diff --git a/modules/video_coding/BUILD.gn b/modules/video_coding/BUILD.gn
index 5154b51..50f2e8d 100644
--- a/modules/video_coding/BUILD.gn
+++ b/modules/video_coding/BUILD.gn
@@ -334,7 +334,6 @@
     "utility/simulcast_utility.h",
     "utility/vp8_header_parser.cc",
     "utility/vp8_header_parser.h",
-    "utility/vp9_constants.h",
     "utility/vp9_uncompressed_header_parser.cc",
     "utility/vp9_uncompressed_header_parser.h",
   ]
diff --git a/modules/video_coding/codecs/vp9/libvpx_vp9_decoder.cc b/modules/video_coding/codecs/vp9/libvpx_vp9_decoder.cc
index d10d8d1..3500ef5 100644
--- a/modules/video_coding/codecs/vp9/libvpx_vp9_decoder.cc
+++ b/modules/video_coding/codecs/vp9/libvpx_vp9_decoder.cc
@@ -206,8 +206,8 @@
   }
 
   if (input_image._frameType == VideoFrameType::kVideoFrameKey) {
-    absl::optional<vp9::UncompressedHeader> frame_info =
-        vp9::ParseUncompressedHeader(input_image.data(), input_image.size());
+    absl::optional<vp9::FrameInfo> frame_info =
+        vp9::ParseIntraFrameInfo(input_image.data(), input_image.size());
     if (frame_info) {
       if (frame_info->frame_width != current_codec_.width ||
           frame_info->frame_height != current_codec_.height) {
diff --git a/modules/video_coding/utility/vp9_constants.h b/modules/video_coding/utility/vp9_constants.h
deleted file mode 100644
index 999e780..0000000
--- a/modules/video_coding/utility/vp9_constants.h
+++ /dev/null
@@ -1,200 +0,0 @@
-/*
- *  Copyright (c) 2021 The WebRTC 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.
- */
-
-#ifndef MODULES_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
-#define MODULES_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
-
-#include <stddef.h>
-#include <stdint.h>
-
-#include <string>
-
-namespace webrtc {
-namespace vp9 {
-
-// Number of frames that can be stored for future reference.
-static constexpr size_t kNumRefFrames = 8;
-// Number of frame contexts that can be store for future reference.
-static constexpr size_t kNumFrameContexts = 4;
-// Each inter frame can use up to 3 frames for reference.
-constexpr size_t kRefsPerFrame = 3;
-// Number of values that can be decoded for mv_fr.
-constexpr size_t kMvFrSize = 4;
-// Number of positions to search in motion vector prediction.
-constexpr size_t kMvrefNeighbours = 8;
-// Number of contexts when decoding intra_mode .
-constexpr size_t kBlockSizeGroups = 4;
-// Number of different block sizes used.
-constexpr size_t kBlockSizes = 13;
-// Sentinel value to mark partition choices that are illegal.
-constexpr size_t kBlockInvalid = 14;
-// Number of contexts when decoding partition.
-constexpr size_t kPartitionContexts = 16;
-// Smallest size of a mode info block.
-constexpr size_t kMiSize = 8;
-// Minimum  width  of a  tile  in  units  of  superblocks  (although tiles on
-// the right hand edge can be narrower).
-constexpr size_t kMinTileWidth_B64 = 4;
-// Maximum width of a tile in units of superblocks.
-constexpr size_t kMaxTileWidth_B64 = 64;
-// Number of motion vectors returned by find_mv_refs process.
-constexpr size_t kMaxMvRefCandidates = 2;
-// Number of values that can be derived for ref_frame.
-constexpr size_t kMaxRefFrames = 4;
-// Number of contexts for is_inter.
-constexpr size_t kIsInterContexts = 4;
-// Number of contexts for comp_mode.
-constexpr size_t kCompModeContexts = 5;
-// Number of contexts for single_ref and comp_ref.
-constexpr size_t kRefContexts = 5;
-// Number of segments allowed in segmentation map.
-constexpr size_t kMaxSegments = 8;
-// Index for quantizer segment feature.
-constexpr size_t kSegLvlAlt_Q = 0;
-// Index for loop filter segment feature.
-constexpr size_t kSegLvlAlt_L = 1;
-// Index for reference frame segment feature.
-constexpr size_t kSegLvlRefFrame = 2;
-// Index for skip segment feature.
-constexpr size_t kSegLvlSkip = 3;
-// Number of segment features.
-constexpr size_t kSegLvlMax = 4;
-// Number of different plane types (Y or UV).
-constexpr size_t kBlockTypes = 2;
-// Number of different prediction types (intra or inter).
-constexpr size_t kRefTypes = 2;
-// Number of coefficient bands.
-constexpr size_t kCoefBands = 6;
-// Number of contexts for decoding coefficients.
-constexpr size_t kPrevCoefContexts = 6;
-// Number  of  coefficient  probabilities  that  are  directly transmitted.
-constexpr size_t kUnconstrainedNodes = 3;
-// Number of contexts for transform size.
-constexpr size_t kTxSizeContexts = 2;
