media/filters/h264

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This source file includes following definitions.
IsPSlice
IsBSlice
IsISlice
IsSPSlice
IsSISlice
Reset
SetStream
GetPPS
GetSPS
IsStartCode
FindStartCode
LocateNALU
ReadUE
ReadSE
AdvanceToNextNALU
DefaultScalingList4x4
DefaultScalingList8x8
FallbackScalingList4x4
FallbackScalingList8x8
ParseScalingList
ParseSPSScalingLists
ParsePPSScalingLists
ParseAndIgnoreHRDParameters
ParseVUIParameters
FillDefaultSeqScalingLists
ParseSPS
ParsePPS
ParseRefPicListModification
ParseRefPicListModifications
ParseWeightingFactors
ParsePredWeightTable
ParseDecRefPicMarking
ParseSliceHeader
ParseSEI
// Copyright 2014 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/stl_util.h"

#include "media/filters/h264_parser.h"

namespace media {

bool H264SliceHeader::IsPSlice() const {
  return (slice_type % 5 == kPSlice);
}

bool H264SliceHeader::IsBSlice() const {
  return (slice_type % 5 == kBSlice);
}

bool H264SliceHeader::IsISlice() const {
  return (slice_type % 5 == kISlice);
}

bool H264SliceHeader::IsSPSlice() const {
  return (slice_type % 5 == kSPSlice);
}

bool H264SliceHeader::IsSISlice() const {
  return (slice_type % 5 == kSISlice);
}

H264NALU::H264NALU() {
  memset(this, 0, sizeof(*this));
}

H264SPS::H264SPS() {
  memset(this, 0, sizeof(*this));
}

H264PPS::H264PPS() {
  memset(this, 0, sizeof(*this));
}

H264SliceHeader::H264SliceHeader() {
  memset(this, 0, sizeof(*this));
}

H264SEIMessage::H264SEIMessage() {
  memset(this, 0, sizeof(*this));
}

#define READ_BITS_OR_RETURN(num_bits, out)                                 \
  do {                                                                     \
    int _out;                                                              \
    if (!br_.ReadBits(num_bits, &_out)) {                                  \
      DVLOG(1)                                                             \
          << "Error in stream: unexpected EOS while trying to read " #out; \
      return kInvalidStream;                                               \
    }                                                                      \
    *out = _out;                                                           \
  } while (0)

#define READ_BOOL_OR_RETURN(out)                                           \
  do {                                                                     \
    int _out;                                                              \
    if (!br_.ReadBits(1, &_out)) {                                         \
      DVLOG(1)                                                             \
          << "Error in stream: unexpected EOS while trying to read " #out; \
      return kInvalidStream;                                               \
    }                                                                      \
    *out = _out != 0;                                                      \
  } while (0)

#define READ_UE_OR_RETURN(out)                                                 \
  do {                                                                         \
    if (ReadUE(out) != kOk) {                                                  \
      DVLOG(1) << "Error in stream: invalid value while trying to read " #out; \
      return kInvalidStream;                                                   \
    }                                                                          \
  } while (0)

#define READ_SE_OR_RETURN(out)                                                 \
  do {                                                                         \
    if (ReadSE(out) != kOk) {                                                  \
      DVLOG(1) << "Error in stream: invalid value while trying to read " #out; \
      return kInvalidStream;                                                   \
    }                                                                          \
  } while (0)

#define IN_RANGE_OR_RETURN(val, min, max)                                   \
  do {                                                                      \
    if ((val) < (min) || (val) > (max)) {                                   \
      DVLOG(1) << "Error in stream: invalid value, expected " #val " to be" \
               << " in range [" << (min) << ":" << (max) << "]"             \
               << " found " << (val) << " instead";                         \
      return kInvalidStream;                                                \
    }                                                                       \
  } while (0)

#define TRUE_OR_RETURN(a)                                            \
  do {                                                               \
    if (!(a)) {                                                      \
      DVLOG(1) << "Error in stream: invalid value, expected " << #a; \
      return kInvalidStream;                                         \
    }                                                                \
  } while (0)

enum AspectRatioIdc {
  kExtendedSar = 255,
};

// ISO 14496 part 10
// VUI parameters: Table E-1 "Meaning of sample aspect ratio indicator"
static const int kTableSarWidth[] = {
  0, 1, 12, 10, 16, 40, 24, 20, 32, 80, 18, 15, 64, 160, 4, 3, 2
};
static const int kTableSarHeight[] = {
  0, 1, 11, 11, 11, 33, 11, 11, 11, 33, 11, 11, 33, 99, 3, 2, 1
};
COMPILE_ASSERT(arraysize(kTableSarWidth) == arraysize(kTableSarHeight),
               sar_tables_must_have_same_size);

H264Parser::H264Parser() {
  Reset();
}

H264Parser::~H264Parser() {
  STLDeleteValues(&active_SPSes_);
  STLDeleteValues(&active_PPSes_);
}

void H264Parser::Reset() {
  stream_ = NULL;
  bytes_left_ = 0;
}

void H264Parser::SetStream(const uint8* stream, off_t stream_size) {
  DCHECK(stream);
  DCHECK_GT(stream_size, 0);

  stream_ = stream;
  bytes_left_ = stream_size;
}

const H264PPS* H264Parser::GetPPS(int pps_id) {
  return active_PPSes_[pps_id];
}

const H264SPS* H264Parser::GetSPS(int sps_id) {
  return active_SPSes_[sps_id];
}

static inline bool IsStartCode(const uint8* data) {
  return data[0] == 0x00 && data[1] == 0x00 && data[2] == 0x01;
}

// static
bool H264Parser::FindStartCode(const uint8* data, off_t data_size,
                               off_t* offset, off_t* start_code_size) {
  DCHECK_GE(data_size, 0);
  off_t bytes_left = data_size;

  while (bytes_left >= 3) {
    if (IsStartCode(data)) {
      // Found three-byte start code, set pointer at its beginning.
      *offset = data_size - bytes_left;
      *start_code_size = 3;

