/*
 *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */
#include "modules/video_coding/packet_buffer.h"

#include <cstring>
#include <limits>
#include <ostream>
#include <string>
#include <utility>

#include "api/array_view.h"
#include "common_video/h264/h264_common.h"
#include "modules/video_coding/frame_object.h"
#include "rtc_base/random.h"
#include "system_wrappers/include/clock.h"
#include "test/field_trial.h"
#include "test/gmock.h"
#include "test/gtest.h"

namespace webrtc {
namespace video_coding {
namespace {

using ::testing::ElementsAre;
using ::testing::ElementsAreArray;
using ::testing::IsEmpty;
using ::testing::Matches;
using ::testing::Pointee;
using ::testing::SizeIs;

constexpr int kStartSize = 16;
constexpr int kMaxSize = 64;

void IgnoreResult(PacketBuffer::InsertResult /*result*/) {}

std::vector<uint16_t> StartSeqNums(
    rtc::ArrayView<const std::unique_ptr<RtpFrameObject>> frames) {
  std::vector<uint16_t> result;
  for (const auto& frame : frames) {
    result.push_back(frame->first_seq_num());
  }
  return result;
}

MATCHER_P(StartSeqNumsAre, seq_num, "") {
  return Matches(ElementsAre(seq_num))(StartSeqNums(arg.frames));
}

MATCHER_P2(StartSeqNumsAre, seq_num1, seq_num2, "") {
  return Matches(ElementsAre(seq_num1, seq_num2))(StartSeqNums(arg.frames));
}

MATCHER(KeyFrame, "") {
  return arg->frame_type() == VideoFrameType::kVideoFrameKey;
}

MATCHER(DeltaFrame, "") {
  return arg->frame_type() == VideoFrameType::kVideoFrameDelta;
}

struct PacketBufferInsertResult : public PacketBuffer::InsertResult {
  explicit PacketBufferInsertResult(PacketBuffer::InsertResult result)
      : InsertResult(std::move(result)) {}
};

void PrintTo(const PacketBufferInsertResult& result, std::ostream* os) {
  *os << "frames: { ";
  for (size_t i = 0; i < result.frames.size(); ++i) {
    const RtpFrameObject& frame = *result.frames[i];
    if (i > 0) {
      *os << ", ";
    }
    *os << "{sn: ";
    if (frame.first_seq_num() == frame.last_seq_num()) {
      *os << frame.first_seq_num();
    } else {
      *os << "[" << frame.first_seq_num() << "-" << frame.last_seq_num() << "]";
    }
    *os << "}";
  }
  *os << " }";
  if (result.buffer_cleared) {
    *os << ", buffer_cleared";
  }
}

class PacketBufferTest : public ::testing::Test {
 protected:
  explicit PacketBufferTest(std::string field_trials = "")
      : scoped_field_trials_(field_trials),
        rand_(0x7732213),
        clock_(new SimulatedClock(0)),
        packet_buffer_(clock_.get(), kStartSize, kMaxSize) {}

  uint16_t Rand() { return rand_.Rand<uint16_t>(); }

  enum IsKeyFrame { kKeyFrame, kDeltaFrame };
  enum IsFirst { kFirst, kNotFirst };
  enum IsLast { kLast, kNotLast };

  PacketBufferInsertResult Insert(uint16_t seq_num,  // packet sequence number
                                  IsKeyFrame keyframe,  // is keyframe
                                  IsFirst first,  // is first packet of frame
                                  IsLast last,    // is last packet of frame
                                  int data_size = 0,            // size of data
                                  uint8_t* data = nullptr,      // data pointer
                                  uint32_t timestamp = 123u) {  // rtp timestamp
    PacketBuffer::Packet packet;
    packet.video_header.codec = kVideoCodecGeneric;
    packet.timestamp = timestamp;
    packet.seq_num = seq_num;
    packet.video_header.frame_type = keyframe == kKeyFrame
                                         ? VideoFrameType::kVideoFrameKey
                                         : VideoFrameType::kVideoFrameDelta;
    packet.video_header.is_first_packet_in_frame = first == kFirst;
    packet.video_header.is_last_packet_in_frame = last == kLast;
    packet.size_bytes = data_size;
    packet.data = data;

    return PacketBufferInsertResult(packet_buffer_.InsertPacket(&packet));
  }

  const test::ScopedFieldTrials scoped_field_trials_;
  Random rand_;
  std::unique_ptr<SimulatedClock> clock_;
  PacketBuffer packet_buffer_;
};

TEST_F(PacketBufferTest, InsertOnePacket) {
  const uint16_t seq_num = Rand();
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast).frames, SizeIs(1));
}

TEST_F(PacketBufferTest, InsertMultiplePackets) {
  const uint16_t seq_num = Rand();
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast).frames, SizeIs(1));
  EXPECT_THAT(Insert(seq_num + 1, kKeyFrame, kFirst, kLast).frames, SizeIs(1));
  EXPECT_THAT(Insert(seq_num + 2, kKeyFrame, kFirst, kLast).frames, SizeIs(1));
  EXPECT_THAT(Insert(seq_num + 3, kKeyFrame, kFirst, kLast).frames, SizeIs(1));
}

