Update upstream source from tag 'upstream/0.17.0'

Update to upstream version '0.17.0'
with Debian dir 5b612b6a2d67788b0c85bac59e50edc1545bfd7e

5 files changed, 415 insertions, 239 deletions

diff --git a/src/tile/bitstream/mode_info.cc b/src/tile/bitstream/mode_info.cc
index 0b22eb0..cb7b311 100644
--- a/src/tile/bitstream/mode_info.cc
+++ b/src/tile/bitstream/mode_info.cc
@@ -185,19 +185,22 @@ int GetReferenceContext(const Tile::Block& block,
 }  // namespace
 
 bool Tile::ReadSegmentId(const Block& block) {
+  // These two asserts ensure that current_frame_.segmentation_map() is not
+  // nullptr.
+  assert(frame_header_.segmentation.enabled);
+  assert(frame_header_.segmentation.update_map);
+  const SegmentationMap& map = *current_frame_.segmentation_map();
   int top_left = -1;
   if (block.top_available[kPlaneY] && block.left_available[kPlaneY]) {
-    top_left =
-        block_parameters_holder_.Find(block.row4x4 - 1, block.column4x4 - 1)
-            ->segment_id;
+    top_left = map.segment_id(block.row4x4 - 1, block.column4x4 - 1);
   }
   int top = -1;
   if (block.top_available[kPlaneY]) {
-    top = block.bp_top->segment_id;
+    top = map.segment_id(block.row4x4 - 1, block.column4x4);
   }
   int left = -1;
   if (block.left_available[kPlaneY]) {
-    left = block.bp_left->segment_id;
+    left = map.segment_id(block.row4x4, block.column4x4 - 1);
   }
   int pred;
   if (top == -1) {
@@ -209,7 +212,7 @@ bool Tile::ReadSegmentId(const Block& block) {
   }
   BlockParameters& bp = *block.bp;
   if (bp.skip) {
-    bp.segment_id = pred;
+    bp.prediction_parameters->segment_id = pred;
     return true;
   }
   int context = 0;
@@ -224,17 +227,18 @@ bool Tile::ReadSegmentId(const Block& block) {
       symbol_decoder_context_.segment_id_cdf[context];
   const int encoded_segment_id =
       reader_.ReadSymbol<kMaxSegments>(segment_id_cdf);
-  bp.segment_id =
+  bp.prediction_parameters->segment_id =
       DecodeSegmentId(encoded_segment_id, pred,
                       frame_header_.segmentation.last_active_segment_id + 1);
   // Check the bitstream conformance requirement in Section 6.10.8 of the spec.
-  if (bp.segment_id < 0 ||
-      bp.segment_id > frame_header_.segmentation.last_active_segment_id) {
+  if (bp.prediction_parameters->segment_id < 0 ||
+      bp.prediction_parameters->segment_id >
+          frame_header_.segmentation.last_active_segment_id) {
     LIBGAV1_DLOG(
         ERROR,
         "Corrupted segment_ids: encoded %d, last active %d, postprocessed %d",
         encoded_segment_id, frame_header_.segmentation.last_active_segment_id,
-        bp.segment_id);
+        bp.prediction_parameters->segment_id);
     return false;
   }
   return true;
@@ -243,7 +247,7 @@ bool Tile::ReadSegmentId(const Block& block) {
 bool Tile::ReadIntraSegmentId(const Block& block) {
   BlockParameters& bp = *block.bp;
   if (!frame_header_.segmentation.enabled) {
-    bp.segment_id = 0;
+    bp.prediction_parameters->segment_id = 0;
     return true;
   }
   return ReadSegmentId(block);
@@ -252,8 +256,8 @@ bool Tile::ReadIntraSegmentId(const Block& block) {
 void Tile::ReadSkip(const Block& block) {
   BlockParameters& bp = *block.bp;
   if (frame_header_.segmentation.segment_id_pre_skip &&
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureSkip)) {
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureSkip)) {
     bp.skip = true;
     return;
   }
@@ -268,51 +272,53 @@ void Tile::ReadSkip(const Block& block) {
   bp.skip = reader_.ReadSymbol(skip_cdf);
 }
 
-void Tile::ReadSkipMode(const Block& block) {
+bool Tile::ReadSkipMode(const Block& block) {
   BlockParameters& bp = *block.bp;
   if (!frame_header_.skip_mode_present ||
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureSkip) ||
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureReferenceFrame) ||
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureGlobalMv) ||
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureSkip) ||
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id,
+          kSegmentFeatureReferenceFrame) ||
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureGlobalMv) ||
       IsBlockDimension4(block.size)) {
-    bp.skip_mode = false;
-    return;
+    return false;
   }
   const int context =
       (block.left_available[kPlaneY]
-           ? static_cast<int>(block.bp_left->skip_mode)
+           ? static_cast<int>(left_context_.skip_mode[block.left_context_index])
            : 0) +
-      (block.top_available[kPlaneY] ? static_cast<int>(block.bp_top->skip_mode)
-                                    : 0);
-  bp.skip_mode =
-      reader_.ReadSymbol(symbol_decoder_context_.skip_mode_cdf[context]);
+      (block.top_available[kPlaneY]
+           ? static_cast<int>(
+                 block.top_context->skip_mode[block.top_context_index])
+           : 0);
+  return reader_.ReadSymbol(symbol_decoder_context_.skip_mode_cdf[context]);
 }
 