      // If there is a zero byte before this start code,
      // then it's actually a four-byte start code, so backtrack one byte.
      if (*offset > 0 && *(data - 1) == 0x00) {
        --(*offset);
        ++(*start_code_size);
      }

      return true;
    }

    ++data;
    --bytes_left;
  }

  // End of data: offset is pointing to the first byte that was not considered
  // as a possible start of a start code.
  // Note: there is no security issue when receiving a negative |data_size|
  // since in this case, |bytes_left| is equal to |data_size| and thus
  // |*offset| is equal to 0 (valid offset).
  *offset = data_size - bytes_left;
  *start_code_size = 0;
  return false;
}

bool H264Parser::LocateNALU(off_t* nalu_size, off_t* start_code_size) {
  // Find the start code of next NALU.
  off_t nalu_start_off = 0;
  off_t annexb_start_code_size = 0;
  if (!FindStartCode(stream_, bytes_left_,
                     &nalu_start_off, &annexb_start_code_size)) {
    DVLOG(4) << "Could not find start code, end of stream?";
    return false;
  }

  // Move the stream to the beginning of the NALU (pointing at the start code).
  stream_ += nalu_start_off;
  bytes_left_ -= nalu_start_off;

  const uint8* nalu_data = stream_ + annexb_start_code_size;
  off_t max_nalu_data_size = bytes_left_ - annexb_start_code_size;
  if (max_nalu_data_size <= 0) {
    DVLOG(3) << "End of stream";
    return false;
  }

  // Find the start code of next NALU;
  // if successful, |nalu_size_without_start_code| is the number of bytes from
  // after previous start code to before this one;
  // if next start code is not found, it is still a valid NALU since there
  // are some bytes left after the first start code: all the remaining bytes
  // belong to the current NALU.
  off_t next_start_code_size = 0;
  off_t nalu_size_without_start_code = 0;
  if (!FindStartCode(nalu_data, max_nalu_data_size,
                     &nalu_size_without_start_code, &next_start_code_size)) {
    nalu_size_without_start_code = max_nalu_data_size;
  }
  *nalu_size = nalu_size_without_start_code + annexb_start_code_size;
  *start_code_size = annexb_start_code_size;
  return true;
}

H264Parser::Result H264Parser::ReadUE(int* val) {
  int num_bits = -1;
  int bit;
  int rest;

  // Count the number of contiguous zero bits.
  do {
    READ_BITS_OR_RETURN(1, &bit);
    num_bits++;
  } while (bit == 0);

  if (num_bits > 31)
    return kInvalidStream;

  // Calculate exp-Golomb code value of size num_bits.
  *val = (1 << num_bits) - 1;

  if (num_bits > 0) {
    READ_BITS_OR_RETURN(num_bits, &rest);
    *val += rest;
  }

  return kOk;
}

H264Parser::Result H264Parser::ReadSE(int* val) {
  int ue;
  Result res;

  // See Chapter 9 in the spec.
  res = ReadUE(&ue);
  if (res != kOk)
    return res;

  if (ue % 2 == 0)
    *val = -(ue / 2);
  else
    *val = ue / 2 + 1;

  return kOk;
}

H264Parser::Result H264Parser::AdvanceToNextNALU(H264NALU* nalu) {
  off_t start_code_size;
  off_t nalu_size_with_start_code;
  if (!LocateNALU(&nalu_size_with_start_code, &start_code_size)) {
    DVLOG(4) << "Could not find next NALU, bytes left in stream: "
             << bytes_left_;
    return kEOStream;
  }

  nalu->data = stream_ + start_code_size;
  nalu->size = nalu_size_with_start_code - start_code_size;
  DVLOG(4) << "NALU found: size=" << nalu_size_with_start_code;

  // Initialize bit reader at the start of found NALU.
  if (!br_.Initialize(nalu->data, nalu->size))
    return kEOStream;

  // Move parser state to after this NALU, so next time AdvanceToNextNALU
  // is called, we will effectively be skipping it;
  // other parsing functions will use the position saved
  // in bit reader for parsing, so we don't have to remember it here.
  stream_ += nalu_size_with_start_code;
  bytes_left_ -= nalu_size_with_start_code;

  // Read NALU header, skip the forbidden_zero_bit, but check for it.
  int data;
  READ_BITS_OR_RETURN(1, &data);
  TRUE_OR_RETURN(data == 0);

  READ_BITS_OR_RETURN(2, &nalu->nal_ref_idc);
  READ_BITS_OR_RETURN(5, &nalu->nal_unit_type);

  DVLOG(4) << "NALU type: " << static_cast<int>(nalu->nal_unit_type)
           << " at: " << reinterpret_cast<const void*>(nalu->data)
           << " size: " << nalu->size
           << " ref: " << static_cast<int>(nalu->nal_ref_idc);

  return kOk;
}

// Default scaling lists (per spec).
static const int kDefault4x4Intra[kH264ScalingList4x4Length] = {
    6, 13, 13, 20, 20, 20, 28, 28, 28, 28, 32, 32, 32, 37, 37, 42, };

static const int kDefault4x4Inter[kH264ScalingList4x4Length] = {
    10, 14, 14, 20, 20, 20, 24, 24, 24, 24, 27, 27, 27, 30, 30, 34, };

static const int kDefault8x8Intra[kH264ScalingList8x8Length] = {
    6,  10, 10, 13, 11, 13, 16, 16, 16, 16, 18, 18, 18, 18, 18, 23,
    23, 23, 23, 23, 23, 25, 25, 25, 25, 25, 25, 25, 27, 27, 27, 27,
    27, 27, 27, 27, 29, 29, 29, 29, 29, 29, 29, 31, 31, 31, 31, 31,
    31, 33, 33, 33, 33, 33, 36, 36, 36, 36, 38, 38, 38, 40, 40, 42, };

static const int kDefault8x8Inter[kH264ScalingList8x8Length] = {
    9,  13, 13, 15, 13, 15, 17, 17, 17, 17, 19, 19, 19, 19, 19, 21,
    21, 21, 21, 21, 21, 22, 22, 22, 22, 22, 22, 22, 24, 24, 24, 24,
    24, 24, 24, 24, 25, 25, 25, 25, 25, 25, 25, 27, 27, 27, 27, 27,
    27, 28, 28, 28, 28, 28, 30, 30, 30, 30, 32, 32, 32, 33, 33, 35, };

static inline void DefaultScalingList4x4(
    int i,
    int scaling_list4x4[][kH264ScalingList4x4Length]) {
  DCHECK_LT(i, 6);

  if (i < 3)
    memcpy(scaling_list4x4[i], kDefault4x4Intra, sizeof(kDefault4x4Intra));
  else if (i < 6)
    memcpy(scaling_list4x4[i], kDefault4x4Inter, sizeof(kDefault4x4Inter));
}

