Add libvpx thirdparty library

Only necessary files

1 files changed, 2271 insertions, 0 deletions

diff --git a/thirdparty/libvpx/vp9/decoder/vp9_decodeframe.c b/thirdparty/libvpx/vp9/decoder/vp9_decodeframe.c
new file mode 100644
index 0000000000..d63912932c
--- /dev/null
+++ b/thirdparty/libvpx/vp9/decoder/vp9_decodeframe.c
@@ -0,0 +1,2271 @@
+/*
+ *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#include <assert.h>
+#include <stdlib.h>  // qsort()
+
+#include "./vp9_rtcd.h"
+#include "./vpx_dsp_rtcd.h"
+#include "./vpx_scale_rtcd.h"
+
+#include "vpx_dsp/bitreader_buffer.h"
+#include "vpx_dsp/bitreader.h"
+#include "vpx_dsp/vpx_dsp_common.h"
+#include "vpx_mem/vpx_mem.h"
+#include "vpx_ports/mem.h"
+#include "vpx_ports/mem_ops.h"
+#include "vpx_scale/vpx_scale.h"
+#include "vpx_util/vpx_thread.h"
+
+#include "vp9/common/vp9_alloccommon.h"
+#include "vp9/common/vp9_common.h"
+#include "vp9/common/vp9_entropy.h"
+#include "vp9/common/vp9_entropymode.h"
+#include "vp9/common/vp9_idct.h"
+#include "vp9/common/vp9_thread_common.h"
+#include "vp9/common/vp9_pred_common.h"
+#include "vp9/common/vp9_quant_common.h"
+#include "vp9/common/vp9_reconintra.h"
+#include "vp9/common/vp9_reconinter.h"
+#include "vp9/common/vp9_seg_common.h"
+#include "vp9/common/vp9_tile_common.h"
+
+#include "vp9/decoder/vp9_decodeframe.h"
+#include "vp9/decoder/vp9_detokenize.h"
+#include "vp9/decoder/vp9_decodemv.h"
+#include "vp9/decoder/vp9_decoder.h"
+#include "vp9/decoder/vp9_dsubexp.h"
+
+#define MAX_VP9_HEADER_SIZE 80
+
+static int is_compound_reference_allowed(const VP9_COMMON *cm) {
+  int i;
+  for (i = 1; i < REFS_PER_FRAME; ++i)
+    if (cm->ref_frame_sign_bias[i + 1] != cm->ref_frame_sign_bias[1])
+      return 1;
+
+  return 0;
+}
+
+static void setup_compound_reference_mode(VP9_COMMON *cm) {
+  if (cm->ref_frame_sign_bias[LAST_FRAME] ==
+          cm->ref_frame_sign_bias[GOLDEN_FRAME]) {
+    cm->comp_fixed_ref = ALTREF_FRAME;
+    cm->comp_var_ref[0] = LAST_FRAME;
+    cm->comp_var_ref[1] = GOLDEN_FRAME;
+  } else if (cm->ref_frame_sign_bias[LAST_FRAME] ==
+                 cm->ref_frame_sign_bias[ALTREF_FRAME]) {
+    cm->comp_fixed_ref = GOLDEN_FRAME;
+    cm->comp_var_ref[0] = LAST_FRAME;
+    cm->comp_var_ref[1] = ALTREF_FRAME;
+  } else {
+    cm->comp_fixed_ref = LAST_FRAME;
+    cm->comp_var_ref[0] = GOLDEN_FRAME;
+    cm->comp_var_ref[1] = ALTREF_FRAME;
+  }
+}
+
+static int read_is_valid(const uint8_t *start, size_t len, const uint8_t *end) {
+  return len != 0 && len <= (size_t)(end - start);
+}
+
+static int decode_unsigned_max(struct vpx_read_bit_buffer *rb, int max) {
+  const int data = vpx_rb_read_literal(rb, get_unsigned_bits(max));
+  return data > max ? max : data;
+}
+
+static TX_MODE read_tx_mode(vpx_reader *r) {
+  TX_MODE tx_mode = vpx_read_literal(r, 2);
+  if (tx_mode == ALLOW_32X32)
+    tx_mode += vpx_read_bit(r);
+  return tx_mode;
+}
+
+static void read_tx_mode_probs(struct tx_probs *tx_probs, vpx_reader *r) {
+  int i, j;
+
+  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
+    for (j = 0; j < TX_SIZES - 3; ++j)
+      vp9_diff_update_prob(r, &tx_probs->p8x8[i][j]);
+
+  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
+    for (j = 0; j < TX_SIZES - 2; ++j)
+      vp9_diff_update_prob(r, &tx_probs->p16x16[i][j]);
+
+  for (i = 0; i < TX_SIZE_CONTEXTS; ++i)
+    for (j = 0; j < TX_SIZES - 1; ++j)
+      vp9_diff_update_prob(r, &tx_probs->p32x32[i][j]);
+}
+
+static void read_switchable_interp_probs(FRAME_CONTEXT *fc, vpx_reader *r) {
+  int i, j;
+  for (j = 0; j < SWITCHABLE_FILTER_CONTEXTS; ++j)
+    for (i = 0; i < SWITCHABLE_FILTERS - 1; ++i)
+      vp9_diff_update_prob(r, &fc->switchable_interp_prob[j][i]);
+}
+
+static void read_inter_mode_probs(FRAME_CONTEXT *fc, vpx_reader *r) {
+  int i, j;
+  for (i = 0; i < INTER_MODE_CONTEXTS; ++i)
+    for (j = 0; j < INTER_MODES - 1; ++j)
+      vp9_diff_update_prob(r, &fc->inter_mode_probs[i][j]);
+}
+
+static REFERENCE_MODE read_frame_reference_mode(const VP9_COMMON *cm,
+                                                vpx_reader *r) {
+  if (is_compound_reference_allowed(cm)) {
+    return vpx_read_bit(r) ? (vpx_read_bit(r) ? REFERENCE_MODE_SELECT
+                                              : COMPOUND_REFERENCE)
+                           : SINGLE_REFERENCE;
+  } else {
+    return SINGLE_REFERENCE;
+  }
+}
+
+static void read_frame_reference_mode_probs(VP9_COMMON *cm, vpx_reader *r) {
+  FRAME_CONTEXT *const fc = cm->fc;
+  int i;
+
+  if (cm->reference_mode == REFERENCE_MODE_SELECT)
+    for (i = 0; i < COMP_INTER_CONTEXTS; ++i)
+      vp9_diff_update_prob(r, &fc->comp_inter_prob[i]);
+
+  if (cm->reference_mode != COMPOUND_REFERENCE)
+    for (i = 0; i < REF_CONTEXTS; ++i) {
+      vp9_diff_update_prob(r, &fc->single_ref_prob[i][0]);
+      vp9_diff_update_prob(r, &fc->single_ref_prob[i][1]);
+    }
+
+  if (cm->reference_mode != SINGLE_REFERENCE)
+    for (i = 0; i < REF_CONTEXTS; ++i)
+      vp9_diff_update_prob(r, &fc->comp_ref_prob[i]);
+}
+
+static void update_mv_probs(vpx_prob *p, int n, vpx_reader *r) {
+  int i;
+  for (i = 0; i < n; ++i)
+    if (vpx_read(r, MV_UPDATE_PROB))
+      p[i] = (vpx_read_literal(r, 7) << 1) | 1;
+}
+
+static void read_mv_probs(nmv_context *ctx, int allow_hp, vpx_reader *r) {
+  int i, j;
+
+  update_mv_probs(ctx->joints, MV_JOINTS - 1, r);
+
+  for (i = 0; i < 2; ++i) {
+    nmv_component *const comp_ctx = &ctx->comps[i];
+    update_mv_probs(&comp_ctx->sign, 1, r);
+    update_mv_probs(comp_ctx->classes, MV_CLASSES - 1, r);
+    update_mv_probs(comp_ctx->class0, CLASS0_SIZE - 1, r);
+    update_mv_probs(comp_ctx->bits, MV_OFFSET_BITS, r);
+  }
+
+  for (i = 0; i < 2; ++i) {
+    nmv_component *const comp_ctx = &ctx->comps[i];
+    for (j = 0; j < CLASS0_SIZE; ++j)
+      update_mv_probs(comp_ctx->class0_fp[j], MV_FP_SIZE - 1, r);
+    update_mv_probs(comp_ctx->fp, 3, r);
+  }
+
+  if (allow_hp) {
+    for (i = 0; i < 2; ++i) {
+      nmv_component *const comp_ctx = &ctx->comps[i];
+      update_mv_probs(&comp_ctx->class0_hp, 1, r);
+      update_mv_probs(&comp_ctx->hp, 1, r);
+    }
+  }
+}
+
+static void inverse_transform_block_inter(MACROBLOCKD* xd, int plane,
+                                          const TX_SIZE tx_size,
+                                          uint8_t *dst, int stride,
+                                          int eob) {
+  struct macroblockd_plane *const pd = &xd->plane[plane];
+  tran_low_t *const dqcoeff = pd->dqcoeff;
+  assert(eob > 0);
+#if CONFIG_VP9_HIGHBITDEPTH
+  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
+    if (xd->lossless) {
+      vp9_highbd_iwht4x4_add(dqcoeff, dst, stride, eob, xd->bd);
+    } else {
+      switch (tx_size) {
+        case TX_4X4:
+          vp9_highbd_idct4x4_add(dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_8X8:
+          vp9_highbd_idct8x8_add(dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_16X16:
+          vp9_highbd_idct16x16_add(dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_32X32:
+          vp9_highbd_idct32x32_add(dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        default:
+          assert(0 && "Invalid transform size");
+      }
+    }
+  } else {
+    if (xd->lossless) {
+      vp9_iwht4x4_add(dqcoeff, dst, stride, eob);
+    } else {
+      switch (tx_size) {
+        case TX_4X4:
+          vp9_idct4x4_add(dqcoeff, dst, stride, eob);
+          break;
+        case TX_8X8:
+          vp9_idct8x8_add(dqcoeff, dst, stride, eob);
+          break;
+        case TX_16X16:
+          vp9_idct16x16_add(dqcoeff, dst, stride, eob);
+          break;
+        case TX_32X32:
+          vp9_idct32x32_add(dqcoeff, dst, stride, eob);
+          break;
+        default:
+          assert(0 && "Invalid transform size");
+          return;
+      }
+    }
+  }
+#else
+  if (xd->lossless) {
+    vp9_iwht4x4_add(dqcoeff, dst, stride, eob);
+  } else {
+    switch (tx_size) {
+      case TX_4X4:
+        vp9_idct4x4_add(dqcoeff, dst, stride, eob);
+        break;
+      case TX_8X8:
+        vp9_idct8x8_add(dqcoeff, dst, stride, eob);
+        break;
+      case TX_16X16:
+        vp9_idct16x16_add(dqcoeff, dst, stride, eob);
+        break;
+      case TX_32X32:
+        vp9_idct32x32_add(dqcoeff, dst, stride, eob);
+        break;
+      default:
+        assert(0 && "Invalid transform size");
+        return;
+    }
+  }
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+
+  if (eob == 1) {
+    dqcoeff[0] = 0;
+  } else {
+    if (tx_size <= TX_16X16 && eob <= 10)
+      memset(dqcoeff, 0, 4 * (4 << tx_size) * sizeof(dqcoeff[0]));
+    else if (tx_size == TX_32X32 && eob <= 34)
+      memset(dqcoeff, 0, 256 * sizeof(dqcoeff[0]));
+    else
+      memset(dqcoeff, 0, (16 << (tx_size << 1)) * sizeof(dqcoeff[0]));
+  }
+}
+
+static void inverse_transform_block_intra(MACROBLOCKD* xd, int plane,
+                                          const TX_TYPE tx_type,
+                                          const TX_SIZE tx_size,
+                                          uint8_t *dst, int stride,
+                                          int eob) {
+  struct macroblockd_plane *const pd = &xd->plane[plane];
+  tran_low_t *const dqcoeff = pd->dqcoeff;
+  assert(eob > 0);
+#if CONFIG_VP9_HIGHBITDEPTH
+  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
+    if (xd->lossless) {
+      vp9_highbd_iwht4x4_add(dqcoeff, dst, stride, eob, xd->bd);
+    } else {
+      switch (tx_size) {
+        case TX_4X4:
+          vp9_highbd_iht4x4_add(tx_type, dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_8X8:
+          vp9_highbd_iht8x8_add(tx_type, dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_16X16:
+          vp9_highbd_iht16x16_add(tx_type, dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        case TX_32X32:
+          vp9_highbd_idct32x32_add(dqcoeff, dst, stride, eob, xd->bd);
+          break;
+        default:
+          assert(0 && "Invalid transform size");
+      }
+    }
+  } else {
+    if (xd->lossless) {
+      vp9_iwht4x4_add(dqcoeff, dst, stride, eob);
+    } else {
+      switch (tx_size) {
+        case TX_4X4:
+          vp9_iht4x4_add(tx_type, dqcoeff, dst, stride, eob);
+          break;
+        case TX_8X8:
+          vp9_iht8x8_add(tx_type, dqcoeff, dst, stride, eob);
+          break;
+        case TX_16X16:
+          vp9_iht16x16_add(tx_type, dqcoeff, dst, stride, eob);
+          break;
+        case TX_32X32:
+          vp9_idct32x32_add(dqcoeff, dst, stride, eob);
+          break;
+        default:
+          assert(0 && "Invalid transform size");
+          return;
+      }
+    }
+  }
+#else
+  if (xd->lossless) {
+    vp9_iwht4x4_add(dqcoeff, dst, stride, eob);
+  } else {
+    switch (tx_size) {
+      case TX_4X4:
+        vp9_iht4x4_add(tx_type, dqcoeff, dst, stride, eob);
+        break;
+      case TX_8X8:
+        vp9_iht8x8_add(tx_type, dqcoeff, dst, stride, eob);
+        break;
+      case TX_16X16:
+        vp9_iht16x16_add(tx_type, dqcoeff, dst, stride, eob);
+        break;
+      case TX_32X32:
+        vp9_idct32x32_add(dqcoeff, dst, stride, eob);
+        break;
+      default:
+        assert(0 && "Invalid transform size");
+        return;
+    }
+  }
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+
+  if (eob == 1) {
+    dqcoeff[0] = 0;
+  } else {
+    if (tx_type == DCT_DCT && tx_size <= TX_16X16 && eob <= 10)
+      memset(dqcoeff, 0, 4 * (4 << tx_size) * sizeof(dqcoeff[0]));
+    else if (tx_size == TX_32X32 && eob <= 34)
+      memset(dqcoeff, 0, 256 * sizeof(dqcoeff[0]));
+    else
+      memset(dqcoeff, 0, (16 << (tx_size << 1)) * sizeof(dqcoeff[0]));
+  }
+}
+
+static void predict_and_reconstruct_intra_block(MACROBLOCKD *const xd,
+                                                vpx_reader *r,
+                                                MODE_INFO *const mi,
+                                                int plane,
+                                                int row, int col,
+                                                TX_SIZE tx_size) {
+  struct macroblockd_plane *const pd = &xd->plane[plane];
+  PREDICTION_MODE mode = (plane == 0) ? mi->mode : mi->uv_mode;
+  uint8_t *dst;
+  dst = &pd->dst.buf[4 * row * pd->dst.stride + 4 * col];
+
+  if (mi->sb_type < BLOCK_8X8)
+    if (plane == 0)
+      mode = xd->mi[0]->bmi[(row << 1) + col].as_mode;
+
+  vp9_predict_intra_block(xd, pd->n4_wl, tx_size, mode,
+                          dst, pd->dst.stride, dst, pd->dst.stride,
+                          col, row, plane);
+
+  if (!mi->skip) {
+    const TX_TYPE tx_type = (plane || xd->lossless) ?