TEST_F(PacketBufferTest, InsertDuplicatePacket) {
  const uint16_t seq_num = Rand();
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num + 1, kKeyFrame, kNotFirst, kLast).frames,
              SizeIs(1));
}

TEST_F(PacketBufferTest, SeqNumWrapOneFrame) {
  Insert(0xFFFF, kKeyFrame, kFirst, kNotLast);
  EXPECT_THAT(Insert(0x0, kKeyFrame, kNotFirst, kLast),
              StartSeqNumsAre(0xFFFF));
}

TEST_F(PacketBufferTest, SeqNumWrapTwoFrames) {
  EXPECT_THAT(Insert(0xFFFF, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(0xFFFF));
  EXPECT_THAT(Insert(0x0, kKeyFrame, kFirst, kLast), StartSeqNumsAre(0x0));
}

TEST_F(PacketBufferTest, InsertOldPackets) {
  EXPECT_THAT(Insert(100, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(102, kDeltaFrame, kFirst, kLast).frames, SizeIs(1));
  EXPECT_THAT(Insert(101, kKeyFrame, kNotFirst, kLast).frames, SizeIs(1));

  EXPECT_THAT(Insert(100, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(100, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(102, kDeltaFrame, kFirst, kLast).frames, SizeIs(1));

  packet_buffer_.ClearTo(102);
  EXPECT_THAT(Insert(102, kDeltaFrame, kFirst, kLast).frames, IsEmpty());
  EXPECT_THAT(Insert(103, kDeltaFrame, kFirst, kLast).frames, SizeIs(1));
}

TEST_F(PacketBufferTest, NackCount) {
  const uint16_t seq_num = Rand();

  PacketBuffer::Packet packet;
  packet.video_header.codec = kVideoCodecGeneric;
  packet.seq_num = seq_num;
  packet.video_header.frame_type = VideoFrameType::kVideoFrameKey;
  packet.video_header.is_first_packet_in_frame = true;
  packet.video_header.is_last_packet_in_frame = false;
  packet.times_nacked = 0;

  IgnoreResult(packet_buffer_.InsertPacket(&packet));

  packet.seq_num++;
  packet.video_header.is_first_packet_in_frame = false;
  packet.times_nacked = 1;
  IgnoreResult(packet_buffer_.InsertPacket(&packet));

  packet.seq_num++;
  packet.times_nacked = 3;
  IgnoreResult(packet_buffer_.InsertPacket(&packet));

  packet.seq_num++;
  packet.video_header.is_last_packet_in_frame = true;
  packet.times_nacked = 1;
  auto frames = packet_buffer_.InsertPacket(&packet).frames;

  ASSERT_THAT(frames, SizeIs(1));
  EXPECT_EQ(frames.front()->times_nacked(), 3);
}

TEST_F(PacketBufferTest, FrameSize) {
  const uint16_t seq_num = Rand();
  uint8_t* data1 = new uint8_t[5]();
  uint8_t* data2 = new uint8_t[5]();
  uint8_t* data3 = new uint8_t[5]();
  uint8_t* data4 = new uint8_t[5]();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast, 5, data1);
  Insert(seq_num + 1, kKeyFrame, kNotFirst, kNotLast, 5, data2);
  Insert(seq_num + 2, kKeyFrame, kNotFirst, kNotLast, 5, data3);
  EXPECT_THAT(Insert(seq_num + 3, kKeyFrame, kNotFirst, kLast, 5, data4).frames,
              ElementsAre(Pointee(SizeIs(20))));
}

TEST_F(PacketBufferTest, ExpandBuffer) {
  const uint16_t seq_num = Rand();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast);
  for (int i = 1; i < kStartSize; ++i)
    EXPECT_FALSE(
        Insert(seq_num + i, kKeyFrame, kNotFirst, kNotLast).buffer_cleared);

  // Already inserted kStartSize number of packets, inserting the last packet
  // should increase the buffer size and also result in an assembled frame.
  EXPECT_FALSE(
      Insert(seq_num + kStartSize, kKeyFrame, kNotFirst, kLast).buffer_cleared);
}

TEST_F(PacketBufferTest, SingleFrameExpandsBuffer) {
  const uint16_t seq_num = Rand();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast);
  for (int i = 1; i < kStartSize; ++i)
    Insert(seq_num + i, kKeyFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num + kStartSize, kKeyFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num));
}

TEST_F(PacketBufferTest, ExpandBufferOverflow) {
  const uint16_t seq_num = Rand();

  EXPECT_FALSE(Insert(seq_num, kKeyFrame, kFirst, kNotLast).buffer_cleared);
  for (int i = 1; i < kMaxSize; ++i)
    EXPECT_FALSE(
        Insert(seq_num + i, kKeyFrame, kNotFirst, kNotLast).buffer_cleared);

  // Already inserted kMaxSize number of packets, inserting the last packet
  // should overflow the buffer and result in false being returned.
  EXPECT_TRUE(
      Insert(seq_num + kMaxSize, kKeyFrame, kNotFirst, kLast).buffer_cleared);
}

TEST_F(PacketBufferTest, OnePacketOneFrame) {
  const uint16_t seq_num = Rand();
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num));
}