 void Tile::ReadCdef(const Block& block) {
   BlockParameters& bp = *block.bp;
   if (bp.skip || frame_header_.coded_lossless ||
-      !sequence_header_.enable_cdef || frame_header_.allow_intrabc) {
+      !sequence_header_.enable_cdef || frame_header_.allow_intrabc ||
+      frame_header_.cdef.bits == 0) {
     return;
   }
-  const int cdef_size4x4 = kNum4x4BlocksWide[kBlock64x64];
-  const int cdef_mask4x4 = ~(cdef_size4x4 - 1);
-  const int row4x4 = block.row4x4 & cdef_mask4x4;
-  const int column4x4 = block.column4x4 & cdef_mask4x4;
-  const int row = DivideBy16(row4x4);
-  const int column = DivideBy16(column4x4);
-  if (cdef_index_[row][column] == -1) {
-    cdef_index_[row][column] =
-        frame_header_.cdef.bits > 0
-            ? static_cast<int16_t>(reader_.ReadLiteral(frame_header_.cdef.bits))
-            : 0;
-    for (int i = row4x4; i < row4x4 + block.height4x4; i += cdef_size4x4) {
-      for (int j = column4x4; j < column4x4 + block.width4x4;
-           j += cdef_size4x4) {
-        cdef_index_[DivideBy16(i)][DivideBy16(j)] = cdef_index_[row][column];
-      }
+  int8_t* const cdef_index =
+      &cdef_index_[DivideBy16(block.row4x4)][DivideBy16(block.column4x4)];
+  int stride = cdef_index_.columns();
+  if (cdef_index[0] == -1) {
+    cdef_index[0] =
+        static_cast<int8_t>(reader_.ReadLiteral(frame_header_.cdef.bits));
+    if (block.size == kBlock128x128) {
+      // This condition is shorthand for block.width4x4 > 16 && block.height4x4
+      // > 16.
+      cdef_index[1] = cdef_index[0];
+      cdef_index[stride] = cdef_index[0];
+      cdef_index[stride + 1] = cdef_index[0];
+    } else if (block.width4x4 > 16) {
+      cdef_index[1] = cdef_index[0];
+    } else if (block.height4x4 > 16) {
+      cdef_index[stride] = cdef_index[0];
     }
   }
 }
@@ -328,7 +334,7 @@ int Tile::ReadAndClipDelta(uint16_t* const cdf, int delta_small, int scale,
     abs = abs_remaining_bits + (1 << remaining_bit_count) + 1;
   }
   if (abs != 0) {
-    const bool sign = static_cast<bool>(reader_.ReadBit());
+    const bool sign = reader_.ReadBit() != 0;
     const int scaled_abs = abs << scale;
     const int reduced_delta = sign ? -scaled_abs : scaled_abs;
     value += reduced_delta;
@@ -404,8 +410,9 @@ void Tile::ReadIntraAngleInfo(const Block& block, PlaneType plane_type) {
   PredictionParameters& prediction_parameters =
       *block.bp->prediction_parameters;
   prediction_parameters.angle_delta[plane_type] = 0;
-  const PredictionMode mode =
-      (plane_type == kPlaneTypeY) ? bp.y_mode : bp.uv_mode;
+  const PredictionMode mode = (plane_type == kPlaneTypeY)
+                                  ? bp.y_mode
+                                  : bp.prediction_parameters->uv_mode;
   if (IsBlockSmallerThan8x8(block.size) || !IsDirectionalMode(mode)) return;
   uint16_t* const cdf =
       symbol_decoder_context_.angle_delta_cdf[mode - kPredictionModeVertical];
@@ -445,7 +452,8 @@ void Tile::ReadCflAlpha(const Block& block) {
 void Tile::ReadPredictionModeUV(const Block& block) {
   BlockParameters& bp = *block.bp;
   bool chroma_from_luma_allowed;
-  if (frame_header_.segmentation.lossless[bp.segment_id]) {
+  if (frame_header_.segmentation
+          .lossless[bp.prediction_parameters->segment_id]) {
     chroma_from_luma_allowed = block.residual_size[kPlaneU] == kBlock4x4;
   } else {
     chroma_from_luma_allowed = IsBlockDimensionLessThan64(block.size);
@@ -454,10 +462,10 @@ void Tile::ReadPredictionModeUV(const Block& block) {
       symbol_decoder_context_
           .uv_mode_cdf[static_cast<int>(chroma_from_luma_allowed)][bp.y_mode];
   if (chroma_from_luma_allowed) {
-    bp.uv_mode = static_cast<PredictionMode>(
+    bp.prediction_parameters->uv_mode = static_cast<PredictionMode>(
         reader_.ReadSymbol<kIntraPredictionModesUV>(cdf));
   } else {
-    bp.uv_mode = static_cast<PredictionMode>(
+    bp.prediction_parameters->uv_mode = static_cast<PredictionMode>(
         reader_.ReadSymbol<kIntraPredictionModesUV - 1>(cdf));
   }
 }
@@ -528,7 +536,7 @@ void Tile::ReadFilterIntraModeInfo(const Block& block) {
       *block.bp->prediction_parameters;
   prediction_parameters.use_filter_intra = false;
   if (!sequence_header_.enable_filter_intra || bp.y_mode != kPredictionModeDc ||
-      bp.palette_mode_info.size[kPlaneTypeY] != 0 ||
+      bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] != 0 ||
       !IsBlockDimensionLessThan64(block.size)) {
     return;
   }
@@ -548,7 +556,7 @@ bool Tile::DecodeIntraModeInfo(const Block& block) {
       !ReadIntraSegmentId(block)) {
     return false;
   }
-  bp.skip_mode = false;
+  SetCdfContextSkipMode(block, false);
   ReadSkip(block);
   if (!frame_header_.segmentation.segment_id_pre_skip &&
       !ReadIntraSegmentId(block)) {
@@ -572,12 +580,14 @@ bool Tile::DecodeIntraModeInfo(const Block& block) {
     bp.reference_frame[0] = kReferenceFrameIntra;
     bp.reference_frame[1] = kReferenceFrameNone;
     bp.y_mode = kPredictionModeDc;
-    bp.uv_mode = kPredictionModeDc;
+    bp.prediction_parameters->uv_mode = kPredictionModeDc;
+    SetCdfContextUVMode(block);
     prediction_parameters.motion_mode = kMotionModeSimple;
     prediction_parameters.compound_prediction_type =
         kCompoundPredictionTypeAverage;
-    bp.palette_mode_info.size[kPlaneTypeY] = 0;
-    bp.palette_mode_info.size[kPlaneTypeUV] = 0;
+    bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] = 0;
+    bp.prediction_parameters->palette_mode_info.size[kPlaneTypeUV] = 0;
+    SetCdfContextPaletteSize(block);
     bp.interpolation_filter[0] = kInterpolationFilterBilinear;
     bp.interpolation_filter[1] = kInterpolationFilterBilinear;
     MvContexts dummy_mode_contexts;
@@ -608,59 +618,73 @@ int8_t Tile::ComputePredictedSegmentId(const Block& block) const {
   return id;
 }
 
+void Tile::SetCdfContextUsePredictedSegmentId(const Block& block,
+                                              bool use_predicted_segment_id) {
+  memset(left_context_.use_predicted_segment_id + block.left_context_index,
+         static_cast<int>(use_predicted_segment_id), block.height4x4);
+  memset(block.top_context->use_predicted_segment_id + block.top_context_index,
+         static_cast<int>(use_predicted_segment_id), block.width4x4);
+}
+
 bool Tile::ReadInterSegmentId(const Block& block, bool pre_skip) {
   BlockParameters& bp = *block.bp;
   if (!frame_header_.segmentation.enabled) {
-    bp.segment_id = 0;
+    bp.prediction_parameters->segment_id = 0;
     return true;
   }
   if (!frame_header_.segmentation.update_map) {
-    bp.segment_id = ComputePredictedSegmentId(block);
+    bp.prediction_parameters->segment_id = ComputePredictedSegmentId(block);
     return true;
   }
   if (pre_skip) {
     if (!frame_header_.segmentation.segment_id_pre_skip) {
-      bp.segment_id = 0;
+      bp.prediction_parameters->segment_id = 0;
       return true;
     }
   } else if (bp.skip) {
-    bp.use_predicted_segment_id = false;
+    SetCdfContextUsePredictedSegmentId(block, false);
     return ReadSegmentId(block);
   }
   if (frame_header_.segmentation.temporal_update) {
     const int context =
         (block.left_available[kPlaneY]
-             ? static_cast<int>(block.bp_left->use_predicted_segment_id)
+             ? static_cast<int>(
+                   left_context_
+                       .use_predicted_segment_id[block.left_context_index])
              : 0) +
         (block.top_available[kPlaneY]
-             ? static_cast<int>(block.bp_top->use_predicted_segment_id)
+             ? static_cast<int>(
+                   block.top_context
+                       ->use_predicted_segment_id[block.top_context_index])
              : 0);
-    bp.use_predicted_segment_id = reader_.ReadSymbol(
+    const bool use_predicted_segment_id = reader_.ReadSymbol(
         symbol_decoder_context_.use_predicted_segment_id_cdf[context]);
-    if (bp.use_predicted_segment_id) {
-      bp.segment_id = ComputePredictedSegmentId(block);
+    SetCdfContextUsePredictedSegmentId(block, use_predicted_segment_id);
+    if (use_predicted_segment_id) {
+      bp.prediction_parameters->segment_id = ComputePredictedSegmentId(block);
       return true;
     }
   }
   return ReadSegmentId(block);
 }
 
-void Tile::ReadIsInter(const Block& block) {
+void Tile::ReadIsInter(const Block& block, bool skip_mode) {
   BlockParameters& bp = *block.bp;
-  if (bp.skip_mode) {
+  if (skip_mode) {
     bp.is_inter = true;
     return;
   }
-  if (frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureReferenceFrame)) {
-    bp.is_inter =
-        frame_header_.segmentation
-            .feature_data[bp.segment_id][kSegmentFeatureReferenceFrame] !=
-        kReferenceFrameIntra;
+  if (frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id,
+          kSegmentFeatureReferenceFrame)) {
+    bp.is_inter = frame_header_.segmentation
+                      .feature_data[bp.prediction_parameters->segment_id]
+                                   [kSegmentFeatureReferenceFrame] !=
+                  kReferenceFrameIntra;
     return;
   }
-  if (frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureGlobalMv)) {
+  if (frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureGlobalMv)) {
     bp.is_inter = true;
     return;
   }
@@ -678,6 +702,49 @@ void Tile::ReadIsInter(const Block& block) {
       reader_.ReadSymbol(symbol_decoder_context_.is_inter_cdf[context]);
 }
 