+        DCT_DCT : intra_mode_to_tx_type_lookup[mode];
+    const scan_order *sc = (plane || xd->lossless) ?
+        &vp9_default_scan_orders[tx_size] : &vp9_scan_orders[tx_size][tx_type];
+    const int eob = vp9_decode_block_tokens(xd, plane, sc, col, row, tx_size,
+                                            r, mi->segment_id);
+    if (eob > 0) {
+      inverse_transform_block_intra(xd, plane, tx_type, tx_size,
+                                    dst, pd->dst.stride, eob);
+    }
+  }
+}
+
+static int reconstruct_inter_block(MACROBLOCKD *const xd, vpx_reader *r,
+                                   MODE_INFO *const mi, int plane,
+                                   int row, int col, TX_SIZE tx_size) {
+  struct macroblockd_plane *const pd = &xd->plane[plane];
+  const scan_order *sc = &vp9_default_scan_orders[tx_size];
+  const int eob = vp9_decode_block_tokens(xd, plane, sc, col, row, tx_size, r,
+                                          mi->segment_id);
+
+  if (eob > 0) {
+    inverse_transform_block_inter(
+        xd, plane, tx_size, &pd->dst.buf[4 * row * pd->dst.stride + 4 * col],
+        pd->dst.stride, eob);
+  }
+  return eob;
+}
+
+static void build_mc_border(const uint8_t *src, int src_stride,
+                            uint8_t *dst, int dst_stride,
+                            int x, int y, int b_w, int b_h, int w, int h) {
+  // Get a pointer to the start of the real data for this row.
+  const uint8_t *ref_row = src - x - y * src_stride;
+
+  if (y >= h)
+    ref_row += (h - 1) * src_stride;
+  else if (y > 0)
+    ref_row += y * src_stride;
+
+  do {
+    int right = 0, copy;
+    int left = x < 0 ? -x : 0;
+
+    if (left > b_w)
+      left = b_w;
+
+    if (x + b_w > w)
+      right = x + b_w - w;
+
+    if (right > b_w)
+      right = b_w;
+
+    copy = b_w - left - right;
+
+    if (left)
+      memset(dst, ref_row[0], left);
+
+    if (copy)
+      memcpy(dst + left, ref_row + x + left, copy);
+
+    if (right)
+      memset(dst + left + copy, ref_row[w - 1], right);
+
+    dst += dst_stride;
+    ++y;
+
+    if (y > 0 && y < h)
+      ref_row += src_stride;
+  } while (--b_h);
+}
+
+#if CONFIG_VP9_HIGHBITDEPTH
+static void high_build_mc_border(const uint8_t *src8, int src_stride,
+                                 uint16_t *dst, int dst_stride,
+                                 int x, int y, int b_w, int b_h,
+                                 int w, int h) {
+  // Get a pointer to the start of the real data for this row.
+  const uint16_t *src = CONVERT_TO_SHORTPTR(src8);
+  const uint16_t *ref_row = src - x - y * src_stride;
+
+  if (y >= h)
+    ref_row += (h - 1) * src_stride;
+  else if (y > 0)
+    ref_row += y * src_stride;
+
+  do {
+    int right = 0, copy;
+    int left = x < 0 ? -x : 0;
+
+    if (left > b_w)
+      left = b_w;
+
+    if (x + b_w > w)
+      right = x + b_w - w;
+
+    if (right > b_w)
+      right = b_w;
+
+    copy = b_w - left - right;
+
+    if (left)
+      vpx_memset16(dst, ref_row[0], left);
+
+    if (copy)
+      memcpy(dst + left, ref_row + x + left, copy * sizeof(uint16_t));
+
+    if (right)
+      vpx_memset16(dst + left + copy, ref_row[w - 1], right);
+
+    dst += dst_stride;
+    ++y;
+
+    if (y > 0 && y < h)
+      ref_row += src_stride;
+  } while (--b_h);
+}
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+
+#if CONFIG_VP9_HIGHBITDEPTH
+static void extend_and_predict(const uint8_t *buf_ptr1, int pre_buf_stride,
+                               int x0, int y0, int b_w, int b_h,
+                               int frame_width, int frame_height,
+                               int border_offset,
+                               uint8_t *const dst, int dst_buf_stride,
+                               int subpel_x, int subpel_y,
+                               const InterpKernel *kernel,
+                               const struct scale_factors *sf,
+                               MACROBLOCKD *xd,
+                               int w, int h, int ref, int xs, int ys) {
+  DECLARE_ALIGNED(16, uint16_t, mc_buf_high[80 * 2 * 80 * 2]);
+  const uint8_t *buf_ptr;
+
+  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
+    high_build_mc_border(buf_ptr1, pre_buf_stride, mc_buf_high, b_w,
+                         x0, y0, b_w, b_h, frame_width, frame_height);
+    buf_ptr = CONVERT_TO_BYTEPTR(mc_buf_high) + border_offset;
+  } else {
+    build_mc_border(buf_ptr1, pre_buf_stride, (uint8_t *)mc_buf_high, b_w,
+                    x0, y0, b_w, b_h, frame_width, frame_height);
+    buf_ptr = ((uint8_t *)mc_buf_high) + border_offset;
+  }
+
+  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
+    highbd_inter_predictor(buf_ptr, b_w, dst, dst_buf_stride, subpel_x,
+                           subpel_y, sf, w, h, ref, kernel, xs, ys, xd->bd);
+  } else {
+    inter_predictor(buf_ptr, b_w, dst, dst_buf_stride, subpel_x,
+                    subpel_y, sf, w, h, ref, kernel, xs, ys);
+  }
+}
+#else
+static void extend_and_predict(const uint8_t *buf_ptr1, int pre_buf_stride,
+                               int x0, int y0, int b_w, int b_h,
+                               int frame_width, int frame_height,
+                               int border_offset,
+                               uint8_t *const dst, int dst_buf_stride,
+                               int subpel_x, int subpel_y,
+                               const InterpKernel *kernel,
+                               const struct scale_factors *sf,
+                               int w, int h, int ref, int xs, int ys) {
+  DECLARE_ALIGNED(16, uint8_t, mc_buf[80 * 2 * 80 * 2]);
+  const uint8_t *buf_ptr;
+
+  build_mc_border(buf_ptr1, pre_buf_stride, mc_buf, b_w,
+                  x0, y0, b_w, b_h, frame_width, frame_height);
+  buf_ptr = mc_buf + border_offset;
+
+  inter_predictor(buf_ptr, b_w, dst, dst_buf_stride, subpel_x,
+                  subpel_y, sf, w, h, ref, kernel, xs, ys);
+}
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+
+static void dec_build_inter_predictors(VPxWorker *const worker, MACROBLOCKD *xd,
+                                       int plane, int bw, int bh, int x,
+                                       int y, int w, int h, int mi_x, int mi_y,
+                                       const InterpKernel *kernel,
+                                       const struct scale_factors *sf,
+                                       struct buf_2d *pre_buf,
+                                       struct buf_2d *dst_buf, const MV* mv,
+                                       RefCntBuffer *ref_frame_buf,
+                                       int is_scaled, int ref) {
+  struct macroblockd_plane *const pd = &xd->plane[plane];
+  uint8_t *const dst = dst_buf->buf + dst_buf->stride * y + x;
+  MV32 scaled_mv;
+  int xs, ys, x0, y0, x0_16, y0_16, frame_width, frame_height,
+      buf_stride, subpel_x, subpel_y;
+  uint8_t *ref_frame, *buf_ptr;
+
+  // Get reference frame pointer, width and height.
+  if (plane == 0) {
+    frame_width = ref_frame_buf->buf.y_crop_width;
+    frame_height = ref_frame_buf->buf.y_crop_height;
+    ref_frame = ref_frame_buf->buf.y_buffer;
+  } else {
+    frame_width = ref_frame_buf->buf.uv_crop_width;
+    frame_height = ref_frame_buf->buf.uv_crop_height;
+    ref_frame = plane == 1 ? ref_frame_buf->buf.u_buffer
+                         : ref_frame_buf->buf.v_buffer;
+  }
+
+  if (is_scaled) {
+    const MV mv_q4 = clamp_mv_to_umv_border_sb(xd, mv, bw, bh,
+                                               pd->subsampling_x,
+                                               pd->subsampling_y);
+    // Co-ordinate of containing block to pixel precision.
+    int x_start = (-xd->mb_to_left_edge >> (3 + pd->subsampling_x));
+    int y_start = (-xd->mb_to_top_edge >> (3 + pd->subsampling_y));
+#if CONFIG_BETTER_HW_COMPATIBILITY
+    assert(xd->mi[0]->sb_type != BLOCK_4X8 &&
+           xd->mi[0]->sb_type != BLOCK_8X4);
+    assert(mv_q4.row == mv->row * (1 << (1 - pd->subsampling_y)) &&
+           mv_q4.col == mv->col * (1 << (1 - pd->subsampling_x)));
+#endif
+    // Co-ordinate of the block to 1/16th pixel precision.
+    x0_16 = (x_start + x) << SUBPEL_BITS;
+    y0_16 = (y_start + y) << SUBPEL_BITS;
+
+    // Co-ordinate of current block in reference frame
+    // to 1/16th pixel precision.
+    x0_16 = sf->scale_value_x(x0_16, sf);
+    y0_16 = sf->scale_value_y(y0_16, sf);
+
+    // Map the top left corner of the block into the reference frame.
+    x0 = sf->scale_value_x(x_start + x, sf);
+    y0 = sf->scale_value_y(y_start + y, sf);
+
+    // Scale the MV and incorporate the sub-pixel offset of the block
+    // in the reference frame.