TEST_F(PacketBufferTest, TwoPacketsTwoFrames) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num));
  EXPECT_THAT(Insert(seq_num + 1, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 1));
}

TEST_F(PacketBufferTest, TwoPacketsOneFrames) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num + 1, kKeyFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num));
}

TEST_F(PacketBufferTest, ThreePacketReorderingOneFrame) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num + 2, kKeyFrame, kNotFirst, kLast).frames,
              IsEmpty());
  EXPECT_THAT(Insert(seq_num + 1, kKeyFrame, kNotFirst, kNotLast),
              StartSeqNumsAre(seq_num));
}

TEST_F(PacketBufferTest, Frames) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num));
  EXPECT_THAT(Insert(seq_num + 1, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 1));
  EXPECT_THAT(Insert(seq_num + 2, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 2));
  EXPECT_THAT(Insert(seq_num + 3, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 3));
}

TEST_F(PacketBufferTest, ClearSinglePacket) {
  const uint16_t seq_num = Rand();

  for (int i = 0; i < kMaxSize; ++i)
    Insert(seq_num + i, kDeltaFrame, kFirst, kLast);

  packet_buffer_.ClearTo(seq_num);
  EXPECT_FALSE(
      Insert(seq_num + kMaxSize, kDeltaFrame, kFirst, kLast).buffer_cleared);
}

TEST_F(PacketBufferTest, ClearFullBuffer) {
  for (int i = 0; i < kMaxSize; ++i)
    Insert(i, kDeltaFrame, kFirst, kLast);

  packet_buffer_.ClearTo(kMaxSize - 1);

  for (int i = kMaxSize; i < 2 * kMaxSize; ++i)
    EXPECT_FALSE(Insert(i, kDeltaFrame, kFirst, kLast).buffer_cleared);
}

TEST_F(PacketBufferTest, DontClearNewerPacket) {
  EXPECT_THAT(Insert(0, kKeyFrame, kFirst, kLast), StartSeqNumsAre(0));
  packet_buffer_.ClearTo(0);
  EXPECT_THAT(Insert(2 * kStartSize, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(2 * kStartSize));
  EXPECT_THAT(Insert(3 * kStartSize + 1, kKeyFrame, kFirst, kNotLast).frames,
              IsEmpty());
  packet_buffer_.ClearTo(2 * kStartSize);
  EXPECT_THAT(Insert(3 * kStartSize + 2, kKeyFrame, kNotFirst, kLast),
              StartSeqNumsAre(3 * kStartSize + 1));
}

TEST_F(PacketBufferTest, OneIncompleteFrame) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num, kDeltaFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num + 1, kDeltaFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num));
  EXPECT_THAT(Insert(seq_num - 1, kDeltaFrame, kNotFirst, kLast).frames,
              IsEmpty());
}

TEST_F(PacketBufferTest, TwoIncompleteFramesFullBuffer) {
  const uint16_t seq_num = Rand();

  for (int i = 1; i < kMaxSize - 1; ++i)
    Insert(seq_num + i, kDeltaFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num, kDeltaFrame, kFirst, kNotLast).frames, IsEmpty());
  EXPECT_THAT(Insert(seq_num - 1, kDeltaFrame, kNotFirst, kLast).frames,
              IsEmpty());
}

TEST_F(PacketBufferTest, FramesReordered) {
  const uint16_t seq_num = Rand();

  EXPECT_THAT(Insert(seq_num + 1, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 1));
  EXPECT_THAT(Insert(seq_num, kKeyFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num));
  EXPECT_THAT(Insert(seq_num + 3, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 3));
  EXPECT_THAT(Insert(seq_num + 2, kDeltaFrame, kFirst, kLast),
              StartSeqNumsAre(seq_num + 2));
}

TEST_F(PacketBufferTest, GetBitstream) {
  // "many bitstream, such data" with null termination.
  uint8_t many_data[] = {0x6d, 0x61, 0x6e, 0x79, 0x20};
  uint8_t bitstream_data[] = {0x62, 0x69, 0x74, 0x73, 0x74, 0x72,
                              0x65, 0x61, 0x6d, 0x2c, 0x20};
  uint8_t such_data[] = {0x73, 0x75, 0x63, 0x68, 0x20};
  uint8_t data_data[] = {0x64, 0x61, 0x74, 0x61, 0x0};

  uint8_t* many = new uint8_t[sizeof(many_data)];
  uint8_t* bitstream = new uint8_t[sizeof(bitstream_data)];
  uint8_t* such = new uint8_t[sizeof(such_data)];
  uint8_t* data = new uint8_t[sizeof(data_data)];

  memcpy(many, many_data, sizeof(many_data));
  memcpy(bitstream, bitstream_data, sizeof(bitstream_data));
  memcpy(such, such_data, sizeof(such_data));
  memcpy(data, data_data, sizeof(data_data));

  const uint16_t seq_num = Rand();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast, sizeof(many_data), many);
  Insert(seq_num + 1, kDeltaFrame, kNotFirst, kNotLast, sizeof(bitstream_data),
         bitstream);
  Insert(seq_num + 2, kDeltaFrame, kNotFirst, kNotLast, sizeof(such_data),
         such);
  auto frames = Insert(seq_num + 3, kDeltaFrame, kNotFirst, kLast,
                       sizeof(data_data), data)
                    .frames;