+void Tile::SetCdfContextPaletteSize(const Block& block) {
+  const PaletteModeInfo& palette_mode_info =
+      block.bp->prediction_parameters->palette_mode_info;
+  for (int plane_type = kPlaneTypeY; plane_type <= kPlaneTypeUV; ++plane_type) {
+    memset(left_context_.palette_size[plane_type] + block.left_context_index,
+           palette_mode_info.size[plane_type], block.height4x4);
+    memset(
+        block.top_context->palette_size[plane_type] + block.top_context_index,
+        palette_mode_info.size[plane_type], block.width4x4);
+    if (palette_mode_info.size[plane_type] == 0) continue;
+    for (int i = block.left_context_index;
+         i < block.left_context_index + block.height4x4; ++i) {
+      memcpy(left_context_.palette_color[i][plane_type],
+             palette_mode_info.color[plane_type],
+             kMaxPaletteSize * sizeof(palette_mode_info.color[0][0]));
+    }
+    for (int i = block.top_context_index;
+         i < block.top_context_index + block.width4x4; ++i) {
+      memcpy(block.top_context->palette_color[i][plane_type],
+             palette_mode_info.color[plane_type],
+             kMaxPaletteSize * sizeof(palette_mode_info.color[0][0]));
+    }
+  }
+}
+
+void Tile::SetCdfContextUVMode(const Block& block) {
+  // BlockCdfContext.uv_mode is only used to compute is_smooth_prediction for
+  // the intra edge upsamplers in the subsequent blocks. They have some special
+  // rules for subsampled UV planes. For subsampled UV planes, update left
+  // context only if current block contains the last odd column and update top
+  // context only if current block contains the last odd row.
+  if (subsampling_x_[kPlaneU] == 0 || (block.column4x4 & 1) == 1 ||
+      block.width4x4 > 1) {
+    memset(left_context_.uv_mode + block.left_context_index,
+           block.bp->prediction_parameters->uv_mode, block.height4x4);
+  }
+  if (subsampling_y_[kPlaneU] == 0 || (block.row4x4 & 1) == 1 ||
+      block.height4x4 > 1) {
+    memset(block.top_context->uv_mode + block.top_context_index,
+           block.bp->prediction_parameters->uv_mode, block.width4x4);
+  }
+}
+
 bool Tile::ReadIntraBlockModeInfo(const Block& block, bool intra_y_mode) {
   BlockParameters& bp = *block.bp;
   bp.reference_frame[0] = kReferenceFrameIntra;
@@ -686,12 +753,39 @@ bool Tile::ReadIntraBlockModeInfo(const Block& block, bool intra_y_mode) {
   ReadIntraAngleInfo(block, kPlaneTypeY);
   if (block.HasChroma()) {
     ReadPredictionModeUV(block);
-    if (bp.uv_mode == kPredictionModeChromaFromLuma) {
+    if (bp.prediction_parameters->uv_mode == kPredictionModeChromaFromLuma) {
       ReadCflAlpha(block);
     }
+    if (block.left_available[kPlaneU]) {
+      const int smooth_row =
+          block.row4x4 + (~block.row4x4 & subsampling_y_[kPlaneU]);
+      const int smooth_column =
+          block.column4x4 - 1 - (block.column4x4 & subsampling_x_[kPlaneU]);
+      const BlockParameters& bp_left =
+          *block_parameters_holder_.Find(smooth_row, smooth_column);
+      bp.prediction_parameters->chroma_left_uses_smooth_prediction =
+          (bp_left.reference_frame[0] <= kReferenceFrameIntra) &&
+          kPredictionModeSmoothMask.Contains(
+              left_context_.uv_mode[CdfContextIndex(smooth_row)]);
+    }
+    if (block.top_available[kPlaneU]) {
+      const int smooth_row =
+          block.row4x4 - 1 - (block.row4x4 & subsampling_y_[kPlaneU]);
+      const int smooth_column =
+          block.column4x4 + (~block.column4x4 & subsampling_x_[kPlaneU]);
+      const BlockParameters& bp_top =
+          *block_parameters_holder_.Find(smooth_row, smooth_column);
+      bp.prediction_parameters->chroma_top_uses_smooth_prediction =
+          (bp_top.reference_frame[0] <= kReferenceFrameIntra) &&
+          kPredictionModeSmoothMask.Contains(
+              top_context_.get()[SuperBlockColumnIndex(smooth_column)]
+                  .uv_mode[CdfContextIndex(smooth_column)]);
+    }
+    SetCdfContextUVMode(block);
     ReadIntraAngleInfo(block, kPlaneTypeUV);
   }
   ReadPaletteModeInfo(block);
+  SetCdfContextPaletteSize(block);
   ReadFilterIntraModeInfo(block);
   return true;
 }
@@ -808,25 +902,27 @@ uint16_t* Tile::GetReferenceCdf(
   return symbol_decoder_context_.compound_reference_cdf[type][context][index];
 }
 
-void Tile::ReadReferenceFrames(const Block& block) {
+void Tile::ReadReferenceFrames(const Block& block, bool skip_mode) {
   BlockParameters& bp = *block.bp;
-  if (bp.skip_mode) {
+  if (skip_mode) {
     bp.reference_frame[0] = frame_header_.skip_mode_frame[0];
     bp.reference_frame[1] = frame_header_.skip_mode_frame[1];
     return;
   }
-  if (frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureReferenceFrame)) {
+  if (frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id,
+          kSegmentFeatureReferenceFrame)) {
     bp.reference_frame[0] = static_cast<ReferenceFrameType>(
         frame_header_.segmentation
-            .feature_data[bp.segment_id][kSegmentFeatureReferenceFrame]);
+            .feature_data[bp.prediction_parameters->segment_id]
+                         [kSegmentFeatureReferenceFrame]);
     bp.reference_frame[1] = kReferenceFrameNone;
     return;
   }
-  if (frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureSkip) ||
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureGlobalMv)) {
+  if (frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureSkip) ||
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureGlobalMv)) {
     bp.reference_frame[0] = kReferenceFrameLast;
     bp.reference_frame[1] = kReferenceFrameNone;
     return;
@@ -927,16 +1023,17 @@ void Tile::ReadReferenceFrames(const Block& block) {
 }
 
 void Tile::ReadInterPredictionModeY(const Block& block,
-                                    const MvContexts& mode_contexts) {
+                                    const MvContexts& mode_contexts,
+                                    bool skip_mode) {
   BlockParameters& bp = *block.bp;
-  if (bp.skip_mode) {
+  if (skip_mode) {
     bp.y_mode = kPredictionModeNearestNearestMv;
     return;
   }
-  if (frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureSkip) ||
-      frame_header_.segmentation.FeatureActive(bp.segment_id,
-                                               kSegmentFeatureGlobalMv)) {
+  if (frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureSkip) ||
+      frame_header_.segmentation.FeatureActive(
+          bp.prediction_parameters->segment_id, kSegmentFeatureGlobalMv)) {
     bp.y_mode = kPredictionModeGlobalMv;
     return;
   }
@@ -995,13 +1092,14 @@ void Tile::ReadRefMvIndex(const Block& block) {
   }
 }
 
-void Tile::ReadInterIntraMode(const Block& block, bool is_compound) {
+void Tile::ReadInterIntraMode(const Block& block, bool is_compound,
+                              bool skip_mode) {
   BlockParameters& bp = *block.bp;
   PredictionParameters& prediction_parameters =
       *block.bp->prediction_parameters;
   prediction_parameters.inter_intra_mode = kNumInterIntraModes;
   prediction_parameters.is_wedge_inter_intra = false;
-  if (bp.skip_mode || !sequence_header_.enable_interintra_compound ||
+  if (skip_mode || !sequence_header_.enable_interintra_compound ||
       is_compound || !kIsInterIntraModeAllowedMask.Contains(block.size)) {
     return;
   }
@@ -1031,13 +1129,14 @@ void Tile::ReadInterIntraMode(const Block& block, bool is_compound) {
   prediction_parameters.wedge_sign = 0;
 }
 
