// Copyright 2015 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
//
// This file contains an implementation of a VP8 raw stream parser,
// as defined in RFC 6386.

#include "media/parsers/vp8_parser.h"

#include <array>
#include <cstring>

#include "base/auto_reset.h"
#include "base/check_op.h"
#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/numerics/byte_conversions.h"
#include "base/numerics/checked_math.h"
#include "base/numerics/safe_conversions.h"

namespace media {

#define ERROR_RETURN(what)                           \
  do {                                               \
    DVLOG(1) << "Error while trying to read " #what; \
    return false;                                    \
  } while (0)

#define BD_READ_BOOL_OR_RETURN(out) \
  do {                              \
    if (!bd_.ReadBool(out))         \
      ERROR_RETURN(out);            \
  } while (0)

#define BD_READ_BOOL_WITH_PROB_OR_RETURN(out, prob) \
  do {                                              \
    if (!bd_.ReadBool(out, prob))                   \
      ERROR_RETURN(out);                            \
  } while (0)

#define BD_READ_UNSIGNED_OR_RETURN(num_bits, out) \
  do {                                            \
    int _out;                                     \
    if (!bd_.ReadLiteral(num_bits, &_out))        \
      ERROR_RETURN(out);                          \
    *out = _out;                                  \
  } while (0)

#define BD_READ_SIGNED_OR_RETURN(num_bits, out)    \
  do {                                             \
    int _out;                                      \
    if (!bd_.ReadLiteralWithSign(num_bits, &_out)) \
      ERROR_RETURN(out);                           \
    *out = _out;                                   \
  } while (0)

Vp8FrameHeader::Vp8FrameHeader() = default;

Vp8FrameHeader::~Vp8FrameHeader() = default;

Vp8FrameHeader::Vp8FrameHeader(const Vp8FrameHeader& fhdr) = default;

Vp8FrameHeader& Vp8FrameHeader::operator=(const Vp8FrameHeader& fhdr) = default;

Vp8Parser::Vp8Parser() = default;

Vp8Parser::~Vp8Parser() = default;

bool Vp8Parser::ParseFrame(base::span<const uint8_t> frame,
                           Vp8FrameHeader* fhdr) {
  base::AutoReset reset_stream(&stream_, frame);

  *fhdr = Vp8FrameHeader();
  fhdr->data = stream_.data();
  fhdr->frame_size = stream_.size();

  if (!ParseFrameTag(fhdr)) {
    return false;
  }

  fhdr->first_part_offset = stream_.data() - fhdr->data;

  if (!ParseFrameHeader(fhdr)) {
    return false;
  }

  if (!ParsePartitions(fhdr)) {
    return false;
  }

  DVLOG(4) << "Frame parsed, start: " << static_cast<const void*>(frame.data())
           << ", size: " << frame.size()
           << ", offsets: to first_part=" << fhdr->first_part_offset
           << ", to macroblock data (in bits)=" << fhdr->macroblock_bit_offset;

  return true;
}

static inline uint32_t GetBitsAt(uint32_t data, size_t shift, size_t num_bits) {
  return ((data >> shift) & ((1 << num_bits) - 1));
}

bool Vp8Parser::ParseFrameTag(Vp8FrameHeader* fhdr) {
  const size_t kFrameTagSize = 3;
  if (stream_.size() < kFrameTagSize) {
    return false;
  }

  // Converting from little Endian, since kFrameTagSize is only 3, we set the
  // fourth byte to 0.
  uint32_t frame_tag = base::U32FromLittleEndian(
      std::to_array<uint8_t>({stream_[0], stream_[1], stream_[2], 0}));
  stream_.take_first<kFrameTagSize>();
  fhdr->frame_type =
      static_cast<Vp8FrameHeader::FrameType>(GetBitsAt(frame_tag, 0, 1));
  fhdr->version = GetBitsAt(frame_tag, 1, 2);
  fhdr->is_experimental = !!GetBitsAt(frame_tag, 3, 1);
  fhdr->show_frame =!!GetBitsAt(frame_tag, 4, 1);
  fhdr->first_part_size = GetBitsAt(frame_tag, 5, 19);

  if (fhdr->IsKeyframe()) {
    const size_t kKeyframeTagSize = 7;
    if (stream_.size() < kKeyframeTagSize) {
      return false;
    }

    constexpr auto kVp8StartCode = std::to_array<uint8_t>({0x9d, 0x01, 0x2a});
    if (stream_.first<sizeof(kVp8StartCode)>() != kVp8StartCode) {
      return false;
    }