-// Number of values for interp_filter.
-constexpr size_t kSwitchableFilters = 3;
-// Number of contexts for interp_filter.
-constexpr size_t kInterpFilterContexts = 4;
-// Number of contexts for decoding skip.
-constexpr size_t kSkipContexts = 3;
-// Number of values for partition.
-constexpr size_t kPartitionTypes = 4;
-// Number of values for tx_size.
-constexpr size_t kTxSizes = 4;
-// Number of values for tx_mode.
-constexpr size_t kTxModes = 5;
-// Inverse transform rows with DCT and columns with DCT.
-constexpr size_t kDctDct = 0;
-// Inverse transform rows with DCT and columns with ADST.
-constexpr size_t kAdstDct = 1;
-// Inverse transform rows with ADST and columns with DCT.
-constexpr size_t kDctAdst = 2;
-// Inverse transform rows with ADST and columns with ADST.
-constexpr size_t kAdstAdst = 3;
-// Number of values for y_mode.
-constexpr size_t kMbModeCount = 14;
-// Number of values for intra_mode.
-constexpr size_t kIntraModes = 10;
-// Number of values for inter_mode.
-constexpr size_t kInterModes = 4;
-// Number of contexts for inter_mode.
-constexpr size_t kInterModeContexts = 7;
-// Number of values for mv_joint.
-constexpr size_t kMvJoints = 4;
-// Number of values for mv_class.
-constexpr size_t kMvClasses = 11;
-// Number of values for mv_class0_bit.
-constexpr size_t kClass0Size = 2;
-// Maximum number of bits for decoding motion vectors.
-constexpr size_t kMvOffsetBits = 10;
-// Number of values allowed for a probability adjustment.
-constexpr size_t kMaxProb = 255;
-// Number of different mode types for loop filtering.
-constexpr size_t kMaxModeLfDeltas = 2;
-// Threshold at which motion vectors are considered large.
-constexpr size_t kCompandedMvrefThresh = 8;
-// Maximum value used for loop filtering.
-constexpr size_t kMaxLoopFilter = 63;
-// Number of bits of precision when scaling reference frames.
-constexpr size_t kRefScaleShift = 14;
-// Number of bits of precision when performing inter prediction.
-constexpr size_t kSubpelBits = 4;
-// 1 << kSubpelBits.
-constexpr size_t kSubpelShifts = 16;
-// kSubpelShifts - 1.
-constexpr size_t kSubpelMask = 15;
-// Value used when clipping motion vectors.
-constexpr size_t kMvBorder = 128;
-// Value used when clipping motion vectors.
-constexpr size_t kInterpExtend = 4;
-// Value used when clipping motion vectors.
-constexpr size_t kBorderinpixels = 160;
-// Value used in adapting probabilities.
-constexpr size_t kMaxUpdateFactor = 128;
-// Value used in adapting probabilities.
-constexpr size_t kCountSat = 20;
-// Both candidates use ZEROMV.
-constexpr size_t kBothZero = 0;
-// One  candidate uses ZEROMV, one uses NEARMV or NEARESTMV.
-constexpr size_t kZeroPlusPredicted = 1;
-// Both candidates use NEARMV or NEARESTMV.
-constexpr size_t kBothPredicted = 2;
-// One candidate uses NEWMV, one uses ZEROMV.
-constexpr size_t kNewPlusNonIntra = 3;
-// Both candidates use NEWMV.
-constexpr size_t kBothNew = 4;
-// One candidate uses intra prediction, one uses inter prediction.
-constexpr size_t kIntraPlusNonIntra = 5;
-// Both candidates use intra prediction.
-constexpr size_t kBothIntra = 6;
-// Sentinel value marking a case that can never occur.
-constexpr size_t kInvalidCase = 9;
-
-enum class TxMode : uint8_t {
-  kOnly4X4 = 0,
-  kAllow8X8 = 1,
-  kAllow16x16 = 2,
-  kAllow32x32 = 3,
-  kTxModeSelect = 4
-};
-
-enum BlockSize : uint8_t {
-  kBlock4X4 = 0,
-  kBlock4X8 = 1,
-  kBlock8X4 = 2,
-  kBlock8X8 = 3,
-  kBlock8X16 = 4,
-  kBlock16X8 = 5,
-  kBlock16X16 = 6,
-  kBlock16X32 = 7,
-  kBlock32X16 = 8,
-  kBlock32X32 = 9,
-  kBlock32X64 = 10,
-  kBlock64X32 = 11,
-  kBlock64X64 = 12
-};
-
-enum Partition : uint8_t {
-  kPartitionNone = 0,
-  kPartitionHorizontal = 1,
-  kPartitionVertical = 2,
-  kPartitionSplit = 3
-};
-
-enum class ReferenceMode : uint8_t {
-  kSingleReference = 0,
-  kCompoundReference = 1,
-  kReferenceModeSelect = 2,
-};
-
-}  // namespace vp9
-}  // namespace webrtc
-
-#endif  // MODULES_VIDEO_CODING_UTILITY_VP9_CONSTANTS_H_
diff --git a/modules/video_coding/utility/vp9_uncompressed_header_parser.cc b/modules/video_coding/utility/vp9_uncompressed_header_parser.cc
index 7fbdd58..07ba325 100644
--- a/modules/video_coding/utility/vp9_uncompressed_header_parser.cc
+++ b/modules/video_coding/utility/vp9_uncompressed_header_parser.cc
@@ -12,7 +12,6 @@
 #include "absl/strings/string_view.h"
 #include "rtc_base/bit_buffer.h"
 #include "rtc_base/logging.h"
-#include "rtc_base/strings/string_builder.h"
 