+    scaled_mv = vp9_scale_mv(&mv_q4, mi_x + x, mi_y + y, sf);
+    xs = sf->x_step_q4;
+    ys = sf->y_step_q4;
+  } else {
+    // Co-ordinate of containing block to pixel precision.
+    x0 = (-xd->mb_to_left_edge >> (3 + pd->subsampling_x)) + x;
+    y0 = (-xd->mb_to_top_edge >> (3 + pd->subsampling_y)) + y;
+
+    // Co-ordinate of the block to 1/16th pixel precision.
+    x0_16 = x0 << SUBPEL_BITS;
+    y0_16 = y0 << SUBPEL_BITS;
+
+    scaled_mv.row = mv->row * (1 << (1 - pd->subsampling_y));
+    scaled_mv.col = mv->col * (1 << (1 - pd->subsampling_x));
+    xs = ys = 16;
+  }
+  subpel_x = scaled_mv.col & SUBPEL_MASK;
+  subpel_y = scaled_mv.row & SUBPEL_MASK;
+
+  // Calculate the top left corner of the best matching block in the
+  // reference frame.
+  x0 += scaled_mv.col >> SUBPEL_BITS;
+  y0 += scaled_mv.row >> SUBPEL_BITS;
+  x0_16 += scaled_mv.col;
+  y0_16 += scaled_mv.row;
+
+  // Get reference block pointer.
+  buf_ptr = ref_frame + y0 * pre_buf->stride + x0;
+  buf_stride = pre_buf->stride;
+
+  // Do border extension if there is motion or the
+  // width/height is not a multiple of 8 pixels.
+  if (is_scaled || scaled_mv.col || scaled_mv.row ||
+      (frame_width & 0x7) || (frame_height & 0x7)) {
+    int y1 = ((y0_16 + (h - 1) * ys) >> SUBPEL_BITS) + 1;
+
+    // Get reference block bottom right horizontal coordinate.
+    int x1 = ((x0_16 + (w - 1) * xs) >> SUBPEL_BITS) + 1;
+    int x_pad = 0, y_pad = 0;
+
+    if (subpel_x || (sf->x_step_q4 != SUBPEL_SHIFTS)) {
+      x0 -= VP9_INTERP_EXTEND - 1;
+      x1 += VP9_INTERP_EXTEND;
+      x_pad = 1;
+    }
+
+    if (subpel_y || (sf->y_step_q4 != SUBPEL_SHIFTS)) {
+      y0 -= VP9_INTERP_EXTEND - 1;
+      y1 += VP9_INTERP_EXTEND;
+      y_pad = 1;
+    }
+
+    // Wait until reference block is ready. Pad 7 more pixels as last 7
+    // pixels of each superblock row can be changed by next superblock row.
+    if (worker != NULL)
+      vp9_frameworker_wait(worker, ref_frame_buf,
+                           VPXMAX(0, (y1 + 7)) << (plane == 0 ? 0 : 1));
+
+    // Skip border extension if block is inside the frame.
+    if (x0 < 0 || x0 > frame_width - 1 || x1 < 0 || x1 > frame_width - 1 ||
+        y0 < 0 || y0 > frame_height - 1 || y1 < 0 || y1 > frame_height - 1) {
+      // Extend the border.
+      const uint8_t *const buf_ptr1 = ref_frame + y0 * buf_stride + x0;
+      const int b_w = x1 - x0 + 1;
+      const int b_h = y1 - y0 + 1;
+      const int border_offset = y_pad * 3 * b_w + x_pad * 3;
+
+      extend_and_predict(buf_ptr1, buf_stride, x0, y0, b_w, b_h,
+                         frame_width, frame_height, border_offset,
+                         dst, dst_buf->stride,
+                         subpel_x, subpel_y,
+                         kernel, sf,
+#if CONFIG_VP9_HIGHBITDEPTH
+                         xd,
+#endif
+                         w, h, ref, xs, ys);
+      return;
+    }
+  } else {
+    // Wait until reference block is ready. Pad 7 more pixels as last 7
+    // pixels of each superblock row can be changed by next superblock row.
+    if (worker != NULL) {
+      const int y1 = (y0_16 + (h - 1) * ys) >> SUBPEL_BITS;
+      vp9_frameworker_wait(worker, ref_frame_buf,
+                           VPXMAX(0, (y1 + 7)) << (plane == 0 ? 0 : 1));
+    }
+  }
+#if CONFIG_VP9_HIGHBITDEPTH
+  if (xd->cur_buf->flags & YV12_FLAG_HIGHBITDEPTH) {
+    highbd_inter_predictor(buf_ptr, buf_stride, dst, dst_buf->stride, subpel_x,
+                           subpel_y, sf, w, h, ref, kernel, xs, ys, xd->bd);
+  } else {
+    inter_predictor(buf_ptr, buf_stride, dst, dst_buf->stride, subpel_x,
+                    subpel_y, sf, w, h, ref, kernel, xs, ys);
+  }
+#else
+  inter_predictor(buf_ptr, buf_stride, dst, dst_buf->stride, subpel_x,
+                  subpel_y, sf, w, h, ref, kernel, xs, ys);
+#endif  // CONFIG_VP9_HIGHBITDEPTH
+}
+
+static void dec_build_inter_predictors_sb(VP9Decoder *const pbi,
+                                          MACROBLOCKD *xd,
+                                          int mi_row, int mi_col) {
+  int plane;
+  const int mi_x = mi_col * MI_SIZE;
+  const int mi_y = mi_row * MI_SIZE;
+  const MODE_INFO *mi = xd->mi[0];
+  const InterpKernel *kernel = vp9_filter_kernels[mi->interp_filter];
+  const BLOCK_SIZE sb_type = mi->sb_type;
+  const int is_compound = has_second_ref(mi);
+  int ref;
+  int is_scaled;
+  VPxWorker *const fwo = pbi->frame_parallel_decode ?
+      pbi->frame_worker_owner : NULL;
+
+  for (ref = 0; ref < 1 + is_compound; ++ref) {
+    const MV_REFERENCE_FRAME frame = mi->ref_frame[ref];
+    RefBuffer *ref_buf = &pbi->common.frame_refs[frame - LAST_FRAME];
+    const struct scale_factors *const sf = &ref_buf->sf;
+    const int idx = ref_buf->idx;
+    BufferPool *const pool = pbi->common.buffer_pool;
+    RefCntBuffer *const ref_frame_buf = &pool->frame_bufs[idx];
+
+    if (!vp9_is_valid_scale(sf))
+      vpx_internal_error(xd->error_info, VPX_CODEC_UNSUP_BITSTREAM,
+                         "Reference frame has invalid dimensions");
+
+    is_scaled = vp9_is_scaled(sf);
+    vp9_setup_pre_planes(xd, ref, ref_buf->buf, mi_row, mi_col,
+                         is_scaled ? sf : NULL);
+    xd->block_refs[ref] = ref_buf;
+
+    if (sb_type < BLOCK_8X8) {
+      for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
+        struct macroblockd_plane *const pd = &xd->plane[plane];
+        struct buf_2d *const dst_buf = &pd->dst;
+        const int num_4x4_w = pd->n4_w;
+        const int num_4x4_h = pd->n4_h;
+        const int n4w_x4 = 4 * num_4x4_w;
+        const int n4h_x4 = 4 * num_4x4_h;
+        struct buf_2d *const pre_buf = &pd->pre[ref];
+        int i = 0, x, y;
+        for (y = 0; y < num_4x4_h; ++y) {
+          for (x = 0; x < num_4x4_w; ++x) {
+            const MV mv = average_split_mvs(pd, mi, ref, i++);
+            dec_build_inter_predictors(fwo, xd, plane, n4w_x4, n4h_x4,
+                                       4 * x, 4 * y, 4, 4, mi_x, mi_y, kernel,
+                                       sf, pre_buf, dst_buf, &mv,
+                                       ref_frame_buf, is_scaled, ref);
+          }
+        }
+      }
+    } else {
+      const MV mv = mi->mv[ref].as_mv;
+      for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
+        struct macroblockd_plane *const pd = &xd->plane[plane];
+        struct buf_2d *const dst_buf = &pd->dst;
+        const int num_4x4_w = pd->n4_w;
+        const int num_4x4_h = pd->n4_h;
+        const int n4w_x4 = 4 * num_4x4_w;
+        const int n4h_x4 = 4 * num_4x4_h;
+        struct buf_2d *const pre_buf = &pd->pre[ref];
+        dec_build_inter_predictors(fwo, xd, plane, n4w_x4, n4h_x4,
+                                   0, 0, n4w_x4, n4h_x4, mi_x, mi_y, kernel,
+                                   sf, pre_buf, dst_buf, &mv,
+                                   ref_frame_buf, is_scaled, ref);
+      }
+    }
+  }
+}
+
+static INLINE TX_SIZE dec_get_uv_tx_size(const MODE_INFO *mi,
+                                         int n4_wl, int n4_hl) {
+  // get minimum log2 num4x4s dimension
+  const int x = VPXMIN(n4_wl, n4_hl);
+  return VPXMIN(mi->tx_size,  x);
+}
+
+static INLINE void dec_reset_skip_context(MACROBLOCKD *xd) {
+  int i;
+  for (i = 0; i < MAX_MB_PLANE; i++) {
+    struct macroblockd_plane *const pd = &xd->plane[i];
+    memset(pd->above_context, 0, sizeof(ENTROPY_CONTEXT) * pd->n4_w);
+    memset(pd->left_context, 0, sizeof(ENTROPY_CONTEXT) * pd->n4_h);
+  }
+}
+
+static void set_plane_n4(MACROBLOCKD *const xd, int bw, int bh, int bwl,
+                         int bhl) {
+  int i;
+  for (i = 0; i < MAX_MB_PLANE; i++) {
+    xd->plane[i].n4_w = (bw << 1) >> xd->plane[i].subsampling_x;
+    xd->plane[i].n4_h = (bh << 1) >> xd->plane[i].subsampling_y;
+    xd->plane[i].n4_wl = bwl - xd->plane[i].subsampling_x;
+    xd->plane[i].n4_hl = bhl - xd->plane[i].subsampling_y;
+  }
+}
+
+static MODE_INFO *set_offsets(VP9_COMMON *const cm, MACROBLOCKD *const xd,
+                              BLOCK_SIZE bsize, int mi_row, int mi_col,
+                              int bw, int bh, int x_mis, int y_mis,
+                              int bwl, int bhl) {
+  const int offset = mi_row * cm->mi_stride + mi_col;
+  int x, y;
+  const TileInfo *const tile = &xd->tile;
+
+  xd->mi = cm->mi_grid_visible + offset;
+  xd->mi[0] = &cm->mi[offset];
+  // TODO(slavarnway): Generate sb_type based on bwl and bhl, instead of
+  // passing bsize from decode_partition().
+  xd->mi[0]->sb_type = bsize;
+  for (y = 0; y < y_mis; ++y)
+    for (x = !y; x < x_mis; ++x) {
+      xd->mi[y * cm->mi_stride + x] = xd->mi[0];
+    }
+
+  set_plane_n4(xd, bw, bh, bwl, bhl);
+
+  set_skip_context(xd, mi_row, mi_col);
+
+  // Distance of Mb to the various image edges. These are specified to 8th pel
+  // as they are always compared to values that are in 1/8th pel units
+  set_mi_row_col(xd, tile, mi_row, bh, mi_col, bw, cm->mi_rows, cm->mi_cols);
+
+  vp9_setup_dst_planes(xd->plane, get_frame_new_buffer(cm), mi_row, mi_col);
+  return xd->mi[0];
+}
+
+static void decode_block(VP9Decoder *const pbi, MACROBLOCKD *const xd,
+                         int mi_row, int mi_col,
+                         vpx_reader *r, BLOCK_SIZE bsize,
+                         int bwl, int bhl) {
+  VP9_COMMON *const cm = &pbi->common;
+  const int less8x8 = bsize < BLOCK_8X8;
+  const int bw = 1 << (bwl - 1);
+  const int bh = 1 << (bhl - 1);
+  const int x_mis = VPXMIN(bw, cm->mi_cols - mi_col);
+  const int y_mis = VPXMIN(bh, cm->mi_rows - mi_row);
+
+  MODE_INFO *mi = set_offsets(cm, xd, bsize, mi_row, mi_col,
+                              bw, bh, x_mis, y_mis, bwl, bhl);
+
+  if (bsize >= BLOCK_8X8 && (cm->subsampling_x || cm->subsampling_y)) {
+    const BLOCK_SIZE uv_subsize =
+        ss_size_lookup[bsize][cm->subsampling_x][cm->subsampling_y];
+    if (uv_subsize == BLOCK_INVALID)
+      vpx_internal_error(xd->error_info,
+                         VPX_CODEC_CORRUPT_FRAME, "Invalid block size.");
+  }
+
+  vp9_read_mode_info(pbi, xd, mi_row, mi_col, r, x_mis, y_mis);
+
+  if (mi->skip) {
+    dec_reset_skip_context(xd);
+  }
+
+  if (!is_inter_block(mi)) {
+    int plane;
+    for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
+      const struct macroblockd_plane *const pd = &xd->plane[plane];
+      const TX_SIZE tx_size =
+          plane ? dec_get_uv_tx_size(mi, pd->n4_wl, pd->n4_hl)
+                  : mi->tx_size;
+      const int num_4x4_w = pd->n4_w;
+      const int num_4x4_h = pd->n4_h;
+      const int step = (1 << tx_size);
+      int row, col;
+      const int max_blocks_wide = num_4x4_w + (xd->mb_to_right_edge >= 0 ?