-void Tile::ReadMotionMode(const Block& block, bool is_compound) {
+void Tile::ReadMotionMode(const Block& block, bool is_compound,
+                          bool skip_mode) {
   BlockParameters& bp = *block.bp;
   PredictionParameters& prediction_parameters =
       *block.bp->prediction_parameters;
   const auto global_motion_type =
       frame_header_.global_motion[bp.reference_frame[0]].type;
-  if (bp.skip_mode || !frame_header_.is_motion_mode_switchable ||
+  if (skip_mode || !frame_header_.is_motion_mode_switchable ||
       IsBlockDimension4(block.size) ||
       (frame_header_.force_integer_mv == 0 &&
        (bp.y_mode == kPredictionModeGlobalMv ||
@@ -1073,14 +1172,17 @@ uint16_t* Tile::GetIsExplicitCompoundTypeCdf(const Block& block) {
   int context = 0;
   if (block.top_available[kPlaneY]) {
     if (!block.IsTopSingle()) {
-      context += static_cast<int>(block.bp_top->is_explicit_compound_type);
+      context += static_cast<int>(
+          block.top_context
+              ->is_explicit_compound_type[block.top_context_index]);
     } else if (block.TopReference(0) == kReferenceFrameAlternate) {
       context += 3;
     }
   }
   if (block.left_available[kPlaneY]) {
     if (!block.IsLeftSingle()) {
-      context += static_cast<int>(block.bp_left->is_explicit_compound_type);
+      context += static_cast<int>(
+          left_context_.is_explicit_compound_type[block.left_context_index]);
     } else if (block.LeftReference(0) == kReferenceFrameAlternate) {
       context += 3;
     }
@@ -1099,14 +1201,16 @@ uint16_t* Tile::GetIsCompoundTypeAverageCdf(const Block& block) {
   int context = (forward == backward) ? 3 : 0;
   if (block.top_available[kPlaneY]) {
     if (!block.IsTopSingle()) {
-      context += static_cast<int>(block.bp_top->is_compound_type_average);
+      context += static_cast<int>(
+          block.top_context->is_compound_type_average[block.top_context_index]);
     } else if (block.TopReference(0) == kReferenceFrameAlternate) {
       ++context;
     }
   }
   if (block.left_available[kPlaneY]) {
     if (!block.IsLeftSingle()) {
-      context += static_cast<int>(block.bp_left->is_compound_type_average);
+      context += static_cast<int>(
+          left_context_.is_compound_type_average[block.left_context_index]);
     } else if (block.LeftReference(0) == kReferenceFrameAlternate) {
       ++context;
     }
@@ -1114,23 +1218,25 @@ uint16_t* Tile::GetIsCompoundTypeAverageCdf(const Block& block) {
   return symbol_decoder_context_.is_compound_type_average_cdf[context];
 }
 
-void Tile::ReadCompoundType(const Block& block, bool is_compound) {
-  BlockParameters& bp = *block.bp;
-  bp.is_explicit_compound_type = false;
-  bp.is_compound_type_average = true;
+void Tile::ReadCompoundType(const Block& block, bool is_compound,
+                            bool skip_mode,
+                            bool* const is_explicit_compound_type,
+                            bool* const is_compound_type_average) {
+  *is_explicit_compound_type = false;
+  *is_compound_type_average = true;
   PredictionParameters& prediction_parameters =
       *block.bp->prediction_parameters;
-  if (bp.skip_mode) {
+  if (skip_mode) {
     prediction_parameters.compound_prediction_type =
         kCompoundPredictionTypeAverage;
     return;
   }
   if (is_compound) {
     if (sequence_header_.enable_masked_compound) {
-      bp.is_explicit_compound_type =
+      *is_explicit_compound_type =
           reader_.ReadSymbol(GetIsExplicitCompoundTypeCdf(block));
     }
-    if (bp.is_explicit_compound_type) {
+    if (*is_explicit_compound_type) {
       if (kIsWedgeCompoundModeAllowed.Contains(block.size)) {
         // Only kCompoundPredictionTypeWedge and
         // kCompoundPredictionTypeDiffWeighted are signaled explicitly.
@@ -1143,11 +1249,11 @@ void Tile::ReadCompoundType(const Block& block, bool is_compound) {
       }
     } else {
       if (sequence_header_.enable_jnt_comp) {
-        bp.is_compound_type_average =
+        *is_compound_type_average =
             reader_.ReadSymbol(GetIsCompoundTypeAverageCdf(block));
         prediction_parameters.compound_prediction_type =
-            bp.is_compound_type_average ? kCompoundPredictionTypeAverage
-                                        : kCompoundPredictionTypeDistance;
+            *is_compound_type_average ? kCompoundPredictionTypeAverage
+                                      : kCompoundPredictionTypeDistance;
       } else {
         prediction_parameters.compound_prediction_type =
             kCompoundPredictionTypeAverage;
@@ -1162,8 +1268,7 @@ void Tile::ReadCompoundType(const Block& block, bool is_compound) {
       prediction_parameters.wedge_sign = static_cast<int>(reader_.ReadBit());
     } else if (prediction_parameters.compound_prediction_type ==
                kCompoundPredictionTypeDiffWeighted) {
-      prediction_parameters.mask_is_inverse =
-          static_cast<bool>(reader_.ReadBit());
+      prediction_parameters.mask_is_inverse = reader_.ReadBit() != 0;
     }
     return;
   }
@@ -1209,7 +1314,7 @@ uint16_t* Tile::GetInterpolationFilterCdf(const Block& block, int direction) {
   return symbol_decoder_context_.interpolation_filter_cdf[context];
 }
 
-void Tile::ReadInterpolationFilter(const Block& block) {
+void Tile::ReadInterpolationFilter(const Block& block, bool skip_mode) {
   BlockParameters& bp = *block.bp;
   if (frame_header_.interpolation_filter != kInterpolationFilterSwitchable) {
     static_assert(
@@ -1222,7 +1327,7 @@ void Tile::ReadInterpolationFilter(const Block& block) {
     return;
   }
   bool interpolation_filter_present = true;
-  if (bp.skip_mode ||
+  if (skip_mode ||
       block.bp->prediction_parameters->motion_mode == kMotionModeLocalWarp) {
     interpolation_filter_present = false;
   } else if (!IsBlockDimension4(block.size) &&
@@ -1251,31 +1356,58 @@ void Tile::ReadInterpolationFilter(const Block& block) {
   }
 }
 
-bool Tile::ReadInterBlockModeInfo(const Block& block) {
+void Tile::SetCdfContextCompoundType(const Block& block,
+                                     bool is_explicit_compound_type,
+                                     bool is_compound_type_average) {
+  memset(left_context_.is_explicit_compound_type + block.left_context_index,
+         static_cast<int>(is_explicit_compound_type), block.height4x4);
+  memset(left_context_.is_compound_type_average + block.left_context_index,
+         static_cast<int>(is_compound_type_average), block.height4x4);
+  memset(block.top_context->is_explicit_compound_type + block.top_context_index,
+         static_cast<int>(is_explicit_compound_type), block.width4x4);
+  memset(block.top_context->is_compound_type_average + block.top_context_index,
+         static_cast<int>(is_compound_type_average), block.width4x4);
+}
+
+bool Tile::ReadInterBlockModeInfo(const Block& block, bool skip_mode) {
   BlockParameters& bp = *block.bp;
-  bp.palette_mode_info.size[kPlaneTypeY] = 0;
-  bp.palette_mode_info.size[kPlaneTypeUV] = 0;
-  ReadReferenceFrames(block);
+  bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] = 0;
+  bp.prediction_parameters->palette_mode_info.size[kPlaneTypeUV] = 0;
+  SetCdfContextPaletteSize(block);
+  ReadReferenceFrames(block, skip_mode);
   const bool is_compound = bp.reference_frame[1] > kReferenceFrameIntra;
   MvContexts mode_contexts;
   FindMvStack(block, is_compound, &mode_contexts);
-  ReadInterPredictionModeY(block, mode_contexts);
+  ReadInterPredictionModeY(block, mode_contexts, skip_mode);
   ReadRefMvIndex(block);
   if (!AssignInterMv(block, is_compound)) return false;
-  ReadInterIntraMode(block, is_compound);
-  ReadMotionMode(block, is_compound);
-  ReadCompoundType(block, is_compound);
-  ReadInterpolationFilter(block);
+  ReadInterIntraMode(block, is_compound, skip_mode);
+  ReadMotionMode(block, is_compound, skip_mode);
+  bool is_explicit_compound_type;
+  bool is_compound_type_average;
+  ReadCompoundType(block, is_compound, skip_mode, &is_explicit_compound_type,
+                   &is_compound_type_average);
+  SetCdfContextCompoundType(block, is_explicit_compound_type,
+                            is_compound_type_average);
+  ReadInterpolationFilter(block, skip_mode);
   return true;
 }
 