 namespace webrtc {
 
@@ -153,15 +152,11 @@
   // Returns true if full number of bits were read, false otherwise.
   bool ConsumeBits(int bits) { return buffer_->ConsumeBits(bits); }
 
-  void GetPosition(size_t* out_byte_offset, size_t* out_bit_offset) const {
-    buffer_->GetCurrentOffset(out_byte_offset, out_bit_offset);
-  }
-
  private:
   rtc::BitBuffer* buffer_;
 };
 
-bool Vp9ReadColorConfig(BitstreamReader* br, UncompressedHeader* frame_info) {
+bool Vp9ReadColorConfig(BitstreamReader* br, FrameInfo* frame_info) {
   if (frame_info->profile == 2 || frame_info->profile == 3) {
     READ_OR_RETURN(br->ReadBoolean(), [frame_info](bool ten_or_twelve_bits) {
       frame_info->bit_detph =
@@ -224,18 +219,7 @@
   return true;
 }
 
-bool ReadRefreshFrameFlags(BitstreamReader* br,
-                           UncompressedHeader* frame_info) {
-  // Refresh frame flags.
-  READ_OR_RETURN(br->ReadUnsigned<uint8_t>(), [frame_info](uint8_t flags) {
-    for (int i = 0; i < 8; ++i) {
-      frame_info->updated_buffers.set(i, (flags & (0x01 << (7 - i))) != 0);
-    }
-  });
-  return true;
-}
-
-bool Vp9ReadFrameSize(BitstreamReader* br, UncompressedHeader* frame_info) {
+bool Vp9ReadFrameSize(BitstreamReader* br, FrameInfo* frame_info) {
   // 16 bits: frame (width|height) - 1.
   READ_OR_RETURN(br->ReadUnsigned<uint16_t>(), [frame_info](uint16_t width) {
     frame_info->frame_width = width + 1;
@@ -246,12 +230,10 @@
   return true;
 }
 
-bool Vp9ReadRenderSize(BitstreamReader* br, UncompressedHeader* frame_info) {
+bool Vp9ReadRenderSize(BitstreamReader* br, FrameInfo* frame_info) {
   // render_and_frame_size_different
   return br->IfNextBoolean(
       [&] {
-        auto& pos = frame_info->render_size_position.emplace();
-        br->GetPosition(&pos.byte_offset, &pos.bit_offset);
         // 16 bits: render (width|height) - 1.
         READ_OR_RETURN(br->ReadUnsigned<uint16_t>(),
                        [frame_info](uint16_t width) {
@@ -271,16 +253,11 @@
       });
 }
 
-bool Vp9ReadFrameSizeFromRefs(BitstreamReader* br,
-                              UncompressedHeader* frame_info) {
+bool Vp9ReadFrameSizeFromRefs(BitstreamReader* br, FrameInfo* frame_info) {
   bool found_ref = false;
   for (size_t i = 0; !found_ref && i < kVp9NumRefsPerFrame; i++) {
     // Size in refs.
-    br->IfNextBoolean([&] {
-      frame_info->infer_size_from_reference = frame_info->reference_buffers[i];
-      found_ref = true;
-      return true;
-    });
+    READ_OR_RETURN(br->ReadBoolean(), [&](bool ref) { found_ref = ref; });
   }
 
   if (!found_ref) {
@@ -309,104 +286,58 @@
   });
 }
 
-bool Vp9ReadQp(BitstreamReader* br, UncompressedHeader* frame_info) {
+bool Vp9ReadQp(BitstreamReader* br, FrameInfo* frame_info) {
   READ_OR_RETURN(br->ReadUnsigned<uint8_t>(),
                  [frame_info](uint8_t qp) { frame_info->base_qp = qp; });
 
   // yuv offsets
-  frame_info->is_lossless = frame_info->base_qp == 0;
   for (int i = 0; i < 3; ++i) {
-    RETURN_IF_FALSE(br->IfNextBoolean([&] {  // if delta_coded
-      READ_OR_RETURN(br->ReadUnsigned<int>(4), [&](int delta) {
-        if (delta != 0) {
-          frame_info->is_lossless = false;
-        }
-      });
-      return true;
+    RETURN_IF_FALSE(br->IfNextBoolean([br] {  // if delta_coded
+      return br->ConsumeBits(5);
     }));
   }
   return true;
 }
 