static inline void DefaultScalingList8x8(
    int i,
    int scaling_list8x8[][kH264ScalingList8x8Length]) {
  DCHECK_LT(i, 6);

  if (i % 2 == 0)
    memcpy(scaling_list8x8[i], kDefault8x8Intra, sizeof(kDefault8x8Intra));
  else
    memcpy(scaling_list8x8[i], kDefault8x8Inter, sizeof(kDefault8x8Inter));
}

static void FallbackScalingList4x4(
    int i,
    const int default_scaling_list_intra[],
    const int default_scaling_list_inter[],
    int scaling_list4x4[][kH264ScalingList4x4Length]) {
  static const int kScalingList4x4ByteSize =
      sizeof(scaling_list4x4[0][0]) * kH264ScalingList4x4Length;

  switch (i) {
    case 0:
      memcpy(scaling_list4x4[i], default_scaling_list_intra,
             kScalingList4x4ByteSize);
      break;

    case 1:
      memcpy(scaling_list4x4[i], scaling_list4x4[0], kScalingList4x4ByteSize);
      break;

    case 2:
      memcpy(scaling_list4x4[i], scaling_list4x4[1], kScalingList4x4ByteSize);
      break;

    case 3:
      memcpy(scaling_list4x4[i], default_scaling_list_inter,
             kScalingList4x4ByteSize);
      break;

    case 4:
      memcpy(scaling_list4x4[i], scaling_list4x4[3], kScalingList4x4ByteSize);
      break;

    case 5:
      memcpy(scaling_list4x4[i], scaling_list4x4[4], kScalingList4x4ByteSize);
      break;

    default:
      NOTREACHED();
      break;
  }
}

static void FallbackScalingList8x8(
    int i,
    const int default_scaling_list_intra[],
    const int default_scaling_list_inter[],
    int scaling_list8x8[][kH264ScalingList8x8Length]) {
  static const int kScalingList8x8ByteSize =
      sizeof(scaling_list8x8[0][0]) * kH264ScalingList8x8Length;

  switch (i) {
    case 0:
      memcpy(scaling_list8x8[i], default_scaling_list_intra,
             kScalingList8x8ByteSize);
      break;

    case 1:
      memcpy(scaling_list8x8[i], default_scaling_list_inter,
             kScalingList8x8ByteSize);
      break;

    case 2:
      memcpy(scaling_list8x8[i], scaling_list8x8[0], kScalingList8x8ByteSize);
      break;

    case 3:
      memcpy(scaling_list8x8[i], scaling_list8x8[1], kScalingList8x8ByteSize);
      break;

    case 4:
      memcpy(scaling_list8x8[i], scaling_list8x8[2], kScalingList8x8ByteSize);
      break;

    case 5:
      memcpy(scaling_list8x8[i], scaling_list8x8[3], kScalingList8x8ByteSize);
      break;

    default:
      NOTREACHED();
      break;
  }
}

H264Parser::Result H264Parser::ParseScalingList(int size,
                                                int* scaling_list,
                                                bool* use_default) {
  // See chapter 7.3.2.1.1.1.
  int last_scale = 8;
  int next_scale = 8;
  int delta_scale;

  *use_default = false;

  for (int j = 0; j < size; ++j) {
    if (next_scale != 0) {
      READ_SE_OR_RETURN(&delta_scale);
      IN_RANGE_OR_RETURN(delta_scale, -128, 127);
      next_scale = (last_scale + delta_scale + 256) & 0xff;

      if (j == 0 && next_scale == 0) {
        *use_default = true;
        return kOk;
      }
    }

    scaling_list[j] = (next_scale == 0) ? last_scale : next_scale;
    last_scale = scaling_list[j];
  }

  return kOk;
}

H264Parser::Result H264Parser::ParseSPSScalingLists(H264SPS* sps) {
  // See 7.4.2.1.1.
  bool seq_scaling_list_present_flag;
  bool use_default;
  Result res;

  // Parse scaling_list4x4.
  for (int i = 0; i < 6; ++i) {
    READ_BOOL_OR_RETURN(&seq_scaling_list_present_flag);

    if (seq_scaling_list_present_flag) {
      res = ParseScalingList(arraysize(sps->scaling_list4x4[i]),
                             sps->scaling_list4x4[i],
                             &use_default);
      if (res != kOk)
        return res;

      if (use_default)
        DefaultScalingList4x4(i, sps->scaling_list4x4);

    } else {
      FallbackScalingList4x4(
          i, kDefault4x4Intra, kDefault4x4Inter, sps->scaling_list4x4);
    }
  }

  // Parse scaling_list8x8.
  for (int i = 0; i < ((sps->chroma_format_idc != 3) ? 2 : 6); ++i) {
    READ_BOOL_OR_RETURN(&seq_scaling_list_present_flag);

    if (seq_scaling_list_present_flag) {
      res = ParseScalingList(arraysize(sps->scaling_list8x8[i]),
                             sps->scaling_list8x8[i],
                             &use_default);
      if (res != kOk)
        return res;

      if (use_default)
        DefaultScalingList8x8(i, sps->scaling_list8x8);

    } else {
      FallbackScalingList8x8(
          i, kDefault8x8Intra, kDefault8x8Inter, sps->scaling_list8x8);
    }
  }

  return kOk;
}

H264Parser::Result H264Parser::ParsePPSScalingLists(const H264SPS& sps,
                                                    H264PPS* pps) {
  // See 7.4.2.2.
  bool pic_scaling_list_present_flag;
  bool use_default;
  Result res;

  for (int i = 0; i < 6; ++i) {
    READ_BOOL_OR_RETURN(&pic_scaling_list_present_flag);

    if (pic_scaling_list_present_flag) {
      res = ParseScalingList(arraysize(pps->scaling_list4x4[i]),
                             pps->scaling_list4x4[i],
                             &use_default);
      if (res != kOk)
        return res;

      if (use_default)
        DefaultScalingList4x4(i, pps->scaling_list4x4);