  ASSERT_THAT(frames, SizeIs(1));
  EXPECT_EQ(frames[0]->first_seq_num(), seq_num);
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray("many bitstream, such data"));
}

TEST_F(PacketBufferTest, GetBitstreamOneFrameOnePacket) {
  uint8_t bitstream_data[] = "All the bitstream data for this frame!";
  uint8_t* data = new uint8_t[sizeof(bitstream_data)];
  memcpy(data, bitstream_data, sizeof(bitstream_data));

  auto frames =
      Insert(0, kKeyFrame, kFirst, kLast, sizeof(bitstream_data), data).frames;
  ASSERT_THAT(StartSeqNums(frames), ElementsAre(0));
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(bitstream_data));
}

TEST_F(PacketBufferTest, GetBitstreamOneFrameFullBuffer) {
  uint8_t* data_arr[kStartSize];
  uint8_t expected[kStartSize];

  for (uint8_t i = 0; i < kStartSize; ++i) {
    data_arr[i] = new uint8_t[1];
    data_arr[i][0] = i;
    expected[i] = i;
  }

  Insert(0, kKeyFrame, kFirst, kNotLast, 1, data_arr[0]);
  for (uint8_t i = 1; i < kStartSize - 1; ++i)
    Insert(i, kKeyFrame, kNotFirst, kNotLast, 1, data_arr[i]);
  auto frames = Insert(kStartSize - 1, kKeyFrame, kNotFirst, kLast, 1,
                       data_arr[kStartSize - 1])
                    .frames;

  ASSERT_THAT(StartSeqNums(frames), ElementsAre(0));
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(expected));
}

TEST_F(PacketBufferTest, InsertPacketAfterSequenceNumberWrapAround) {
  uint16_t kFirstSeqNum = 0;
  uint32_t kTimestampDelta = 100;
  uint32_t timestamp = 10000;
  uint16_t seq_num = kFirstSeqNum;

  // Loop until seq_num wraps around.
  SeqNumUnwrapper<uint16_t> unwrapper;
  while (unwrapper.Unwrap(seq_num) < std::numeric_limits<uint16_t>::max()) {
    Insert(seq_num++, kKeyFrame, kFirst, kNotLast, 0, nullptr, timestamp);
    for (int i = 0; i < 5; ++i) {
      Insert(seq_num++, kKeyFrame, kNotFirst, kNotLast, 0, nullptr, timestamp);
    }
    Insert(seq_num++, kKeyFrame, kNotFirst, kLast, 0, nullptr, timestamp);
    timestamp += kTimestampDelta;
  }

  // Receive frame with overlapping sequence numbers.
  Insert(seq_num++, kKeyFrame, kFirst, kNotLast, 0, nullptr, timestamp);
  for (int i = 0; i < 5; ++i) {
    Insert(seq_num++, kKeyFrame, kNotFirst, kNotLast, 0, nullptr, timestamp);
  }
  EXPECT_THAT(
      Insert(seq_num++, kKeyFrame, kNotFirst, kLast, 0, nullptr, timestamp)
          .frames,
      SizeIs(1));
}

// If |sps_pps_idr_is_keyframe| is true, we require keyframes to contain
// SPS/PPS/IDR and the keyframes we create as part of the test do contain
// SPS/PPS/IDR. If |sps_pps_idr_is_keyframe| is false, we only require and
// create keyframes containing only IDR.
class PacketBufferH264Test : public PacketBufferTest {
 protected:
  explicit PacketBufferH264Test(bool sps_pps_idr_is_keyframe)
      : PacketBufferTest(sps_pps_idr_is_keyframe
                             ? "WebRTC-SpsPpsIdrIsH264Keyframe/Enabled/"
                             : ""),
        sps_pps_idr_is_keyframe_(sps_pps_idr_is_keyframe) {}

  PacketBufferInsertResult InsertH264(
      uint16_t seq_num,         // packet sequence number
      IsKeyFrame keyframe,      // is keyframe
      IsFirst first,            // is first packet of frame
      IsLast last,              // is last packet of frame
      uint32_t timestamp,       // rtp timestamp
      int data_size = 0,        // size of data
      uint8_t* data = nullptr,  // data pointer
      uint32_t width = 0,       // width of frame (SPS/IDR)
      uint32_t height = 0) {    // height of frame (SPS/IDR)
    PacketBuffer::Packet packet;
    packet.video_header.codec = kVideoCodecH264;
    auto& h264_header =
        packet.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
    packet.seq_num = seq_num;
    packet.timestamp = timestamp;
    if (keyframe == kKeyFrame) {
      if (sps_pps_idr_is_keyframe_) {
        h264_header.nalus[0].type = H264::NaluType::kSps;
        h264_header.nalus[1].type = H264::NaluType::kPps;
        h264_header.nalus[2].type = H264::NaluType::kIdr;
        h264_header.nalus_length = 3;
      } else {
        h264_header.nalus[0].type = H264::NaluType::kIdr;
        h264_header.nalus_length = 1;
      }
    }
    packet.video_header.width = width;
    packet.video_header.height = height;
    packet.video_header.is_first_packet_in_frame = first == kFirst;
    packet.video_header.is_last_packet_in_frame = last == kLast;
    packet.size_bytes = data_size;
    packet.data = data;