-bool Vp9ReadSegmentationParams(BitstreamReader* br,
-                               UncompressedHeader* frame_info) {
-  constexpr int kSegmentationFeatureBits[kSegLvlMax] = {8, 6, 2, 0};
-  constexpr bool kSegmentationFeatureSigned[kSegLvlMax] = {1, 1, 0, 0};
+bool Vp9ReadSegmentationParams(BitstreamReader* br) {
+  constexpr int kVp9MaxSegments = 8;
+  constexpr int kVp9SegLvlMax = 4;
+  constexpr int kSegmentationFeatureBits[kVp9SegLvlMax] = {8, 6, 2, 0};
+  constexpr bool kSegmentationFeatureSigned[kVp9SegLvlMax] = {1, 1, 0, 0};
 
-  return br->IfNextBoolean([&] {  // segmentation_enabled
-    frame_info->segmentation_enabled = true;
-    RETURN_IF_FALSE(br->IfNextBoolean([&] {  // update_map
-      frame_info->segmentation_tree_probs.emplace();
+  RETURN_IF_FALSE(br->IfNextBoolean([&] {  // segmentation_enabled
+    return br->IfNextBoolean([&] {  // update_map
+      // Consume probs.
       for (int i = 0; i < 7; ++i) {
-        RETURN_IF_FALSE(br->IfNextBoolean(
-            [&] {
-              READ_OR_RETURN(br->ReadUnsigned<uint8_t>(), [&](uint8_t prob) {
-                (*frame_info->segmentation_tree_probs)[i] = prob;
-              });
-              return true;
-            },
-            [&] {
-              (*frame_info->segmentation_tree_probs)[i] = 255;
-              return true;
-            }));
+        RETURN_IF_FALSE(br->IfNextBoolean([br] { return br->ConsumeBits(7); }));
       }
 
-      // temporal_update
-      return br->IfNextBoolean(
-          [&] {
-            frame_info->segmentation_pred_prob.emplace();
-            for (int i = 0; i < 3; ++i) {
-              RETURN_IF_FALSE(br->IfNextBoolean(
-                  [&] {
-                    READ_OR_RETURN(
-                        br->ReadUnsigned<uint8_t>(), [&](uint8_t prob) {
-                          (*frame_info->segmentation_pred_prob)[i] = prob;
-                        });
-                    return true;
-                  },
-                  [&] {
-                    (*frame_info->segmentation_pred_prob)[i] = 255;
-                    return true;
-                  }));
-            }
-            return true;
-          },
-          [&] {
-            frame_info->segmentation_pred_prob->fill(255);
-            return true;
-          });
-    }));
-
-    return br->IfNextBoolean([&] {  // segmentation_update_data
-      RETURN_IF_FALSE(br->IfNextBoolean([&] {
-        frame_info->segmentation_is_delta = true;
-        return true;
-      }));
-
-      for (size_t i = 0; i < kMaxSegments; ++i) {
-        for (size_t j = 0; j < kSegLvlMax; ++j) {
-          RETURN_IF_FALSE(br->IfNextBoolean([&] {  // feature_enabled
-            READ_OR_RETURN(
-                br->ReadUnsigned<uint8_t>(kSegmentationFeatureBits[j]),
-                [&](uint8_t feature_value) {
-                  frame_info->segmentation_features[i][j] = feature_value;
-                });
-            if (kSegmentationFeatureSigned[j]) {
-              RETURN_IF_FALSE(br->IfNextBoolean([&] {
-                (*frame_info->segmentation_features[i][j]) *= -1;
-                return true;
-              }));
-            }
-            return true;
-          }));
+      return br->IfNextBoolean([&] {  // temporal_update
+        // Consume probs.
+        for (int i = 0; i < 3; ++i) {
+          RETURN_IF_FALSE(
+              br->IfNextBoolean([br] { return br->ConsumeBits(7); }));
         }
-      }
-      return true;
+        return true;
+      });
     });
+  }));
+
+  return br->IfNextBoolean([&] {
+    RETURN_IF_FALSE(br->ConsumeBits(1));  // abs_or_delta
+    for (int i = 0; i < kVp9MaxSegments; ++i) {
+      for (int j = 0; j < kVp9SegLvlMax; ++j) {
+        RETURN_IF_FALSE(br->IfNextBoolean([&] {  // feature_enabled
+          return br->ConsumeBits(kSegmentationFeatureBits[j] +
+                                 kSegmentationFeatureSigned[j]);
+        }));
+      }
+    }
+    return true;
   });
 }
 
-bool Vp9ReadTileInfo(BitstreamReader* br, UncompressedHeader* frame_info) {
+bool Vp9ReadTileInfo(BitstreamReader* br, FrameInfo* frame_info) {
   size_t mi_cols = (frame_info->frame_width + 7) >> 3;
   size_t sb64_cols = (mi_cols + 7) >> 3;
 
@@ -421,12 +352,12 @@
   }
   --max_log2;
 