    } else {
      if (sps.seq_scaling_matrix_present_flag) {
        // Table 7-2 fallback rule A in spec.
        FallbackScalingList4x4(
            i, kDefault4x4Intra, kDefault4x4Inter, pps->scaling_list4x4);
      } else {
        // Table 7-2 fallback rule B in spec.
        FallbackScalingList4x4(i,
                               sps.scaling_list4x4[0],
                               sps.scaling_list4x4[3],
                               pps->scaling_list4x4);
      }
    }
  }

  if (pps->transform_8x8_mode_flag) {
    for (int i = 0; i < ((sps.chroma_format_idc != 3) ? 2 : 6); ++i) {
      READ_BOOL_OR_RETURN(&pic_scaling_list_present_flag);

      if (pic_scaling_list_present_flag) {
        res = ParseScalingList(arraysize(pps->scaling_list8x8[i]),
                               pps->scaling_list8x8[i],
                               &use_default);
        if (res != kOk)
          return res;

        if (use_default)
          DefaultScalingList8x8(i, pps->scaling_list8x8);

      } else {
        if (sps.seq_scaling_matrix_present_flag) {
          // Table 7-2 fallback rule A in spec.
          FallbackScalingList8x8(
              i, kDefault8x8Intra, kDefault8x8Inter, pps->scaling_list8x8);
        } else {
          // Table 7-2 fallback rule B in spec.
          FallbackScalingList8x8(i,
                                 sps.scaling_list8x8[0],
                                 sps.scaling_list8x8[1],
                                 pps->scaling_list8x8);
        }
      }
    }
  }
  return kOk;
}

H264Parser::Result H264Parser::ParseAndIgnoreHRDParameters(
    bool* hrd_parameters_present) {
  int data;
  READ_BOOL_OR_RETURN(&data);  // {nal,vcl}_hrd_parameters_present_flag
  if (!data)
    return kOk;

  *hrd_parameters_present = true;

  int cpb_cnt_minus1;
  READ_UE_OR_RETURN(&cpb_cnt_minus1);
  IN_RANGE_OR_RETURN(cpb_cnt_minus1, 0, 31);
  READ_BITS_OR_RETURN(8, &data);  // bit_rate_scale, cpb_size_scale
  for (int i = 0; i <= cpb_cnt_minus1; ++i) {
    READ_UE_OR_RETURN(&data);  // bit_rate_value_minus1[i]
    READ_UE_OR_RETURN(&data);  // cpb_size_value_minus1[i]
    READ_BOOL_OR_RETURN(&data);  // cbr_flag
  }
  READ_BITS_OR_RETURN(20, &data);  // cpb/dpb delays, etc.

  return kOk;
}

H264Parser::Result H264Parser::ParseVUIParameters(H264SPS* sps) {
  bool aspect_ratio_info_present_flag;
  READ_BOOL_OR_RETURN(&aspect_ratio_info_present_flag);
  if (aspect_ratio_info_present_flag) {
    int aspect_ratio_idc;
    READ_BITS_OR_RETURN(8, &aspect_ratio_idc);
    if (aspect_ratio_idc == kExtendedSar) {
      READ_BITS_OR_RETURN(16, &sps->sar_width);
      READ_BITS_OR_RETURN(16, &sps->sar_height);
    } else {
      const int max_aspect_ratio_idc = arraysize(kTableSarWidth) - 1;
      IN_RANGE_OR_RETURN(aspect_ratio_idc, 0, max_aspect_ratio_idc);
      sps->sar_width = kTableSarWidth[aspect_ratio_idc];
      sps->sar_height = kTableSarHeight[aspect_ratio_idc];
    }
  }

  int data;
  // Read and ignore overscan and video signal type info.
  READ_BOOL_OR_RETURN(&data);  // overscan_info_present_flag
  if (data)
    READ_BOOL_OR_RETURN(&data);  // overscan_appropriate_flag

  READ_BOOL_OR_RETURN(&data);  // video_signal_type_present_flag
  if (data) {
    READ_BITS_OR_RETURN(3, &data);  // video_format
    READ_BOOL_OR_RETURN(&data);  // video_full_range_flag
    READ_BOOL_OR_RETURN(&data);  // colour_description_present_flag
    if (data)
      READ_BITS_OR_RETURN(24, &data);  // color description syntax elements
  }

  READ_BOOL_OR_RETURN(&data);  // chroma_loc_info_present_flag
  if (data) {
    READ_UE_OR_RETURN(&data);  // chroma_sample_loc_type_top_field
    READ_UE_OR_RETURN(&data);  // chroma_sample_loc_type_bottom_field
  }

  // Read and ignore timing info.
  READ_BOOL_OR_RETURN(&data);  // timing_info_present_flag
  if (data) {
    READ_BITS_OR_RETURN(16, &data);  // num_units_in_tick
    READ_BITS_OR_RETURN(16, &data);  // num_units_in_tick
    READ_BITS_OR_RETURN(16, &data);  // time_scale
    READ_BITS_OR_RETURN(16, &data);  // time_scale
    READ_BOOL_OR_RETURN(&data);  // fixed_frame_rate_flag
  }

  // Read and ignore NAL HRD parameters, if present.
  bool hrd_parameters_present = false;
  Result res = ParseAndIgnoreHRDParameters(&hrd_parameters_present);
  if (res != kOk)
    return res;

  // Read and ignore VCL HRD parameters, if present.
  res = ParseAndIgnoreHRDParameters(&hrd_parameters_present);
  if (res != kOk)
    return res;

  if (hrd_parameters_present)  // One of NAL or VCL params present is enough.
    READ_BOOL_OR_RETURN(&data);  // low_delay_hrd_flag

  READ_BOOL_OR_RETURN(&data);  // pic_struct_present_flag
  READ_BOOL_OR_RETURN(&sps->bitstream_restriction_flag);
  if (sps->bitstream_restriction_flag) {
    READ_BOOL_OR_RETURN(&data);  // motion_vectors_over_pic_boundaries_flag
    READ_UE_OR_RETURN(&data);  // max_bytes_per_pic_denom
    READ_UE_OR_RETURN(&data);  // max_bits_per_mb_denom
    READ_UE_OR_RETURN(&data);  // log2_max_mv_length_horizontal
    READ_UE_OR_RETURN(&data);  // log2_max_mv_length_vertical
    READ_UE_OR_RETURN(&sps->max_num_reorder_frames);
    READ_UE_OR_RETURN(&sps->max_dec_frame_buffering);
    TRUE_OR_RETURN(sps->max_dec_frame_buffering >= sps->max_num_ref_frames);
    IN_RANGE_OR_RETURN(
        sps->max_num_reorder_frames, 0, sps->max_dec_frame_buffering);
  }

  return kOk;
}

static void FillDefaultSeqScalingLists(H264SPS* sps) {
  for (int i = 0; i < 6; ++i)
    for (int j = 0; j < kH264ScalingList4x4Length; ++j)
      sps->scaling_list4x4[i][j] = 16;

  for (int i = 0; i < 6; ++i)
    for (int j = 0; j < kH264ScalingList8x8Length; ++j)
      sps->scaling_list8x8[i][j] = 16;
}