    // Advance the span only if the first bytes match kVp8StartCode.
    stream_.take_first<sizeof(kVp8StartCode)>();

    // width & height are stored in little-endian as per spec.
    // See: https://datatracker.ietf.org/doc/html/rfc6386
    uint16_t data = base::U16FromLittleEndian(stream_.take_first<2>());
    fhdr->width = data & 0x3fff;
    fhdr->horizontal_scale = data >> 14;

    data = base::U16FromLittleEndian(stream_.take_first<2>());
    fhdr->height = data & 0x3fff;
    fhdr->vertical_scale = data >> 14;
  }

  return true;
}

bool Vp8Parser::ParseFrameHeader(Vp8FrameHeader* fhdr) {
  if (!bd_.Initialize(stream_.data(), stream_.size())) {
    return false;
  }

  bool keyframe = fhdr->IsKeyframe();
  if (keyframe) {
    unsigned int data;
    BD_READ_UNSIGNED_OR_RETURN(1, &data);  // color_space
    BD_READ_UNSIGNED_OR_RETURN(1, &data);  // clamping_type
    fhdr->is_full_range = data == 1;
  } else {
    fhdr->is_full_range = false;
  }

  if (!ParseSegmentationHeader(keyframe))
    return false;

  fhdr->segmentation_hdr = curr_segmentation_hdr_;

  if (!ParseLoopFilterHeader(keyframe))
    return false;

  fhdr->loopfilter_hdr = curr_loopfilter_hdr_;

  int log2_nbr_of_dct_partitions;
  BD_READ_UNSIGNED_OR_RETURN(2, &log2_nbr_of_dct_partitions);
  fhdr->num_of_dct_partitions = static_cast<size_t>(1)
                                << log2_nbr_of_dct_partitions;

  if (!ParseQuantizationHeader(&fhdr->quantization_hdr))
    return false;

  if (keyframe) {
    BD_READ_BOOL_OR_RETURN(&fhdr->refresh_entropy_probs);
  } else {
    BD_READ_BOOL_OR_RETURN(&fhdr->refresh_golden_frame);
    BD_READ_BOOL_OR_RETURN(&fhdr->refresh_alternate_frame);

    int refresh_mode;
    if (!fhdr->refresh_golden_frame) {
      BD_READ_UNSIGNED_OR_RETURN(2, &refresh_mode);
      fhdr->copy_buffer_to_golden =
          static_cast<Vp8FrameHeader::GoldenRefreshMode>(refresh_mode);
    }

    if (!fhdr->refresh_alternate_frame) {
      BD_READ_UNSIGNED_OR_RETURN(2, &refresh_mode);
      fhdr->copy_buffer_to_alternate =
          static_cast<Vp8FrameHeader::AltRefreshMode>(refresh_mode);
    }

    BD_READ_UNSIGNED_OR_RETURN(1, &fhdr->sign_bias_golden);
    BD_READ_UNSIGNED_OR_RETURN(1, &fhdr->sign_bias_alternate);
    BD_READ_BOOL_OR_RETURN(&fhdr->refresh_entropy_probs);
    BD_READ_BOOL_OR_RETURN(&fhdr->refresh_last);
  }

  if (keyframe)
    ResetProbs();

  fhdr->entropy_hdr = curr_entropy_hdr_;

  if (!ParseTokenProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs))
    return false;