-  frame_info->tile_cols_log2 = min_log2;
+  size_t cols_log2 = min_log2;
   bool done = false;
-  while (!done && frame_info->tile_cols_log2 < max_log2) {
+  while (!done && cols_log2 < max_log2) {
     RETURN_IF_FALSE(br->IfNextBoolean(
         [&] {
-          ++frame_info->tile_cols_log2;
+          ++cols_log2;
           return true;
         },
         [&] {
@@ -434,157 +365,13 @@
           return true;
         }));
   }
-  frame_info->tile_rows_log2 = 0;
-  RETURN_IF_FALSE(br->IfNextBoolean([&] {
-    ++frame_info->tile_rows_log2;
-    return br->IfNextBoolean([&] {
-      ++frame_info->tile_rows_log2;
-      return true;
-    });
-  }));
-  return true;
-}
 
-const InterpolationFilter kLiteralToType[4] = {
-    InterpolationFilter::kEightTapSmooth, InterpolationFilter::kEightTap,
-    InterpolationFilter::kEightTapSharp, InterpolationFilter::kBilinear};
+  // rows_log2;
+  return br->IfNextBoolean([&] { return br->ConsumeBits(1); });
+}
 }  // namespace
 
-std::string UncompressedHeader::ToString() const {
-  char buf[1024];
-  rtc::SimpleStringBuilder oss(buf);
-
-  oss << "Vp9UncompressedHeader { "
-      << "profile = " << profile;
-
-  if (show_existing_frame) {
-    oss << ", show_existing_frame = " << *show_existing_frame << " }";
-    return oss.str();
-  }
-
-  oss << ", frame type = " << (is_keyframe ? "key" : "delta")
-      << ", show_frame = " << (show_frame ? "true" : "false")
-      << ", error_resilient = " << (error_resilient ? "true" : "false");
-
-  oss << ", bit_depth = ";
-  switch (bit_detph) {
-    case BitDept::k8Bit:
-      oss << "8bit";
-      break;
-    case BitDept::k10Bit:
-      oss << "10bit";
-      break;
-    case BitDept::k12Bit:
-      oss << "12bit";
-      break;
-  }
-
-  if (color_space) {
-    oss << ", color_space = ";
-    switch (*color_space) {
-      case ColorSpace::CS_UNKNOWN:
-        oss << "unknown";
-        break;
-      case ColorSpace::CS_BT_601:
-        oss << "CS_BT_601 Rec. ITU-R BT.601-7";
-        break;
-      case ColorSpace::CS_BT_709:
-        oss << "Rec. ITU-R BT.709-6";
-        break;
-      case ColorSpace::CS_SMPTE_170:
-        oss << "SMPTE-170";
-        break;
-      case ColorSpace::CS_SMPTE_240:
-        oss << "SMPTE-240";
-        break;
-      case ColorSpace::CS_BT_2020:
-        oss << "Rec. ITU-R BT.2020-2";
-        break;
-      case ColorSpace::CS_RESERVED:
-        oss << "Reserved";
-        break;
-      case ColorSpace::CS_RGB:
-        oss << "sRGB (IEC 61966-2-1)";
-        break;
-    }
-  }
-
-  if (color_range) {
-    oss << ", color_range = ";
-    switch (*color_range) {
-      case ColorRange::kFull:
-        oss << "full";
-        break;
-      case ColorRange::kStudio:
-        oss << "studio";
-        break;
-    }
-  }
-
-  if (sub_sampling) {
-    oss << ", sub_sampling = ";
-    switch (*sub_sampling) {
-      case YuvSubsampling::k444:
-        oss << "444";
-        break;
-      case YuvSubsampling::k440:
-        oss << "440";
-        break;
-      case YuvSubsampling::k422:
-        oss << "422";
-        break;
-      case YuvSubsampling::k420:
-        oss << "420";
-        break;
-    }
-  }
-
-  if (infer_size_from_reference) {
-    oss << ", infer_frame_resolution_from = " << *infer_size_from_reference;
-  } else {
-    oss << ", frame_width = " << frame_width
-        << ", frame_height = " << frame_height;
-  }
-  if (render_width != 0 && render_height != 0) {
-    oss << ", render_width = " << render_width
-        << ", render_height = " << render_height;
-  }
-
-  oss << ", base qp = " << base_qp;
-  if (reference_buffers[0] != -1) {
-    oss << ", last_buffer = " << reference_buffers[0];
-  }
-  if (reference_buffers[1] != -1) {
-    oss << ", golden_buffer = " << reference_buffers[1];
-  }
-  if (reference_buffers[2] != -1) {
-    oss << ", altref_buffer = " << reference_buffers[2];
-  }
-
-  oss << ", updated buffers = { ";
-  bool first = true;
-  for (int i = 0; i < 8; ++i) {
-    if (updated_buffers.test(i)) {
-      if (first) {
-        first = false;
-      } else {
-        oss << ", ";
-      }
-      oss << i;
-    }
-  }
-  oss << " }";
-
-  oss << ", compressed_header_size_bytes = " << compressed_header_size;
-
-  oss << " }";
-  return oss.str();
-}
-
-bool Parse(const uint8_t* buf,
-           size_t length,
-           UncompressedHeader* frame_info,
-           bool qp_only) {
+bool Parse(const uint8_t* buf, size_t length, FrameInfo* frame_info) {
   rtc::BitBuffer bit_buffer(buf, length);
   BitstreamReader br(&bit_buffer);
 