+void Tile::SetCdfContextSkipMode(const Block& block, bool skip_mode) {
+  memset(left_context_.skip_mode + block.left_context_index,
+         static_cast<int>(skip_mode), block.height4x4);
+  memset(block.top_context->skip_mode + block.top_context_index,
+         static_cast<int>(skip_mode), block.width4x4);
+}
+
 bool Tile::DecodeInterModeInfo(const Block& block) {
   BlockParameters& bp = *block.bp;
   block.bp->prediction_parameters->use_intra_block_copy = false;
   bp.skip = false;
   if (!ReadInterSegmentId(block, /*pre_skip=*/true)) return false;
-  ReadSkipMode(block);
-  if (bp.skip_mode) {
+  bool skip_mode = ReadSkipMode(block);
+  SetCdfContextSkipMode(block, skip_mode);
+  if (skip_mode) {
     bp.skip = true;
   } else {
     ReadSkip(block);
@@ -1290,8 +1422,8 @@ bool Tile::DecodeInterModeInfo(const Block& block) {
     ReadLoopFilterDelta(block);
     read_deltas_ = false;
   }
-  ReadIsInter(block);
-  return bp.is_inter ? ReadInterBlockModeInfo(block)
+  ReadIsInter(block, skip_mode);
+  return bp.is_inter ? ReadInterBlockModeInfo(block, skip_mode)
                      : ReadIntraBlockModeInfo(block, /*intra_y_mode=*/false);
 }
 
diff --git a/src/tile/bitstream/palette.cc b/src/tile/bitstream/palette.cc
index 41b42d6..27e5110 100644
--- a/src/tile/bitstream/palette.cc
+++ b/src/tile/bitstream/palette.cc
@@ -35,20 +35,23 @@ int Tile::GetPaletteCache(const Block& block, PlaneType plane_type,
                           uint16_t* const cache) {
   const int top_size =
       (block.top_available[kPlaneY] && Mod64(MultiplyBy4(block.row4x4)) != 0)
-          ? block.bp_top->palette_mode_info.size[plane_type]
+          ? block.top_context->palette_size[plane_type][block.top_context_index]
+          : 0;
+  const int left_size =
+      block.left_available[kPlaneY]
+          ? left_context_.palette_size[plane_type][block.left_context_index]
           : 0;
-  const int left_size = block.left_available[kPlaneY]
-                            ? block.bp_left->palette_mode_info.size[plane_type]
-                            : 0;
   if (left_size == 0 && top_size == 0) return 0;
   // Merge the left and top colors in sorted order and store them in |cache|.
-  uint16_t dummy[1];
-  const uint16_t* top = (top_size > 0)
-                            ? block.bp_top->palette_mode_info.color[plane_type]
-                            : dummy;
+  uint16_t empty_palette[1];
+  const uint16_t* top =
+      (top_size > 0) ? block.top_context
+                           ->palette_color[block.top_context_index][plane_type]
+                     : empty_palette;
   const uint16_t* left =
-      (left_size > 0) ? block.bp_left->palette_mode_info.color[plane_type]
-                      : dummy;
+      (left_size > 0)
+          ? left_context_.palette_color[block.left_context_index][plane_type]
+          : empty_palette;
   std::merge(top, top + top_size, left, left + left_size, cache);
   // Deduplicate the entries in |cache| and return the number of unique
   // entries.
@@ -61,8 +64,10 @@ void Tile::ReadPaletteColors(const Block& block, Plane plane) {
   uint16_t cache[2 * kMaxPaletteSize];
   const int n = GetPaletteCache(block, plane_type, cache);
   BlockParameters& bp = *block.bp;
-  const uint8_t palette_size = bp.palette_mode_info.size[plane_type];
-  uint16_t* const palette_color = bp.palette_mode_info.color[plane];
+  const uint8_t palette_size =
+      bp.prediction_parameters->palette_mode_info.size[plane_type];
+  uint16_t* const palette_color =
+      bp.prediction_parameters->palette_mode_info.color[plane];
   const int8_t bitdepth = sequence_header_.color_config.bitdepth;
   int index = 0;
   for (int i = 0; i < n && index < palette_size; ++i) {
@@ -101,7 +106,8 @@ void Tile::ReadPaletteColors(const Block& block, Plane plane) {
   std::inplace_merge(palette_color, palette_color + merge_pivot,
                      palette_color + palette_size);
   if (plane_type == kPlaneTypeUV) {
-    uint16_t* const palette_color_v = bp.palette_mode_info.color[kPlaneV];
+    uint16_t* const palette_color_v =
+        bp.prediction_parameters->palette_mode_info.color[kPlaneV];
     if (reader_.ReadBit() != 0) {  // delta_encode_palette_colors_v.
       const int bits = bitdepth - 4 + static_cast<int>(reader_.ReadLiteral(2));
       palette_color_v[0] = reader_.ReadLiteral(bitdepth);
@@ -130,8 +136,8 @@ void Tile::ReadPaletteColors(const Block& block, Plane plane) {
 
 void Tile::ReadPaletteModeInfo(const Block& block) {
   BlockParameters& bp = *block.bp;
-  bp.palette_mode_info.size[kPlaneTypeY] = 0;
-  bp.palette_mode_info.size[kPlaneTypeUV] = 0;
+  bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] = 0;
+  bp.prediction_parameters->palette_mode_info.size[kPlaneTypeUV] = 0;
   if (IsBlockSmallerThan8x8(block.size) || block.size > kBlock64x64 ||
       !frame_header_.allow_screen_content_tools) {
     return;
@@ -140,29 +146,32 @@ void Tile::ReadPaletteModeInfo(const Block& block) {
       k4x4WidthLog2[block.size] + k4x4HeightLog2[block.size] - 2;
   if (bp.y_mode == kPredictionModeDc) {
     const int context =
-        static_cast<int>(block.top_available[kPlaneY] &&
-                         block.bp_top->palette_mode_info.size[kPlaneTypeY] >
-                             0) +
-        static_cast<int>(block.left_available[kPlaneY] &&
-                         block.bp_left->palette_mode_info.size[kPlaneTypeY] >
-                             0);
+        static_cast<int>(
+            block.top_available[kPlaneY] &&
+            block.top_context
+                    ->palette_size[kPlaneTypeY][block.top_context_index] > 0) +
+        static_cast<int>(
+            block.left_available[kPlaneY] &&
+            left_context_.palette_size[kPlaneTypeY][block.left_context_index] >
+                0);
     const bool has_palette_y = reader_.ReadSymbol(
         symbol_decoder_context_.has_palette_y_cdf[block_size_context][context]);
     if (has_palette_y) {
-      bp.palette_mode_info.size[kPlaneTypeY] =
+      bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] =
           kMinPaletteSize +
           reader_.ReadSymbol<kPaletteSizeSymbolCount>(
               symbol_decoder_context_.palette_y_size_cdf[block_size_context]);
       ReadPaletteColors(block, kPlaneY);
     }
   }
-  if (block.HasChroma() && bp.uv_mode == kPredictionModeDc) {
-    const int context =
-        static_cast<int>(bp.palette_mode_info.size[kPlaneTypeY] > 0);
+  if (block.HasChroma() &&
+      bp.prediction_parameters->uv_mode == kPredictionModeDc) {
+    const int context = static_cast<int>(
+        bp.prediction_parameters->palette_mode_info.size[kPlaneTypeY] > 0);
     const bool has_palette_uv =
         reader_.ReadSymbol(symbol_decoder_context_.has_palette_uv_cdf[context]);
     if (has_palette_uv) {
-      bp.palette_mode_info.size[kPlaneTypeUV] =
+      bp.prediction_parameters->palette_mode_info.size[kPlaneTypeUV] =
           kMinPaletteSize +
           reader_.ReadSymbol<kPaletteSizeSymbolCount>(
               symbol_decoder_context_.palette_uv_size_cdf[block_size_context]);
@@ -244,7 +253,8 @@ void Tile::PopulatePaletteColorContexts(
 }
 
 bool Tile::ReadPaletteTokens(const Block& block) {
-  const PaletteModeInfo& palette_mode_info = block.bp->palette_mode_info;
+  const PaletteModeInfo& palette_mode_info =
+      block.bp->prediction_parameters->palette_mode_info;
   PredictionParameters& prediction_parameters =
       *block.bp->prediction_parameters;
   for (int plane_type = kPlaneTypeY;
diff --git a/src/tile/bitstream/transform_size.cc b/src/tile/bitstream/transform_size.cc
index b79851d..7197400 100644
--- a/src/tile/bitstream/transform_size.cc
+++ b/src/tile/bitstream/transform_size.cc
@@ -95,7 +95,8 @@ int Tile::GetLeftTransformHeight(const Block& block, int row4x4, int column4x4,
 
 TransformSize Tile::ReadFixedTransformSize(const Block& block) {
   BlockParameters& bp = *block.bp;
-  if (frame_header_.segmentation.lossless[bp.segment_id]) {
+  if (frame_header_.segmentation
+          .lossless[bp.prediction_parameters->segment_id]) {
     return kTransformSize4x4;
   }
   const TransformSize max_rect_tx_size = kMaxTransformSizeRectangle[block.size];
@@ -189,8 +190,6 @@ void Tile::ReadVariableTransformTree(const Block& block, int row4x4,
       memset(&inter_transform_sizes_[node.y + i][node.x], node.tx_size,
              tx_width4x4);
     }
-    block_parameters_holder_.Find(node.y, node.x)->transform_size =
-        node.tx_size;
   } while (!stack.Empty());
 }
 