H264Parser::Result H264Parser::ParseSPS(int* sps_id) {
  // See 7.4.2.1.
  int data;
  Result res;

  *sps_id = -1;

  scoped_ptr<H264SPS> sps(new H264SPS());

  READ_BITS_OR_RETURN(8, &sps->profile_idc);
  READ_BOOL_OR_RETURN(&sps->constraint_set0_flag);
  READ_BOOL_OR_RETURN(&sps->constraint_set1_flag);
  READ_BOOL_OR_RETURN(&sps->constraint_set2_flag);
  READ_BOOL_OR_RETURN(&sps->constraint_set3_flag);
  READ_BOOL_OR_RETURN(&sps->constraint_set4_flag);
  READ_BOOL_OR_RETURN(&sps->constraint_set5_flag);
  READ_BITS_OR_RETURN(2, &data);  // reserved_zero_2bits
  READ_BITS_OR_RETURN(8, &sps->level_idc);
  READ_UE_OR_RETURN(&sps->seq_parameter_set_id);
  TRUE_OR_RETURN(sps->seq_parameter_set_id < 32);

  if (sps->profile_idc == 100 || sps->profile_idc == 110 ||
      sps->profile_idc == 122 || sps->profile_idc == 244 ||
      sps->profile_idc == 44 || sps->profile_idc == 83 ||
      sps->profile_idc == 86 || sps->profile_idc == 118 ||
      sps->profile_idc == 128) {
    READ_UE_OR_RETURN(&sps->chroma_format_idc);
    TRUE_OR_RETURN(sps->chroma_format_idc < 4);

    if (sps->chroma_format_idc == 3)
      READ_BOOL_OR_RETURN(&sps->separate_colour_plane_flag);

    READ_UE_OR_RETURN(&sps->bit_depth_luma_minus8);
    TRUE_OR_RETURN(sps->bit_depth_luma_minus8 < 7);

    READ_UE_OR_RETURN(&sps->bit_depth_chroma_minus8);
    TRUE_OR_RETURN(sps->bit_depth_chroma_minus8 < 7);

    READ_BOOL_OR_RETURN(&sps->qpprime_y_zero_transform_bypass_flag);
    READ_BOOL_OR_RETURN(&sps->seq_scaling_matrix_present_flag);

    if (sps->seq_scaling_matrix_present_flag) {
      DVLOG(4) << "Scaling matrix present";
      res = ParseSPSScalingLists(sps.get());
      if (res != kOk)
        return res;
    } else {
      FillDefaultSeqScalingLists(sps.get());
    }
  } else {
    sps->chroma_format_idc = 1;
    FillDefaultSeqScalingLists(sps.get());
  }

  if (sps->separate_colour_plane_flag)
    sps->chroma_array_type = 0;
  else
    sps->chroma_array_type = sps->chroma_format_idc;

  READ_UE_OR_RETURN(&sps->log2_max_frame_num_minus4);
  TRUE_OR_RETURN(sps->log2_max_frame_num_minus4 < 13);

  READ_UE_OR_RETURN(&sps->pic_order_cnt_type);
  TRUE_OR_RETURN(sps->pic_order_cnt_type < 3);

  sps->expected_delta_per_pic_order_cnt_cycle = 0;
  if (sps->pic_order_cnt_type == 0) {
    READ_UE_OR_RETURN(&sps->log2_max_pic_order_cnt_lsb_minus4);
    TRUE_OR_RETURN(sps->log2_max_pic_order_cnt_lsb_minus4 < 13);
  } else if (sps->pic_order_cnt_type == 1) {
    READ_BOOL_OR_RETURN(&sps->delta_pic_order_always_zero_flag);
    READ_SE_OR_RETURN(&sps->offset_for_non_ref_pic);
    READ_SE_OR_RETURN(&sps->offset_for_top_to_bottom_field);
    READ_UE_OR_RETURN(&sps->num_ref_frames_in_pic_order_cnt_cycle);
    TRUE_OR_RETURN(sps->num_ref_frames_in_pic_order_cnt_cycle < 255);

    for (int i = 0; i < sps->num_ref_frames_in_pic_order_cnt_cycle; ++i) {
      READ_SE_OR_RETURN(&sps->offset_for_ref_frame[i]);
      sps->expected_delta_per_pic_order_cnt_cycle +=
          sps->offset_for_ref_frame[i];
    }
  }

  READ_UE_OR_RETURN(&sps->max_num_ref_frames);
  READ_BOOL_OR_RETURN(&sps->gaps_in_frame_num_value_allowed_flag);

  if (sps->gaps_in_frame_num_value_allowed_flag)
    return kUnsupportedStream;

  READ_UE_OR_RETURN(&sps->pic_width_in_mbs_minus1);
  READ_UE_OR_RETURN(&sps->pic_height_in_map_units_minus1);

  READ_BOOL_OR_RETURN(&sps->frame_mbs_only_flag);
  if (!sps->frame_mbs_only_flag)
    READ_BOOL_OR_RETURN(&sps->mb_adaptive_frame_field_flag);

  READ_BOOL_OR_RETURN(&sps->direct_8x8_inference_flag);

  READ_BOOL_OR_RETURN(&sps->frame_cropping_flag);
  if (sps->frame_cropping_flag) {
    READ_UE_OR_RETURN(&sps->frame_crop_left_offset);
    READ_UE_OR_RETURN(&sps->frame_crop_right_offset);
    READ_UE_OR_RETURN(&sps->frame_crop_top_offset);
    READ_UE_OR_RETURN(&sps->frame_crop_bottom_offset);
  }

  READ_BOOL_OR_RETURN(&sps->vui_parameters_present_flag);
  if (sps->vui_parameters_present_flag) {
    DVLOG(4) << "VUI parameters present";
    res = ParseVUIParameters(sps.get());
    if (res != kOk)
      return res;
  }

