// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "media/parsers/h264_parser.h"

#include <array>
#include <limits>
#include <memory>
#include <optional>
#include <variant>
#include <vector>

#include "base/command_line.h"
#include "base/files/memory_mapped_file.h"
#include "base/logging.h"
#include "base/strings/string_number_conversions.h"
#include "media/base/subsample_entry.h"
#include "media/base/test_data_util.h"
#include "media/filters/h26x_annex_b_bitstream_builder.h"
#include "media/gpu/h264_builder.h"
#include "media/parsers/h26x_parser.h"
#include "testing/gtest/include/gtest/gtest.h"
#include "third_party/abseil-cpp/absl/functional/overload.h"
#include "ui/gfx/geometry/rect.h"
#include "ui/gfx/geometry/size.h"

namespace media {

constexpr char kTestFile[] = "test-25fps.h264";
constexpr size_t kTestFileNALUnits = 1009;

class H264SPSTest : public ::testing::Test {
 public:
  // An exact clone of an SPS from Big Buck Bunny 480p.
  std::unique_ptr<H264SPS> MakeSPS_BBB480p() {
    std::unique_ptr<H264SPS> sps = std::make_unique<H264SPS>();
    sps->profile_idc = 100;
    sps->level_idc = 30;
    sps->chroma_format_idc = 1;
    sps->log2_max_pic_order_cnt_lsb_minus4 = 2;
    sps->max_num_ref_frames = 5;
    sps->pic_width_in_mbs_minus1 = 52;
    sps->pic_height_in_map_units_minus1 = 29;
    sps->frame_mbs_only_flag = true;
    sps->direct_8x8_inference_flag = true;
    sps->vui_parameters_present_flag = true;
    sps->timing_info_present_flag = true;
    sps->num_units_in_tick = 1;
    sps->time_scale = 48;
    sps->fixed_frame_rate_flag = true;
    sps->bitstream_restriction_flag = true;
    // These next three fields are not part of our SPS struct yet.
    // sps->motion_vectors_over_pic_boundaries_flag = true;
    // sps->log2_max_mv_length_horizontal = 10;
    // sps->log2_max_mv_length_vertical = 10;
    sps->max_num_reorder_frames = 2;
    sps->max_dec_frame_buffering = 5;

    // Computed field, matches |chroma_format_idc| in this case.
    // TODO(sandersd): Extract that computation from the parsing step.
    sps->chroma_array_type = 1;

    return sps;
  }
};

TEST_F(H264SPSTest, GetCodedSize) {
  std::unique_ptr<H264SPS> sps = MakeSPS_BBB480p();
  EXPECT_EQ(gfx::Size(848, 480), sps->GetCodedSize());

  // Overflow.
  sps->pic_width_in_mbs_minus1 = std::numeric_limits<int>::max();
  EXPECT_EQ(std::nullopt, sps->GetCodedSize());
}

TEST_F(H264SPSTest, GetVisibleRect) {
  std::unique_ptr<H264SPS> sps = MakeSPS_BBB480p();
  EXPECT_EQ(gfx::Rect(0, 0, 848, 480), sps->GetVisibleRect());

  // Add some cropping.
  sps->frame_cropping_flag = true;
  sps->frame_crop_left_offset = 1;
  sps->frame_crop_right_offset = 2;
  sps->frame_crop_top_offset = 3;
  sps->frame_crop_bottom_offset = 4;
  EXPECT_EQ(gfx::Rect(2, 6, 848 - 6, 480 - 14), sps->GetVisibleRect());

  // Not quite invalid.
  sps->frame_crop_left_offset = 422;
  sps->frame_crop_right_offset = 1;
  sps->frame_crop_top_offset = 0;
  sps->frame_crop_bottom_offset = 0;
  EXPECT_EQ(gfx::Rect(844, 0, 2, 480), sps->GetVisibleRect());

  // Invalid crop.
  sps->frame_crop_left_offset = 423;
  sps->frame_crop_right_offset = 1;
  sps->frame_crop_top_offset = 0;
  sps->frame_crop_bottom_offset = 0;
  EXPECT_EQ(std::nullopt, sps->GetVisibleRect());