@@ -198,7 +197,8 @@ void Tile::DecodeTransformSize(const Block& block) {
   BlockParameters& bp = *block.bp;
   if (frame_header_.tx_mode == kTxModeSelect && block.size > kBlock4x4 &&
       bp.is_inter && !bp.skip &&
-      !frame_header_.segmentation.lossless[bp.segment_id]) {
+      !frame_header_.segmentation
+           .lossless[bp.prediction_parameters->segment_id]) {
     const TransformSize max_tx_size = kMaxTransformSizeRectangle[block.size];
     const int tx_width4x4 = kTransformWidth4x4[max_tx_size];
     const int tx_height4x4 = kTransformHeight4x4[max_tx_size];
@@ -210,10 +210,10 @@ void Tile::DecodeTransformSize(const Block& block) {
       }
     }
   } else {
-    bp.transform_size = ReadFixedTransformSize(block);
+    const TransformSize transform_size = ReadFixedTransformSize(block);
     for (int row = block.row4x4; row < block.row4x4 + block.height4x4; ++row) {
       static_assert(sizeof(TransformSize) == 1, "");
-      memset(&inter_transform_sizes_[row][block.column4x4], bp.transform_size,
+      memset(&inter_transform_sizes_[row][block.column4x4], transform_size,
              block.width4x4);
     }
   }
diff --git a/src/tile/prediction.cc b/src/tile/prediction.cc
index c5560a6..bba5a69 100644
--- a/src/tile/prediction.cc
+++ b/src/tile/prediction.cc
@@ -226,8 +226,8 @@ void Tile::IntraPrediction(const Block& block, Plane plane, int x, int y,
                            bool has_left, bool has_top, bool has_top_right,
                            bool has_bottom_left, PredictionMode mode,
                            TransformSize tx_size) {
-  const int width = 1 << kTransformWidthLog2[tx_size];
-  const int height = 1 << kTransformHeightLog2[tx_size];
+  const int width = kTransformWidth[tx_size];
+  const int height = kTransformHeight[tx_size];
   const int x_shift = subsampling_x_[plane];
   const int y_shift = subsampling_y_[plane];
   const int max_x = (MultiplyBy4(frame_header_.columns4x4) >> x_shift) - 1;
@@ -386,36 +386,21 @@ template void Tile::IntraPrediction<uint16_t>(const Block& block, Plane plane,
                                               TransformSize tx_size);
 #endif
 
-constexpr BitMaskSet kPredictionModeSmoothMask(kPredictionModeSmooth,
-                                               kPredictionModeSmoothHorizontal,
-                                               kPredictionModeSmoothVertical);
-
-bool Tile::IsSmoothPrediction(int row, int column, Plane plane) const {
-  const BlockParameters& bp = *block_parameters_holder_.Find(row, column);
-  PredictionMode mode;
+int Tile::GetIntraEdgeFilterType(const Block& block, Plane plane) const {
+  bool top;
+  bool left;
   if (plane == kPlaneY) {
-    mode = bp.y_mode;
+    top = block.top_available[kPlaneY] &&
+          kPredictionModeSmoothMask.Contains(block.bp_top->y_mode);
+    left = block.left_available[kPlaneY] &&
+           kPredictionModeSmoothMask.Contains(block.bp_left->y_mode);
   } else {
-    if (bp.reference_frame[0] > kReferenceFrameIntra) return false;
-    mode = bp.uv_mode;
-  }
-  return kPredictionModeSmoothMask.Contains(mode);
-}
-
-int Tile::GetIntraEdgeFilterType(const Block& block, Plane plane) const {
-  const int subsampling_x = subsampling_x_[plane];
-  const int subsampling_y = subsampling_y_[plane];
-  if (block.top_available[plane]) {
-    const int row = block.row4x4 - 1 - (block.row4x4 & subsampling_y);
-    const int column = block.column4x4 + (~block.column4x4 & subsampling_x);
-    if (IsSmoothPrediction(row, column, plane)) return 1;
+    top = block.top_available[plane] &&
+          block.bp->prediction_parameters->chroma_top_uses_smooth_prediction;
+    left = block.left_available[plane] &&
+           block.bp->prediction_parameters->chroma_left_uses_smooth_prediction;
   }
-  if (block.left_available[plane]) {
-    const int row = block.row4x4 + (~block.row4x4 & subsampling_y);
-    const int column = block.column4x4 - 1 - (block.column4x4 & subsampling_x);
-    if (IsSmoothPrediction(row, column, plane)) return 1;
-  }
-  return 0;
+  return static_cast<int>(top || left);
 }
 
 template <typename Pixel>
@@ -510,7 +495,8 @@ void Tile::PalettePrediction(const Block& block, const Plane plane,
                              const int y, const TransformSize tx_size) {
   const int tx_width = kTransformWidth[tx_size];
   const int tx_height = kTransformHeight[tx_size];
-  const uint16_t* const palette = block.bp->palette_mode_info.color[plane];
+  const uint16_t* const palette =
+      block.bp->prediction_parameters->palette_mode_info.color[plane];
   const PlaneType plane_type = GetPlaneType(plane);
   const int x4 = MultiplyBy4(x);
   const int y4 = MultiplyBy4(y);
@@ -695,7 +681,7 @@ GlobalMotion* Tile::GetWarpParams(
             ? global_motion_params->type
             : kNumGlobalMotionTransformationTypes;
     const bool is_global_valid =
-        IsGlobalMvBlock(block.bp->is_global_mv_block, global_motion_type) &&
+        IsGlobalMvBlock(*block.bp, global_motion_type) &&
         SetupShear(global_motion_params);
     // Valid global motion type implies reference type can't be intra.
     assert(!is_global_valid || reference_type != kReferenceFrameIntra);
@@ -1028,6 +1014,7 @@ bool Tile::GetReferenceBlockPosition(
         (((height - 1) * step_y + (1 << kScaleSubPixelBits) - 1) >>
          kScaleSubPixelBits) +
         kSubPixelTaps;
+    *ref_block_end_x += kConvolveScaleBorderRight - kConvolveBorderRight;
     ref_block_end_y = *ref_block_start_y + block_height - 1;
   }
   // Determines if we need to extend beyond the left/right/top/bottom border.
@@ -1206,11 +1193,12 @@ bool Tile::BlockInterPrediction(
                     (ref_block_start_x + kConvolveBorderLeftTop) * pixel_size;
     }
   } else {
+    const int border_right =
+        is_scaled ? kConvolveScaleBorderRight : kConvolveBorderRight;
     // The block width can be at most 2 times as much as current
     // block's width because of scaling.
     auto block_extended_width = Align<ptrdiff_t>(
-        (2 * width + kConvolveBorderLeftTop + kConvolveBorderRight) *
-            pixel_size,
+        (2 * width + kConvolveBorderLeftTop + border_right) * pixel_size,
         kMaxAlignment);
     convolve_buffer_stride = block.scratch_buffer->convolve_block_buffer_stride;
 #if LIBGAV1_MAX_BITDEPTH >= 10
diff --git a/src/tile/tile.cc b/src/tile/tile.cc
index 9699517..5070bb6 100644
--- a/src/tile/tile.cc
+++ b/src/tile/tile.cc
@@ -463,6 +463,7 @@ Tile::Tile(int tile_number, const uint8_t* const data, size_t size,
               : 1),
       current_frame_(*current_frame),
       cdef_index_(frame_scratch_buffer->cdef_index),
+      cdef_skip_(frame_scratch_buffer->cdef_skip),
       inter_transform_sizes_(frame_scratch_buffer->inter_transform_sizes),
       thread_pool_(thread_pool),
       residual_buffer_pool_(frame_scratch_buffer->residual_buffer_pool.get()),
@@ -541,16 +542,6 @@ Tile::Tile(int tile_number, const uint8_t* const data, size_t size,
     buffer_[plane].Reset(Align(buffer.height(plane), max_tx_length),
                          buffer.stride(plane),
                          post_filter_.GetUnfilteredBuffer(plane));
-    const int plane_height =
-        SubsampledValue(frame_header_.height, subsampling_y_[plane]);
-    deblock_row_limit_[plane] =
-        std::min(frame_header_.rows4x4, DivideBy4(plane_height + 3)
-                                            << subsampling_y_[plane]);
-    const int plane_width =
-        SubsampledValue(frame_header_.width, subsampling_x_[plane]);
-    deblock_column_limit_[plane] =
-        std::min(frame_header_.columns4x4, DivideBy4(plane_width + 3)
-                                               << subsampling_x_[plane]);
   }
 }
 