  BD_READ_BOOL_OR_RETURN(&fhdr->mb_no_skip_coeff);
  if (fhdr->mb_no_skip_coeff)
    BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_skip_false);

  if (!keyframe) {
    BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_intra);
    BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_last);
    BD_READ_UNSIGNED_OR_RETURN(8, &fhdr->prob_gf);
  }

  if (!ParseIntraProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs,
                       keyframe))
    return false;

  if (!keyframe) {
    if (!ParseMVProbs(&fhdr->entropy_hdr, fhdr->refresh_entropy_probs))
      return false;
  }

  if (fhdr->first_part_size < (bd_.BitOffset() + 7) / 8) {
    // If a video is created in such a way that the `first_part_size` field in
    // the bitstream is smaller than the macroblock_bit_offset/8, the frame is
    // not valid. Calculating the partition size becomes impossible.
    return false;
  }

  fhdr->macroblock_bit_offset = bd_.BitOffset();
  fhdr->bool_dec_range = bd_.GetRange();
  fhdr->bool_dec_value = bd_.GetBottom();
  fhdr->bool_dec_count = 7 - (bd_.BitOffset() + 7) % 8;

  return true;
}

bool Vp8Parser::ParseSegmentationHeader(bool keyframe) {
  Vp8SegmentationHeader* shdr = &curr_segmentation_hdr_;

  if (keyframe)
    UNSAFE_TODO(memset(shdr, 0, sizeof(*shdr)));

  BD_READ_BOOL_OR_RETURN(&shdr->segmentation_enabled);
  if (!shdr->segmentation_enabled)
    return true;

  BD_READ_BOOL_OR_RETURN(&shdr->update_mb_segmentation_map);
  BD_READ_BOOL_OR_RETURN(&shdr->update_segment_feature_data);
  if (shdr->update_segment_feature_data) {
    int mode;
    BD_READ_UNSIGNED_OR_RETURN(1, &mode);
    shdr->segment_feature_mode =
        static_cast<Vp8SegmentationHeader::SegmentFeatureMode>(mode);

    for (size_t i = 0; i < kMaxMBSegments; ++i) {
      bool quantizer_update;
      BD_READ_BOOL_OR_RETURN(&quantizer_update);
      if (quantizer_update)
        BD_READ_SIGNED_OR_RETURN(7, &shdr->quantizer_update_value[i]);
      else
        shdr->quantizer_update_value[i] = 0;
    }

    for (size_t i = 0; i < kMaxMBSegments; ++i) {
      bool loop_filter_update;
      BD_READ_BOOL_OR_RETURN(&loop_filter_update);
      if (loop_filter_update)
        UNSAFE_TODO(BD_READ_SIGNED_OR_RETURN(6, &shdr->lf_update_value[i]));
      else
        UNSAFE_TODO(shdr->lf_update_value[i]) = 0;
    }
  }

  if (shdr->update_mb_segmentation_map) {
    for (size_t i = 0; i < kNumMBFeatureTreeProbs; ++i) {
      bool segment_prob_update;
      BD_READ_BOOL_OR_RETURN(&segment_prob_update);
      if (segment_prob_update)
        UNSAFE_TODO(BD_READ_UNSIGNED_OR_RETURN(8, &shdr->segment_prob[i]));
      else
        UNSAFE_TODO(shdr->segment_prob[i]) =
            Vp8SegmentationHeader::kDefaultSegmentProb;
    }
  }

  return true;
}

bool Vp8Parser::ParseLoopFilterHeader(bool keyframe) {
  Vp8LoopFilterHeader* lfhdr = &curr_loopfilter_hdr_;

  if (keyframe)
    UNSAFE_TODO(memset(lfhdr, 0, sizeof(*lfhdr)));

  int type;
  BD_READ_UNSIGNED_OR_RETURN(1, &type);
  lfhdr->type = static_cast<Vp8LoopFilterHeader::Type>(type);
  BD_READ_UNSIGNED_OR_RETURN(6, &lfhdr->level);
  BD_READ_UNSIGNED_OR_RETURN(3, &lfhdr->sharpness_level);
  BD_READ_BOOL_OR_RETURN(&lfhdr->loop_filter_adj_enable);

