+      }
+      ref_cnt_fb(frame_bufs, &cm->new_fb_idx, frame_to_show);
+
+      aom_wb_write_bit(wb, 1);  // show_existing_frame
+      aom_wb_write_literal(wb, cpi->existing_fb_idx_to_show, 3);
+
+      if (seq_params->decoder_model_info_present_flag &&
+          cm->timing_info.equal_picture_interval == 0) {
+        write_tu_pts_info(cm, wb);
+      }
+      if (seq_params->frame_id_numbers_present_flag) {
+        int frame_id_len = seq_params->frame_id_length;
+        int display_frame_id = cm->ref_frame_id[cpi->existing_fb_idx_to_show];
+        aom_wb_write_literal(wb, display_frame_id, frame_id_len);
+      }
+
+      if (cm->reset_decoder_state &&
+          frame_bufs[frame_to_show].frame_type != KEY_FRAME) {
+        aom_internal_error(
+            &cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+            "show_existing_frame to reset state on KEY_FRAME only");
+      }
+
+      return;
+    } else {
+      aom_wb_write_bit(wb, 0);  // show_existing_frame
+    }
+
+    aom_wb_write_literal(wb, cm->frame_type, 2);
+
+    aom_wb_write_bit(wb, cm->show_frame);
+    if (cm->show_frame) {
+      if (seq_params->decoder_model_info_present_flag &&
+          cm->timing_info.equal_picture_interval == 0)
+        write_tu_pts_info(cm, wb);
+    } else {
+      aom_wb_write_bit(wb, cm->showable_frame);
+    }
+    if (frame_is_sframe(cm)) {
+      assert(cm->error_resilient_mode);
+    } else if (!(cm->frame_type == KEY_FRAME && cm->show_frame)) {
+      aom_wb_write_bit(wb, cm->error_resilient_mode);
+    }
+  }
+  aom_wb_write_bit(wb, cm->disable_cdf_update);
+
+  if (seq_params->force_screen_content_tools == 2) {
+    aom_wb_write_bit(wb, cm->allow_screen_content_tools);
+  } else {
+    assert(cm->allow_screen_content_tools ==
+           seq_params->force_screen_content_tools);
+  }
+
+  if (cm->allow_screen_content_tools) {
+    if (seq_params->force_integer_mv == 2) {
+      aom_wb_write_bit(wb, cm->cur_frame_force_integer_mv);
+    } else {
+      assert(cm->cur_frame_force_integer_mv == seq_params->force_integer_mv);
+    }
+  } else {
+    assert(cm->cur_frame_force_integer_mv == 0);
+  }
+
+  cm->invalid_delta_frame_id_minus_1 = 0;
+  int frame_size_override_flag = 0;
+  cm->frame_refs_short_signaling = 0;
+
+  if (seq_params->reduced_still_picture_hdr) {
+    assert(cm->width == seq_params->max_frame_width &&
+           cm->height == seq_params->max_frame_height);
+  } else {
+    if (seq_params->frame_id_numbers_present_flag) {
+      int frame_id_len = seq_params->frame_id_length;
+      aom_wb_write_literal(wb, cm->current_frame_id, frame_id_len);
+    }
+
+    if (cm->width > seq_params->max_frame_width ||
+        cm->height > seq_params->max_frame_height) {
+      aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+                         "Frame dimensions are larger than the maximum values");
+    }
+
+    frame_size_override_flag =
+        frame_is_sframe(cm) ? 1
+                            : (cm->width != seq_params->max_frame_width ||
+                               cm->height != seq_params->max_frame_height);
+    if (!frame_is_sframe(cm)) aom_wb_write_bit(wb, frame_size_override_flag);
+
+    if (seq_params->enable_order_hint)
+      aom_wb_write_literal(wb, cm->frame_offset,
+                           seq_params->order_hint_bits_minus_1 + 1);
+
+    if (!cm->error_resilient_mode && !frame_is_intra_only(cm)) {
+      aom_wb_write_literal(wb, cm->primary_ref_frame, PRIMARY_REF_BITS);
+    }
+  }
+
+  if (seq_params->decoder_model_info_present_flag) {
+    aom_wb_write_bit(wb, cm->buffer_removal_time_present);
+    if (cm->buffer_removal_time_present) {
+      for (int op_num = 0;
+           op_num < seq_params->operating_points_cnt_minus_1 + 1; op_num++) {
+        if (cm->op_params[op_num].decoder_model_param_present_flag) {
+          if (((seq_params->operating_point_idc[op_num] >>
+                cm->temporal_layer_id) &
+                   0x1 &&
+               (seq_params->operating_point_idc[op_num] >>
+                (cm->spatial_layer_id + 8)) &
+                   0x1) ||
+              seq_params->operating_point_idc[op_num] == 0) {
+            aom_wb_write_unsigned_literal(
+                wb, cm->op_frame_timing[op_num].buffer_removal_time,
+                cm->buffer_model.buffer_removal_time_length);
+            cm->op_frame_timing[op_num].buffer_removal_time++;
+            if (cm->op_frame_timing[op_num].buffer_removal_time == 0) {
+              aom_internal_error(&cm->error, AOM_CODEC_UNSUP_BITSTREAM,
+                                 "buffer_removal_time overflowed");
+            }
+          }
+        }
+      }
+    }
+  }
+  cpi->refresh_frame_mask = get_refresh_mask(cpi);
+  if (cm->frame_type == KEY_FRAME) {
+    if (!cm->show_frame) {  // unshown keyframe (forward keyframe)
+      aom_wb_write_literal(wb, cpi->refresh_frame_mask, REF_FRAMES);
+    } else {
+      assert(cpi->refresh_frame_mask == 0xFF);
+    }
+  } else {
+    if (cm->frame_type == INTRA_ONLY_FRAME) {
+      assert(cpi->refresh_frame_mask != 0xFF);
+      int updated_fb = -1;
+      for (int i = 0; i < REF_FRAMES; i++) {
+        // If more than one frame is refreshed, it doesn't matter which one
+        // we pick, so pick the first.