@@ -636,9 +423,6 @@
       return false;
     if (!Vp9ReadRenderSize(&br, frame_info))
       return false;
-
-    // Key-frames implicitly update all buffers.
-    frame_info->updated_buffers.set();
   } else {
     // Non-keyframe.
     bool is_intra_only = false;
@@ -657,49 +441,31 @@
       if (frame_info->profile > 0) {
         if (!Vp9ReadColorConfig(&br, frame_info))
           return false;
-      } else {
-        frame_info->color_space = ColorSpace::CS_BT_601;
-        frame_info->sub_sampling = YuvSubsampling::k420;
-        frame_info->bit_detph = BitDept::k8Bit;
       }
-      frame_info->reference_buffers.fill(-1);
-      RETURN_IF_FALSE(ReadRefreshFrameFlags(&br, frame_info));
-      RETURN_IF_FALSE(Vp9ReadFrameSize(&br, frame_info));
-      RETURN_IF_FALSE(Vp9ReadRenderSize(&br, frame_info));
+      // Refresh frame flags.
+      RETURN_IF_FALSE(br.ConsumeBits(8));
+      if (!Vp9ReadFrameSize(&br, frame_info))
+        return false;
+      if (!Vp9ReadRenderSize(&br, frame_info))
+        return false;
     } else {
-      RETURN_IF_FALSE(ReadRefreshFrameFlags(&br, frame_info));
+      // Refresh frame flags.
+      RETURN_IF_FALSE(br.ConsumeBits(8));
 
-      frame_info->reference_buffers_sign_bias[0] = false;
       for (size_t i = 0; i < kVp9NumRefsPerFrame; i++) {
-        READ_OR_RETURN(br.ReadUnsigned<uint8_t>(3), [&](uint8_t idx) {
-          frame_info->reference_buffers[i] = idx;
-        });
-        READ_OR_RETURN(br.ReadBoolean(), [&](bool sign_bias) {
-          frame_info->reference_buffers_sign_bias[ReferenceFrame::kLast + i] =
-              sign_bias;
-        });
+        // 3 bits: Ref frame index.
+        // 1 bit: Ref frame sign biases.
+        RETURN_IF_FALSE(br.ConsumeBits(4));
       }
 
       if (!Vp9ReadFrameSizeFromRefs(&br, frame_info))
         return false;
 
-      READ_OR_RETURN(br.ReadBoolean(), [&](bool allow_high_precision_mv) {
-        frame_info->allow_high_precision_mv = allow_high_precision_mv;
-      });
-
+      // Allow high precision mv.
+      RETURN_IF_FALSE(br.ConsumeBits(1));
       // Interpolation filter.
-      RETURN_IF_FALSE(br.IfNextBoolean(
-          [frame_info] {
-            frame_info->interpolation_filter = InterpolationFilter::kSwitchable;
-            return true;
-          },
-          [&] {
-            READ_OR_RETURN(
-                br.ReadUnsigned<uint8_t>(2), [frame_info](uint8_t filter) {
-                  frame_info->interpolation_filter = kLiteralToType[filter];
-                });
-            return true;
-          }));
+      RETURN_IF_FALSE(br.IfNextBoolean([] { return true; },
+                                       [&br] { return br.ConsumeBits(2); }));
     }
   }
 
@@ -710,8 +476,7 @@
   }
 
   // Frame context index.
-  READ_OR_RETURN(br.ReadUnsigned<uint8_t>(2),
-                 [&](uint8_t idx) { frame_info->frame_context_idx = idx; });
+  RETURN_IF_FALSE(br.ConsumeBits(2));
 
   if (!Vp9ReadLoopfilter(&br))
     return false;
@@ -719,39 +484,33 @@
   // Read base QP.
   RETURN_IF_FALSE(Vp9ReadQp(&br, frame_info));
 
-  if (qp_only) {
-    // Not interested in the rest of the header, return early.
-    return true;
+  const bool kParseFullHeader = false;
+  if (kParseFullHeader) {
+    // Currently not used, but will be needed when parsing beyond the
+    // uncompressed header.
+    RETURN_IF_FALSE(Vp9ReadSegmentationParams(&br));
+
+    RETURN_IF_FALSE(Vp9ReadTileInfo(&br, frame_info));
+
+    RETURN_IF_FALSE(br.ConsumeBits(16));  // header_size_in_bytes
   }
 