    return PacketBufferInsertResult(packet_buffer_.InsertPacket(&packet));
  }

  PacketBufferInsertResult InsertH264KeyFrameWithAud(
      uint16_t seq_num,         // packet sequence number
      IsKeyFrame keyframe,      // is keyframe
      IsFirst first,            // is first packet of frame
      IsLast last,              // is last packet of frame
      uint32_t timestamp,       // rtp timestamp
      int data_size = 0,        // size of data
      uint8_t* data = nullptr,  // data pointer
      uint32_t width = 0,       // width of frame (SPS/IDR)
      uint32_t height = 0) {    // height of frame (SPS/IDR)
    PacketBuffer::Packet packet;
    packet.video_header.codec = kVideoCodecH264;
    auto& h264_header =
        packet.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
    packet.seq_num = seq_num;
    packet.timestamp = timestamp;

    // this should be the start of frame.
    RTC_CHECK(first == kFirst);

    // Insert a AUD NALU / packet without width/height.
    h264_header.nalus[0].type = H264::NaluType::kAud;
    h264_header.nalus_length = 1;
    packet.video_header.is_first_packet_in_frame = true;
    packet.video_header.is_last_packet_in_frame = false;
    packet.size_bytes = 0;
    packet.data = nullptr;
    IgnoreResult(packet_buffer_.InsertPacket(&packet));
    // insert IDR
    return InsertH264(seq_num + 1, keyframe, kNotFirst, last, timestamp,
                      data_size, data, width, height);
  }

  const bool sps_pps_idr_is_keyframe_;
};

// This fixture is used to test the general behaviour of the packet buffer
// in both configurations.
class PacketBufferH264ParameterizedTest
    : public ::testing::WithParamInterface<bool>,
      public PacketBufferH264Test {
 protected:
  PacketBufferH264ParameterizedTest() : PacketBufferH264Test(GetParam()) {}
};

INSTANTIATE_TEST_SUITE_P(SpsPpsIdrIsKeyframe,
                         PacketBufferH264ParameterizedTest,
                         ::testing::Bool());

TEST_P(PacketBufferH264ParameterizedTest, DontRemoveMissingPacketOnClearTo) {
  InsertH264(0, kKeyFrame, kFirst, kLast, 0);
  InsertH264(2, kDeltaFrame, kFirst, kNotLast, 2);
  packet_buffer_.ClearTo(0);
  // Expect no frame because of missing of packet #1
  EXPECT_THAT(InsertH264(3, kDeltaFrame, kNotFirst, kLast, 2).frames,
              IsEmpty());
}

TEST_P(PacketBufferH264ParameterizedTest, GetBitstreamOneFrameFullBuffer) {
  uint8_t* data_arr[kStartSize];
  uint8_t expected[kStartSize];

  for (uint8_t i = 0; i < kStartSize; ++i) {
    data_arr[i] = new uint8_t[1];
    data_arr[i][0] = i;
    expected[i] = i;
  }

  InsertH264(0, kKeyFrame, kFirst, kNotLast, 1, 1, data_arr[0]);
  for (uint8_t i = 1; i < kStartSize - 1; ++i) {
    InsertH264(i, kKeyFrame, kNotFirst, kNotLast, 1, 1, data_arr[i]);
  }

  auto frames = InsertH264(kStartSize - 1, kKeyFrame, kNotFirst, kLast, 1, 1,
                           data_arr[kStartSize - 1])
                    .frames;
  ASSERT_THAT(StartSeqNums(frames), ElementsAre(0));
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(expected));
}

TEST_P(PacketBufferH264ParameterizedTest, GetBitstreamBufferPadding) {
  uint16_t seq_num = Rand();
  uint8_t data_data[] = "some plain old data";
  uint8_t* data = new uint8_t[sizeof(data_data)];
  memcpy(data, data_data, sizeof(data_data));

  PacketBuffer::Packet packet;
  auto& h264_header =
      packet.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus_length = 1;
  h264_header.nalus[0].type = H264::NaluType::kIdr;
  h264_header.packetization_type = kH264SingleNalu;
  packet.seq_num = seq_num;
  packet.video_header.codec = kVideoCodecH264;
  packet.data = data;
  packet.size_bytes = sizeof(data_data);
  packet.video_header.is_first_packet_in_frame = true;
  packet.video_header.is_last_packet_in_frame = true;
  auto frames = packet_buffer_.InsertPacket(&packet).frames;

  ASSERT_THAT(frames, SizeIs(1));
  EXPECT_EQ(frames[0]->first_seq_num(), seq_num);
  EXPECT_EQ(frames[0]->EncodedImage().size(), sizeof(data_data));
  EXPECT_EQ(frames[0]->EncodedImage().capacity(), sizeof(data_data));
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(data_data));
}