+        if (cpi->refresh_frame_mask & (1 << i)) {
+          updated_fb = i;
+          break;
+        }
+      }
+      assert(updated_fb >= 0);
+      cm->fb_of_context_type[cm->frame_context_idx] = updated_fb;
+      aom_wb_write_literal(wb, cpi->refresh_frame_mask, REF_FRAMES);
+    } else if (cm->frame_type == INTER_FRAME || frame_is_sframe(cm)) {
+      if (cm->frame_type == INTER_FRAME) {
+        aom_wb_write_literal(wb, cpi->refresh_frame_mask, REF_FRAMES);
+      } else {
+        assert(frame_is_sframe(cm) && cpi->refresh_frame_mask == 0xFF);
+      }
+      int updated_fb = -1;
+      for (int i = 0; i < REF_FRAMES; i++) {
+        // If more than one frame is refreshed, it doesn't matter which one
+        // we pick, so pick the first.
+        if (cpi->refresh_frame_mask & (1 << i)) {
+          updated_fb = i;
+          break;
+        }
+      }
+      // large scale tile sometimes won't refresh any fbs
+      if (updated_fb >= 0) {
+        cm->fb_of_context_type[cm->frame_context_idx] = updated_fb;
+      }
+
+      if (!cpi->refresh_frame_mask) {
+        // NOTE: "cpi->refresh_frame_mask == 0" indicates that the coded frame
+        //       will not be used as a reference
+        cm->is_reference_frame = 0;
+      }
+    }
+  }
+
+  if (!frame_is_intra_only(cm) || cpi->refresh_frame_mask != 0xFF) {
+    // Write all ref frame order hints if error_resilient_mode == 1
+    if (cm->error_resilient_mode && seq_params->enable_order_hint) {
+      RefCntBuffer *const frame_bufs = cm->buffer_pool->frame_bufs;
+      for (int ref_idx = 0; ref_idx < REF_FRAMES; ref_idx++) {
+        // Get buffer index
+        const int buf_idx = cm->ref_frame_map[ref_idx];
+        assert(buf_idx >= 0 && buf_idx < FRAME_BUFFERS);
+
+        // Write order hint to bit stream
+        aom_wb_write_literal(wb, frame_bufs[buf_idx].cur_frame_offset,
+                             seq_params->order_hint_bits_minus_1 + 1);
+      }
+    }
+  }
+
+  if (cm->frame_type == KEY_FRAME) {
+    write_frame_size(cm, frame_size_override_flag, wb);
+    assert(!av1_superres_scaled(cm) || !cm->allow_intrabc);
+    if (cm->allow_screen_content_tools && !av1_superres_scaled(cm))
+      aom_wb_write_bit(wb, cm->allow_intrabc);
+    // all eight fbs are refreshed, pick one that will live long enough
+    cm->fb_of_context_type[REGULAR_FRAME] = 0;
+  } else {
+    if (cm->frame_type == INTRA_ONLY_FRAME) {
+      write_frame_size(cm, frame_size_override_flag, wb);
+      assert(!av1_superres_scaled(cm) || !cm->allow_intrabc);
+      if (cm->allow_screen_content_tools && !av1_superres_scaled(cm))
+        aom_wb_write_bit(wb, cm->allow_intrabc);
+    } else if (cm->frame_type == INTER_FRAME || frame_is_sframe(cm)) {
+      MV_REFERENCE_FRAME ref_frame;
+
+      // NOTE: Error resilient mode turns off frame_refs_short_signaling
+      //       automatically.
+#define FRAME_REFS_SHORT_SIGNALING 0
+#if FRAME_REFS_SHORT_SIGNALING
+      cm->frame_refs_short_signaling = seq_params->enable_order_hint;
+#endif  // FRAME_REFS_SHORT_SIGNALING
+
+      if (cm->frame_refs_short_signaling) {
+        // NOTE(zoeliu@google.com):
+        //   An example solution for encoder-side implementation on frame refs
+        //   short signaling, which is only turned on when the encoder side
+        //   decision on ref frames is identical to that at the decoder side.