-  RETURN_IF_FALSE(Vp9ReadSegmentationParams(&br, frame_info));
-  RETURN_IF_FALSE(Vp9ReadTileInfo(&br, frame_info));
-  READ_OR_RETURN(br.ReadUnsigned<uint16_t>(), [frame_info](uint16_t size) {
-    frame_info->compressed_header_size = size;
-  });
-
-  // Trailing bits.
-  RETURN_IF_FALSE(br.ConsumeBits(bit_buffer.RemainingBitCount() % 8));
-  frame_info->uncompressed_header_size =
-      length - (bit_buffer.RemainingBitCount() / 8);
-
   return true;
 }
 
 bool GetQp(const uint8_t* buf, size_t length, int* qp) {
-  UncompressedHeader frame_info;
-  if (!Parse(buf, length, &frame_info, /*qp_only=*/true)) {
+  FrameInfo frame_info;
+  if (!Parse(buf, length, &frame_info)) {
     return false;
   }
   *qp = frame_info.base_qp;
   return true;
 }
 
-absl::optional<UncompressedHeader> ParseUncompressedHeader(const uint8_t* buf,
-                                                           size_t length) {
-  UncompressedHeader frame_info;
-  if (Parse(buf, length, &frame_info, /*qp_only=*/false) &&
-      frame_info.frame_width > 0) {
+absl::optional<FrameInfo> ParseIntraFrameInfo(const uint8_t* buf,
+                                              size_t length) {
+  FrameInfo frame_info;
+  if (Parse(buf, length, &frame_info) && frame_info.frame_width > 0) {
     return frame_info;
   }
   return absl::nullopt;
diff --git a/modules/video_coding/utility/vp9_uncompressed_header_parser.h b/modules/video_coding/utility/vp9_uncompressed_header_parser.h
index 67166e3..7a5e2c0 100644
--- a/modules/video_coding/utility/vp9_uncompressed_header_parser.h
+++ b/modules/video_coding/utility/vp9_uncompressed_header_parser.h
@@ -13,13 +13,7 @@
 
 #include <stddef.h>
 #include <stdint.h>
-
-#include <array>
-#include <bitset>
-#include <string>
-
 #include "absl/types/optional.h"
-#include "modules/video_coding/utility/vp9_constants.h"
 
 namespace webrtc {
 
@@ -69,86 +63,27 @@
   k420,
 };
 
-enum ReferenceFrame : int {
-  kNone = -1,
-  kIntra = 0,
-  kLast = 1,
-  kGolden = 2,
-  kAltref = 3,
-};
-
-enum class InterpolationFilter : uint8_t {
-  kEightTap = 0,
-  kEightTapSmooth = 1,
-  kEightTapSharp = 2,
-  kBilinear = 3,
-  kSwitchable = 4
-};
-
-struct UncompressedHeader {
-  int profile = 0;  // Profiles 0-3 are valid.
+struct FrameInfo {
+  int profile = 0;  // Profile 0-3 are valid.
   absl::optional<uint8_t> show_existing_frame;
   bool is_keyframe = false;
   bool show_frame = false;
   bool error_resilient = false;
   BitDept bit_detph = BitDept::k8Bit;
-  absl::optional<ColorSpace> color_space;
-  absl::optional<ColorRange> color_range;
-  absl::optional<YuvSubsampling> sub_sampling;
+  ColorSpace color_space = ColorSpace::CS_UNKNOWN;
+  ColorRange color_range;
+  YuvSubsampling sub_sampling;
   int frame_width = 0;
   int frame_height = 0;
   int render_width = 0;
   int render_height = 0;
-  // Width/height of the tiles used (in units of 8x8 blocks).
-  size_t tile_cols_log2 = 0;  // tile_cols = 1 << tile_cols_log2
-  size_t tile_rows_log2 = 0;  // tile_rows = 1 << tile_rows_log2
-  struct BitstreamPosition {
-    size_t byte_offset = 0;
-    size_t bit_offset = 0;
-  };
-  absl::optional<BitstreamPosition> render_size_position;
-  InterpolationFilter interpolation_filter = InterpolationFilter::kEightTap;
-  bool allow_high_precision_mv = false;
   int base_qp = 0;
-  bool is_lossless = false;
-  uint8_t frame_context_idx = 0;
-
-  bool segmentation_enabled = false;
-  absl::optional<std::array<uint8_t, 7>> segmentation_tree_probs;
-  absl::optional<std::array<uint8_t, 3>> segmentation_pred_prob;
-  bool segmentation_is_delta = false;
-  absl::optional<int> segmentation_features[kMaxSegments][kSegLvlMax];
-
-  // Which of the 8 reference buffers may be used as references for this frame.
-  // -1 indicates not used (e.g. {-1, -1, -1} for intra-only frames).
-  std::array<int, kRefsPerFrame> reference_buffers = {-1, -1, -1};
-  // Sign bias corresponding to reference buffers, where the index is a
-  // ReferenceFrame.
-  // false/0 indidate backwards reference, true/1 indicate forwards reference).
-  std::array<bool, kMaxRefFrames> reference_buffers_sign_bias = {false, false,
-                                                                 false, false};
-
-  // Indicates which reference buffer [0,7] to infer the frame size from.
-  absl::optional<int> infer_size_from_reference;
-  // Which of the 8 reference buffers are updated by this frame.
-  std::bitset<kNumRefFrames> updated_buffers = 0;
-
-  // Header sizes, in bytes.
-  uint32_t uncompressed_header_size = 0;
-  uint32_t compressed_header_size = 0;
-
-  bool is_intra_only() const {
-    return reference_buffers[0] == -1 && reference_buffers[1] == -1 &&
-           reference_buffers[2] == -1;
-  }
-
-  std::string ToString() const;
 };
 