TEST_P(PacketBufferH264ParameterizedTest, FrameResolution) {
  uint16_t seq_num = 100;
  uint8_t data_data[] = "some plain old data";
  uint8_t* data = new uint8_t[sizeof(data_data)];
  memcpy(data, data_data, sizeof(data_data));
  uint32_t width = 640;
  uint32_t height = 360;
  uint32_t timestamp = 1000;

  auto frames = InsertH264(seq_num, kKeyFrame, kFirst, kLast, timestamp,
                           sizeof(data_data), data, width, height)
                    .frames;

  ASSERT_THAT(frames, SizeIs(1));
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(data_data));
  EXPECT_EQ(frames[0]->EncodedImage()._encodedWidth, width);
  EXPECT_EQ(frames[0]->EncodedImage()._encodedHeight, height);
}

TEST_P(PacketBufferH264ParameterizedTest, FrameResolutionNaluBeforeSPS) {
  uint16_t seq_num = 100;
  uint8_t data_data[] = "some plain old data";
  uint8_t* data = new uint8_t[sizeof(data_data)];
  memcpy(data, data_data, sizeof(data_data));
  uint32_t width = 640;
  uint32_t height = 360;
  uint32_t timestamp = 1000;

  auto frames =
      InsertH264KeyFrameWithAud(seq_num, kKeyFrame, kFirst, kLast, timestamp,
                                sizeof(data_data), data, width, height)
          .frames;

  ASSERT_THAT(StartSeqNums(frames), ElementsAre(seq_num));

  EXPECT_EQ(frames[0]->EncodedImage().size(), sizeof(data_data));
  EXPECT_EQ(frames[0]->EncodedImage().capacity(), sizeof(data_data));
  EXPECT_EQ(frames[0]->EncodedImage()._encodedWidth, width);
  EXPECT_EQ(frames[0]->EncodedImage()._encodedHeight, height);
  EXPECT_THAT(rtc::MakeArrayView(frames[0]->data(), frames[0]->size()),
              ElementsAreArray(data_data));
}

TEST_F(PacketBufferTest, FreeSlotsOnFrameCreation) {
  const uint16_t seq_num = Rand();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast);
  Insert(seq_num + 1, kDeltaFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num + 2, kDeltaFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num));

  // Insert frame that fills the whole buffer.
  Insert(seq_num + 3, kKeyFrame, kFirst, kNotLast);
  for (int i = 0; i < kMaxSize - 2; ++i)
    Insert(seq_num + i + 4, kDeltaFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num + kMaxSize + 2, kKeyFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num + 3));
}

TEST_F(PacketBufferTest, Clear) {
  const uint16_t seq_num = Rand();

  Insert(seq_num, kKeyFrame, kFirst, kNotLast);
  Insert(seq_num + 1, kDeltaFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num + 2, kDeltaFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num));

  packet_buffer_.Clear();

  Insert(seq_num + kStartSize, kKeyFrame, kFirst, kNotLast);
  Insert(seq_num + kStartSize + 1, kDeltaFrame, kNotFirst, kNotLast);
  EXPECT_THAT(Insert(seq_num + kStartSize + 2, kDeltaFrame, kNotFirst, kLast),
              StartSeqNumsAre(seq_num + kStartSize));
}

TEST_F(PacketBufferTest, FramesAfterClear) {
  Insert(9025, kDeltaFrame, kFirst, kLast);
  Insert(9024, kKeyFrame, kFirst, kLast);
  packet_buffer_.ClearTo(9025);
  EXPECT_THAT(Insert(9057, kDeltaFrame, kFirst, kLast).frames, SizeIs(1));
  EXPECT_THAT(Insert(9026, kDeltaFrame, kFirst, kLast).frames, SizeIs(1));
}

TEST_F(PacketBufferTest, SameFrameDifferentTimestamps) {
  Insert(0, kKeyFrame, kFirst, kNotLast, 0, nullptr, 1000);
  EXPECT_THAT(Insert(1, kKeyFrame, kNotFirst, kLast, 0, nullptr, 1001).frames,
              IsEmpty());
}

TEST_F(PacketBufferTest, DontLeakPayloadData) {
  // NOTE! Any eventual leak is suppose to be detected by valgrind
  //       or any other similar tool.
  uint8_t* data1 = new uint8_t[5];
  uint8_t* data2 = new uint8_t[5];
  uint8_t* data3 = new uint8_t[5];
  uint8_t* data4 = new uint8_t[5];

  // Expected to free data1 upon PacketBuffer destruction.
  Insert(2, kKeyFrame, kFirst, kNotLast, 5, data1);

  // Expect to free data2 upon insertion.
  Insert(2, kKeyFrame, kFirst, kNotLast, 5, data2);

  // Expect to free data3 upon insertion (old packet).
  packet_buffer_.ClearTo(1);
  Insert(1, kKeyFrame, kFirst, kNotLast, 5, data3);

  // Expect to free data4 upon insertion (packet buffer is full).
  Insert(2 + kMaxSize, kKeyFrame, kFirst, kNotLast, 5, data4);
}

TEST_F(PacketBufferTest, ContinuousSeqNumDoubleMarkerBit) {
  Insert(2, kKeyFrame, kNotFirst, kNotLast);
  Insert(1, kKeyFrame, kFirst, kLast);
  EXPECT_THAT(Insert(3, kKeyFrame, kNotFirst, kLast).frames, IsEmpty());
}