+        check_frame_refs_short_signaling(cpi);
+      }
+
+      if (seq_params->enable_order_hint)
+        aom_wb_write_bit(wb, cm->frame_refs_short_signaling);
+
+      if (cm->frame_refs_short_signaling) {
+        const int lst_ref = get_ref_frame_map_idx(cpi, LAST_FRAME);
+        aom_wb_write_literal(wb, lst_ref, REF_FRAMES_LOG2);
+
+        const int gld_ref = get_ref_frame_map_idx(cpi, GOLDEN_FRAME);
+        aom_wb_write_literal(wb, gld_ref, REF_FRAMES_LOG2);
+      }
+
+      for (ref_frame = LAST_FRAME; ref_frame <= ALTREF_FRAME; ++ref_frame) {
+        assert(get_ref_frame_map_idx(cpi, ref_frame) != INVALID_IDX);
+        if (!cm->frame_refs_short_signaling)
+          aom_wb_write_literal(wb, get_ref_frame_map_idx(cpi, ref_frame),
+                               REF_FRAMES_LOG2);
+        if (seq_params->frame_id_numbers_present_flag) {
+          int i = get_ref_frame_map_idx(cpi, ref_frame);
+          int frame_id_len = seq_params->frame_id_length;
+          int diff_len = seq_params->delta_frame_id_length;
+          int delta_frame_id_minus_1 =
+              ((cm->current_frame_id - cm->ref_frame_id[i] +
+                (1 << frame_id_len)) %
+               (1 << frame_id_len)) -
+              1;
+          if (delta_frame_id_minus_1 < 0 ||
+              delta_frame_id_minus_1 >= (1 << diff_len))
+            cm->invalid_delta_frame_id_minus_1 = 1;
+          aom_wb_write_literal(wb, delta_frame_id_minus_1, diff_len);
+        }
+      }
+
+      if (!cm->error_resilient_mode && frame_size_override_flag) {
+        write_frame_size_with_refs(cpi, wb);
+      } else {
+        write_frame_size(cm, frame_size_override_flag, wb);
+      }
+
+      if (cm->cur_frame_force_integer_mv) {
+        cm->allow_high_precision_mv = 0;
+      } else {
+        aom_wb_write_bit(wb, cm->allow_high_precision_mv);
+      }
+      fix_interp_filter(cm, cpi->td.counts);
+      write_frame_interp_filter(cm->interp_filter, wb);
+      aom_wb_write_bit(wb, cm->switchable_motion_mode);
+      if (frame_might_allow_ref_frame_mvs(cm)) {
+        aom_wb_write_bit(wb, cm->allow_ref_frame_mvs);
+      } else {
+        assert(cm->allow_ref_frame_mvs == 0);
+      }
+    }
+  }
+
+  const int might_bwd_adapt =
+      !(seq_params->reduced_still_picture_hdr) && !(cm->disable_cdf_update);
+  if (cm->large_scale_tile)
+    cm->refresh_frame_context = REFRESH_FRAME_CONTEXT_DISABLED;
+
+  if (might_bwd_adapt) {
+    aom_wb_write_bit(
+        wb, cm->refresh_frame_context == REFRESH_FRAME_CONTEXT_DISABLED);
+  }
+
+  write_tile_info(cm, saved_wb, wb);
+  encode_quantization(cm, wb);
+  encode_segmentation(cm, xd, wb);
+
+  if (cm->delta_q_present_flag) assert(cm->base_qindex > 0);
+  if (cm->base_qindex > 0) {
+    aom_wb_write_bit(wb, cm->delta_q_present_flag);
+    if (cm->delta_q_present_flag) {
+      aom_wb_write_literal(wb, get_msb(cm->delta_q_res), 2);
+      xd->current_qindex = cm->base_qindex;
+      if (cm->allow_intrabc)
+        assert(cm->delta_lf_present_flag == 0);
+      else
+        aom_wb_write_bit(wb, cm->delta_lf_present_flag);
+      if (cm->delta_lf_present_flag) {
+        aom_wb_write_literal(wb, get_msb(cm->delta_lf_res), 2);
+        aom_wb_write_bit(wb, cm->delta_lf_multi);
+        av1_reset_loop_filter_delta(xd, av1_num_planes(cm));
+      }
+    }
+  }
+
+  if (cm->all_lossless) {
+    assert(!av1_superres_scaled(cm));
+  } else {
+    if (!cm->coded_lossless) {
+      encode_loopfilter(cm, wb);
+      encode_cdef(cm, wb);
+    }
+    encode_restoration_mode(cm, wb);
+  }
+
+  write_tx_mode(cm, &cm->tx_mode, wb);
+
+  if (cpi->allow_comp_inter_inter) {
+    const int use_hybrid_pred = cm->reference_mode == REFERENCE_MODE_SELECT;
+
+    aom_wb_write_bit(wb, use_hybrid_pred);
+  }
+
+  if (cm->is_skip_mode_allowed) aom_wb_write_bit(wb, cm->skip_mode_flag);
+
+  if (frame_might_allow_warped_motion(cm))
+    aom_wb_write_bit(wb, cm->allow_warped_motion);
+  else
+    assert(!cm->allow_warped_motion);
+
+  aom_wb_write_bit(wb, cm->reduced_tx_set_used);
+
+  if (!frame_is_intra_only(cm)) write_global_motion(cpi, wb);
+
+  if (seq_params->film_grain_params_present &&
+      (cm->show_frame || cm->showable_frame)) {
+    int flip_back_update_parameters_flag = 0;
+    if (cm->frame_type != INTER_FRAME &&
+        cm->film_grain_params.update_parameters == 0) {
+      cm->film_grain_params.update_parameters = 1;
+      flip_back_update_parameters_flag = 1;
+    }
+    write_film_grain_params(cpi, wb);
+
+    if (flip_back_update_parameters_flag)
+      cm->film_grain_params.update_parameters = 0;
+  }
+
+  if (cm->large_scale_tile) write_ext_tile_info(cm, saved_wb, wb);
+}
+
+static int choose_size_bytes(uint32_t size, int spare_msbs) {
+  // Choose the number of bytes required to represent size, without
+  // using the 'spare_msbs' number of most significant bits.
+
+  // Make sure we will fit in 4 bytes to start with..