  // If an SPS with the same id already exists, replace it.
  *sps_id = sps->seq_parameter_set_id;
  delete active_SPSes_[*sps_id];
  active_SPSes_[*sps_id] = sps.release();

  return kOk;
}

H264Parser::Result H264Parser::ParsePPS(int* pps_id) {
  // See 7.4.2.2.
  const H264SPS* sps;
  Result res;

  *pps_id = -1;

  scoped_ptr<H264PPS> pps(new H264PPS());

  READ_UE_OR_RETURN(&pps->pic_parameter_set_id);
  READ_UE_OR_RETURN(&pps->seq_parameter_set_id);
  TRUE_OR_RETURN(pps->seq_parameter_set_id < 32);

  sps = GetSPS(pps->seq_parameter_set_id);
  TRUE_OR_RETURN(sps);

  READ_BOOL_OR_RETURN(&pps->entropy_coding_mode_flag);
  READ_BOOL_OR_RETURN(&pps->bottom_field_pic_order_in_frame_present_flag);

  READ_UE_OR_RETURN(&pps->num_slice_groups_minus1);
  if (pps->num_slice_groups_minus1 > 1) {
    DVLOG(1) << "Slice groups not supported";
    return kUnsupportedStream;
  }

  READ_UE_OR_RETURN(&pps->num_ref_idx_l0_default_active_minus1);
  TRUE_OR_RETURN(pps->num_ref_idx_l0_default_active_minus1 < 32);

  READ_UE_OR_RETURN(&pps->num_ref_idx_l1_default_active_minus1);
  TRUE_OR_RETURN(pps->num_ref_idx_l1_default_active_minus1 < 32);

  READ_BOOL_OR_RETURN(&pps->weighted_pred_flag);
  READ_BITS_OR_RETURN(2, &pps->weighted_bipred_idc);
  TRUE_OR_RETURN(pps->weighted_bipred_idc < 3);

  READ_SE_OR_RETURN(&pps->pic_init_qp_minus26);
  IN_RANGE_OR_RETURN(pps->pic_init_qp_minus26, -26, 25);

  READ_SE_OR_RETURN(&pps->pic_init_qs_minus26);
  IN_RANGE_OR_RETURN(pps->pic_init_qs_minus26, -26, 25);

  READ_SE_OR_RETURN(&pps->chroma_qp_index_offset);
  IN_RANGE_OR_RETURN(pps->chroma_qp_index_offset, -12, 12);
  pps->second_chroma_qp_index_offset = pps->chroma_qp_index_offset;

  READ_BOOL_OR_RETURN(&pps->deblocking_filter_control_present_flag);
  READ_BOOL_OR_RETURN(&pps->constrained_intra_pred_flag);
  READ_BOOL_OR_RETURN(&pps->redundant_pic_cnt_present_flag);

  if (br_.HasMoreRBSPData()) {
    READ_BOOL_OR_RETURN(&pps->transform_8x8_mode_flag);
    READ_BOOL_OR_RETURN(&pps->pic_scaling_matrix_present_flag);

    if (pps->pic_scaling_matrix_present_flag) {
      DVLOG(4) << "Picture scaling matrix present";
      res = ParsePPSScalingLists(*sps, pps.get());
      if (res != kOk)
        return res;
    }

    READ_SE_OR_RETURN(&pps->second_chroma_qp_index_offset);
  }

  // If a PPS with the same id already exists, replace it.
  *pps_id = pps->pic_parameter_set_id;
  delete active_PPSes_[*pps_id];
  active_PPSes_[*pps_id] = pps.release();

  return kOk;
}

H264Parser::Result H264Parser::ParseRefPicListModification(
    int num_ref_idx_active_minus1,
    H264ModificationOfPicNum* ref_list_mods) {
  H264ModificationOfPicNum* pic_num_mod;

  if (num_ref_idx_active_minus1 >= 32)
    return kInvalidStream;

  for (int i = 0; i < 32; ++i) {
    pic_num_mod = &ref_list_mods[i];
    READ_UE_OR_RETURN(&pic_num_mod->modification_of_pic_nums_idc);
    TRUE_OR_RETURN(pic_num_mod->modification_of_pic_nums_idc < 4);

    switch (pic_num_mod->modification_of_pic_nums_idc) {
      case 0:
      case 1:
        READ_UE_OR_RETURN(&pic_num_mod->abs_diff_pic_num_minus1);
        break;

      case 2:
        READ_UE_OR_RETURN(&pic_num_mod->long_term_pic_num);
        break;

      case 3:
        // Per spec, list cannot be empty.
        if (i == 0)
          return kInvalidStream;
        return kOk;

      default:
        return kInvalidStream;
    }
  }

  // If we got here, we didn't get loop end marker prematurely,
  // so make sure it is there for our client.
  int modification_of_pic_nums_idc;
  READ_UE_OR_RETURN(&modification_of_pic_nums_idc);
  TRUE_OR_RETURN(modification_of_pic_nums_idc == 3);

  return kOk;
}

H264Parser::Result H264Parser::ParseRefPicListModifications(
    H264SliceHeader* shdr) {
  Result res;

  if (!shdr->IsISlice() && !shdr->IsSISlice()) {
    READ_BOOL_OR_RETURN(&shdr->ref_pic_list_modification_flag_l0);
    if (shdr->ref_pic_list_modification_flag_l0) {
      res = ParseRefPicListModification(shdr->num_ref_idx_l0_active_minus1,
                                        shdr->ref_list_l0_modifications);
      if (res != kOk)
        return res;
    }
  }

  if (shdr->IsBSlice()) {
    READ_BOOL_OR_RETURN(&shdr->ref_pic_list_modification_flag_l1);
    if (shdr->ref_pic_list_modification_flag_l1) {
      res = ParseRefPicListModification(shdr->num_ref_idx_l1_active_minus1,
                                        shdr->ref_list_l1_modifications);
      if (res != kOk)
        return res;
    }
  }

  return kOk;
}

H264Parser::Result H264Parser::ParseWeightingFactors(
    int num_ref_idx_active_minus1,
    int chroma_array_type,
    int luma_log2_weight_denom,
    int chroma_log2_weight_denom,
    H264WeightingFactors* w_facts) {

  int def_luma_weight = 1 << luma_log2_weight_denom;
  int def_chroma_weight = 1 << chroma_log2_weight_denom;

  for (int i = 0; i < num_ref_idx_active_minus1 + 1; ++i) {
    READ_BOOL_OR_RETURN(&w_facts->luma_weight_flag);
    if (w_facts->luma_weight_flag) {
      READ_SE_OR_RETURN(&w_facts->luma_weight[i]);
      IN_RANGE_OR_RETURN(w_facts->luma_weight[i], -128, 127);