  // Overflow.
  sps->frame_crop_left_offset = std::numeric_limits<int>::max() / 2 + 1;
  sps->frame_crop_right_offset = 0;
  sps->frame_crop_top_offset = 0;
  sps->frame_crop_bottom_offset = 0;
  EXPECT_EQ(std::nullopt, sps->GetVisibleRect());
}

TEST(H264ParserTest, StreamFileParsing) {
  base::FilePath file_path = GetTestDataFilePath(kTestFile);

  base::MemoryMappedFile stream;
  ASSERT_TRUE(stream.Initialize(file_path))
      << "Couldn't open stream file: " << file_path.MaybeAsASCII();

  H264Parser parser;
  parser.SetStream(stream.bytes());

  // Parse until the end of stream/unsupported stream/error in stream is found.
  size_t num_parsed_nalus = 0;
  while (true) {
    media::H264SliceHeader shdr;
    media::H264SEI sei;
    H264NALU nalu;
    H264Parser::Result res = parser.AdvanceToNextNALU(&nalu);
    if (res == H264Parser::kEOStream) {
      DVLOG(1) << "Number of successfully parsed NALUs before EOS: "
               << num_parsed_nalus;
      ASSERT_EQ(kTestFileNALUnits, num_parsed_nalus);
      return;
    }
    ASSERT_EQ(res, H264Parser::kOk);

    ++num_parsed_nalus;

    int id;
    switch (nalu.nal_unit_type) {
      case H264NALU::kIDRSlice:
      case H264NALU::kNonIDRSlice:
        ASSERT_EQ(parser.ParseSliceHeader(nalu, &shdr), H264Parser::kOk);
        break;

      case H264NALU::kSPS:
        ASSERT_EQ(parser.ParseSPS(&id), H264Parser::kOk);
        break;

      case H264NALU::kPPS:
        ASSERT_EQ(parser.ParsePPS(&id), H264Parser::kOk);
        break;

      case H264NALU::kSEIMessage:
        ASSERT_EQ(parser.ParseSEI(&sei), H264Parser::kOk);
        break;

      default:
        // Skip unsupported NALU.
        DVLOG(4) << "Skipping unsupported NALU";
        break;
    }
  }
}

TEST(H264ParserTest, ParseNALUsFromStreamFile) {
  base::FilePath file_path = GetTestDataFilePath(kTestFile);

  base::MemoryMappedFile stream;
  ASSERT_TRUE(stream.Initialize(file_path))
      << "Couldn't open stream file: " << file_path.MaybeAsASCII();

  std::vector<H264NALU> nalus;
  ASSERT_TRUE(H264Parser::ParseNALUs(stream.bytes(), &nalus));
  ASSERT_EQ(kTestFileNALUnits, nalus.size());
}

// Verify that GetCurrentSubsamples works.
TEST(H264ParserTest, GetCurrentSubsamplesNormal) {
  const uint8_t kStream[] = {
      // First NALU.
      // Clear bytes = 4.
      0x00, 0x00, 0x01,  // start code.
      0x65,              // Nalu type = 5, IDR slice.
      // Below is bogus data.
      // Encrypted bytes = 15.
      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x00, 0x01, 0x02, 0x03,
      0x04, 0x05, 0x06,
      // Clear bytes = 5.
      0x07, 0x00, 0x01, 0x02, 0x03,
      // Encrypted until next NALU. Encrypted bytes = 20.
      0x04, 0x05, 0x06, 0x07, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
      // Note that this is still in the encrypted region but looks like a start
      // code.
      0x00, 0x00, 0x01, 0x03, 0x04, 0x05, 0x06, 0x07,
      // Second NALU. Completely clear.
      // Clear bytes = 10.
      0x00, 0x00, 0x01,  // start code.
      0x06,              // nalu type = 6, SEI.
      // Bogus data.
      0xff, 0xfe, 0xfd, 0xee, 0x12, 0x33,
  };
  std::vector<SubsampleEntry> subsamples;
  subsamples.emplace_back(4u, 15u);
  subsamples.emplace_back(5u, 20u);
  subsamples.emplace_back(10u, 0u);
  H264Parser parser;
  parser.SetEncryptedStream(kStream, subsamples);