TEST_F(PacketBufferTest, PacketTimestamps) {
  absl::optional<int64_t> packet_ms;
  absl::optional<int64_t> packet_keyframe_ms;

  packet_ms = packet_buffer_.LastReceivedPacketMs();
  packet_keyframe_ms = packet_buffer_.LastReceivedKeyframePacketMs();
  EXPECT_FALSE(packet_ms);
  EXPECT_FALSE(packet_keyframe_ms);

  int64_t keyframe_ms = clock_->TimeInMilliseconds();
  Insert(100, kKeyFrame, kFirst, kLast);
  packet_ms = packet_buffer_.LastReceivedPacketMs();
  packet_keyframe_ms = packet_buffer_.LastReceivedKeyframePacketMs();
  EXPECT_TRUE(packet_ms);
  EXPECT_TRUE(packet_keyframe_ms);
  EXPECT_EQ(keyframe_ms, *packet_ms);
  EXPECT_EQ(keyframe_ms, *packet_keyframe_ms);

  clock_->AdvanceTimeMilliseconds(100);
  int64_t delta_ms = clock_->TimeInMilliseconds();
  Insert(101, kDeltaFrame, kFirst, kLast);
  packet_ms = packet_buffer_.LastReceivedPacketMs();
  packet_keyframe_ms = packet_buffer_.LastReceivedKeyframePacketMs();
  EXPECT_TRUE(packet_ms);
  EXPECT_TRUE(packet_keyframe_ms);
  EXPECT_EQ(delta_ms, *packet_ms);
  EXPECT_EQ(keyframe_ms, *packet_keyframe_ms);

  packet_buffer_.Clear();
  packet_ms = packet_buffer_.LastReceivedPacketMs();
  packet_keyframe_ms = packet_buffer_.LastReceivedKeyframePacketMs();
  EXPECT_FALSE(packet_ms);
  EXPECT_FALSE(packet_keyframe_ms);
}

TEST_F(PacketBufferTest, IncomingCodecChange) {
  PacketBuffer::Packet packet;
  packet.video_header.is_first_packet_in_frame = true;
  packet.video_header.is_last_packet_in_frame = true;
  packet.size_bytes = 0;
  packet.data = nullptr;

  packet.video_header.codec = kVideoCodecVP8;
  packet.video_header.video_type_header.emplace<RTPVideoHeaderVP8>();
  packet.timestamp = 1;
  packet.seq_num = 1;
  packet.video_header.frame_type = VideoFrameType::kVideoFrameKey;
  EXPECT_THAT(packet_buffer_.InsertPacket(&packet).frames, SizeIs(1));

  packet.video_header.codec = kVideoCodecH264;
  auto& h264_header =
      packet.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus_length = 1;
  packet.timestamp = 3;
  packet.seq_num = 3;
  EXPECT_THAT(packet_buffer_.InsertPacket(&packet).frames, IsEmpty());

  packet.video_header.codec = kVideoCodecVP8;
  packet.video_header.video_type_header.emplace<RTPVideoHeaderVP8>();
  packet.timestamp = 2;
  packet.seq_num = 2;
  packet.video_header.frame_type = VideoFrameType::kVideoFrameDelta;
  EXPECT_THAT(packet_buffer_.InsertPacket(&packet).frames, SizeIs(2));
}

TEST_F(PacketBufferTest, TooManyNalusInPacket) {
  PacketBuffer::Packet packet;
  packet.video_header.codec = kVideoCodecH264;
  packet.timestamp = 1;
  packet.seq_num = 1;
  packet.video_header.frame_type = VideoFrameType::kVideoFrameKey;
  packet.video_header.is_first_packet_in_frame = true;
  packet.video_header.is_last_packet_in_frame = true;
  auto& h264_header =
      packet.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus_length = kMaxNalusPerPacket;
  packet.size_bytes = 0;
  packet.data = nullptr;
  EXPECT_THAT(packet_buffer_.InsertPacket(&packet).frames, IsEmpty());
}

TEST_P(PacketBufferH264ParameterizedTest, OneFrameFillBuffer) {
  InsertH264(0, kKeyFrame, kFirst, kNotLast, 1000);
  for (int i = 1; i < kStartSize - 1; ++i)
    InsertH264(i, kKeyFrame, kNotFirst, kNotLast, 1000);
  EXPECT_THAT(InsertH264(kStartSize - 1, kKeyFrame, kNotFirst, kLast, 1000),
              StartSeqNumsAre(0));
}

TEST_P(PacketBufferH264ParameterizedTest, CreateFramesAfterFilledBuffer) {
  EXPECT_THAT(InsertH264(kStartSize - 2, kKeyFrame, kFirst, kLast, 0).frames,
              SizeIs(1));

  InsertH264(kStartSize, kDeltaFrame, kFirst, kNotLast, 2000);
  for (int i = 1; i < kStartSize; ++i)
    InsertH264(kStartSize + i, kDeltaFrame, kNotFirst, kNotLast, 2000);
  EXPECT_THAT(
      InsertH264(kStartSize + kStartSize, kDeltaFrame, kNotFirst, kLast, 2000)
          .frames,
      IsEmpty());