-// Parses the uncompressed header and populates (most) values in a
-// UncompressedHeader struct. Returns nullopt on failure.
-absl::optional<UncompressedHeader> ParseUncompressedHeader(const uint8_t* buf,
-                                                           size_t length);
+// Parses frame information for a VP9 key-frame or all-intra frame from a
+// bitstream. Returns nullopt on failure or if not a key-frame.
+absl::optional<FrameInfo> ParseIntraFrameInfo(const uint8_t* buf,
+                                              size_t length);
 
 }  // namespace vp9
 
diff --git a/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc b/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc
index 672becc..b69b45d 100644
--- a/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc
+++ b/modules/video_coding/utility/vp9_uncompressed_header_parser_unittest.cc
@@ -15,11 +15,6 @@
 
 namespace webrtc {
 namespace vp9 {
-using ::testing::AllOf;
-using ::testing::ElementsAreArray;
-using ::testing::Eq;
-using ::testing::Field;
-using ::testing::Optional;
 
 TEST(Vp9UncompressedHeaderParserTest, FrameWithSegmentation) {
   // Uncompressed header from a frame generated with libvpx.
@@ -31,46 +26,21 @@
       0x2e, 0x73, 0xb7, 0xee, 0x22, 0x06, 0x81, 0x82, 0xd4, 0xef, 0xc3, 0x58,
       0x1f, 0x12, 0xd2, 0x7b, 0x28, 0x1f, 0x80, 0xfc, 0x07, 0xe0, 0x00, 0x00};
 
-  absl::optional<UncompressedHeader> frame_info =
-      ParseUncompressedHeader(kHeader, sizeof(kHeader));
+  absl::optional<FrameInfo> frame_info =
+      ParseIntraFrameInfo(kHeader, sizeof(kHeader));
+  // Segmentation info is not actually populated in FrameInfo struct, but it
+  // needs to be parsed otherwise we end up on the wrong offset. The check for
+  // segmentation is thus that we have a valid return value.
   ASSERT_TRUE(frame_info.has_value());
 
-  EXPECT_FALSE(frame_info->is_keyframe);
-  EXPECT_TRUE(frame_info->error_resilient);
-  EXPECT_TRUE(frame_info->show_frame);
-  EXPECT_FALSE(frame_info->show_existing_frame);
+  EXPECT_EQ(frame_info->is_keyframe, false);
+  EXPECT_EQ(frame_info->error_resilient, true);
+  EXPECT_EQ(frame_info->show_frame, true);
   EXPECT_EQ(frame_info->base_qp, 185);
   EXPECT_EQ(frame_info->frame_width, 320);
   EXPECT_EQ(frame_info->frame_height, 240);
   EXPECT_EQ(frame_info->render_width, 640);
   EXPECT_EQ(frame_info->render_height, 480);
-  EXPECT_TRUE(frame_info->allow_high_precision_mv);
-  EXPECT_EQ(frame_info->frame_context_idx, 0u);
-  EXPECT_EQ(frame_info->interpolation_filter, InterpolationFilter::kSwitchable);
-  EXPECT_EQ(frame_info->is_lossless, false);
-  EXPECT_EQ(frame_info->profile, 0);
-  EXPECT_THAT(frame_info->reference_buffers, ElementsAreArray({0, 0, 0}));
-  EXPECT_THAT(frame_info->reference_buffers_sign_bias,
-              ElementsAreArray({false, false, false, false}));
-  EXPECT_EQ(frame_info->updated_buffers, 0b10000000);
-  EXPECT_EQ(frame_info->tile_cols_log2, 0u);
-  EXPECT_EQ(frame_info->tile_rows_log2, 0u);
-  EXPECT_THAT(
-      frame_info->render_size_position,
-      ::testing::Optional(AllOf(
-          Field(&UncompressedHeader::BitstreamPosition::byte_offset, 8u),
-          Field(&UncompressedHeader::BitstreamPosition::bit_offset, 0u))));
-  EXPECT_EQ(frame_info->compressed_header_size, 23u);
-  EXPECT_EQ(frame_info->uncompressed_header_size, 37u);
-
-  EXPECT_TRUE(frame_info->segmentation_enabled);
-  EXPECT_FALSE(frame_info->segmentation_is_delta);
-  EXPECT_THAT(frame_info->segmentation_pred_prob,
-              Optional(ElementsAreArray({205, 1, 1})));
-  EXPECT_THAT(frame_info->segmentation_tree_probs,
-              Optional(ElementsAreArray({255, 255, 128, 1, 128, 128, 128})));
-  EXPECT_THAT(frame_info->segmentation_features[1][kSegLvlAlt_Q], Eq(-63));
-  EXPECT_THAT(frame_info->segmentation_features[2][kSegLvlAlt_Q], Eq(-81));
 }
 
 }  // namespace vp9