  H264NALU nalu;
  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
  auto nalu_subsamples = parser.GetCurrentSubsamples();
  ASSERT_EQ(2u, nalu_subsamples.size());

  // Note that nalu->data starts from the NALU header, i.e. does not include
  // the start code.
  EXPECT_EQ(1u, nalu_subsamples[0].clear_bytes);
  EXPECT_EQ(15u, nalu_subsamples[0].cypher_bytes);
  EXPECT_EQ(5u, nalu_subsamples[1].clear_bytes);
  EXPECT_EQ(20u, nalu_subsamples[1].cypher_bytes);

  // Make sure that it reached the next NALU.
  EXPECT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
  nalu_subsamples = parser.GetCurrentSubsamples();
  ASSERT_EQ(1u, nalu_subsamples.size());

  EXPECT_EQ(7u, nalu_subsamples[0].clear_bytes);
  EXPECT_EQ(0u, nalu_subsamples[0].cypher_bytes);
}

// Verify that subsamples starting at non-NALU boundary also works.
TEST(H264ParserTest, GetCurrentSubsamplesSubsampleNotStartingAtNaluBoundary) {
  const uint8_t kStream[] = {
      // First NALU.
      // Clear bytes = 4.
      0x00, 0x00, 0x01,  // start code.
      0x65,              // Nalu type = 5, IDR slice.
      // Below is bogus data.
      // Encrypted bytes = 24.
      0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x00, 0x01, 0x02, 0x03,
      0x04, 0x05, 0x06, 0x07, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
      // Clear bytes = 18. The rest is in the clear. Note that this is not at
      // a NALU boundary and a NALU starts below.
      0xaa, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07,
      // Second NALU. Completely clear.
      0x00, 0x00, 0x01,  // start code.
      0x06,              // nalu type = 6, SEI.
      // Bogus data.
      0xff, 0xfe, 0xfd, 0xee, 0x12, 0x33,
  };

  std::vector<SubsampleEntry> subsamples;
  subsamples.emplace_back(4u, 24u);
  subsamples.emplace_back(18, 0);
  H264Parser parser;
  parser.SetEncryptedStream(kStream, subsamples);

  H264NALU nalu;
  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
  auto nalu_subsamples = parser.GetCurrentSubsamples();
  ASSERT_EQ(2u, nalu_subsamples.size());

  // Note that nalu->data starts from the NALU header, i.e. does not include
  // the start code.
  EXPECT_EQ(1u, nalu_subsamples[0].clear_bytes);
  EXPECT_EQ(24u, nalu_subsamples[0].cypher_bytes);

  // The nalu ends with 8 more clear bytes. The last 10 bytes should be
  // associated with the next nalu.
  EXPECT_EQ(8u, nalu_subsamples[1].clear_bytes);
  EXPECT_EQ(0u, nalu_subsamples[1].cypher_bytes);

  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
  nalu_subsamples = parser.GetCurrentSubsamples();
  ASSERT_EQ(1u, nalu_subsamples.size());

  // Although the input had 10 more bytes, since nalu->data starts from the nalu
  // header, there's only 7 more bytes left.
  EXPECT_EQ(7u, nalu_subsamples[0].clear_bytes);
  EXPECT_EQ(0u, nalu_subsamples[0].cypher_bytes);
}

// Verify recovery point SEI is correctly parsed.
TEST(H264ParserTest, RecoveryPointSEIParsing) {
  constexpr uint8_t kStream[] = {
      // First NALU Start code.
      0x00,
      0x00,
      0x00,
      0x01,
      // NALU type = 6 (kSEIMessage).
      0x06,
      // SEI payload type = 6 (recovery_point).
      0x06,
      // SEI payload size = 1.
      0x01,
      // SEI payload.
      0x7c,
      // RBSP trailing bits.
      0x80,
      // Second NALU Start code.
      0x00,
      0x00,
      0x00,
      0x01,
      // NALU type = 6 (kSEIMessage).
      0x06,
      // SEI payload type = 1 (pic_timing).
      0x01,
      // SEI payload size = 1.
      0x01,
      // SEI payload.
      0x04,
      // RBSP trailing bits.
      0x80,
  };