+  if (spare_msbs > 0 && size >> (32 - spare_msbs) != 0) return -1;
+
+  // Normalise to 32 bits
+  size <<= spare_msbs;
+
+  if (size >> 24 != 0)
+    return 4;
+  else if (size >> 16 != 0)
+    return 3;
+  else if (size >> 8 != 0)
+    return 2;
+  else
+    return 1;
+}
+
+static void mem_put_varsize(uint8_t *const dst, const int sz, const int val) {
+  switch (sz) {
+    case 1: dst[0] = (uint8_t)(val & 0xff); break;
+    case 2: mem_put_le16(dst, val); break;
+    case 3: mem_put_le24(dst, val); break;
+    case 4: mem_put_le32(dst, val); break;
+    default: assert(0 && "Invalid size"); break;
+  }
+}
+
+static int remux_tiles(const AV1_COMMON *const cm, uint8_t *dst,
+                       const uint32_t data_size, const uint32_t max_tile_size,
+                       const uint32_t max_tile_col_size,
+                       int *const tile_size_bytes,
+                       int *const tile_col_size_bytes) {
+  // Choose the tile size bytes (tsb) and tile column size bytes (tcsb)
+  int tsb;
+  int tcsb;
+
+  if (cm->large_scale_tile) {
+    // The top bit in the tile size field indicates tile copy mode, so we
+    // have 1 less bit to code the tile size
+    tsb = choose_size_bytes(max_tile_size, 1);
+    tcsb = choose_size_bytes(max_tile_col_size, 0);
+  } else {
+    tsb = choose_size_bytes(max_tile_size, 0);
+    tcsb = 4;  // This is ignored
+    (void)max_tile_col_size;
+  }
+
+  assert(tsb > 0);
+  assert(tcsb > 0);
+
+  *tile_size_bytes = tsb;
+  *tile_col_size_bytes = tcsb;
+  if (tsb == 4 && tcsb == 4) return data_size;
+
+  uint32_t wpos = 0;
+  uint32_t rpos = 0;
+
+  if (cm->large_scale_tile) {
+    int tile_row;
+    int tile_col;
+
+    for (tile_col = 0; tile_col < cm->tile_cols; tile_col++) {
+      // All but the last column has a column header
+      if (tile_col < cm->tile_cols - 1) {
+        uint32_t tile_col_size = mem_get_le32(dst + rpos);
+        rpos += 4;
+
+        // Adjust the tile column size by the number of bytes removed
+        // from the tile size fields.
+        tile_col_size -= (4 - tsb) * cm->tile_rows;
+
+        mem_put_varsize(dst + wpos, tcsb, tile_col_size);
+        wpos += tcsb;
+      }
+
+      for (tile_row = 0; tile_row < cm->tile_rows; tile_row++) {
+        // All, including the last row has a header
+        uint32_t tile_header = mem_get_le32(dst + rpos);
+        rpos += 4;
+
+        // If this is a copy tile, we need to shift the MSB to the
+        // top bit of the new width, and there is no data to copy.
+        if (tile_header >> 31 != 0) {
+          if (tsb < 4) tile_header >>= 32 - 8 * tsb;
+          mem_put_varsize(dst + wpos, tsb, tile_header);
+          wpos += tsb;
+        } else {
+          mem_put_varsize(dst + wpos, tsb, tile_header);
+          wpos += tsb;
+
+          tile_header += AV1_MIN_TILE_SIZE_BYTES;
+          memmove(dst + wpos, dst + rpos, tile_header);
+          rpos += tile_header;
+          wpos += tile_header;
+        }
+      }
+    }
+
+    assert(rpos > wpos);
+    assert(rpos == data_size);
+
+    return wpos;
+  }
+  const int n_tiles = cm->tile_cols * cm->tile_rows;
+  int n;
+
+  for (n = 0; n < n_tiles; n++) {
+    int tile_size;
+
+    if (n == n_tiles - 1) {
+      tile_size = data_size - rpos;
+    } else {
+      tile_size = mem_get_le32(dst + rpos);
+      rpos += 4;
+      mem_put_varsize(dst + wpos, tsb, tile_size);
+      tile_size += AV1_MIN_TILE_SIZE_BYTES;
+      wpos += tsb;
+    }
+
+    memmove(dst + wpos, dst + rpos, tile_size);
+
+    rpos += tile_size;
+    wpos += tile_size;
+  }
+
+  assert(rpos > wpos);
+  assert(rpos == data_size);
+
+  return wpos;
+}
+
+uint32_t write_obu_header(OBU_TYPE obu_type, int obu_extension,
+                          uint8_t *const dst) {
+  struct aom_write_bit_buffer wb = { dst, 0 };
+  uint32_t size = 0;
+
+  aom_wb_write_literal(&wb, 0, 1);  // forbidden bit.
+  aom_wb_write_literal(&wb, (int)obu_type, 4);
+  aom_wb_write_literal(&wb, obu_extension ? 1 : 0, 1);
+  aom_wb_write_literal(&wb, 1, 1);  // obu_has_payload_length_field
+  aom_wb_write_literal(&wb, 0, 1);  // reserved
+
+  if (obu_extension) {
+    aom_wb_write_literal(&wb, obu_extension & 0xFF, 8);
+  }
+
+  size = aom_wb_bytes_written(&wb);
+  return size;
+}
+
+int write_uleb_obu_size(uint32_t obu_header_size, uint32_t obu_payload_size,
+                        uint8_t *dest) {
+  const uint32_t obu_size = obu_payload_size;
+  const uint32_t offset = obu_header_size;
+  size_t coded_obu_size = 0;
+
+  if (aom_uleb_encode(obu_size, sizeof(obu_size), dest + offset,
+                      &coded_obu_size) != 0) {
+    return AOM_CODEC_ERROR;
+  }
+
+  return AOM_CODEC_OK;
+}
+
+static size_t obu_memmove(uint32_t obu_header_size, uint32_t obu_payload_size,
+                          uint8_t *data) {
+  const size_t length_field_size = aom_uleb_size_in_bytes(obu_payload_size);
+  const uint32_t move_dst_offset =
+      (uint32_t)length_field_size + obu_header_size;
+  const uint32_t move_src_offset = obu_header_size;
+  const uint32_t move_size = obu_payload_size;
+  memmove(data + move_dst_offset, data + move_src_offset, move_size);
+  return length_field_size;
+}
+
+static void add_trailing_bits(struct aom_write_bit_buffer *wb) {
+  if (aom_wb_is_byte_aligned(wb)) {
+    aom_wb_write_literal(wb, 0x80, 8);
+  } else {
+    // assumes that the other bits are already 0s
+    aom_wb_write_bit(wb, 1);
+  }
+}
+
+static void write_bitstream_level(BitstreamLevel bl,