@@ -598,6 +589,10 @@ bool Tile::Init() {
                      column4x4_end_, &motion_field_);
   }
   ResetLoopRestorationParams();
+  if (!top_context_.Resize(superblock_columns_)) {
+    LIBGAV1_DLOG(ERROR, "Allocation of top_context_ failed.");
+    return false;
+  }
   return true;
 }
 
@@ -1019,7 +1014,8 @@ TransformType Tile::ComputeTransformType(const Block& block, Plane plane,
                                          int block_y) {
   const BlockParameters& bp = *block.bp;
   const TransformSize tx_size_square_max = kTransformSizeSquareMax[tx_size];
-  if (frame_header_.segmentation.lossless[bp.segment_id] ||
+  if (frame_header_.segmentation
+          .lossless[bp.prediction_parameters->segment_id] ||
       tx_size_square_max == kTransformSize64x64) {
     return kTransformTypeDctDct;
   }
@@ -1034,7 +1030,7 @@ TransformType Tile::ComputeTransformType(const Block& block, Plane plane,
     const int y4 = std::max(block.row4x4, block_y << subsampling_y_[kPlaneU]);
     tx_type = transform_types_[y4 - block.row4x4][x4 - block.column4x4];
   } else {
-    tx_type = kModeToTransformType[bp.uv_mode];
+    tx_type = kModeToTransformType[bp.prediction_parameters->uv_mode];
   }
   return kTransformTypeInSetMask[tx_set].Contains(tx_type)
              ? tx_type
@@ -1048,7 +1044,8 @@ void Tile::ReadTransformType(const Block& block, int x4, int y4,
 
   TransformType tx_type = kTransformTypeDctDct;
   if (tx_set != kTransformSetDctOnly &&
-      frame_header_.segmentation.qindex[bp.segment_id] > 0) {
+      frame_header_.segmentation.qindex[bp.prediction_parameters->segment_id] >
+          0) {
     const int cdf_index = SymbolDecoderContext::TxTypeIndex(tx_set);
     const int cdf_tx_size_index =
         TransformSizeToSquareTransformIndex(kTransformSizeSquareMin[tx_size]);
@@ -1309,7 +1306,7 @@ bool Tile::ReadSignAndApplyDequantization(
     int length = 0;
     bool golomb_length_bit = false;
     do {
-      golomb_length_bit = static_cast<bool>(reader_.ReadBit());
+      golomb_length_bit = reader_.ReadBit() != 0;
       ++length;
       if (length > 20) {
         LIBGAV1_DLOG(ERROR, "Invalid golomb_length %d", length);
@@ -1454,7 +1451,7 @@ int Tile::ReadTransformCoefficients(const Block& block, Plane plane,
     for (int i = 1; i < eob_pt - 2; ++i) {
       assert(eob_pt - i >= 3);
       assert(eob_pt <= kEobPt1024SymbolCount);
-      if (static_cast<bool>(reader_.ReadBit())) {
+      if (reader_.ReadBit() != 0) {
         eob += 1 << (eob_pt - i - 3);
       }
     }
@@ -1500,15 +1497,17 @@ int Tile::ReadTransformCoefficients(const Block& block, Plane plane,
         coeff_base_range_cdf, residual, level_buffer);
   }
   const int max_value = (1 << (7 + sequence_header_.color_config.bitdepth)) - 1;
-  const int current_quantizer_index = GetQIndex(
-      frame_header_.segmentation, bp.segment_id, current_quantizer_index_);
+  const int current_quantizer_index =
+      GetQIndex(frame_header_.segmentation,
+                bp.prediction_parameters->segment_id, current_quantizer_index_);
   const int dc_q_value = quantizer_.GetDcValue(plane, current_quantizer_index);
   const int ac_q_value = quantizer_.GetAcValue(plane, current_quantizer_index);
   const int shift = kQuantizationShift[tx_size];
   const uint8_t* const quantizer_matrix =
       (frame_header_.quantizer.use_matrix &&
        *tx_type < kTransformTypeIdentityIdentity &&
-       !frame_header_.segmentation.lossless[bp.segment_id] &&
+       !frame_header_.segmentation
+            .lossless[bp.prediction_parameters->segment_id] &&
        frame_header_.quantizer.matrix_level[plane] < 15)
           ? quantizer_matrix_[frame_header_.quantizer.matrix_level[plane]]
                              [plane_type][adjusted_tx_size]
@@ -1587,15 +1586,17 @@ bool Tile::TransformBlock(const Block& block, Plane plane, int base_x,
   const bool do_decode = mode == kProcessingModeDecodeOnly ||
                          mode == kProcessingModeParseAndDecode;
   if (do_decode && !bp.is_inter) {
-    if (bp.palette_mode_info.size[GetPlaneType(plane)] > 0) {
+    if (bp.prediction_parameters->palette_mode_info.size[GetPlaneType(plane)] >
+        0) {
       CALL_BITDEPTH_FUNCTION(PalettePrediction, block, plane, start_x, start_y,
                              x, y, tx_size);
     } else {
       const PredictionMode mode =
-          (plane == kPlaneY)
-              ? bp.y_mode
-              : (bp.uv_mode == kPredictionModeChromaFromLuma ? kPredictionModeDc
-                                                             : bp.uv_mode);
+          (plane == kPlaneY) ? bp.y_mode
+                             : (bp.prediction_parameters->uv_mode ==
+                                        kPredictionModeChromaFromLuma
+                                    ? kPredictionModeDc
+                                    : bp.prediction_parameters->uv_mode);
       const int tr_row4x4 = (sub_block_row4x4 >> subsampling_y);
       const int tr_column4x4 =
           (sub_block_column4x4 >> subsampling_x) + step_x + 1;
@@ -1609,7 +1610,8 @@ bool Tile::TransformBlock(const Block& block, Plane plane, int base_x,
           block.scratch_buffer->block_decoded[plane][tr_row4x4][tr_column4x4],
           block.scratch_buffer->block_decoded[plane][bl_row4x4][bl_column4x4],
           mode, tx_size);
-      if (plane != kPlaneY && bp.uv_mode == kPredictionModeChromaFromLuma) {
+      if (plane != kPlaneY &&
+          bp.prediction_parameters->uv_mode == kPredictionModeChromaFromLuma) {
         CALL_BITDEPTH_FUNCTION(ChromaFromLumaPrediction, block, plane, start_x,
                                start_y, tx_size);
       }
@@ -1738,14 +1740,16 @@ void Tile::ReconstructBlock(const Block& block, Plane plane, int start_x,
         buffer_[plane].rows(), buffer_[plane].columns() / sizeof(uint16_t),
         reinterpret_cast<uint16_t*>(&buffer_[plane][0][0]));
     Reconstruct(dsp_, tx_type, tx_size,
-                frame_header_.segmentation.lossless[block.bp->segment_id],
+                frame_header_.segmentation
+                    .lossless[block.bp->prediction_parameters->segment_id],
                 reinterpret_cast<int32_t*>(*block.residual), start_x, start_y,
                 &buffer, non_zero_coeff_count);
   } else  // NOLINT
 #endif
   {
     Reconstruct(dsp_, tx_type, tx_size,
-                frame_header_.segmentation.lossless[block.bp->segment_id],
+                frame_header_.segmentation
+                    .lossless[block.bp->prediction_parameters->segment_id],
                 reinterpret_cast<int16_t*>(*block.residual), start_x, start_y,
                 &buffer_[plane], non_zero_coeff_count);
   }
@@ -1772,12 +1776,15 @@ bool Tile::Residual(const Block& block, ProcessingMode mode) {
         // kTransformSize4x4. So we can simply use |bp.transform_size| here as
         // the Y plane's transform size (part of Section 5.11.37 in the spec).
         const TransformSize tx_size =
-            (plane == kPlaneY) ? bp.transform_size : bp.uv_transform_size;
+            (plane == kPlaneY)
+                ? inter_transform_sizes_[block.row4x4][block.column4x4]
+                : bp.uv_transform_size;
         const BlockSize plane_size =
             kPlaneResidualSize[size_chunk4x4][subsampling_x][subsampling_y];
         assert(plane_size != kBlockInvalid);
         if (bp.is_inter &&
-            !frame_header_.segmentation.lossless[bp.segment_id] &&
+            !frame_header_.segmentation
+                 .lossless[bp.prediction_parameters->segment_id] &&
             plane == kPlaneY) {
           const int row_chunk4x4 = block.row4x4 + MultiplyBy16(chunk_y);
           const int column_chunk4x4 = block.column4x4 + MultiplyBy16(chunk_x);
@@ -2112,15 +2119,53 @@ void Tile::PopulateDeblockFilterLevel(const Block& block) {
   for (int i = 0; i < kFrameLfCount; ++i) {
     if (delta_lf_all_zero_) {
       bp.deblock_filter_level[i] = post_filter_.GetZeroDeltaDeblockFilterLevel(
-          bp.segment_id, i, bp.reference_frame[0], mode_id);
+          bp.prediction_parameters->segment_id, i, bp.reference_frame[0],
+          mode_id);
     } else {
       bp.deblock_filter_level[i] =
-          deblock_filter_levels_[bp.segment_id][i][bp.reference_frame[0]]
-                                [mode_id];
+          deblock_filter_levels_[bp.prediction_parameters->segment_id][i]
+                                [bp.reference_frame[0]][mode_id];
     }
   }
 }
 