  H264Parser parser;
  parser.SetStream(kStream);

  H264NALU target_nalu;
  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&target_nalu));
  EXPECT_EQ(target_nalu.nal_unit_type, H264NALU::kSEIMessage);

  // Parse the first SEI.
  H264SEI recovery_point_sei;
  EXPECT_EQ(H264Parser::kOk, parser.ParseSEI(&recovery_point_sei));

  // Recovery point present.
  EXPECT_EQ(recovery_point_sei.msgs.size(), 1u);
  for (const auto& sei_msg : recovery_point_sei.msgs) {
    const auto* recovery_point = std::get_if<H264SEIRecoveryPoint>(&sei_msg);
    ASSERT_TRUE(recovery_point);
    EXPECT_EQ(recovery_point->recovery_frame_cnt, 2);
    EXPECT_EQ(recovery_point->exact_match_flag, true);
    EXPECT_EQ(recovery_point->broken_link_flag, true);
    EXPECT_EQ(recovery_point->changing_slice_group_idc, 2);
  }

  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&target_nalu));
  EXPECT_EQ(target_nalu.nal_unit_type, H264NALU::kSEIMessage);

  // Parse the second SEI.
  H264SEI pic_timing_sei;
  EXPECT_EQ(H264Parser::kOk, parser.ParseSEI(&pic_timing_sei));

  // Recovery point not present.
  EXPECT_EQ(pic_timing_sei.msgs.size(), 0u);
}

// Verify T35 SEI is correctly parsed.
TEST(H264ParserTest, T35SEIParsing) {
  constexpr uint8_t kStream[] = {
      // Start code.
      0x00,
      0x00,
      0x00,
      0x01,
      // NALU type = 6 (kSEIMessage).
      0x06,
      // SEI payload type = 4 (user_data_registered_itu_t_t35).
      0x04,
      // SEI payload size = 5.
      0x05,
      // Country code = 0xB5.
      0xB5,
      // Payload data (4 bytes).
      0x01,
      0x02,
      0x03,
      0x04,
      // RBSP trailing bits.
      0x80,
  };

  H264Parser parser;
  parser.SetStream(kStream);

  H264NALU target_nalu;
  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&target_nalu));
  EXPECT_EQ(target_nalu.nal_unit_type, H264NALU::kSEIMessage);

  H264SEI sei;
  ASSERT_EQ(H264Parser::kOk, parser.ParseSEI(&sei));
  ASSERT_EQ(sei.msgs.size(), 1u);

  const auto* t35 = std::get_if<H26xSEIUserDataRegisteredT35>(&sei.msgs[0]);
  ASSERT_TRUE(t35);
  EXPECT_EQ(t35->country_code, 0xB5);
  ASSERT_EQ(t35->payload.size(), 4u);
  EXPECT_EQ(t35->payload[0], 0x01);
  EXPECT_EQ(t35->payload[1], 0x02);
  EXPECT_EQ(t35->payload[2], 0x03);
  EXPECT_EQ(t35->payload[3], 0x04);
}

// Verify both MDCV and CLLI message can be correctly parsed in the same SEI
// NALU.
TEST(H264ParserTest, RecursiveSEIParsing) {
  constexpr uint8_t kStream[] = {
      // Start code.
      0x00,
      0x00,
      0x01,
      // NALU type = 6 (kSEIMessage).
      0x06,
      // SEI payload type = 137 (mastering_display_colour_volume).
      0x89,
      // SEI payload size = 24.
      0x18,
      // SEI payload.
      0x33,
      0xc1,
      0x86,
      0xc3,
      0x1d,
      0x4c,
      0x0b,
      0xb7,
      0x84,
      0xd0,
      0x3e,
      0x7f,
      0x3d,
      0x13,
      0x40,
      0x41,
      0x00,
      0x98,
      0x96,
      0x80,
      0x00,
      0x00,
      // Skipped `0x03`.
      0x03,
      0x00,
      0x32,
      // SEI payload type = 144 (content_light_level_info).
      0x90,
      // SEI payload size = 4.
      0x04,
      // SEI payload.
      0x03,
      0xe8,
      0x00,
      0xc8,
  };