+                                  struct aom_write_bit_buffer *wb) {
+  uint8_t seq_level_idx = major_minor_to_seq_level_idx(bl);
+  assert(is_valid_seq_level_idx(seq_level_idx));
+  aom_wb_write_literal(wb, seq_level_idx, LEVEL_BITS);
+}
+
+uint32_t write_sequence_header_obu(AV1_COMP *cpi, uint8_t *const dst) {
+  AV1_COMMON *const cm = &cpi->common;
+  struct aom_write_bit_buffer wb = { dst, 0 };
+  uint32_t size = 0;
+
+  write_profile(cm->seq_params.profile, &wb);
+
+  // Still picture or not
+  aom_wb_write_bit(&wb, cm->seq_params.still_picture);
+  assert(IMPLIES(!cm->seq_params.still_picture,
+                 !cm->seq_params.reduced_still_picture_hdr));
+  // whether to use reduced still picture header
+  aom_wb_write_bit(&wb, cm->seq_params.reduced_still_picture_hdr);
+
+  if (cm->seq_params.reduced_still_picture_hdr) {
+    assert(cm->timing_info_present == 0);
+    assert(cm->seq_params.decoder_model_info_present_flag == 0);
+    assert(cm->seq_params.display_model_info_present_flag == 0);
+    write_bitstream_level(cm->seq_params.level[0], &wb);
+  } else {
+    aom_wb_write_bit(&wb, cm->timing_info_present);  // timing info present flag
+
+    if (cm->timing_info_present) {
+      // timing_info
+      write_timing_info_header(cm, &wb);
+      aom_wb_write_bit(&wb, cm->seq_params.decoder_model_info_present_flag);
+      if (cm->seq_params.decoder_model_info_present_flag) {
+        write_decoder_model_info(cm, &wb);
+      }
+    }
+    aom_wb_write_bit(&wb, cm->seq_params.display_model_info_present_flag);
+    aom_wb_write_literal(&wb, cm->seq_params.operating_points_cnt_minus_1,
+                         OP_POINTS_CNT_MINUS_1_BITS);
+    int i;
+    for (i = 0; i < cm->seq_params.operating_points_cnt_minus_1 + 1; i++) {
+      aom_wb_write_literal(&wb, cm->seq_params.operating_point_idc[i],
+                           OP_POINTS_IDC_BITS);
+      write_bitstream_level(cm->seq_params.level[i], &wb);
+      if (cm->seq_params.level[i].major > 3)
+        aom_wb_write_bit(&wb, cm->seq_params.tier[i]);
+      if (cm->seq_params.decoder_model_info_present_flag) {
+        aom_wb_write_bit(&wb,
+                         cm->op_params[i].decoder_model_param_present_flag);
+        if (cm->op_params[i].decoder_model_param_present_flag)
+          write_dec_model_op_parameters(cm, &wb, i);
+      }
+      if (cm->seq_params.display_model_info_present_flag) {
+        aom_wb_write_bit(&wb,
+                         cm->op_params[i].display_model_param_present_flag);
+        if (cm->op_params[i].display_model_param_present_flag) {
+          assert(cm->op_params[i].initial_display_delay <= 10);
+          aom_wb_write_literal(&wb, cm->op_params[i].initial_display_delay - 1,
+                               4);
+        }
+      }
+    }
+  }
+  write_sequence_header(cpi, &wb);
+
+  write_color_config(&cm->seq_params, &wb);
+
+  aom_wb_write_bit(&wb, cm->seq_params.film_grain_params_present);
+
+  add_trailing_bits(&wb);
+
+  size = aom_wb_bytes_written(&wb);
+  return size;
+}
+
+static uint32_t write_frame_header_obu(AV1_COMP *cpi,
+                                       struct aom_write_bit_buffer *saved_wb,
+                                       uint8_t *const dst,
+                                       int append_trailing_bits) {
+  struct aom_write_bit_buffer wb = { dst, 0 };
+  write_uncompressed_header_obu(cpi, saved_wb, &wb);
+  if (append_trailing_bits) add_trailing_bits(&wb);
+  return aom_wb_bytes_written(&wb);
+}
+
+static uint32_t write_tile_group_header(uint8_t *const dst, int startTile,
+                                        int endTile, int tiles_log2,
+                                        int tile_start_and_end_present_flag) {
+  struct aom_write_bit_buffer wb = { dst, 0 };
+  uint32_t size = 0;
+
+  if (!tiles_log2) return size;
+
+  aom_wb_write_bit(&wb, tile_start_and_end_present_flag);
+
+  if (tile_start_and_end_present_flag) {
+    aom_wb_write_literal(&wb, startTile, tiles_log2);
+    aom_wb_write_literal(&wb, endTile, tiles_log2);
+  }
+
+  size = aom_wb_bytes_written(&wb);
+  return size;
+}
+
+typedef struct {
+  uint8_t *frame_header;
+  size_t obu_header_byte_offset;
+  size_t total_length;
+} FrameHeaderInfo;
+
+static uint32_t write_tiles_in_tg_obus(AV1_COMP *const cpi, uint8_t *const dst,
+                                       struct aom_write_bit_buffer *saved_wb,
+                                       uint8_t obu_extension_header,
+                                       const FrameHeaderInfo *fh_info) {
+  AV1_COMMON *const cm = &cpi->common;
+  aom_writer mode_bc;
+  int tile_row, tile_col;
+  TileBufferEnc(*const tile_buffers)[MAX_TILE_COLS] = cpi->tile_buffers;
+  uint32_t total_size = 0;
+  const int tile_cols = cm->tile_cols;
+  const int tile_rows = cm->tile_rows;
+  unsigned int tile_size = 0;
+  unsigned int max_tile_size = 0;
+  unsigned int max_tile_col_size = 0;
+  const int n_log2_tiles = cm->log2_tile_rows + cm->log2_tile_cols;
+  // Fixed size tile groups for the moment
+  const int num_tg_hdrs = cm->num_tg;
+  const int tg_size =
+      (cm->large_scale_tile)
+          ? 1
+          : (tile_rows * tile_cols + num_tg_hdrs - 1) / num_tg_hdrs;
+  int tile_count = 0;
+  int curr_tg_data_size = 0;
+  uint8_t *data = dst;
+  int new_tg = 1;
+  const int have_tiles = tile_cols * tile_rows > 1;
+  int first_tg = 1;
+
+  cm->largest_tile_id = 0;
+
+  if (cm->large_scale_tile) {
+    // For large_scale_tile case, we always have only one tile group, so it can
+    // be written as an OBU_FRAME.