      READ_SE_OR_RETURN(&w_facts->luma_offset[i]);
      IN_RANGE_OR_RETURN(w_facts->luma_offset[i], -128, 127);
    } else {
      w_facts->luma_weight[i] = def_luma_weight;
      w_facts->luma_offset[i] = 0;
    }

    if (chroma_array_type != 0) {
      READ_BOOL_OR_RETURN(&w_facts->chroma_weight_flag);
      if (w_facts->chroma_weight_flag) {
        for (int j = 0; j < 2; ++j) {
          READ_SE_OR_RETURN(&w_facts->chroma_weight[i][j]);
          IN_RANGE_OR_RETURN(w_facts->chroma_weight[i][j], -128, 127);

          READ_SE_OR_RETURN(&w_facts->chroma_offset[i][j]);
          IN_RANGE_OR_RETURN(w_facts->chroma_offset[i][j], -128, 127);
        }
      } else {
        for (int j = 0; j < 2; ++j) {
          w_facts->chroma_weight[i][j] = def_chroma_weight;
          w_facts->chroma_offset[i][j] = 0;
        }
      }
    }
  }

  return kOk;
}

H264Parser::Result H264Parser::ParsePredWeightTable(const H264SPS& sps,
                                                    H264SliceHeader* shdr) {
  READ_UE_OR_RETURN(&shdr->luma_log2_weight_denom);
  TRUE_OR_RETURN(shdr->luma_log2_weight_denom < 8);

  if (sps.chroma_array_type != 0)
    READ_UE_OR_RETURN(&shdr->chroma_log2_weight_denom);
  TRUE_OR_RETURN(shdr->chroma_log2_weight_denom < 8);

  Result res = ParseWeightingFactors(shdr->num_ref_idx_l0_active_minus1,
                                     sps.chroma_array_type,
                                     shdr->luma_log2_weight_denom,
                                     shdr->chroma_log2_weight_denom,
                                     &shdr->pred_weight_table_l0);
  if (res != kOk)
    return res;

  if (shdr->IsBSlice()) {
    res = ParseWeightingFactors(shdr->num_ref_idx_l1_active_minus1,
                                sps.chroma_array_type,
                                shdr->luma_log2_weight_denom,
                                shdr->chroma_log2_weight_denom,
                                &shdr->pred_weight_table_l1);
    if (res != kOk)
      return res;
  }

  return kOk;
}

H264Parser::Result H264Parser::ParseDecRefPicMarking(H264SliceHeader* shdr) {
  if (shdr->idr_pic_flag) {
    READ_BOOL_OR_RETURN(&shdr->no_output_of_prior_pics_flag);
    READ_BOOL_OR_RETURN(&shdr->long_term_reference_flag);
  } else {
    READ_BOOL_OR_RETURN(&shdr->adaptive_ref_pic_marking_mode_flag);

    H264DecRefPicMarking* marking;
    if (shdr->adaptive_ref_pic_marking_mode_flag) {
      size_t i;
      for (i = 0; i < arraysize(shdr->ref_pic_marking); ++i) {
        marking = &shdr->ref_pic_marking[i];

        READ_UE_OR_RETURN(&marking->memory_mgmnt_control_operation);
        if (marking->memory_mgmnt_control_operation == 0)
          break;

        if (marking->memory_mgmnt_control_operation == 1 ||
            marking->memory_mgmnt_control_operation == 3)
          READ_UE_OR_RETURN(&marking->difference_of_pic_nums_minus1);

        if (marking->memory_mgmnt_control_operation == 2)
          READ_UE_OR_RETURN(&marking->long_term_pic_num);

        if (marking->memory_mgmnt_control_operation == 3 ||
            marking->memory_mgmnt_control_operation == 6)
          READ_UE_OR_RETURN(&marking->long_term_frame_idx);

        if (marking->memory_mgmnt_control_operation == 4)
          READ_UE_OR_RETURN(&marking->max_long_term_frame_idx_plus1);

        if (marking->memory_mgmnt_control_operation > 6)
          return kInvalidStream;
      }

      if (i == arraysize(shdr->ref_pic_marking)) {
        DVLOG(1) << "Ran out of dec ref pic marking fields";
        return kUnsupportedStream;
      }
    }
  }

  return kOk;
}

H264Parser::Result H264Parser::ParseSliceHeader(const H264NALU& nalu,
                                                H264SliceHeader* shdr) {
  // See 7.4.3.
  const H264SPS* sps;
  const H264PPS* pps;
  Result res;

  memset(shdr, 0, sizeof(*shdr));

  shdr->idr_pic_flag = (nalu.nal_unit_type == 5);
  shdr->nal_ref_idc = nalu.nal_ref_idc;
  shdr->nalu_data = nalu.data;
  shdr->nalu_size = nalu.size;

  READ_UE_OR_RETURN(&shdr->first_mb_in_slice);
  READ_UE_OR_RETURN(&shdr->slice_type);
  TRUE_OR_RETURN(shdr->slice_type < 10);

  READ_UE_OR_RETURN(&shdr->pic_parameter_set_id);

  pps = GetPPS(shdr->pic_parameter_set_id);
  TRUE_OR_RETURN(pps);

  sps = GetSPS(pps->seq_parameter_set_id);
  TRUE_OR_RETURN(sps);

  if (sps->separate_colour_plane_flag) {
    DVLOG(1) << "Interlaced streams not supported";
    return kUnsupportedStream;
  }