  H264Parser parser;
  parser.SetStream(kStream);

  H264NALU target_nalu;
  ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&target_nalu));
  EXPECT_EQ(target_nalu.nal_unit_type, H264NALU::kSEIMessage);

  // Recursively parse SEI.
  H264SEI clli_mdcv_sei;
  EXPECT_EQ(H264Parser::kOk, parser.ParseSEI(&clli_mdcv_sei));
  EXPECT_EQ(clli_mdcv_sei.msgs.size(), 2u);

  for (const auto& sei_msg : clli_mdcv_sei.msgs) {
    std::visit(absl::Overload{[](const H26xSEIContentLightLevelInfo& info) {
                                EXPECT_EQ(info.max_content_light_level, 1000u);
                                EXPECT_EQ(info.max_picture_average_light_level,
                                          200u);
                              },
                              [](const H26xSEIMasteringDisplayInfo& info) {
                                EXPECT_EQ(info.display_primaries[0][0], 13249u);
                                EXPECT_EQ(info.display_primaries[0][1], 34499u);
                                EXPECT_EQ(info.display_primaries[1][0], 7500u);
                                EXPECT_EQ(info.display_primaries[1][1], 2999u);
                                EXPECT_EQ(info.display_primaries[2][0], 34000u);
                                EXPECT_EQ(info.display_primaries[2][1], 15999u);
                                EXPECT_EQ(info.white_points[0], 15635u);
                                EXPECT_EQ(info.white_points[1], 16449u);
                                EXPECT_EQ(info.max_luminance, 10000000u);
                                EXPECT_EQ(info.min_luminance, 50u);
                              },
                              [](const auto&) {
                                EXPECT_TRUE(false) << "Unexpected message type";
                              }},
               sei_msg);
  }
}

TEST(H264ParserTest, RangeChecks) {
  H264Parser parser;
  H264NALU nalu;
  int id;

  // PPS: pic_parameter_set_id = 0, seq_parameter_set_id = 0.
  // second_chroma_qp_index_offset = 13 (invalid, range is -12 to 12).
  // Encoded as se(v) -> ue(25) -> 0000 11010.
  {
    // SPS: High Profile (100), Level 1.0 (10), seq_parameter_set_id = 0.
    // This is required because second_chroma_qp_index_offset is only parsed
    // for High profile or above.
    constexpr auto kSPS = std::to_array<uint8_t>({
        0x00, 0x00, 0x01, 0x67,  // Header
        0x64, 0x00, 0x0A,        // Profile/Level
        0xF3, 0xDC, 0x40         // Payload
    });
    constexpr auto kPPS = std::to_array<uint8_t>({
        0x00, 0x00, 0x01, 0x68,  // Header
        0xCE, 0x38, 0x03, 0x50   // Payload
    });

    // Parse SPS.
    parser.SetStream(kSPS);
    ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
    ASSERT_EQ(H264NALU::kSPS, nalu.nal_unit_type);
    ASSERT_EQ(H264Parser::kOk, parser.ParseSPS(&id));

    // Parse PPS.
    parser.SetStream(kPPS);
    ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
    ASSERT_EQ(H264NALU::kPPS, nalu.nal_unit_type);

    // This should fail because second_chroma_qp_index_offset is out of range.
    EXPECT_EQ(H264Parser::kInvalidStream, parser.ParsePPS(&id));
  }

  // SEI: Recovery Point, changing_slice_group_idc = 3 (invalid, range 0-2).
  {
    media::H264SEI sei;
    constexpr auto kSEI = std::to_array<uint8_t>({
        0x00, 0x00, 0x01, 0x06,  // Header
        0x06,                    // Payload type 6 (Recovery Point)
        0x01,                    // Payload size 1
        0x98,                    // Payload: changing_slice_group_idc = 3
        0x80                     // RBSP stop bit
    });

    parser.SetStream(kSEI);
    ASSERT_EQ(H264Parser::kOk, parser.AdvanceToNextNALU(&nalu));
    ASSERT_EQ(H264NALU::kSEIMessage, nalu.nal_unit_type);