+    const OBU_TYPE obu_type = OBU_FRAME;
+    const uint32_t tg_hdr_size = write_obu_header(obu_type, 0, data);
+    data += tg_hdr_size;
+
+    const uint32_t frame_header_size =
+        write_frame_header_obu(cpi, saved_wb, data, 0);
+    data += frame_header_size;
+    total_size += frame_header_size;
+
+#define EXT_TILE_DEBUG 0
+#if EXT_TILE_DEBUG
+    {
+      char fn[20] = "./fh";
+      fn[4] = cm->current_video_frame / 100 + '0';
+      fn[5] = (cm->current_video_frame % 100) / 10 + '0';
+      fn[6] = (cm->current_video_frame % 10) + '0';
+      fn[7] = '\0';
+      av1_print_uncompressed_frame_header(data - frame_header_size,
+                                          frame_header_size, fn);
+    }
+#endif  // EXT_TILE_DEBUG
+#undef EXT_TILE_DEBUG
+
+    int tile_size_bytes = 0;
+    int tile_col_size_bytes = 0;
+
+    for (tile_col = 0; tile_col < tile_cols; tile_col++) {
+      TileInfo tile_info;
+      const int is_last_col = (tile_col == tile_cols - 1);
+      const uint32_t col_offset = total_size;
+
+      av1_tile_set_col(&tile_info, cm, tile_col);
+
+      // The last column does not have a column header
+      if (!is_last_col) total_size += 4;
+
+      for (tile_row = 0; tile_row < tile_rows; tile_row++) {
+        TileBufferEnc *const buf = &tile_buffers[tile_row][tile_col];
+        const int data_offset = have_tiles ? 4 : 0;
+        const int tile_idx = tile_row * tile_cols + tile_col;
+        TileDataEnc *this_tile = &cpi->tile_data[tile_idx];
+        av1_tile_set_row(&tile_info, cm, tile_row);
+
+        buf->data = dst + total_size + tg_hdr_size;
+
+        // Is CONFIG_EXT_TILE = 1, every tile in the row has a header,
+        // even for the last one, unless no tiling is used at all.
+        total_size += data_offset;
+        // Initialise tile context from the frame context
+        this_tile->tctx = *cm->fc;
+        cpi->td.mb.e_mbd.tile_ctx = &this_tile->tctx;
+        mode_bc.allow_update_cdf = !cm->large_scale_tile;
+        mode_bc.allow_update_cdf =
+            mode_bc.allow_update_cdf && !cm->disable_cdf_update;
+        aom_start_encode(&mode_bc, buf->data + data_offset);
+        write_modes(cpi, &tile_info, &mode_bc, tile_row, tile_col);
+        aom_stop_encode(&mode_bc);
+        tile_size = mode_bc.pos;
+        buf->size = tile_size;
+
+        // Record the maximum tile size we see, so we can compact headers later.
+        if (tile_size > max_tile_size) {
+          max_tile_size = tile_size;
+          cm->largest_tile_id = tile_cols * tile_row + tile_col;
+        }
+
+        if (have_tiles) {
+          // tile header: size of this tile, or copy offset
+          uint32_t tile_header = tile_size - AV1_MIN_TILE_SIZE_BYTES;
+          const int tile_copy_mode =
+              ((AOMMAX(cm->tile_width, cm->tile_height) << MI_SIZE_LOG2) <= 256)
+                  ? 1
+                  : 0;
+
+          // If tile_copy_mode = 1, check if this tile is a copy tile.
+          // Very low chances to have copy tiles on the key frames, so don't
+          // search on key frames to reduce unnecessary search.
+          if (cm->frame_type != KEY_FRAME && tile_copy_mode) {
+            const int identical_tile_offset =
+                find_identical_tile(tile_row, tile_col, tile_buffers);
+
+            if (identical_tile_offset > 0) {
+              tile_size = 0;
+              tile_header = identical_tile_offset | 0x80;
+              tile_header <<= 24;
+            }
+          }
+
+          mem_put_le32(buf->data, tile_header);
+        }
+
+        total_size += tile_size;
+      }
+
+      if (!is_last_col) {
+        uint32_t col_size = total_size - col_offset - 4;
+        mem_put_le32(dst + col_offset + tg_hdr_size, col_size);
+
+        // Record the maximum tile column size we see.
+        max_tile_col_size = AOMMAX(max_tile_col_size, col_size);
+      }
+    }
+
+    if (have_tiles) {
+      total_size = remux_tiles(cm, data, total_size - frame_header_size,
+                               max_tile_size, max_tile_col_size,
+                               &tile_size_bytes, &tile_col_size_bytes);
+      total_size += frame_header_size;
+    }
+
+    // In EXT_TILE case, only use 1 tile group. Follow the obu syntax, write
+    // current tile group size before tile data(include tile column header).