  EXPECT_THAT(InsertH264(kStartSize - 1, kKeyFrame, kFirst, kLast, 1000),
              StartSeqNumsAre(kStartSize - 1, kStartSize));
}

TEST_P(PacketBufferH264ParameterizedTest, OneFrameMaxSeqNum) {
  InsertH264(65534, kKeyFrame, kFirst, kNotLast, 1000);
  EXPECT_THAT(InsertH264(65535, kKeyFrame, kNotFirst, kLast, 1000),
              StartSeqNumsAre(65534));
}

TEST_P(PacketBufferH264ParameterizedTest, ClearMissingPacketsOnKeyframe) {
  InsertH264(0, kKeyFrame, kFirst, kLast, 1000);
  InsertH264(2, kKeyFrame, kFirst, kLast, 3000);
  InsertH264(3, kDeltaFrame, kFirst, kNotLast, 4000);
  InsertH264(4, kDeltaFrame, kNotFirst, kLast, 4000);

  EXPECT_THAT(InsertH264(kStartSize + 1, kKeyFrame, kFirst, kLast, 18000),
              StartSeqNumsAre(kStartSize + 1));
}

TEST_P(PacketBufferH264ParameterizedTest, FindFramesOnPadding) {
  EXPECT_THAT(InsertH264(0, kKeyFrame, kFirst, kLast, 1000),
              StartSeqNumsAre(0));
  EXPECT_THAT(InsertH264(2, kDeltaFrame, kFirst, kLast, 1000).frames,
              IsEmpty());

  EXPECT_THAT(packet_buffer_.InsertPadding(1), StartSeqNumsAre(2));
}

class PacketBufferH264XIsKeyframeTest : public PacketBufferH264Test {
 protected:
  const uint16_t kSeqNum = 5;

  explicit PacketBufferH264XIsKeyframeTest(bool sps_pps_idr_is_keyframe)
      : PacketBufferH264Test(sps_pps_idr_is_keyframe) {
    packet_.video_header.codec = kVideoCodecH264;
    packet_.seq_num = kSeqNum;

    packet_.video_header.is_first_packet_in_frame = true;
    packet_.video_header.is_last_packet_in_frame = true;
  }

  PacketBuffer::Packet packet_;
};

class PacketBufferH264IdrIsKeyframeTest
    : public PacketBufferH264XIsKeyframeTest {
 protected:
  PacketBufferH264IdrIsKeyframeTest()
      : PacketBufferH264XIsKeyframeTest(false) {}
};

TEST_F(PacketBufferH264IdrIsKeyframeTest, IdrIsKeyframe) {
  auto& h264_header =
      packet_.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus[0].type = H264::NaluType::kIdr;
  h264_header.nalus_length = 1;
  EXPECT_THAT(packet_buffer_.InsertPacket(&packet_).frames,
              ElementsAre(KeyFrame()));
}

TEST_F(PacketBufferH264IdrIsKeyframeTest, SpsPpsIdrIsKeyframe) {
  auto& h264_header =
      packet_.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus[0].type = H264::NaluType::kSps;
  h264_header.nalus[1].type = H264::NaluType::kPps;
  h264_header.nalus[2].type = H264::NaluType::kIdr;
  h264_header.nalus_length = 3;

  EXPECT_THAT(packet_buffer_.InsertPacket(&packet_).frames,
              ElementsAre(KeyFrame()));
}

class PacketBufferH264SpsPpsIdrIsKeyframeTest
    : public PacketBufferH264XIsKeyframeTest {
 protected:
  PacketBufferH264SpsPpsIdrIsKeyframeTest()
      : PacketBufferH264XIsKeyframeTest(true) {}
};

TEST_F(PacketBufferH264SpsPpsIdrIsKeyframeTest, IdrIsNotKeyframe) {
  auto& h264_header =
      packet_.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus[0].type = H264::NaluType::kIdr;
  h264_header.nalus_length = 1;

  EXPECT_THAT(packet_buffer_.InsertPacket(&packet_).frames,
              ElementsAre(DeltaFrame()));
}

TEST_F(PacketBufferH264SpsPpsIdrIsKeyframeTest, SpsPpsIsNotKeyframe) {
  auto& h264_header =
      packet_.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus[0].type = H264::NaluType::kSps;
  h264_header.nalus[1].type = H264::NaluType::kPps;
  h264_header.nalus_length = 2;

  EXPECT_THAT(packet_buffer_.InsertPacket(&packet_).frames,
              ElementsAre(DeltaFrame()));
}

TEST_F(PacketBufferH264SpsPpsIdrIsKeyframeTest, SpsPpsIdrIsKeyframe) {
  auto& h264_header =
      packet_.video_header.video_type_header.emplace<RTPVideoHeaderH264>();
  h264_header.nalus[0].type = H264::NaluType::kSps;
  h264_header.nalus[1].type = H264::NaluType::kPps;
  h264_header.nalus[2].type = H264::NaluType::kIdr;
  h264_header.nalus_length = 3;

  EXPECT_THAT(packet_buffer_.InsertPacket(&packet_).frames,
              ElementsAre(KeyFrame()));
}

}  // namespace
}  // namespace video_coding
}  // namespace webrtc