    EXPECT_EQ(H264Parser::kInvalidStream, parser.ParseSEI(&sei));
  }

  // SliceHeader: DecRefPicMarking and RefPicListModification range checks.
  {
    H264SPS sps;
    sps.profile_idc = 66;  // Baseline
    sps.level_idc = 10;
    sps.log2_max_frame_num_minus4 = 0;
    sps.pic_order_cnt_type = 0;
    sps.log2_max_pic_order_cnt_lsb_minus4 = 0;
    sps.max_num_ref_frames = 4;
    sps.pic_width_in_mbs_minus1 = 1;
    sps.pic_height_in_map_units_minus1 = 1;
    sps.frame_mbs_only_flag = true;

    H264PPS pps;
    pps.pic_parameter_set_id = 0;
    pps.seq_parameter_set_id = 0;

    // Helper lambda to build a slice header with custom modification and
    // marking ops.
    auto build_slice = [&](uint32_t ref_mod_idc, uint32_t ref_mod_val,
                           uint32_t mmco, uint32_t mmco_val1,
                           uint32_t mmco_val2 = 0) {
      H26xAnnexBBitstreamBuilder builder(
          /*insert_emulation_prevention_bytes=*/true);
      BuildPackedH264SPS(builder, sps);
      BuildPackedH264PPS(builder, sps, pps);

      builder.BeginNALU(H264NALU::kNonIDRSlice, 1);
      builder.AppendUE(0);       // first_mb_in_slice
      builder.AppendUE(0);       // slice_type (P slice)
      builder.AppendUE(0);       // pic_parameter_set_id
      builder.AppendBits(4, 0);  // frame_num
      builder.AppendBits(4, 0);  // pic_order_cnt_lsb

      builder.AppendBool(false);  // num_ref_idx_active_override_flag
      if (ref_mod_idc != 3) {
        builder.AppendBool(true);  // ref_pic_list_modification_flag_l0
        builder.AppendUE(ref_mod_idc);
        builder.AppendUE(ref_mod_val);
        builder.AppendUE(3);  // end of modifications
      } else {
        builder.AppendBool(false);  // ref_pic_list_modification_flag_l0
      }

      if (mmco != 0) {
        builder.AppendBool(true);  // adaptive_ref_pic_marking_mode_flag
        builder.AppendUE(mmco);
        if (mmco == 1 || mmco == 3) {
          builder.AppendUE(mmco_val1);
        }
        if (mmco == 2) {
          builder.AppendUE(mmco_val1);
        }
        if (mmco == 3 || mmco == 6) {
          builder.AppendUE(mmco == 3 ? mmco_val2 : mmco_val1);
        }
        if (mmco == 4) {
          builder.AppendUE(mmco_val1);
        }
        builder.AppendUE(0);  // end of MMCO
      } else {
        builder.AppendBool(false);  // adaptive_ref_pic_marking_mode_flag
      }

      builder.AppendSE(0);  // slice_qp_delta
      builder.FinishNALU();
      return std::vector<uint8_t>(builder.data().begin(), builder.data().end());
    };

    auto parse_slice = [&](const std::vector<uint8_t>& stream_data) {
      H264Parser p;
      p.SetStream(stream_data);
      H264NALU n;
      int sps_id_out, pps_id_out;
      EXPECT_EQ(H264Parser::kOk, p.AdvanceToNextNALU(&n));  // SPS
      EXPECT_EQ(H264Parser::kOk, p.ParseSPS(&sps_id_out));
      EXPECT_EQ(H264Parser::kOk, p.AdvanceToNextNALU(&n));  // PPS
      EXPECT_EQ(H264Parser::kOk, p.ParsePPS(&pps_id_out));
      EXPECT_EQ(H264Parser::kOk, p.AdvanceToNextNALU(&n));  // Slice
      H264SliceHeader sh;
      return p.ParseSliceHeader(n, &sh);
    };

    // Valid slice header.
    EXPECT_EQ(H264Parser::kOk, parse_slice(build_slice(3, 0, 0, 0)));

    // MMCO 6: long_term_frame_idx = 16 (invalid, max 15).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(3, 0, 6, 16)));