+          0 : xd->mb_to_right_edge >> (5 + pd->subsampling_x));
+      const int max_blocks_high = num_4x4_h + (xd->mb_to_bottom_edge >= 0 ?
+          0 : xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));
+
+      xd->max_blocks_wide = xd->mb_to_right_edge >= 0 ? 0 : max_blocks_wide;
+      xd->max_blocks_high = xd->mb_to_bottom_edge >= 0 ? 0 : max_blocks_high;
+
+      for (row = 0; row < max_blocks_high; row += step)
+        for (col = 0; col < max_blocks_wide; col += step)
+          predict_and_reconstruct_intra_block(xd, r, mi, plane,
+                                              row, col, tx_size);
+    }
+  } else {
+    // Prediction
+    dec_build_inter_predictors_sb(pbi, xd, mi_row, mi_col);
+
+    // Reconstruction
+    if (!mi->skip) {
+      int eobtotal = 0;
+      int plane;
+
+      for (plane = 0; plane < MAX_MB_PLANE; ++plane) {
+        const struct macroblockd_plane *const pd = &xd->plane[plane];
+        const TX_SIZE tx_size =
+            plane ? dec_get_uv_tx_size(mi, pd->n4_wl, pd->n4_hl)
+                    : mi->tx_size;
+        const int num_4x4_w = pd->n4_w;
+        const int num_4x4_h = pd->n4_h;
+        const int step = (1 << tx_size);
+        int row, col;
+        const int max_blocks_wide = num_4x4_w + (xd->mb_to_right_edge >= 0 ?
+            0 : xd->mb_to_right_edge >> (5 + pd->subsampling_x));
+        const int max_blocks_high = num_4x4_h + (xd->mb_to_bottom_edge >= 0 ?
+            0 : xd->mb_to_bottom_edge >> (5 + pd->subsampling_y));
+
+        xd->max_blocks_wide = xd->mb_to_right_edge >= 0 ? 0 : max_blocks_wide;
+        xd->max_blocks_high = xd->mb_to_bottom_edge >= 0 ? 0 : max_blocks_high;
+
+        for (row = 0; row < max_blocks_high; row += step)
+          for (col = 0; col < max_blocks_wide; col += step)
+            eobtotal += reconstruct_inter_block(xd, r, mi, plane, row, col,
+                                                tx_size);
+      }
+
+      if (!less8x8 && eobtotal == 0)
+        mi->skip = 1;  // skip loopfilter
+    }
+  }
+
+  xd->corrupted |= vpx_reader_has_error(r);
+
+  if (cm->lf.filter_level) {
+    vp9_build_mask(cm, mi, mi_row, mi_col, bw, bh);
+  }
+}
+
+static INLINE int dec_partition_plane_context(const MACROBLOCKD *xd,
+                                              int mi_row, int mi_col,
+                                              int bsl) {
+  const PARTITION_CONTEXT *above_ctx = xd->above_seg_context + mi_col;
+  const PARTITION_CONTEXT *left_ctx = xd->left_seg_context + (mi_row & MI_MASK);
+  int above = (*above_ctx >> bsl) & 1 , left = (*left_ctx >> bsl) & 1;
+
+//  assert(bsl >= 0);
+
+  return (left * 2 + above) + bsl * PARTITION_PLOFFSET;
+}
+
+static INLINE void dec_update_partition_context(MACROBLOCKD *xd,
+                                                int mi_row, int mi_col,
+                                                BLOCK_SIZE subsize,
+                                                int bw) {
+  PARTITION_CONTEXT *const above_ctx = xd->above_seg_context + mi_col;
+  PARTITION_CONTEXT *const left_ctx = xd->left_seg_context + (mi_row & MI_MASK);
+
+  // update the partition context at the end notes. set partition bits
+  // of block sizes larger than the current one to be one, and partition
+  // bits of smaller block sizes to be zero.
+  memset(above_ctx, partition_context_lookup[subsize].above, bw);
+  memset(left_ctx, partition_context_lookup[subsize].left, bw);
+}
+
+static PARTITION_TYPE read_partition(MACROBLOCKD *xd, int mi_row, int mi_col,
+                                     vpx_reader *r,
+                                     int has_rows, int has_cols, int bsl) {
+  const int ctx = dec_partition_plane_context(xd, mi_row, mi_col, bsl);
+  const vpx_prob *const probs = get_partition_probs(xd, ctx);
+  FRAME_COUNTS *counts = xd->counts;
+  PARTITION_TYPE p;
+
+  if (has_rows && has_cols)
+    p = (PARTITION_TYPE)vpx_read_tree(r, vp9_partition_tree, probs);
+  else if (!has_rows && has_cols)
+    p = vpx_read(r, probs[1]) ? PARTITION_SPLIT : PARTITION_HORZ;
+  else if (has_rows && !has_cols)
+    p = vpx_read(r, probs[2]) ? PARTITION_SPLIT : PARTITION_VERT;
+  else
+    p = PARTITION_SPLIT;
+
+  if (counts)
+    ++counts->partition[ctx][p];
+
+  return p;
+}
+
+// TODO(slavarnway): eliminate bsize and subsize in future commits
+static void decode_partition(VP9Decoder *const pbi, MACROBLOCKD *const xd,
+                             int mi_row, int mi_col,
+                             vpx_reader* r, BLOCK_SIZE bsize, int n4x4_l2) {
+  VP9_COMMON *const cm = &pbi->common;
+  const int n8x8_l2 = n4x4_l2 - 1;
+  const int num_8x8_wh = 1 << n8x8_l2;
+  const int hbs = num_8x8_wh >> 1;
+  PARTITION_TYPE partition;
+  BLOCK_SIZE subsize;
+  const int has_rows = (mi_row + hbs) < cm->mi_rows;
+  const int has_cols = (mi_col + hbs) < cm->mi_cols;
+
+  if (mi_row >= cm->mi_rows || mi_col >= cm->mi_cols)
+    return;
+
+  partition = read_partition(xd, mi_row, mi_col, r, has_rows, has_cols,
+                             n8x8_l2);
+  subsize = subsize_lookup[partition][bsize];  // get_subsize(bsize, partition);
+  if (!hbs) {
+    // calculate bmode block dimensions (log 2)
+    xd->bmode_blocks_wl = 1 >> !!(partition & PARTITION_VERT);
+    xd->bmode_blocks_hl = 1 >> !!(partition & PARTITION_HORZ);
+    decode_block(pbi, xd, mi_row, mi_col, r, subsize, 1, 1);
+  } else {
+    switch (partition) {
+      case PARTITION_NONE:
+        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n4x4_l2, n4x4_l2);
+        break;
+      case PARTITION_HORZ:
+        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n4x4_l2, n8x8_l2);
+        if (has_rows)
+          decode_block(pbi, xd, mi_row + hbs, mi_col, r, subsize, n4x4_l2,
+                       n8x8_l2);
+        break;
+      case PARTITION_VERT:
+        decode_block(pbi, xd, mi_row, mi_col, r, subsize, n8x8_l2, n4x4_l2);
+        if (has_cols)
+          decode_block(pbi, xd, mi_row, mi_col + hbs, r, subsize, n8x8_l2,
+                       n4x4_l2);
+        break;
+      case PARTITION_SPLIT:
+        decode_partition(pbi, xd, mi_row, mi_col, r, subsize, n8x8_l2);
+        decode_partition(pbi, xd, mi_row, mi_col + hbs, r, subsize, n8x8_l2);
+        decode_partition(pbi, xd, mi_row + hbs, mi_col, r, subsize, n8x8_l2);
+        decode_partition(pbi, xd, mi_row + hbs, mi_col + hbs, r, subsize,
+                         n8x8_l2);
+        break;
+      default:
+        assert(0 && "Invalid partition type");
+    }
+  }
+
+  // update partition context
+  if (bsize >= BLOCK_8X8 &&
+      (bsize == BLOCK_8X8 || partition != PARTITION_SPLIT))
+    dec_update_partition_context(xd, mi_row, mi_col, subsize, num_8x8_wh);
+}
+
+static void setup_token_decoder(const uint8_t *data,
+                                const uint8_t *data_end,
+                                size_t read_size,
+                                struct vpx_internal_error_info *error_info,
+                                vpx_reader *r,
+                                vpx_decrypt_cb decrypt_cb,
+                                void *decrypt_state) {
+  // Validate the calculated partition length. If the buffer
+  // described by the partition can't be fully read, then restrict
+  // it to the portion that can be (for EC mode) or throw an error.
+  if (!read_is_valid(data, read_size, data_end))
+    vpx_internal_error(error_info, VPX_CODEC_CORRUPT_FRAME,
+                       "Truncated packet or corrupt tile length");
+
+  if (vpx_reader_init(r, data, read_size, decrypt_cb, decrypt_state))
+    vpx_internal_error(error_info, VPX_CODEC_MEM_ERROR,
+                       "Failed to allocate bool decoder %d", 1);
+}
+
+static void read_coef_probs_common(vp9_coeff_probs_model *coef_probs,
+                                   vpx_reader *r) {
+  int i, j, k, l, m;
+
+  if (vpx_read_bit(r))
+    for (i = 0; i < PLANE_TYPES; ++i)
+      for (j = 0; j < REF_TYPES; ++j)
+        for (k = 0; k < COEF_BANDS; ++k)
+          for (l = 0; l < BAND_COEFF_CONTEXTS(k); ++l)
+            for (m = 0; m < UNCONSTRAINED_NODES; ++m)
+              vp9_diff_update_prob(r, &coef_probs[i][j][k][l][m]);
+}
+
+static void read_coef_probs(FRAME_CONTEXT *fc, TX_MODE tx_mode,
+                            vpx_reader *r) {
+    const TX_SIZE max_tx_size = tx_mode_to_biggest_tx_size[tx_mode];
+    TX_SIZE tx_size;
+    for (tx_size = TX_4X4; tx_size <= max_tx_size; ++tx_size)
+      read_coef_probs_common(fc->coef_probs[tx_size], r);
+}
+
+static void setup_segmentation(struct segmentation *seg,
+                               struct vpx_read_bit_buffer *rb) {
+  int i, j;
+
+  seg->update_map = 0;
+  seg->update_data = 0;
+
+  seg->enabled = vpx_rb_read_bit(rb);
+  if (!seg->enabled)
+    return;
+
+  // Segmentation map update
+  seg->update_map = vpx_rb_read_bit(rb);
+  if (seg->update_map) {
+    for (i = 0; i < SEG_TREE_PROBS; i++)
+      seg->tree_probs[i] = vpx_rb_read_bit(rb) ? vpx_rb_read_literal(rb, 8)
+                                               : MAX_PROB;
+
+    seg->temporal_update = vpx_rb_read_bit(rb);
+    if (seg->temporal_update) {
+      for (i = 0; i < PREDICTION_PROBS; i++)
+        seg->pred_probs[i] = vpx_rb_read_bit(rb) ? vpx_rb_read_literal(rb, 8)
+                                                 : MAX_PROB;
+    } else {
+      for (i = 0; i < PREDICTION_PROBS; i++)
+        seg->pred_probs[i] = MAX_PROB;
+    }
+  }
+
+  // Segmentation data update
+  seg->update_data = vpx_rb_read_bit(rb);
+  if (seg->update_data) {
+    seg->abs_delta = vpx_rb_read_bit(rb);
+
+    vp9_clearall_segfeatures(seg);
+
+    for (i = 0; i < MAX_SEGMENTS; i++) {
+      for (j = 0; j < SEG_LVL_MAX; j++) {
+        int data = 0;
+        const int feature_enabled = vpx_rb_read_bit(rb);
+        if (feature_enabled) {
+          vp9_enable_segfeature(seg, i, j);
+          data = decode_unsigned_max(rb, vp9_seg_feature_data_max(j));
+          if (vp9_is_segfeature_signed(j))
+            data = vpx_rb_read_bit(rb) ? -data : data;
+        }
+        vp9_set_segdata(seg, i, j, data);
+      }
+    }
+  }
+}
+
+static void setup_loopfilter(struct loopfilter *lf,
+                             struct vpx_read_bit_buffer *rb) {
+  lf->filter_level = vpx_rb_read_literal(rb, 6);
+  lf->sharpness_level = vpx_rb_read_literal(rb, 3);
+
+  // Read in loop filter deltas applied at the MB level based on mode or ref
+  // frame.