  if (lfhdr->loop_filter_adj_enable) {
    BD_READ_BOOL_OR_RETURN(&lfhdr->mode_ref_lf_delta_update);
    if (lfhdr->mode_ref_lf_delta_update) {
      for (size_t i = 0; i < kNumBlockContexts; ++i) {
        bool ref_frame_delta_update_flag;
        BD_READ_BOOL_OR_RETURN(&ref_frame_delta_update_flag);
        if (ref_frame_delta_update_flag)
          UNSAFE_TODO(BD_READ_SIGNED_OR_RETURN(6, &lfhdr->ref_frame_delta[i]));
      }

      for (size_t i = 0; i < kNumBlockContexts; ++i) {
        bool mb_mode_delta_update_flag;
        BD_READ_BOOL_OR_RETURN(&mb_mode_delta_update_flag);
        if (mb_mode_delta_update_flag)
          UNSAFE_TODO(BD_READ_SIGNED_OR_RETURN(6, &lfhdr->mb_mode_delta[i]));
      }
    }
  }

  return true;
}

bool Vp8Parser::ParseQuantizationHeader(Vp8QuantizationHeader* qhdr) {
  // If any of the delta values is not present, the delta should be zero.
  UNSAFE_TODO(memset(qhdr, 0, sizeof(*qhdr)));

  BD_READ_UNSIGNED_OR_RETURN(7, &qhdr->y_ac_qi);

  bool delta_present;

  BD_READ_BOOL_OR_RETURN(&delta_present);
  if (delta_present)
    BD_READ_SIGNED_OR_RETURN(4, &qhdr->y_dc_delta);

  BD_READ_BOOL_OR_RETURN(&delta_present);
  if (delta_present)
    BD_READ_SIGNED_OR_RETURN(4, &qhdr->y2_dc_delta);

  BD_READ_BOOL_OR_RETURN(&delta_present);
  if (delta_present)
    BD_READ_SIGNED_OR_RETURN(4, &qhdr->y2_ac_delta);

  BD_READ_BOOL_OR_RETURN(&delta_present);
  if (delta_present)
    BD_READ_SIGNED_OR_RETURN(4, &qhdr->uv_dc_delta);

  BD_READ_BOOL_OR_RETURN(&delta_present);
  if (delta_present)
    BD_READ_SIGNED_OR_RETURN(4, &qhdr->uv_ac_delta);

  return true;
}

// See spec for details on these values.
static constexpr std::array<
    std::array<std::array<std::array<const uint8_t, kNumEntropyNodes>,
                          kNumPrevCoeffContexts>,
               kNumCoeffBands>,
    kNumBlockTypes>
    kCoeffUpdateProbs = {{
        {{
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{176, 246, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{223, 241, 252, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{249, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 244, 252, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{234, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 246, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{239, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{251, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{251, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 253, 255, 254, 255, 255, 255, 255, 255, 255}},
                {{250, 255, 254, 255, 254, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
        }},
        {{
            {{
                {{217, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{225, 252, 241, 253, 255, 255, 254, 255, 255, 255, 255}},
                {{234, 250, 241, 250, 253, 255, 253, 254, 255, 255, 255}},
            }},
            {{
                {{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{223, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{238, 253, 254, 254, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 248, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{249, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 253, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{247, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{252, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{253, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
        }},
        {{
            {{
                {{186, 251, 250, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{234, 251, 244, 254, 255, 255, 255, 255, 255, 255, 255}},
                {{251, 251, 243, 253, 254, 255, 254, 255, 255, 255, 255}},
            }},
            {{
                {{255, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{236, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{251, 253, 253, 254, 254, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 254, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
        }},
        {{
            {{
                {{248, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{250, 254, 252, 254, 255, 255, 255, 255, 255, 255, 255}},
                {{248, 254, 249, 253, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{246, 253, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{252, 254, 251, 254, 254, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 254, 252, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{248, 254, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{253, 255, 254, 254, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{245, 251, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{253, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 251, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{252, 253, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 254, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 252, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{249, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 254, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 253, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{250, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
            {{
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{254, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
                {{255, 255, 255, 255, 255, 255, 255, 255, 255, 255, 255}},
            }},
        }},
    }};