+void Tile::PopulateCdefSkip(const Block& block) {
+  if (!post_filter_.DoCdef() || block.bp->skip ||
+      (frame_header_.cdef.bits > 0 &&
+       cdef_index_[DivideBy16(block.row4x4)][DivideBy16(block.column4x4)] ==
+           -1)) {
+    return;
+  }
+  // The rest of this function is an efficient version of the following code:
+  // for (int y = block.row4x4; y < block.row4x4 + block.height4x4; y++) {
+  //   for (int x = block.column4x4; y < block.column4x4 + block.width4x4;
+  //        x++) {
+  //     const uint8_t mask = uint8_t{1} << ((x >> 1) & 0x7);
+  //     cdef_skip_[y >> 1][x >> 4] |= mask;
+  //   }
+  // }
+
+  // For all block widths other than 32, the mask will fit in uint8_t. For
+  // block width == 32, the mask is always 0xFFFF.
+  const int bw4 =
+      std::max(DivideBy2(block.width4x4) + (block.column4x4 & 1), 1);
+  const uint8_t mask = (block.width4x4 == 32)
+                           ? 0xFF
+                           : (uint8_t{0xFF} >> (8 - bw4))
+                                 << (DivideBy2(block.column4x4) & 0x7);
+  uint8_t* cdef_skip = &cdef_skip_[block.row4x4 >> 1][block.column4x4 >> 4];
+  const int stride = cdef_skip_.columns();
+  int row = 0;
+  do {
+    *cdef_skip |= mask;
+    if (block.width4x4 == 32) {
+      *(cdef_skip + 1) = 0xFF;
+    }
+    cdef_skip += stride;
+    row += 2;
+  } while (row < block.height4x4);
+}
+
 bool Tile::ProcessBlock(int row4x4, int column4x4, BlockSize block_size,
                         TileScratchBuffer* const scratch_buffer,
                         ResidualPtr* residual) {
@@ -2150,7 +2195,7 @@ bool Tile::ProcessBlock(int row4x4, int column4x4, BlockSize block_size,
     return false;
   }
   BlockParameters& bp = *bp_ptr;
-  Block block(*this, block_size, row4x4, column4x4, scratch_buffer, residual);
+  Block block(this, block_size, row4x4, column4x4, scratch_buffer, residual);
   bp.size = block_size;
   bp.prediction_parameters =
       split_parse_and_decode_ ? std::unique_ptr<PredictionParameters>(
@@ -2158,17 +2203,16 @@ bool Tile::ProcessBlock(int row4x4, int column4x4, BlockSize block_size,
                               : std::move(prediction_parameters_);
   if (bp.prediction_parameters == nullptr) return false;
   if (!DecodeModeInfo(block)) return false;
-  bp.is_global_mv_block = (bp.y_mode == kPredictionModeGlobalMv ||
-                           bp.y_mode == kPredictionModeGlobalGlobalMv) &&
-                          !IsBlockDimension4(bp.size);
   PopulateDeblockFilterLevel(block);
   if (!ReadPaletteTokens(block)) return false;
   DecodeTransformSize(block);
   // Part of Section 5.11.37 in the spec (implemented as a simple lookup).
-  bp.uv_transform_size = frame_header_.segmentation.lossless[bp.segment_id]
-                             ? kTransformSize4x4
-                             : kUVTransformSize[block.residual_size[kPlaneU]];
+  bp.uv_transform_size =
+      frame_header_.segmentation.lossless[bp.prediction_parameters->segment_id]
+          ? kTransformSize4x4
+          : kUVTransformSize[block.residual_size[kPlaneU]];
   if (bp.skip) ResetEntropyContext(block);
+  PopulateCdefSkip(block);
   if (split_parse_and_decode_) {
     if (!Residual(block, kProcessingModeParseOnly)) return false;
   } else {
@@ -2177,22 +2221,24 @@ bool Tile::ProcessBlock(int row4x4, int column4x4, BlockSize block_size,
       return false;
     }
   }
-  // If frame_header_.segmentation.enabled is false, bp.segment_id is 0 for all
-  // blocks. We don't need to call save bp.segment_id in the current frame
-  // because the current frame's segmentation map will be cleared to all 0s.
+  // If frame_header_.segmentation.enabled is false,
+  // bp.prediction_parameters->segment_id is 0 for all blocks. We don't need to
+  // call save bp.prediction_parameters->segment_id in the current frame because
+  // the current frame's segmentation map will be cleared to all 0s.
   //
   // If frame_header_.segmentation.enabled is true and
   // frame_header_.segmentation.update_map is false, we will copy the previous
   // frame's segmentation map to the current frame. So we don't need to call
-  // save bp.segment_id in the current frame.
+  // save bp.prediction_parameters->segment_id in the current frame.
   if (frame_header_.segmentation.enabled &&
       frame_header_.segmentation.update_map) {
     const int x_limit = std::min(frame_header_.columns4x4 - column4x4,
                                  static_cast<int>(block.width4x4));
     const int y_limit = std::min(frame_header_.rows4x4 - row4x4,
                                  static_cast<int>(block.height4x4));
-    current_frame_.segmentation_map()->FillBlock(row4x4, column4x4, x_limit,
-                                                 y_limit, bp.segment_id);
+    current_frame_.segmentation_map()->FillBlock(
+        row4x4, column4x4, x_limit, y_limit,
+        bp.prediction_parameters->segment_id);
   }
   StoreMotionFieldMvsIntoCurrentFrame(block);
   if (!split_parse_and_decode_) {
@@ -2208,7 +2254,7 @@ bool Tile::DecodeBlock(int row4x4, int column4x4, BlockSize block_size,
       column4x4 >= frame_header_.columns4x4) {
     return true;
   }
-  Block block(*this, block_size, row4x4, column4x4, scratch_buffer, residual);
+  Block block(this, block_size, row4x4, column4x4, scratch_buffer, residual);
   if (!ComputePrediction(block) ||
       !Residual(block, kProcessingModeDecodeOnly)) {
     return false;
@@ -2382,7 +2428,7 @@ void Tile::ResetLoopRestorationParams() {
 }
 
 void Tile::ResetCdef(const int row4x4, const int column4x4) {
-  if (!sequence_header_.enable_cdef) return;
+  if (frame_header_.cdef.bits == 0) return;
   const int row = DivideBy16(row4x4);
   const int column = DivideBy16(column4x4);
   cdef_index_[row][column] = -1;
@@ -2562,8 +2608,8 @@ void Tile::StoreMotionFieldMvsIntoCurrentFrame(const Block& block) {
     // Must make a local copy so that StoreMotionFieldMvs() knows there is no
     // overlap between load and store.
     const MotionVector mv_to_store = bp.mv.mv[i];
-    const int mv_row = std::abs(mv_to_store.mv[MotionVector::kRow]);
-    const int mv_column = std::abs(mv_to_store.mv[MotionVector::kColumn]);
+    const int mv_row = std::abs(mv_to_store.mv[0]);
+    const int mv_column = std::abs(mv_to_store.mv[1]);
     if (reference_frame_to_store > kReferenceFrameIntra &&
         // kRefMvsLimit equals 0x07FF, so we can first bitwise OR the two
         // absolute values and then compare with kRefMvsLimit to save a branch.