+  lf->mode_ref_delta_update = 0;
+
+  lf->mode_ref_delta_enabled = vpx_rb_read_bit(rb);
+  if (lf->mode_ref_delta_enabled) {
+    lf->mode_ref_delta_update = vpx_rb_read_bit(rb);
+    if (lf->mode_ref_delta_update) {
+      int i;
+
+      for (i = 0; i < MAX_REF_LF_DELTAS; i++)
+        if (vpx_rb_read_bit(rb))
+          lf->ref_deltas[i] = vpx_rb_read_signed_literal(rb, 6);
+
+      for (i = 0; i < MAX_MODE_LF_DELTAS; i++)
+        if (vpx_rb_read_bit(rb))
+          lf->mode_deltas[i] = vpx_rb_read_signed_literal(rb, 6);
+    }
+  }
+}
+
+static INLINE int read_delta_q(struct vpx_read_bit_buffer *rb) {
+  return vpx_rb_read_bit(rb) ? vpx_rb_read_signed_literal(rb, 4) : 0;
+}
+
+static void setup_quantization(VP9_COMMON *const cm, MACROBLOCKD *const xd,
+                               struct vpx_read_bit_buffer *rb) {
+  cm->base_qindex = vpx_rb_read_literal(rb, QINDEX_BITS);
+  cm->y_dc_delta_q = read_delta_q(rb);
+  cm->uv_dc_delta_q = read_delta_q(rb);
+  cm->uv_ac_delta_q = read_delta_q(rb);
+  cm->dequant_bit_depth = cm->bit_depth;
+  xd->lossless = cm->base_qindex == 0 &&
+                 cm->y_dc_delta_q == 0 &&
+                 cm->uv_dc_delta_q == 0 &&
+                 cm->uv_ac_delta_q == 0;
+
+#if CONFIG_VP9_HIGHBITDEPTH
+  xd->bd = (int)cm->bit_depth;
+#endif
+}
+
+static void setup_segmentation_dequant(VP9_COMMON *const cm) {
+  // Build y/uv dequant values based on segmentation.
+  if (cm->seg.enabled) {
+    int i;
+    for (i = 0; i < MAX_SEGMENTS; ++i) {
+      const int qindex = vp9_get_qindex(&cm->seg, i, cm->base_qindex);
+      cm->y_dequant[i][0] = vp9_dc_quant(qindex, cm->y_dc_delta_q,
+                                         cm->bit_depth);
+      cm->y_dequant[i][1] = vp9_ac_quant(qindex, 0, cm->bit_depth);
+      cm->uv_dequant[i][0] = vp9_dc_quant(qindex, cm->uv_dc_delta_q,
+                                          cm->bit_depth);
+      cm->uv_dequant[i][1] = vp9_ac_quant(qindex, cm->uv_ac_delta_q,
+                                          cm->bit_depth);
+    }
+  } else {
+    const int qindex = cm->base_qindex;
+    // When segmentation is disabled, only the first value is used.  The
+    // remaining are don't cares.
+    cm->y_dequant[0][0] = vp9_dc_quant(qindex, cm->y_dc_delta_q, cm->bit_depth);
+    cm->y_dequant[0][1] = vp9_ac_quant(qindex, 0, cm->bit_depth);
+    cm->uv_dequant[0][0] = vp9_dc_quant(qindex, cm->uv_dc_delta_q,
+                                        cm->bit_depth);
+    cm->uv_dequant[0][1] = vp9_ac_quant(qindex, cm->uv_ac_delta_q,
+                                        cm->bit_depth);
+  }
+}
+
+static INTERP_FILTER read_interp_filter(struct vpx_read_bit_buffer *rb) {
+  const INTERP_FILTER literal_to_filter[] = { EIGHTTAP_SMOOTH,
+                                              EIGHTTAP,
+                                              EIGHTTAP_SHARP,
+                                              BILINEAR };
+  return vpx_rb_read_bit(rb) ? SWITCHABLE
+                             : literal_to_filter[vpx_rb_read_literal(rb, 2)];
+}
+
+static void setup_render_size(VP9_COMMON *cm, struct vpx_read_bit_buffer *rb) {
+  cm->render_width = cm->width;
+  cm->render_height = cm->height;
+  if (vpx_rb_read_bit(rb))
+    vp9_read_frame_size(rb, &cm->render_width, &cm->render_height);
+}
+
+static void resize_mv_buffer(VP9_COMMON *cm) {
+  vpx_free(cm->cur_frame->mvs);
+  cm->cur_frame->mi_rows = cm->mi_rows;
+  cm->cur_frame->mi_cols = cm->mi_cols;
+  CHECK_MEM_ERROR(cm, cm->cur_frame->mvs,
+                  (MV_REF *)vpx_calloc(cm->mi_rows * cm->mi_cols,
+                                       sizeof(*cm->cur_frame->mvs)));
+}
+
+static void resize_context_buffers(VP9_COMMON *cm, int width, int height) {
+#if CONFIG_SIZE_LIMIT
+  if (width > DECODE_WIDTH_LIMIT || height > DECODE_HEIGHT_LIMIT)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Dimensions of %dx%d beyond allowed size of %dx%d.",
+                       width, height, DECODE_WIDTH_LIMIT, DECODE_HEIGHT_LIMIT);
+#endif
+  if (cm->width != width || cm->height != height) {
+    const int new_mi_rows =
+        ALIGN_POWER_OF_TWO(height, MI_SIZE_LOG2) >> MI_SIZE_LOG2;
+    const int new_mi_cols =
+        ALIGN_POWER_OF_TWO(width,  MI_SIZE_LOG2) >> MI_SIZE_LOG2;
+
+    // Allocations in vp9_alloc_context_buffers() depend on individual
+    // dimensions as well as the overall size.
+    if (new_mi_cols > cm->mi_cols || new_mi_rows > cm->mi_rows) {
+      if (vp9_alloc_context_buffers(cm, width, height))
+        vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
+                           "Failed to allocate context buffers");
+    } else {
+      vp9_set_mb_mi(cm, width, height);
+    }
+    vp9_init_context_buffers(cm);
+    cm->width = width;
+    cm->height = height;
+  }
+  if (cm->cur_frame->mvs == NULL || cm->mi_rows > cm->cur_frame->mi_rows ||
+      cm->mi_cols > cm->cur_frame->mi_cols) {
+    resize_mv_buffer(cm);
+  }
+}
+
+static void setup_frame_size(VP9_COMMON *cm, struct vpx_read_bit_buffer *rb) {
+  int width, height;
+  BufferPool *const pool = cm->buffer_pool;
+  vp9_read_frame_size(rb, &width, &height);
+  resize_context_buffers(cm, width, height);
+  setup_render_size(cm, rb);
+
+  lock_buffer_pool(pool);
+  if (vpx_realloc_frame_buffer(
+          get_frame_new_buffer(cm), cm->width, cm->height,
+          cm->subsampling_x, cm->subsampling_y,
+#if CONFIG_VP9_HIGHBITDEPTH
+          cm->use_highbitdepth,
+#endif
+          VP9_DEC_BORDER_IN_PIXELS,
+          cm->byte_alignment,
+          &pool->frame_bufs[cm->new_fb_idx].raw_frame_buffer, pool->get_fb_cb,
+          pool->cb_priv)) {
+    unlock_buffer_pool(pool);
+    vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
+                       "Failed to allocate frame buffer");
+  }
+  unlock_buffer_pool(pool);
+
+  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_x = cm->subsampling_x;
+  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_y = cm->subsampling_y;
+  pool->frame_bufs[cm->new_fb_idx].buf.bit_depth = (unsigned int)cm->bit_depth;
+  pool->frame_bufs[cm->new_fb_idx].buf.color_space = cm->color_space;
+  pool->frame_bufs[cm->new_fb_idx].buf.color_range = cm->color_range;
+  pool->frame_bufs[cm->new_fb_idx].buf.render_width  = cm->render_width;
+  pool->frame_bufs[cm->new_fb_idx].buf.render_height = cm->render_height;
+}
+
+static INLINE int valid_ref_frame_img_fmt(vpx_bit_depth_t ref_bit_depth,
+                                          int ref_xss, int ref_yss,
+                                          vpx_bit_depth_t this_bit_depth,
+                                          int this_xss, int this_yss) {
+  return ref_bit_depth == this_bit_depth && ref_xss == this_xss &&
+         ref_yss == this_yss;
+}
+
+static void setup_frame_size_with_refs(VP9_COMMON *cm,
+                                       struct vpx_read_bit_buffer *rb) {
+  int width, height;
+  int found = 0, i;
+  int has_valid_ref_frame = 0;
+  BufferPool *const pool = cm->buffer_pool;
+  for (i = 0; i < REFS_PER_FRAME; ++i) {
+    if (vpx_rb_read_bit(rb)) {
+      if (cm->frame_refs[i].idx != INVALID_IDX) {
+        YV12_BUFFER_CONFIG *const buf = cm->frame_refs[i].buf;
+        width = buf->y_crop_width;
+        height = buf->y_crop_height;
+        found = 1;
+        break;
+      } else {
+        vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                           "Failed to decode frame size");
+      }
+    }
+  }
+
+  if (!found)
+    vp9_read_frame_size(rb, &width, &height);
+
+  if (width <= 0 || height <= 0)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Invalid frame size");
+
+  // Check to make sure at least one of frames that this frame references
+  // has valid dimensions.
+  for (i = 0; i < REFS_PER_FRAME; ++i) {
+    RefBuffer *const ref_frame = &cm->frame_refs[i];
+    has_valid_ref_frame |= (ref_frame->idx != INVALID_IDX &&
+                            valid_ref_frame_size(ref_frame->buf->y_crop_width,
+                                                 ref_frame->buf->y_crop_height,
+                                                 width, height));
+  }
+  if (!has_valid_ref_frame)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Referenced frame has invalid size");
+  for (i = 0; i < REFS_PER_FRAME; ++i) {
+    RefBuffer *const ref_frame = &cm->frame_refs[i];
+    if (ref_frame->idx == INVALID_IDX ||
+        !valid_ref_frame_img_fmt(ref_frame->buf->bit_depth,
+                                 ref_frame->buf->subsampling_x,
+                                 ref_frame->buf->subsampling_y,
+                                 cm->bit_depth,
+                                 cm->subsampling_x,
+                                 cm->subsampling_y))
+      vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                         "Referenced frame has incompatible color format");
+  }
+
+  resize_context_buffers(cm, width, height);
+  setup_render_size(cm, rb);
+
+  lock_buffer_pool(pool);
+  if (vpx_realloc_frame_buffer(
+          get_frame_new_buffer(cm), cm->width, cm->height,
+          cm->subsampling_x, cm->subsampling_y,
+#if CONFIG_VP9_HIGHBITDEPTH
+          cm->use_highbitdepth,
+#endif
+          VP9_DEC_BORDER_IN_PIXELS,
+          cm->byte_alignment,
+          &pool->frame_bufs[cm->new_fb_idx].raw_frame_buffer, pool->get_fb_cb,
+          pool->cb_priv)) {
+    unlock_buffer_pool(pool);
+    vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
+                       "Failed to allocate frame buffer");
+  }
+  unlock_buffer_pool(pool);
+
+  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_x = cm->subsampling_x;
+  pool->frame_bufs[cm->new_fb_idx].buf.subsampling_y = cm->subsampling_y;
+  pool->frame_bufs[cm->new_fb_idx].buf.bit_depth = (unsigned int)cm->bit_depth;
+  pool->frame_bufs[cm->new_fb_idx].buf.color_space = cm->color_space;
+  pool->frame_bufs[cm->new_fb_idx].buf.color_range = cm->color_range;
+  pool->frame_bufs[cm->new_fb_idx].buf.render_width  = cm->render_width;
+  pool->frame_bufs[cm->new_fb_idx].buf.render_height = cm->render_height;
+}
+
+static void setup_tile_info(VP9_COMMON *cm, struct vpx_read_bit_buffer *rb) {
+  int min_log2_tile_cols, max_log2_tile_cols, max_ones;
+  vp9_get_tile_n_bits(cm->mi_cols, &min_log2_tile_cols, &max_log2_tile_cols);
+
+  // columns
+  max_ones = max_log2_tile_cols - min_log2_tile_cols;
+  cm->log2_tile_cols = min_log2_tile_cols;
+  while (max_ones-- && vpx_rb_read_bit(rb))
+    cm->log2_tile_cols++;
+
+  if (cm->log2_tile_cols > 6)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Invalid number of tile columns");
+
+  // rows
+  cm->log2_tile_rows = vpx_rb_read_bit(rb);
+  if (cm->log2_tile_rows)
+    cm->log2_tile_rows += vpx_rb_read_bit(rb);
+}
+
+// Reads the next tile returning its size and adjusting '*data' accordingly
+// based on 'is_last'.