static constexpr std::array<uint8_t, kNumYModeProbs> kKeyframeYModeProbs = {
    145, 156, 163, 128};
static constexpr std::array<uint8_t, kNumUVModeProbs> kKeyframeUVModeProbs = {
    142, 114, 183};

static constexpr std::array<uint8_t, kNumYModeProbs> kDefaultYModeProbs = {
    112, 86, 140, 37};
static constexpr std::array<uint8_t, kNumUVModeProbs> kDefaultUVModeProbs = {
    162, 101, 204};

static constexpr std::array<
    std::array<std::array<std::array<uint8_t, kNumEntropyNodes>,
                          kNumPrevCoeffContexts>,
               kNumCoeffBands>,
    kNumBlockTypes>
    kDefaultCoeffProbs = {{
        {{{{
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
          }},
          {{
              {{253, 136, 254, 255, 228, 219, 128, 128, 128, 128, 128}},
              {{189, 129, 242, 255, 227, 213, 255, 219, 128, 128, 128}},
              {{106, 126, 227, 252, 214, 209, 255, 255, 128, 128, 128}},
          }},
          {{
              {{1, 98, 248, 255, 236, 226, 255, 255, 128, 128, 128}},
              {{181, 133, 238, 254, 221, 234, 255, 154, 128, 128, 128}},
              {{78, 134, 202, 247, 198, 180, 255, 219, 128, 128, 128}},
          }},
          {{
              {{1, 185, 249, 255, 243, 255, 128, 128, 128, 128, 128}},
              {{184, 150, 247, 255, 236, 224, 128, 128, 128, 128, 128}},
              {{77, 110, 216, 255, 236, 230, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 101, 251, 255, 241, 255, 128, 128, 128, 128, 128}},
              {{170, 139, 241, 252, 236, 209, 255, 255, 128, 128, 128}},
              {{37, 116, 196, 243, 228, 255, 255, 255, 128, 128, 128}},
          }},
          {{
              {{1, 204, 254, 255, 245, 255, 128, 128, 128, 128, 128}},
              {{207, 160, 250, 255, 238, 128, 128, 128, 128, 128, 128}},
              {{102, 103, 231, 255, 211, 171, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 152, 252, 255, 240, 255, 128, 128, 128, 128, 128}},
              {{177, 135, 243, 255, 234, 225, 128, 128, 128, 128, 128}},
              {{80, 129, 211, 255, 194, 224, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{246, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{255, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
          }}}},
        {{{{
              {{198, 35, 237, 223, 193, 187, 162, 160, 145, 155, 62}},
              {{131, 45, 198, 221, 172, 176, 220, 157, 252, 221, 1}},
              {{68, 47, 146, 208, 149, 167, 221, 162, 255, 223, 128}},
          }},
          {{
              {{1, 149, 241, 255, 221, 224, 255, 255, 128, 128, 128}},
              {{184, 141, 234, 253, 222, 220, 255, 199, 128, 128, 128}},
              {{81, 99, 181, 242, 176, 190, 249, 202, 255, 255, 128}},
          }},
          {{
              {{1, 129, 232, 253, 214, 197, 242, 196, 255, 255, 128}},
              {{99, 121, 210, 250, 201, 198, 255, 202, 128, 128, 128}},
              {{23, 91, 163, 242, 170, 187, 247, 210, 255, 255, 128}},
          }},
          {{
              {{1, 200, 246, 255, 234, 255, 128, 128, 128, 128, 128}},
              {{109, 178, 241, 255, 231, 245, 255, 255, 128, 128, 128}},
              {{44, 130, 201, 253, 205, 192, 255, 255, 128, 128, 128}},
          }},
          {{
              {{1, 132, 239, 251, 219, 209, 255, 165, 128, 128, 128}},
              {{94, 136, 225, 251, 218, 190, 255, 255, 128, 128, 128}},
              {{22, 100, 174, 245, 186, 161, 255, 199, 128, 128, 128}},
          }},
          {{
              {{1, 182, 249, 255, 232, 235, 128, 128, 128, 128, 128}},
              {{124, 143, 241, 255, 227, 234, 128, 128, 128, 128, 128}},
              {{35, 77, 181, 251, 193, 211, 255, 205, 128, 128, 128}},
          }},
          {{
              {{1, 157, 247, 255, 236, 231, 255, 255, 128, 128, 128}},
              {{121, 141, 235, 255, 225, 227, 255, 255, 128, 128, 128}},
              {{45, 99, 188, 251, 195, 217, 255, 224, 128, 128, 128}},
          }},
          {{