+    // Tile group size doesn't include the bytes storing tg size.
+    total_size += tg_hdr_size;
+    const uint32_t obu_payload_size = total_size - tg_hdr_size;
+    const size_t length_field_size =
+        obu_memmove(tg_hdr_size, obu_payload_size, dst);
+    if (write_uleb_obu_size(tg_hdr_size, obu_payload_size, dst) !=
+        AOM_CODEC_OK) {
+      assert(0);
+    }
+    total_size += (uint32_t)length_field_size;
+    saved_wb->bit_buffer += length_field_size;
+
+    // Now fill in the gaps in the uncompressed header.
+    if (have_tiles) {
+      assert(tile_col_size_bytes >= 1 && tile_col_size_bytes <= 4);
+      aom_wb_overwrite_literal(saved_wb, tile_col_size_bytes - 1, 2);
+
+      assert(tile_size_bytes >= 1 && tile_size_bytes <= 4);
+      aom_wb_overwrite_literal(saved_wb, tile_size_bytes - 1, 2);
+    }
+    return total_size;
+  }
+
+  uint32_t obu_header_size = 0;
+  uint8_t *tile_data_start = dst + total_size;
+  for (tile_row = 0; tile_row < tile_rows; tile_row++) {
+    TileInfo tile_info;
+    av1_tile_set_row(&tile_info, cm, tile_row);
+
+    for (tile_col = 0; tile_col < tile_cols; tile_col++) {
+      const int tile_idx = tile_row * tile_cols + tile_col;
+      TileBufferEnc *const buf = &tile_buffers[tile_row][tile_col];
+      TileDataEnc *this_tile = &cpi->tile_data[tile_idx];
+      int is_last_tile_in_tg = 0;
+
+      if (new_tg) {
+        data = dst + total_size;
+
+        // A new tile group begins at this tile.  Write the obu header and
+        // tile group header
+        const OBU_TYPE obu_type =
+            (num_tg_hdrs == 1) ? OBU_FRAME : OBU_TILE_GROUP;
+        curr_tg_data_size =
+            write_obu_header(obu_type, obu_extension_header, data);
+        obu_header_size = curr_tg_data_size;
+
+        if (num_tg_hdrs == 1) {
+          curr_tg_data_size += write_frame_header_obu(
+              cpi, saved_wb, data + curr_tg_data_size, 0);
+        }
+        curr_tg_data_size += write_tile_group_header(
+            data + curr_tg_data_size, tile_idx,
+            AOMMIN(tile_idx + tg_size - 1, tile_cols * tile_rows - 1),
+            n_log2_tiles, cm->num_tg > 1);
+        total_size += curr_tg_data_size;
+        tile_data_start += curr_tg_data_size;
+        new_tg = 0;
+        tile_count = 0;
+      }
+      tile_count++;
+      av1_tile_set_col(&tile_info, cm, tile_col);
+
+      if (tile_count == tg_size || tile_idx == (tile_cols * tile_rows - 1)) {
+        is_last_tile_in_tg = 1;
+        new_tg = 1;
+      } else {
+        is_last_tile_in_tg = 0;
+      }
+
+      buf->data = dst + total_size;
+
+      // The last tile of the tile group does not have a header.
+      if (!is_last_tile_in_tg) total_size += 4;
+
+      // Initialise tile context from the frame context
+      this_tile->tctx = *cm->fc;
+      cpi->td.mb.e_mbd.tile_ctx = &this_tile->tctx;
+      mode_bc.allow_update_cdf = 1;
+      mode_bc.allow_update_cdf =
+          mode_bc.allow_update_cdf && !cm->disable_cdf_update;
+      const int num_planes = av1_num_planes(cm);
+      av1_reset_loop_restoration(&cpi->td.mb.e_mbd, num_planes);
+
+      aom_start_encode(&mode_bc, dst + total_size);
+      write_modes(cpi, &tile_info, &mode_bc, tile_row, tile_col);
+      aom_stop_encode(&mode_bc);
+      tile_size = mode_bc.pos;
+      assert(tile_size >= AV1_MIN_TILE_SIZE_BYTES);
+
+      curr_tg_data_size += (tile_size + (is_last_tile_in_tg ? 0 : 4));
+      buf->size = tile_size;
+      if (tile_size > max_tile_size) {
+        cm->largest_tile_id = tile_cols * tile_row + tile_col;
+        max_tile_size = tile_size;
+      }
+
+      if (!is_last_tile_in_tg) {
+        // size of this tile
+        mem_put_le32(buf->data, tile_size - AV1_MIN_TILE_SIZE_BYTES);
+      } else {
+        // write current tile group size
+        const uint32_t obu_payload_size = curr_tg_data_size - obu_header_size;
+        const size_t length_field_size =
+            obu_memmove(obu_header_size, obu_payload_size, data);
+        if (write_uleb_obu_size(obu_header_size, obu_payload_size, data) !=
+            AOM_CODEC_OK) {
+          assert(0);
+        }
+        curr_tg_data_size += (int)length_field_size;
+        total_size += (uint32_t)length_field_size;
+        tile_data_start += length_field_size;
+        if (num_tg_hdrs == 1) {
+          // if this tg is combined with the frame header then update saved
+          // frame header base offset accroding to length field size
+          saved_wb->bit_buffer += length_field_size;
+        }
+
+        if (!first_tg && cm->error_resilient_mode) {
+          // Make room for a duplicate Frame Header OBU.
+          memmove(data + fh_info->total_length, data, curr_tg_data_size);
+
+          // Insert a copy of the Frame Header OBU.
+          memcpy(data, fh_info->frame_header, fh_info->total_length);
+
+          // Force context update tile to be the first tile in error
+          // resiliant mode as the duplicate frame headers will have
+          // context_update_tile_id set to 0
+          cm->largest_tile_id = 0;
+
+          // Rewrite the OBU header to change the OBU type to Redundant Frame
+          // Header.