+static void get_tile_buffer(const uint8_t *const data_end,
+                            int is_last,
+                            struct vpx_internal_error_info *error_info,
+                            const uint8_t **data,
+                            vpx_decrypt_cb decrypt_cb, void *decrypt_state,
+                            TileBuffer *buf) {
+  size_t size;
+
+  if (!is_last) {
+    if (!read_is_valid(*data, 4, data_end))
+      vpx_internal_error(error_info, VPX_CODEC_CORRUPT_FRAME,
+                         "Truncated packet or corrupt tile length");
+
+    if (decrypt_cb) {
+      uint8_t be_data[4];
+      decrypt_cb(decrypt_state, *data, be_data, 4);
+      size = mem_get_be32(be_data);
+    } else {
+      size = mem_get_be32(*data);
+    }
+    *data += 4;
+
+    if (size > (size_t)(data_end - *data))
+      vpx_internal_error(error_info, VPX_CODEC_CORRUPT_FRAME,
+                         "Truncated packet or corrupt tile size");
+  } else {
+    size = data_end - *data;
+  }
+
+  buf->data = *data;
+  buf->size = size;
+
+  *data += size;
+}
+
+static void get_tile_buffers(VP9Decoder *pbi,
+                             const uint8_t *data, const uint8_t *data_end,
+                             int tile_cols, int tile_rows,
+                             TileBuffer (*tile_buffers)[1 << 6]) {
+  int r, c;
+
+  for (r = 0; r < tile_rows; ++r) {
+    for (c = 0; c < tile_cols; ++c) {
+      const int is_last = (r == tile_rows - 1) && (c == tile_cols - 1);
+      TileBuffer *const buf = &tile_buffers[r][c];
+      buf->col = c;
+      get_tile_buffer(data_end, is_last, &pbi->common.error, &data,
+                      pbi->decrypt_cb, pbi->decrypt_state, buf);
+    }
+  }
+}
+
+static const uint8_t *decode_tiles(VP9Decoder *pbi,
+                                   const uint8_t *data,
+                                   const uint8_t *data_end) {
+  VP9_COMMON *const cm = &pbi->common;
+  const VPxWorkerInterface *const winterface = vpx_get_worker_interface();
+  const int aligned_cols = mi_cols_aligned_to_sb(cm->mi_cols);
+  const int tile_cols = 1 << cm->log2_tile_cols;
+  const int tile_rows = 1 << cm->log2_tile_rows;
+  TileBuffer tile_buffers[4][1 << 6];
+  int tile_row, tile_col;
+  int mi_row, mi_col;
+  TileWorkerData *tile_data = NULL;
+
+  if (cm->lf.filter_level && !cm->skip_loop_filter &&
+      pbi->lf_worker.data1 == NULL) {
+    CHECK_MEM_ERROR(cm, pbi->lf_worker.data1,
+                    vpx_memalign(32, sizeof(LFWorkerData)));
+    pbi->lf_worker.hook = (VPxWorkerHook)vp9_loop_filter_worker;
+    if (pbi->max_threads > 1 && !winterface->reset(&pbi->lf_worker)) {
+      vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
+                         "Loop filter thread creation failed");
+    }
+  }
+
+  if (cm->lf.filter_level && !cm->skip_loop_filter) {
+    LFWorkerData *const lf_data = (LFWorkerData*)pbi->lf_worker.data1;
+    // Be sure to sync as we might be resuming after a failed frame decode.
+    winterface->sync(&pbi->lf_worker);
+    vp9_loop_filter_data_reset(lf_data, get_frame_new_buffer(cm), cm,
+                               pbi->mb.plane);
+  }
+
+  assert(tile_rows <= 4);
+  assert(tile_cols <= (1 << 6));
+
+  // Note: this memset assumes above_context[0], [1] and [2]
+  // are allocated as part of the same buffer.
+  memset(cm->above_context, 0,
+         sizeof(*cm->above_context) * MAX_MB_PLANE * 2 * aligned_cols);
+
+  memset(cm->above_seg_context, 0,
+         sizeof(*cm->above_seg_context) * aligned_cols);
+
+  vp9_reset_lfm(cm);
+
+  get_tile_buffers(pbi, data, data_end, tile_cols, tile_rows, tile_buffers);
+
+  // Load all tile information into tile_data.
+  for (tile_row = 0; tile_row < tile_rows; ++tile_row) {
+    for (tile_col = 0; tile_col < tile_cols; ++tile_col) {
+      const TileBuffer *const buf = &tile_buffers[tile_row][tile_col];
+      tile_data = pbi->tile_worker_data + tile_cols * tile_row + tile_col;
+      tile_data->xd = pbi->mb;
+      tile_data->xd.corrupted = 0;
+      tile_data->xd.counts =
+          cm->frame_parallel_decoding_mode ? NULL : &cm->counts;
+      vp9_zero(tile_data->dqcoeff);
+      vp9_tile_init(&tile_data->xd.tile, cm, tile_row, tile_col);
+      setup_token_decoder(buf->data, data_end, buf->size, &cm->error,
+                          &tile_data->bit_reader, pbi->decrypt_cb,
+                          pbi->decrypt_state);
+      vp9_init_macroblockd(cm, &tile_data->xd, tile_data->dqcoeff);
+    }
+  }
+
+  for (tile_row = 0; tile_row < tile_rows; ++tile_row) {
+    TileInfo tile;
+    vp9_tile_set_row(&tile, cm, tile_row);
+    for (mi_row = tile.mi_row_start; mi_row < tile.mi_row_end;
+         mi_row += MI_BLOCK_SIZE) {
+      for (tile_col = 0; tile_col < tile_cols; ++tile_col) {
+        const int col = pbi->inv_tile_order ?
+                        tile_cols - tile_col - 1 : tile_col;
+        tile_data = pbi->tile_worker_data + tile_cols * tile_row + col;
+        vp9_tile_set_col(&tile, cm, col);
+        vp9_zero(tile_data->xd.left_context);
+        vp9_zero(tile_data->xd.left_seg_context);
+        for (mi_col = tile.mi_col_start; mi_col < tile.mi_col_end;
+             mi_col += MI_BLOCK_SIZE) {
+          decode_partition(pbi, &tile_data->xd, mi_row,
+                           mi_col, &tile_data->bit_reader, BLOCK_64X64, 4);
+        }
+        pbi->mb.corrupted |= tile_data->xd.corrupted;
+        if (pbi->mb.corrupted)
+            vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                               "Failed to decode tile data");
+      }
+      // Loopfilter one row.
+      if (cm->lf.filter_level && !cm->skip_loop_filter) {
+        const int lf_start = mi_row - MI_BLOCK_SIZE;
+        LFWorkerData *const lf_data = (LFWorkerData*)pbi->lf_worker.data1;
+
+        // delay the loopfilter by 1 macroblock row.
+        if (lf_start < 0) continue;
+
+        // decoding has completed: finish up the loop filter in this thread.
+        if (mi_row + MI_BLOCK_SIZE >= cm->mi_rows) continue;
+
+        winterface->sync(&pbi->lf_worker);
+        lf_data->start = lf_start;
+        lf_data->stop = mi_row;
+        if (pbi->max_threads > 1) {
+          winterface->launch(&pbi->lf_worker);
+        } else {
+          winterface->execute(&pbi->lf_worker);
+        }
+      }
+      // After loopfiltering, the last 7 row pixels in each superblock row may
+      // still be changed by the longest loopfilter of the next superblock
+      // row.
+      if (pbi->frame_parallel_decode)
+        vp9_frameworker_broadcast(pbi->cur_buf,
+                                  mi_row << MI_BLOCK_SIZE_LOG2);
+    }
+  }
+
+  // Loopfilter remaining rows in the frame.
+  if (cm->lf.filter_level && !cm->skip_loop_filter) {
+    LFWorkerData *const lf_data = (LFWorkerData*)pbi->lf_worker.data1;
+    winterface->sync(&pbi->lf_worker);
+    lf_data->start = lf_data->stop;
+    lf_data->stop = cm->mi_rows;
+    winterface->execute(&pbi->lf_worker);
+  }
+
+  // Get last tile data.
+  tile_data = pbi->tile_worker_data + tile_cols * tile_rows - 1;
+
+  if (pbi->frame_parallel_decode)
+    vp9_frameworker_broadcast(pbi->cur_buf, INT_MAX);
+  return vpx_reader_find_end(&tile_data->bit_reader);
+}
+
+// On entry 'tile_data->data_end' points to the end of the input frame, on exit
+// it is updated to reflect the bitreader position of the final tile column if
+// present in the tile buffer group or NULL otherwise.
+static int tile_worker_hook(TileWorkerData *const tile_data,
+                            VP9Decoder *const pbi) {
+  TileInfo *volatile tile = &tile_data->xd.tile;
+  const int final_col = (1 << pbi->common.log2_tile_cols) - 1;
+  const uint8_t *volatile bit_reader_end = NULL;
+  volatile int n = tile_data->buf_start;
+  tile_data->error_info.setjmp = 1;
+
+  if (setjmp(tile_data->error_info.jmp)) {
+    tile_data->error_info.setjmp = 0;
+    tile_data->xd.corrupted = 1;
+    tile_data->data_end = NULL;
+    return 0;
+  }
+
+  tile_data->xd.error_info = &tile_data->error_info;
+  tile_data->xd.corrupted = 0;
+
+  do {
+    int mi_row, mi_col;
+    const TileBuffer *const buf = pbi->tile_buffers + n;
+    vp9_zero(tile_data->dqcoeff);
+    vp9_tile_init(tile, &pbi->common, 0, buf->col);
+    setup_token_decoder(buf->data, tile_data->data_end, buf->size,
+                        &tile_data->error_info, &tile_data->bit_reader,
+                        pbi->decrypt_cb, pbi->decrypt_state);
+    vp9_init_macroblockd(&pbi->common, &tile_data->xd, tile_data->dqcoeff);
+
+    for (mi_row = tile->mi_row_start; mi_row < tile->mi_row_end;
+         mi_row += MI_BLOCK_SIZE) {
+      vp9_zero(tile_data->xd.left_context);
+      vp9_zero(tile_data->xd.left_seg_context);
+      for (mi_col = tile->mi_col_start; mi_col < tile->mi_col_end;
+           mi_col += MI_BLOCK_SIZE) {
+        decode_partition(pbi, &tile_data->xd, mi_row, mi_col,
+                         &tile_data->bit_reader, BLOCK_64X64, 4);
+      }
+    }
+
+    if (buf->col == final_col) {
+      bit_reader_end = vpx_reader_find_end(&tile_data->bit_reader);
+    }
+  } while (!tile_data->xd.corrupted && ++n <= tile_data->buf_end);
+
+  tile_data->data_end = bit_reader_end;
+  return !tile_data->xd.corrupted;
+}
+
+// sorts in descending order
+static int compare_tile_buffers(const void *a, const void *b) {
+  const TileBuffer *const buf1 = (const TileBuffer*)a;
+  const TileBuffer *const buf2 = (const TileBuffer*)b;
+  return (int)(buf2->size - buf1->size);
+}
+
+static const uint8_t *decode_tiles_mt(VP9Decoder *pbi,
+                                      const uint8_t *data,
+                                      const uint8_t *data_end) {
+  VP9_COMMON *const cm = &pbi->common;
+  const VPxWorkerInterface *const winterface = vpx_get_worker_interface();
+  const uint8_t *bit_reader_end = NULL;
+  const int aligned_mi_cols = mi_cols_aligned_to_sb(cm->mi_cols);
+  const int tile_cols = 1 << cm->log2_tile_cols;
+  const int tile_rows = 1 << cm->log2_tile_rows;
+  const int num_workers = VPXMIN(pbi->max_threads, tile_cols);
+  int n;
+
+  assert(tile_cols <= (1 << 6));
+  assert(tile_rows == 1);
+  (void)tile_rows;
+
+  if (pbi->num_tile_workers == 0) {
+    const int num_threads = pbi->max_threads;
+    CHECK_MEM_ERROR(cm, pbi->tile_workers,
+                    vpx_malloc(num_threads * sizeof(*pbi->tile_workers)));
+    for (n = 0; n < num_threads; ++n) {
+      VPxWorker *const worker = &pbi->tile_workers[n];
+      ++pbi->num_tile_workers;
+
+      winterface->init(worker);
+      if (n < num_threads - 1 && !winterface->reset(worker)) {
+        vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
+                           "Tile decoder thread creation failed");
+      }
+    }
+  }
+
+  // Reset tile decoding hook
+  for (n = 0; n < num_workers; ++n) {
+    VPxWorker *const worker = &pbi->tile_workers[n];
+    TileWorkerData *const tile_data =
+        &pbi->tile_worker_data[n + pbi->total_tiles];
+    winterface->sync(worker);
+    tile_data->xd = pbi->mb;
+    tile_data->xd.counts =
+        cm->frame_parallel_decoding_mode ? NULL : &tile_data->counts;
+    worker->hook = (VPxWorkerHook)tile_worker_hook;
+    worker->data1 = tile_data;
+    worker->data2 = pbi;
+  }
+
+  // Note: this memset assumes above_context[0], [1] and [2]
+  // are allocated as part of the same buffer.