              {{1, 1, 251, 255, 213, 255, 128, 128, 128, 128, 128}},
              {{203, 1, 248, 255, 255, 128, 128, 128, 128, 128, 128}},
              {{137, 1, 177, 255, 224, 255, 128, 128, 128, 128, 128}},
          }}}},
        {{{{
              {{253, 9, 248, 251, 207, 208, 255, 192, 128, 128, 128}},
              {{175, 13, 224, 243, 193, 185, 249, 198, 255, 255, 128}},
              {{73, 17, 171, 221, 161, 179, 236, 167, 255, 234, 128}},
          }},
          {{
              {{1, 95, 247, 253, 212, 183, 255, 255, 128, 128, 128}},
              {{239, 90, 244, 250, 211, 209, 255, 255, 128, 128, 128}},
              {{155, 77, 195, 248, 188, 195, 255, 255, 128, 128, 128}},
          }},
          {{
              {{1, 24, 239, 251, 218, 219, 255, 205, 128, 128, 128}},
              {{201, 51, 219, 255, 196, 186, 128, 128, 128, 128, 128}},
              {{69, 46, 190, 239, 201, 218, 255, 228, 128, 128, 128}},
          }},
          {{
              {{1, 191, 251, 255, 255, 128, 128, 128, 128, 128, 128}},
              {{223, 165, 249, 255, 213, 255, 128, 128, 128, 128, 128}},
              {{141, 124, 248, 255, 255, 128, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 16, 248, 255, 255, 128, 128, 128, 128, 128, 128}},
              {{190, 36, 230, 255, 236, 255, 128, 128, 128, 128, 128}},
              {{149, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 226, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{247, 192, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{240, 128, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
          }},
          {{
              {{1, 134, 252, 255, 255, 128, 128, 128, 128, 128, 128}},
              {{213, 62, 250, 255, 255, 128, 128, 128, 128, 128, 128}},
              {{55, 93, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
          }},
          {{
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
              {{128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128}},
          }}}},
        {{
            {{
                {{202, 24, 213, 235, 186, 191, 220, 160, 240, 175, 255}},
                {{126, 38, 182, 232, 169, 184, 228, 174, 255, 187, 128}},
                {{61, 46, 138, 219, 151, 178, 240, 170, 255, 216, 128}},
            }},
            {{
                {{1, 112, 230, 250, 199, 191, 247, 159, 255, 255, 128}},
                {{166, 109, 228, 252, 211, 215, 255, 174, 128, 128, 128}},
                {{39, 77, 162, 232, 172, 180, 245, 178, 255, 255, 128}},
            }},
            {{
                {{1, 52, 220, 246, 198, 199, 249, 220, 255, 255, 128}},
                {{124, 74, 191, 243, 183, 193, 250, 221, 255, 255, 128}},
                {{24, 71, 130, 219, 154, 170, 243, 182, 255, 255, 128}},
            }},
            {{{{1, 182, 225, 249, 219, 240, 255, 224, 128, 128, 128}},
              {{149, 150, 226, 252, 216, 205, 255, 171, 128, 128, 128}},
              {{28, 108, 170, 242, 183, 194, 254, 223, 255, 255, 128}}}},
            {{
                {{1, 81, 230, 252, 204, 203, 255, 192, 128, 128, 128}},
                {{123, 102, 209, 247, 188, 196, 255, 233, 128, 128, 128}},
                {{20, 95, 153, 243, 164, 173, 255, 203, 128, 128, 128}},
            }},
            {{
                {{1, 222, 248, 255, 216, 213, 128, 128, 128, 128, 128}},
                {{168, 175, 246, 252, 235, 205, 255, 255, 128, 128, 128}},
                {{47, 116, 215, 255, 211, 212, 255, 255, 128, 128, 128}},
            }},
            {{
                {{1, 121, 236, 253, 212, 214, 255, 255, 128, 128, 128}},
                {{141, 84, 213, 252, 201, 202, 255, 219, 128, 128, 128}},
                {{42, 80, 160, 240, 162, 185, 255, 205, 128, 128, 128}},
            }},
            {{
                {{1, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
                {{244, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
                {{238, 1, 255, 128, 128, 128, 128, 128, 128, 128, 128}},
            }},
        }},
    }};