  READ_BITS_OR_RETURN(sps->log2_max_frame_num_minus4 + 4, &shdr->frame_num);
  if (!sps->frame_mbs_only_flag) {
    READ_BOOL_OR_RETURN(&shdr->field_pic_flag);
    if (shdr->field_pic_flag) {
      DVLOG(1) << "Interlaced streams not supported";
      return kUnsupportedStream;
    }
  }

  if (shdr->idr_pic_flag)
    READ_UE_OR_RETURN(&shdr->idr_pic_id);

  if (sps->pic_order_cnt_type == 0) {
    READ_BITS_OR_RETURN(sps->log2_max_pic_order_cnt_lsb_minus4 + 4,
                        &shdr->pic_order_cnt_lsb);
    if (pps->bottom_field_pic_order_in_frame_present_flag &&
        !shdr->field_pic_flag)
      READ_SE_OR_RETURN(&shdr->delta_pic_order_cnt_bottom);
  }

  if (sps->pic_order_cnt_type == 1 && !sps->delta_pic_order_always_zero_flag) {
    READ_SE_OR_RETURN(&shdr->delta_pic_order_cnt[0]);
    if (pps->bottom_field_pic_order_in_frame_present_flag &&
        !shdr->field_pic_flag)
      READ_SE_OR_RETURN(&shdr->delta_pic_order_cnt[1]);
  }

  if (pps->redundant_pic_cnt_present_flag) {
    READ_UE_OR_RETURN(&shdr->redundant_pic_cnt);
    TRUE_OR_RETURN(shdr->redundant_pic_cnt < 128);
  }

  if (shdr->IsBSlice())
    READ_BOOL_OR_RETURN(&shdr->direct_spatial_mv_pred_flag);

  if (shdr->IsPSlice() || shdr->IsSPSlice() || shdr->IsBSlice()) {
    READ_BOOL_OR_RETURN(&shdr->num_ref_idx_active_override_flag);
    if (shdr->num_ref_idx_active_override_flag) {
      READ_UE_OR_RETURN(&shdr->num_ref_idx_l0_active_minus1);
      if (shdr->IsBSlice())
        READ_UE_OR_RETURN(&shdr->num_ref_idx_l1_active_minus1);
    } else {
      shdr->num_ref_idx_l0_active_minus1 =
          pps->num_ref_idx_l0_default_active_minus1;
      if (shdr->IsBSlice()) {
        shdr->num_ref_idx_l1_active_minus1 =
            pps->num_ref_idx_l1_default_active_minus1;
      }
    }
  }
  if (shdr->field_pic_flag) {
    TRUE_OR_RETURN(shdr->num_ref_idx_l0_active_minus1 < 32);
    TRUE_OR_RETURN(shdr->num_ref_idx_l1_active_minus1 < 32);
  } else {
    TRUE_OR_RETURN(shdr->num_ref_idx_l0_active_minus1 < 16);
    TRUE_OR_RETURN(shdr->num_ref_idx_l1_active_minus1 < 16);
  }

  if (nalu.nal_unit_type == H264NALU::kCodedSliceExtension) {
    return kUnsupportedStream;
  } else {
    res = ParseRefPicListModifications(shdr);
    if (res != kOk)
      return res;
  }

  if ((pps->weighted_pred_flag && (shdr->IsPSlice() || shdr->IsSPSlice())) ||
      (pps->weighted_bipred_idc == 1 && shdr->IsBSlice())) {
    res = ParsePredWeightTable(*sps, shdr);
    if (res != kOk)
      return res;
  }

  if (nalu.nal_ref_idc != 0) {
    res = ParseDecRefPicMarking(shdr);
    if (res != kOk)
      return res;
  }

  if (pps->entropy_coding_mode_flag && !shdr->IsISlice() &&
      !shdr->IsSISlice()) {
    READ_UE_OR_RETURN(&shdr->cabac_init_idc);
    TRUE_OR_RETURN(shdr->cabac_init_idc < 3);
  }

  READ_SE_OR_RETURN(&shdr->slice_qp_delta);

  if (shdr->IsSPSlice() || shdr->IsSISlice()) {
    if (shdr->IsSPSlice())
      READ_BOOL_OR_RETURN(&shdr->sp_for_switch_flag);
    READ_SE_OR_RETURN(&shdr->slice_qs_delta);
  }

  if (pps->deblocking_filter_control_present_flag) {
    READ_UE_OR_RETURN(&shdr->disable_deblocking_filter_idc);
    TRUE_OR_RETURN(shdr->disable_deblocking_filter_idc < 3);

    if (shdr->disable_deblocking_filter_idc != 1) {
      READ_SE_OR_RETURN(&shdr->slice_alpha_c0_offset_div2);
      IN_RANGE_OR_RETURN(shdr->slice_alpha_c0_offset_div2, -6, 6);

      READ_SE_OR_RETURN(&shdr->slice_beta_offset_div2);
      IN_RANGE_OR_RETURN(shdr->slice_beta_offset_div2, -6, 6);
    }
  }

  if (pps->num_slice_groups_minus1 > 0) {
    DVLOG(1) << "Slice groups not supported";
    return kUnsupportedStream;
  }

  size_t epb = br_.NumEmulationPreventionBytesRead();
  shdr->header_bit_size = (shdr->nalu_size - epb) * 8 - br_.NumBitsLeft();

  return kOk;
}

H264Parser::Result H264Parser::ParseSEI(H264SEIMessage* sei_msg) {
  int byte;

  memset(sei_msg, 0, sizeof(*sei_msg));

  READ_BITS_OR_RETURN(8, &byte);
  while (byte == 0xff) {
    sei_msg->type += 255;
    READ_BITS_OR_RETURN(8, &byte);
  }
  sei_msg->type += byte;

  READ_BITS_OR_RETURN(8, &byte);
  while (byte == 0xff) {
    sei_msg->payload_size += 255;
    READ_BITS_OR_RETURN(8, &byte);
  }
  sei_msg->payload_size += byte;

  DVLOG(4) << "Found SEI message type: " << sei_msg->type
           << " payload size: " << sei_msg->payload_size;

  switch (sei_msg->type) {
    case H264SEIMessage::kSEIRecoveryPoint:
      READ_UE_OR_RETURN(&sei_msg->recovery_point.recovery_frame_cnt);
      READ_BOOL_OR_RETURN(&sei_msg->recovery_point.exact_match_flag);
      READ_BOOL_OR_RETURN(&sei_msg->recovery_point.broken_link_flag);
      READ_BITS_OR_RETURN(2, &sei_msg->recovery_point.changing_slice_group_idc);
      break;

    default:
      DVLOG(4) << "Unsupported SEI message";
      break;
  }

  return kOk;
}

}  // namespace media
/* [<][>][^][v][top][bottom][index][help] */
root/media/filters/h264_parser.cc

DEFINITIONS