+  memset(cm->above_context, 0,
+         sizeof(*cm->above_context) * MAX_MB_PLANE * 2 * aligned_mi_cols);
+  memset(cm->above_seg_context, 0,
+         sizeof(*cm->above_seg_context) * aligned_mi_cols);
+
+  vp9_reset_lfm(cm);
+
+  // Load tile data into tile_buffers
+  get_tile_buffers(pbi, data, data_end, tile_cols, tile_rows,
+                   &pbi->tile_buffers);
+
+  // Sort the buffers based on size in descending order.
+  qsort(pbi->tile_buffers, tile_cols, sizeof(pbi->tile_buffers[0]),
+        compare_tile_buffers);
+
+  if (num_workers == tile_cols) {
+    // Rearrange the tile buffers such that the largest, and
+    // presumably the most difficult, tile will be decoded in the main thread.
+    // This should help minimize the number of instances where the main thread
+    // is waiting for a worker to complete.
+    const TileBuffer largest = pbi->tile_buffers[0];
+    memmove(pbi->tile_buffers, pbi->tile_buffers + 1,
+            (tile_cols - 1) * sizeof(pbi->tile_buffers[0]));
+    pbi->tile_buffers[tile_cols - 1] = largest;
+  } else {
+    int start = 0, end = tile_cols - 2;
+    TileBuffer tmp;
+
+    // Interleave the tiles to distribute the load between threads, assuming a
+    // larger tile implies it is more difficult to decode.
+    while (start < end) {
+      tmp = pbi->tile_buffers[start];
+      pbi->tile_buffers[start] = pbi->tile_buffers[end];
+      pbi->tile_buffers[end] = tmp;
+      start += 2;
+      end -= 2;
+    }
+  }
+
+  // Initialize thread frame counts.
+  if (!cm->frame_parallel_decoding_mode) {
+    for (n = 0; n < num_workers; ++n) {
+      TileWorkerData *const tile_data =
+          (TileWorkerData*)pbi->tile_workers[n].data1;
+      vp9_zero(tile_data->counts);
+    }
+  }
+
+  {
+    const int base = tile_cols / num_workers;
+    const int remain = tile_cols % num_workers;
+    int buf_start = 0;
+
+    for (n = 0; n < num_workers; ++n) {
+      const int count = base + (remain + n) / num_workers;
+      VPxWorker *const worker = &pbi->tile_workers[n];
+      TileWorkerData *const tile_data = (TileWorkerData*)worker->data1;
+
+      tile_data->buf_start = buf_start;
+      tile_data->buf_end = buf_start + count - 1;
+      tile_data->data_end = data_end;
+      buf_start += count;
+
+      worker->had_error = 0;
+      if (n == num_workers - 1) {
+        assert(tile_data->buf_end == tile_cols - 1);
+        winterface->execute(worker);
+      } else {
+        winterface->launch(worker);
+      }
+    }
+
+    for (; n > 0; --n) {
+      VPxWorker *const worker = &pbi->tile_workers[n - 1];
+      TileWorkerData *const tile_data = (TileWorkerData*)worker->data1;
+      // TODO(jzern): The tile may have specific error data associated with
+      // its vpx_internal_error_info which could be propagated to the main info
+      // in cm. Additionally once the threads have been synced and an error is
+      // detected, there's no point in continuing to decode tiles.
+      pbi->mb.corrupted |= !winterface->sync(worker);
+      if (!bit_reader_end) bit_reader_end = tile_data->data_end;
+    }
+  }
+
+  // Accumulate thread frame counts.
+  if (!cm->frame_parallel_decoding_mode) {
+    for (n = 0; n < num_workers; ++n) {
+      TileWorkerData *const tile_data =
+          (TileWorkerData*)pbi->tile_workers[n].data1;
+      vp9_accumulate_frame_counts(&cm->counts, &tile_data->counts, 1);
+    }
+  }
+
+  assert(bit_reader_end || pbi->mb.corrupted);
+  return bit_reader_end;
+}
+
+static void error_handler(void *data) {
+  VP9_COMMON *const cm = (VP9_COMMON *)data;
+  vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME, "Truncated packet");
+}
+
+static void read_bitdepth_colorspace_sampling(
+    VP9_COMMON *cm, struct vpx_read_bit_buffer *rb) {
+  if (cm->profile >= PROFILE_2) {
+    cm->bit_depth = vpx_rb_read_bit(rb) ? VPX_BITS_12 : VPX_BITS_10;
+#if CONFIG_VP9_HIGHBITDEPTH
+    cm->use_highbitdepth = 1;
+#endif
+  } else {
+    cm->bit_depth = VPX_BITS_8;
+#if CONFIG_VP9_HIGHBITDEPTH
+    cm->use_highbitdepth = 0;
+#endif
+  }
+  cm->color_space = vpx_rb_read_literal(rb, 3);
+  if (cm->color_space != VPX_CS_SRGB) {
+    cm->color_range = (vpx_color_range_t)vpx_rb_read_bit(rb);
+    if (cm->profile == PROFILE_1 || cm->profile == PROFILE_3) {
+      cm->subsampling_x = vpx_rb_read_bit(rb);
+      cm->subsampling_y = vpx_rb_read_bit(rb);
+      if (cm->subsampling_x == 1 && cm->subsampling_y == 1)
+        vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                           "4:2:0 color not supported in profile 1 or 3");
+      if (vpx_rb_read_bit(rb))
+        vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                           "Reserved bit set");
+    } else {
+      cm->subsampling_y = cm->subsampling_x = 1;
+    }
+  } else {
+    cm->color_range = VPX_CR_FULL_RANGE;
+    if (cm->profile == PROFILE_1 || cm->profile == PROFILE_3) {
+      // Note if colorspace is SRGB then 4:4:4 chroma sampling is assumed.
+      // 4:2:2 or 4:4:0 chroma sampling is not allowed.
+      cm->subsampling_y = cm->subsampling_x = 0;
+      if (vpx_rb_read_bit(rb))
+        vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                           "Reserved bit set");
+    } else {
+      vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                         "4:4:4 color not supported in profile 0 or 2");
+    }
+  }
+}
+
+static size_t read_uncompressed_header(VP9Decoder *pbi,
+                                       struct vpx_read_bit_buffer *rb) {
+  VP9_COMMON *const cm = &pbi->common;
+  BufferPool *const pool = cm->buffer_pool;
+  RefCntBuffer *const frame_bufs = pool->frame_bufs;
+  int i, mask, ref_index = 0;
+  size_t sz;
+
+  cm->last_frame_type = cm->frame_type;
+  cm->last_intra_only = cm->intra_only;
+
+  if (vpx_rb_read_literal(rb, 2) != VP9_FRAME_MARKER)
+      vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                         "Invalid frame marker");
+
+  cm->profile = vp9_read_profile(rb);
+#if CONFIG_VP9_HIGHBITDEPTH
+  if (cm->profile >= MAX_PROFILES)
+    vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                       "Unsupported bitstream profile");
+#else
+  if (cm->profile >= PROFILE_2)
+    vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                       "Unsupported bitstream profile");
+#endif
+
+  cm->show_existing_frame = vpx_rb_read_bit(rb);
+  if (cm->show_existing_frame) {
+    // Show an existing frame directly.
+    const int frame_to_show = cm->ref_frame_map[vpx_rb_read_literal(rb, 3)];
+    lock_buffer_pool(pool);
+    if (frame_to_show < 0 || frame_bufs[frame_to_show].ref_count < 1) {
+      unlock_buffer_pool(pool);
+      vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                         "Buffer %d does not contain a decoded frame",
+                         frame_to_show);
+    }
+
+    ref_cnt_fb(frame_bufs, &cm->new_fb_idx, frame_to_show);
+    unlock_buffer_pool(pool);
+    pbi->refresh_frame_flags = 0;
+    cm->lf.filter_level = 0;
+    cm->show_frame = 1;
+
+    if (pbi->frame_parallel_decode) {
+      for (i = 0; i < REF_FRAMES; ++i)
+        cm->next_ref_frame_map[i] = cm->ref_frame_map[i];
+    }
+    return 0;
+  }
+
+  cm->frame_type = (FRAME_TYPE) vpx_rb_read_bit(rb);
+  cm->show_frame = vpx_rb_read_bit(rb);
+  cm->error_resilient_mode = vpx_rb_read_bit(rb);
+
+  if (cm->frame_type == KEY_FRAME) {
+    if (!vp9_read_sync_code(rb))
+      vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                         "Invalid frame sync code");
+
+    read_bitdepth_colorspace_sampling(cm, rb);
+    pbi->refresh_frame_flags = (1 << REF_FRAMES) - 1;
+
+    for (i = 0; i < REFS_PER_FRAME; ++i) {
+      cm->frame_refs[i].idx = INVALID_IDX;
+      cm->frame_refs[i].buf = NULL;
+    }
+
+    setup_frame_size(cm, rb);
+    if (pbi->need_resync) {
+      memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
+      pbi->need_resync = 0;
+    }
+  } else {
+    cm->intra_only = cm->show_frame ? 0 : vpx_rb_read_bit(rb);
+
+    cm->reset_frame_context = cm->error_resilient_mode ?
+        0 : vpx_rb_read_literal(rb, 2);
+
+    if (cm->intra_only) {
+      if (!vp9_read_sync_code(rb))
+        vpx_internal_error(&cm->error, VPX_CODEC_UNSUP_BITSTREAM,
+                           "Invalid frame sync code");
+      if (cm->profile > PROFILE_0) {
+        read_bitdepth_colorspace_sampling(cm, rb);
+      } else {
+        // NOTE: The intra-only frame header does not include the specification
+        // of either the color format or color sub-sampling in profile 0. VP9
+        // specifies that the default color format should be YUV 4:2:0 in this
+        // case (normative).
+        cm->color_space = VPX_CS_BT_601;
+        cm->color_range = VPX_CR_STUDIO_RANGE;
+        cm->subsampling_y = cm->subsampling_x = 1;
+        cm->bit_depth = VPX_BITS_8;
+#if CONFIG_VP9_HIGHBITDEPTH
+        cm->use_highbitdepth = 0;
+#endif
+      }
+
+      pbi->refresh_frame_flags = vpx_rb_read_literal(rb, REF_FRAMES);
+      setup_frame_size(cm, rb);
+      if (pbi->need_resync) {
+        memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
+        pbi->need_resync = 0;
+      }
+    } else if (pbi->need_resync != 1) {  /* Skip if need resync */
+      pbi->refresh_frame_flags = vpx_rb_read_literal(rb, REF_FRAMES);
+      for (i = 0; i < REFS_PER_FRAME; ++i) {
+        const int ref = vpx_rb_read_literal(rb, REF_FRAMES_LOG2);
+        const int idx = cm->ref_frame_map[ref];
+        RefBuffer *const ref_frame = &cm->frame_refs[i];
+        ref_frame->idx = idx;
+        ref_frame->buf = &frame_bufs[idx].buf;
+        cm->ref_frame_sign_bias[LAST_FRAME + i] = vpx_rb_read_bit(rb);
+      }
+
+      setup_frame_size_with_refs(cm, rb);
+
+      cm->allow_high_precision_mv = vpx_rb_read_bit(rb);
+      cm->interp_filter = read_interp_filter(rb);
+
+      for (i = 0; i < REFS_PER_FRAME; ++i) {
+        RefBuffer *const ref_buf = &cm->frame_refs[i];
+#if CONFIG_VP9_HIGHBITDEPTH
+        vp9_setup_scale_factors_for_frame(&ref_buf->sf,
+                                          ref_buf->buf->y_crop_width,
+                                          ref_buf->buf->y_crop_height,
+                                          cm->width, cm->height,
+                                          cm->use_highbitdepth);
+#else
+        vp9_setup_scale_factors_for_frame(&ref_buf->sf,
+                                          ref_buf->buf->y_crop_width,
+                                          ref_buf->buf->y_crop_height,
+                                          cm->width, cm->height);
+#endif
+      }
+    }
+  }
+#if CONFIG_VP9_HIGHBITDEPTH
+  get_frame_new_buffer(cm)->bit_depth = cm->bit_depth;
+#endif
+  get_frame_new_buffer(cm)->color_space = cm->color_space;
+  get_frame_new_buffer(cm)->color_range = cm->color_range;
+  get_frame_new_buffer(cm)->render_width  = cm->render_width;
+  get_frame_new_buffer(cm)->render_height = cm->render_height;
+
+  if (pbi->need_resync) {
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Keyframe / intra-only frame required to reset decoder"
+                       " state");
+  }
+
+  if (!cm->error_resilient_mode) {
+    cm->refresh_frame_context = vpx_rb_read_bit(rb);
+    cm->frame_parallel_decoding_mode = vpx_rb_read_bit(rb);
+    if (!cm->frame_parallel_decoding_mode)
+      vp9_zero(cm->counts);
+  } else {
+    cm->refresh_frame_context = 0;
+    cm->frame_parallel_decoding_mode = 1;
+  }
+
+  // This flag will be overridden by the call to vp9_setup_past_independence
+  // below, forcing the use of context 0 for those frame types.