+          write_obu_header(OBU_REDUNDANT_FRAME_HEADER, obu_extension_header,
+                           &data[fh_info->obu_header_byte_offset]);
+
+          data += fh_info->total_length;
+
+          curr_tg_data_size += (int)(fh_info->total_length);
+          total_size += (uint32_t)(fh_info->total_length);
+        }
+        first_tg = 0;
+      }
+
+      total_size += tile_size;
+    }
+  }
+
+  if (have_tiles) {
+    // Fill in context_update_tile_id indicating the tile to use for the
+    // cdf update. The encoder currently sets it to the largest tile
+    // (but is up to the encoder)
+    aom_wb_overwrite_literal(saved_wb, cm->largest_tile_id,
+                             cm->log2_tile_cols + cm->log2_tile_rows);
+    // If more than one tile group. tile_size_bytes takes the default value 4
+    // and does not need to be set. For a single tile group it is set in the
+    // section below.
+    if (num_tg_hdrs == 1) {
+      int tile_size_bytes = 4, unused;
+      const uint32_t tile_data_offset = (uint32_t)(tile_data_start - dst);
+      const uint32_t tile_data_size = total_size - tile_data_offset;
+
+      total_size =
+          remux_tiles(cm, tile_data_start, tile_data_size, max_tile_size,
+                      max_tile_col_size, &tile_size_bytes, &unused);
+      total_size += tile_data_offset;
+      assert(tile_size_bytes >= 1 && tile_size_bytes <= 4);
+
+      aom_wb_overwrite_literal(saved_wb, tile_size_bytes - 1, 2);
+
+      // Update the OBU length if remux_tiles() reduced the size.
+      uint64_t payload_size;
+      size_t length_field_size;
+      int res =
+          aom_uleb_decode(dst + obu_header_size, total_size - obu_header_size,
+                          &payload_size, &length_field_size);
+      assert(res == 0);
+      (void)res;
+
+      const uint64_t new_payload_size =
+          total_size - obu_header_size - length_field_size;
+      if (new_payload_size != payload_size) {
+        size_t new_length_field_size;
+        res = aom_uleb_encode(new_payload_size, length_field_size,
+                              dst + obu_header_size, &new_length_field_size);
+        assert(res == 0);
+        if (new_length_field_size < length_field_size) {
+          const size_t src_offset = obu_header_size + length_field_size;
+          const size_t dst_offset = obu_header_size + new_length_field_size;
+          memmove(dst + dst_offset, dst + src_offset, (size_t)payload_size);
+          total_size -= (int)(length_field_size - new_length_field_size);
+        }
+      }
+    }
+  }
+  return total_size;
+}
+
+int av1_pack_bitstream(AV1_COMP *const cpi, uint8_t *dst, size_t *size) {
+  uint8_t *data = dst;
+  uint32_t data_size;
+  AV1_COMMON *const cm = &cpi->common;
+  uint32_t obu_header_size = 0;
+  uint32_t obu_payload_size = 0;
+  FrameHeaderInfo fh_info = { NULL, 0, 0 };
+  const uint8_t obu_extension_header =
+      cm->temporal_layer_id << 5 | cm->spatial_layer_id << 3 | 0;
+
+#if CONFIG_BITSTREAM_DEBUG
+  bitstream_queue_reset_write();
+#endif
+
+  // The TD is now written outside the frame encode loop
+
+  // write sequence header obu if KEY_FRAME, preceded by 4-byte size
+  if (cm->frame_type == KEY_FRAME && cm->show_frame) {
+    obu_header_size = write_obu_header(OBU_SEQUENCE_HEADER, 0, data);
+
+    obu_payload_size = write_sequence_header_obu(cpi, data + obu_header_size);
+    const size_t length_field_size =
+        obu_memmove(obu_header_size, obu_payload_size, data);
+    if (write_uleb_obu_size(obu_header_size, obu_payload_size, data) !=
+        AOM_CODEC_OK) {
+      return AOM_CODEC_ERROR;
+    }
+
+    data += obu_header_size + obu_payload_size + length_field_size;
+  }
+
+  const int write_frame_header =
+      (cm->num_tg > 1 || encode_show_existing_frame(cm));
+  struct aom_write_bit_buffer saved_wb;
+  if (write_frame_header) {
+    // Write Frame Header OBU.
+    fh_info.frame_header = data;
+    obu_header_size =
+        write_obu_header(OBU_FRAME_HEADER, obu_extension_header, data);
+    obu_payload_size =
+        write_frame_header_obu(cpi, &saved_wb, data + obu_header_size, 1);
+
+    const size_t length_field_size =
+        obu_memmove(obu_header_size, obu_payload_size, data);
+    if (write_uleb_obu_size(obu_header_size, obu_payload_size, data) !=
+        AOM_CODEC_OK) {
+      return AOM_CODEC_ERROR;
+    }
+
+    fh_info.obu_header_byte_offset = 0;
+    fh_info.total_length =
+        obu_header_size + obu_payload_size + length_field_size;
+    data += fh_info.total_length;
+
+    // Since length_field_size is determined adaptively after frame header
+    // encoding, saved_wb must be adjusted accordingly.
+    saved_wb.bit_buffer += length_field_size;
+  }
+
+  if (encode_show_existing_frame(cm)) {
+    data_size = 0;
+  } else {
+    //  Each tile group obu will be preceded by 4-byte size of the tile group
+    //  obu
+    data_size = write_tiles_in_tg_obus(cpi, data, &saved_wb,
+                                       obu_extension_header, &fh_info);
+  }
+  data += data_size;
+  *size = data - dst;
+  return AOM_CODEC_OK;
+}