static constexpr std::array<std::array<uint8_t, kNumMVProbs>, kNumMVContexts>
    kMVUpdateProbs = {{
        {{
            237, 246, 253, 253, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 250, 250, 252, 254, 254,
        }},
        {{
            231, 243, 245, 253, 254, 254, 254, 254, 254, 254,
            254, 254, 254, 254, 251, 251, 254, 254, 254,
        }},
    }};

static constexpr std::array<std::array<uint8_t, kNumMVProbs>, kNumMVContexts>
    kDefaultMVProbs = {{
        {{
            162, 128, 225, 146, 172, 147, 214, 39,  156, 128,
            129, 132, 75,  145, 178, 206, 239, 254, 254,
        }},
        {{
            164, 128, 204, 170, 119, 235, 140, 230, 228, 128,
            130, 130, 74,  148, 180, 203, 236, 254, 254,
        }},
    }};

void Vp8Parser::ResetProbs() {
  curr_entropy_hdr_.coeff_probs = kDefaultCoeffProbs;

  curr_entropy_hdr_.mv_probs = kDefaultMVProbs;

  curr_entropy_hdr_.y_mode_probs = kDefaultYModeProbs;

  curr_entropy_hdr_.uv_mode_probs = kDefaultUVModeProbs;
}

bool Vp8Parser::ParseTokenProbs(Vp8EntropyHeader* ehdr,
                                bool update_curr_probs) {
  for (size_t i = 0; i < kNumBlockTypes; ++i) {
    for (size_t j = 0; j < kNumCoeffBands; ++j) {
      for (size_t k = 0; k < kNumPrevCoeffContexts; ++k) {
        for (size_t l = 0; l < kNumEntropyNodes; ++l) {
          bool coeff_prob_update_flag;
          UNSAFE_TODO(BD_READ_BOOL_WITH_PROB_OR_RETURN(
              &coeff_prob_update_flag, kCoeffUpdateProbs[i][j][k][l]));
          if (coeff_prob_update_flag)
            UNSAFE_TODO(
                BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->coeff_probs[i][j][k][l]));
        }
      }
    }
  }

  if (update_curr_probs) {
    curr_entropy_hdr_.coeff_probs = ehdr->coeff_probs;
  }

  return true;
}

bool Vp8Parser::ParseIntraProbs(Vp8EntropyHeader* ehdr,
                                bool update_curr_probs,
                                bool keyframe) {
  if (keyframe) {
    ehdr->y_mode_probs = kKeyframeYModeProbs;

    ehdr->uv_mode_probs = kKeyframeUVModeProbs;
  } else {
    bool intra_16x16_prob_update_flag;
    BD_READ_BOOL_OR_RETURN(&intra_16x16_prob_update_flag);
    if (intra_16x16_prob_update_flag) {
      for (size_t i = 0; i < kNumYModeProbs; ++i)
        UNSAFE_TODO(BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->y_mode_probs[i]));

      if (update_curr_probs) {
        curr_entropy_hdr_.y_mode_probs = ehdr->y_mode_probs;
      }
    }