    // MMCO 2: long_term_pic_num = 16 (invalid, max 15).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(3, 0, 2, 16)));

    // MMCO 1: difference_of_pic_nums_minus1 = 65536 (invalid, max 65535).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(3, 0, 1, 65536)));

    // MMCO 4: max_long_term_frame_idx_plus1 = 17 (invalid, max 16).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(3, 0, 4, 17)));

    // RefPicListModification 2: long_term_pic_num = 16 (invalid, max 15).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(2, 16, 0, 0)));

    // RefPicListModification 0: abs_diff_pic_num_minus1 = 65536 (invalid, max
    // 65535).
    EXPECT_EQ(H264Parser::kInvalidStream,
              parse_slice(build_slice(0, 65536, 0, 0)));
  }
}

TEST(H264ParserTest, SpsOverwritesInvalidatesPps) {
  H264SPS sps;
  sps.profile_idc = 100;
  sps.level_idc = 13;
  sps.chroma_format_idc = 1;
  sps.log2_max_frame_num_minus4 = 5;
  sps.log2_max_pic_order_cnt_lsb_minus4 = 6;
  sps.max_num_ref_frames = 4;
  sps.pic_width_in_mbs_minus1 = 19;
  sps.pic_height_in_map_units_minus1 = 11;

  H264PPS pps;
  pps.entropy_coding_mode_flag = true;
  pps.weighted_bipred_idc = 2;
  pps.chroma_qp_index_offset = -2;
  pps.deblocking_filter_control_present_flag = true;
  pps.transform_8x8_mode_flag = true;
  pps.second_chroma_qp_index_offset = -2;

  H26xAnnexBBitstreamBuilder bitstream_builder(
      /*insert_emulation_prevention_bytes=*/true);
  BuildPackedH264SPS(bitstream_builder, sps);
  BuildPackedH264PPS(bitstream_builder, sps, pps);

  // Re-append the SPS to simulate an overwrite.
  BuildPackedH264SPS(bitstream_builder, sps);

  // Now change the SPS to simulate an overwrite with different parameters.
  sps.pic_width_in_mbs_minus1 = 20;
  BuildPackedH264SPS(bitstream_builder, sps);

  H264Parser parser;
  parser.SetStream(bitstream_builder.data());

  H264NALU nalu;
  EXPECT_EQ(parser.AdvanceToNextNALU(&nalu), H264Parser::Result::kOk);
  EXPECT_EQ(nalu.nal_unit_type, H264NALU::kSPS);
  int sps_id;
  EXPECT_EQ(parser.ParseSPS(&sps_id), H264Parser::Result::kOk);

  EXPECT_EQ(parser.AdvanceToNextNALU(&nalu), H264Parser::Result::kOk);
  EXPECT_EQ(nalu.nal_unit_type, H264NALU::kPPS);
  int pps_id;
  EXPECT_EQ(parser.ParsePPS(&pps_id), H264Parser::Result::kOk);

  EXPECT_NE(parser.GetPPS(pps_id), nullptr);

  // Parse the second SPS (identical to the first).
  EXPECT_EQ(parser.AdvanceToNextNALU(&nalu), H264Parser::Result::kOk);
  EXPECT_EQ(nalu.nal_unit_type, H264NALU::kSPS);
  int new_sps_id;
  EXPECT_EQ(parser.ParseSPS(&new_sps_id), H264Parser::Result::kOk);
  EXPECT_EQ(new_sps_id, sps_id);

  // The PPS should NOT be invalidated because the SPS hasn't changed.
  EXPECT_NE(parser.GetPPS(pps_id), nullptr);

  // Parse the third SPS (different from the first).
  EXPECT_EQ(parser.AdvanceToNextNALU(&nalu), H264Parser::Result::kOk);
  EXPECT_EQ(nalu.nal_unit_type, H264NALU::kSPS);
  EXPECT_EQ(parser.ParseSPS(&new_sps_id), H264Parser::Result::kOk);
  EXPECT_EQ(new_sps_id, sps_id);

  // The PPS should be invalidated because the SPS has changed.
  EXPECT_EQ(parser.GetPPS(pps_id), nullptr);
}

}  // namespace media