+  cm->frame_context_idx = vpx_rb_read_literal(rb, FRAME_CONTEXTS_LOG2);
+
+  // Generate next_ref_frame_map.
+  lock_buffer_pool(pool);
+  for (mask = pbi->refresh_frame_flags; mask; mask >>= 1) {
+    if (mask & 1) {
+      cm->next_ref_frame_map[ref_index] = cm->new_fb_idx;
+      ++frame_bufs[cm->new_fb_idx].ref_count;
+    } else {
+      cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
+    }
+    // Current thread holds the reference frame.
+    if (cm->ref_frame_map[ref_index] >= 0)
+      ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
+    ++ref_index;
+  }
+
+  for (; ref_index < REF_FRAMES; ++ref_index) {
+    cm->next_ref_frame_map[ref_index] = cm->ref_frame_map[ref_index];
+    // Current thread holds the reference frame.
+    if (cm->ref_frame_map[ref_index] >= 0)
+      ++frame_bufs[cm->ref_frame_map[ref_index]].ref_count;
+  }
+  unlock_buffer_pool(pool);
+  pbi->hold_ref_buf = 1;
+
+  if (frame_is_intra_only(cm) || cm->error_resilient_mode)
+    vp9_setup_past_independence(cm);
+
+  setup_loopfilter(&cm->lf, rb);
+  setup_quantization(cm, &pbi->mb, rb);
+  setup_segmentation(&cm->seg, rb);
+  setup_segmentation_dequant(cm);
+
+  setup_tile_info(cm, rb);
+  sz = vpx_rb_read_literal(rb, 16);
+
+  if (sz == 0)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Invalid header size");
+
+  return sz;
+}
+
+static int read_compressed_header(VP9Decoder *pbi, const uint8_t *data,
+                                  size_t partition_size) {
+  VP9_COMMON *const cm = &pbi->common;
+  MACROBLOCKD *const xd = &pbi->mb;
+  FRAME_CONTEXT *const fc = cm->fc;
+  vpx_reader r;
+  int k;
+
+  if (vpx_reader_init(&r, data, partition_size, pbi->decrypt_cb,
+                      pbi->decrypt_state))
+    vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
+                       "Failed to allocate bool decoder 0");
+
+  cm->tx_mode = xd->lossless ? ONLY_4X4 : read_tx_mode(&r);
+  if (cm->tx_mode == TX_MODE_SELECT)
+    read_tx_mode_probs(&fc->tx_probs, &r);
+  read_coef_probs(fc, cm->tx_mode, &r);
+
+  for (k = 0; k < SKIP_CONTEXTS; ++k)
+    vp9_diff_update_prob(&r, &fc->skip_probs[k]);
+
+  if (!frame_is_intra_only(cm)) {
+    nmv_context *const nmvc = &fc->nmvc;
+    int i, j;
+
+    read_inter_mode_probs(fc, &r);
+
+    if (cm->interp_filter == SWITCHABLE)
+      read_switchable_interp_probs(fc, &r);
+
+    for (i = 0; i < INTRA_INTER_CONTEXTS; i++)
+      vp9_diff_update_prob(&r, &fc->intra_inter_prob[i]);
+
+    cm->reference_mode = read_frame_reference_mode(cm, &r);
+    if (cm->reference_mode != SINGLE_REFERENCE)
+      setup_compound_reference_mode(cm);
+    read_frame_reference_mode_probs(cm, &r);
+
+    for (j = 0; j < BLOCK_SIZE_GROUPS; j++)
+      for (i = 0; i < INTRA_MODES - 1; ++i)
+        vp9_diff_update_prob(&r, &fc->y_mode_prob[j][i]);
+
+    for (j = 0; j < PARTITION_CONTEXTS; ++j)
+      for (i = 0; i < PARTITION_TYPES - 1; ++i)
+        vp9_diff_update_prob(&r, &fc->partition_prob[j][i]);
+
+    read_mv_probs(nmvc, cm->allow_high_precision_mv, &r);
+  }
+
+  return vpx_reader_has_error(&r);
+}
+
+static struct vpx_read_bit_buffer *init_read_bit_buffer(
+    VP9Decoder *pbi,
+    struct vpx_read_bit_buffer *rb,
+    const uint8_t *data,
+    const uint8_t *data_end,
+    uint8_t clear_data[MAX_VP9_HEADER_SIZE]) {
+  rb->bit_offset = 0;
+  rb->error_handler = error_handler;
+  rb->error_handler_data = &pbi->common;
+  if (pbi->decrypt_cb) {
+    const int n = (int)VPXMIN(MAX_VP9_HEADER_SIZE, data_end - data);
+    pbi->decrypt_cb(pbi->decrypt_state, data, clear_data, n);
+    rb->bit_buffer = clear_data;
+    rb->bit_buffer_end = clear_data + n;
+  } else {
+    rb->bit_buffer = data;
+    rb->bit_buffer_end = data_end;
+  }
+  return rb;
+}
+
+//------------------------------------------------------------------------------
+
+int vp9_read_sync_code(struct vpx_read_bit_buffer *const rb) {
+  return vpx_rb_read_literal(rb, 8) == VP9_SYNC_CODE_0 &&
+         vpx_rb_read_literal(rb, 8) == VP9_SYNC_CODE_1 &&
+         vpx_rb_read_literal(rb, 8) == VP9_SYNC_CODE_2;
+}
+
+void vp9_read_frame_size(struct vpx_read_bit_buffer *rb,
+                         int *width, int *height) {
+  *width = vpx_rb_read_literal(rb, 16) + 1;
+  *height = vpx_rb_read_literal(rb, 16) + 1;
+}
+
+BITSTREAM_PROFILE vp9_read_profile(struct vpx_read_bit_buffer *rb) {
+  int profile = vpx_rb_read_bit(rb);
+  profile |= vpx_rb_read_bit(rb) << 1;
+  if (profile > 2)
+    profile += vpx_rb_read_bit(rb);
+  return (BITSTREAM_PROFILE) profile;
+}
+
+void vp9_decode_frame(VP9Decoder *pbi,
+                      const uint8_t *data, const uint8_t *data_end,
+                      const uint8_t **p_data_end) {
+  VP9_COMMON *const cm = &pbi->common;
+  MACROBLOCKD *const xd = &pbi->mb;
+  struct vpx_read_bit_buffer rb;
+  int context_updated = 0;
+  uint8_t clear_data[MAX_VP9_HEADER_SIZE];
+  const size_t first_partition_size = read_uncompressed_header(pbi,
+      init_read_bit_buffer(pbi, &rb, data, data_end, clear_data));
+  const int tile_rows = 1 << cm->log2_tile_rows;
+  const int tile_cols = 1 << cm->log2_tile_cols;
+  YV12_BUFFER_CONFIG *const new_fb = get_frame_new_buffer(cm);
+  xd->cur_buf = new_fb;
+
+  if (!first_partition_size) {
+    // showing a frame directly
+    *p_data_end = data + (cm->profile <= PROFILE_2 ? 1 : 2);
+    return;
+  }
+
+  data += vpx_rb_bytes_read(&rb);
+  if (!read_is_valid(data, first_partition_size, data_end))
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Truncated packet or corrupt header length");
+
+  cm->use_prev_frame_mvs = !cm->error_resilient_mode &&
+                           cm->width == cm->last_width &&
+                           cm->height == cm->last_height &&
+                           !cm->last_intra_only &&
+                           cm->last_show_frame &&
+                           (cm->last_frame_type != KEY_FRAME);
+
+  vp9_setup_block_planes(xd, cm->subsampling_x, cm->subsampling_y);
+
+  *cm->fc = cm->frame_contexts[cm->frame_context_idx];
+  if (!cm->fc->initialized)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Uninitialized entropy context.");
+
+  xd->corrupted = 0;
+  new_fb->corrupted = read_compressed_header(pbi, data, first_partition_size);
+  if (new_fb->corrupted)
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Decode failed. Frame data header is corrupted.");
+
+  if (cm->lf.filter_level && !cm->skip_loop_filter) {
+    vp9_loop_filter_frame_init(cm, cm->lf.filter_level);
+  }
+
+  // If encoded in frame parallel mode, frame context is ready after decoding
+  // the frame header.
+  if (pbi->frame_parallel_decode && cm->frame_parallel_decoding_mode) {
+    VPxWorker *const worker = pbi->frame_worker_owner;
+    FrameWorkerData *const frame_worker_data = worker->data1;
+    if (cm->refresh_frame_context) {
+      context_updated = 1;
+      cm->frame_contexts[cm->frame_context_idx] = *cm->fc;
+    }
+    vp9_frameworker_lock_stats(worker);
+    pbi->cur_buf->row = -1;
+    pbi->cur_buf->col = -1;
+    frame_worker_data->frame_context_ready = 1;
+    // Signal the main thread that context is ready.
+    vp9_frameworker_signal_stats(worker);
+    vp9_frameworker_unlock_stats(worker);
+  }
+
+  if (pbi->tile_worker_data == NULL ||
+      (tile_cols * tile_rows) != pbi->total_tiles) {
+    const int num_tile_workers = tile_cols * tile_rows +
+        ((pbi->max_threads > 1) ? pbi->max_threads : 0);
+    const size_t twd_size = num_tile_workers * sizeof(*pbi->tile_worker_data);
+    // Ensure tile data offsets will be properly aligned. This may fail on
+    // platforms without DECLARE_ALIGNED().
+    assert((sizeof(*pbi->tile_worker_data) % 16) == 0);
+    vpx_free(pbi->tile_worker_data);
+    CHECK_MEM_ERROR(cm, pbi->tile_worker_data, vpx_memalign(32, twd_size));
+    pbi->total_tiles = tile_rows * tile_cols;
+  }
+
+  if (pbi->max_threads > 1 && tile_rows == 1 && tile_cols > 1) {
+    // Multi-threaded tile decoder
+    *p_data_end = decode_tiles_mt(pbi, data + first_partition_size, data_end);
+    if (!xd->corrupted) {
+      if (!cm->skip_loop_filter) {
+        // If multiple threads are used to decode tiles, then we use those
+        // threads to do parallel loopfiltering.
+        vp9_loop_filter_frame_mt(new_fb, cm, pbi->mb.plane,
+                                 cm->lf.filter_level, 0, 0, pbi->tile_workers,
+                                 pbi->num_tile_workers, &pbi->lf_row_sync);
+      }
+    } else {
+      vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                         "Decode failed. Frame data is corrupted.");
+    }
+  } else {
+    *p_data_end = decode_tiles(pbi, data + first_partition_size, data_end);
+  }
+
+  if (!xd->corrupted) {
+    if (!cm->error_resilient_mode && !cm->frame_parallel_decoding_mode) {
+      vp9_adapt_coef_probs(cm);
+
+      if (!frame_is_intra_only(cm)) {
+        vp9_adapt_mode_probs(cm);
+        vp9_adapt_mv_probs(cm, cm->allow_high_precision_mv);
+      }
+    }
+  } else {
+    vpx_internal_error(&cm->error, VPX_CODEC_CORRUPT_FRAME,
+                       "Decode failed. Frame data is corrupted.");
+  }
+
+  // Non frame parallel update frame context here.
+  if (cm->refresh_frame_context && !context_updated)
+    cm->frame_contexts[cm->frame_context_idx] = *cm->fc;
+}