    bool intra_chroma_prob_update_flag;
    BD_READ_BOOL_OR_RETURN(&intra_chroma_prob_update_flag);
    if (intra_chroma_prob_update_flag) {
      for (size_t i = 0; i < kNumUVModeProbs; ++i)
        UNSAFE_TODO(BD_READ_UNSIGNED_OR_RETURN(8, &ehdr->uv_mode_probs[i]));

      if (update_curr_probs) {
        curr_entropy_hdr_.uv_mode_probs = ehdr->uv_mode_probs;
      }
    }
  }

  return true;
}

bool Vp8Parser::ParseMVProbs(Vp8EntropyHeader* ehdr, bool update_curr_probs) {
  for (size_t mv_ctx = 0; mv_ctx < kNumMVContexts; ++mv_ctx) {
    for (size_t p = 0; p < kNumMVProbs; ++p) {
      bool mv_prob_update_flag;
      BD_READ_BOOL_WITH_PROB_OR_RETURN(&mv_prob_update_flag,
                                       kMVUpdateProbs[mv_ctx][p]);
      if (mv_prob_update_flag) {
        uint8_t prob;
        BD_READ_UNSIGNED_OR_RETURN(7, &prob);
        UNSAFE_TODO(ehdr->mv_probs[mv_ctx][p]) = prob ? (prob << 1) : 1;
      }
    }
  }

  if (update_curr_probs) {
    curr_entropy_hdr_.mv_probs = ehdr->mv_probs;
  }

  return true;
}

bool Vp8Parser::ParsePartitions(Vp8FrameHeader* fhdr) {
  CHECK_GE(fhdr->num_of_dct_partitions, 1u);
  CHECK_LE(fhdr->num_of_dct_partitions, kMaxDCTPartitions);

  // DCT partitions start after the first partition and partition size values
  // that follow it. There are num_of_dct_partitions - 1 sizes stored in the
  // stream after the first partition, each 3 bytes long. The size of last
  // DCT partition is not stored in the stream, but is instead calculated by
  // taking the remainder of the frame size after the penultimate DCT partition.
  size_t first_dct_pos;
  base::CheckedNumeric<size_t> first_dct_pos_checked = fhdr->first_part_offset;
  first_dct_pos_checked += fhdr->first_part_size;
  first_dct_pos_checked += (fhdr->num_of_dct_partitions - 1) * 3;
  if (!first_dct_pos_checked.AssignIfValid(&first_dct_pos)) {
    return false;
  }

  // Make sure we have enough data for the first partition and partition sizes.
  if (fhdr->frame_size < first_dct_pos)
    return false;

  // Total size of all DCT partitions.
  size_t bytes_left = fhdr->frame_size - first_dct_pos;

  // Position ourselves at the beginning of partition size values.
  const uint8_t* ptr = UNSAFE_TODO(
      fhdr->data + base::checked_cast<size_t>(fhdr->first_part_offset) +
      fhdr->first_part_size);

  // Read sizes from the stream (if present).
  for (size_t i = 0; i < fhdr->num_of_dct_partitions - 1; ++i) {
    fhdr->dct_partition_sizes[i] =
        (UNSAFE_TODO(ptr[2]) << 16) | (UNSAFE_TODO(ptr[1]) << 8) | ptr[0];

    // Make sure we have enough data in the stream for ith partition and
    // subtract its size from total.
    if (bytes_left < fhdr->dct_partition_sizes[i])
      return false;

    bytes_left -= fhdr->dct_partition_sizes[i];

    // Move to the position of the next partition size value.
    UNSAFE_TODO(ptr += 3);
  }

  // The remainder of the data belongs to the last DCT partition.
  fhdr->dct_partition_sizes[fhdr->num_of_dct_partitions - 1] = bytes_left;

  DVLOG(4) << "Control part size: " << fhdr->first_part_size;
  for (size_t i = 0; i < fhdr->num_of_dct_partitions; ++i)
    DVLOG(4) << "DCT part " << i << " size: " << fhdr->dct_partition_sizes[i];

  return true;
}

}  // namespace media