Packet buffer for the new jitter buffer.

BUG=webrtc:5514
R=stefan@webrtc.org, mflodman@webrtc.org

Review URL: https://codereview.webrtc.org/1772383002

Cr-Commit-Position: refs/heads/master@{#12194}

webrtc/modules/modules.gyp

@@ -370,6 +370,7 @@
             'video_coding/jitter_estimator_tests.cc',
             'video_coding/media_optimization_unittest.cc',
             'video_coding/nack_module_unittest.cc',
+            'video_coding/packet_buffer_unittest.cc',
             'video_coding/percentile_filter_unittest.cc',
             'video_coding/receiver_unittest.cc',
             'video_coding/session_info_unittest.cc',

webrtc/modules/video_coding/BUILD.gn

@@ -25,6 +25,8 @@ source_set("video_coding") {
     "fec_tables_xor.h",
     "frame_buffer.cc",
     "frame_buffer.h",
+    "frame_object.cc",
+    "frame_object.h",
     "generic_decoder.cc",
     "generic_decoder.h",
     "generic_encoder.cc",
@@ -50,6 +52,8 @@ source_set("video_coding") {
     "nack_module.h",
     "packet.cc",
     "packet.h",
+    "packet_buffer.cc",
+    "packet_buffer.h",
     "percentile_filter.cc",
     "percentile_filter.h",
     "qm_select.cc",

webrtc/modules/video_coding/frame_object.cc

@@ -0,0 +1,47 @@
+/*
+ *  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 "webrtc/modules/video_coding/frame_object.h"
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/modules/video_coding/packet_buffer.h"
+
+namespace webrtc {
+namespace video_coding {
+
+RtpFrameObject::RtpFrameObject(PacketBuffer* packet_buffer,
+                               uint16_t picture_id,
+                               uint16_t first_packet,
+                               uint16_t last_packet)
+    : packet_buffer_(packet_buffer),
+      first_packet_(first_packet),
+      last_packet_(last_packet) {}
+
+RtpFrameObject::~RtpFrameObject() {
+  packet_buffer_->ReturnFrame(this);
+}
+
+uint16_t RtpFrameObject::first_packet() const {
+  return first_packet_;
+}
+
+uint16_t RtpFrameObject::last_packet() const {
+  return last_packet_;
+}
+
+uint16_t RtpFrameObject::picture_id() const {
+  return picture_id_;
+}
+
+bool RtpFrameObject::GetBitstream(uint8_t* destination) const {
+  return packet_buffer_->GetBitstream(*this, destination);
+}
+
+}  // namespace video_coding
+}  // namespace webrtc

webrtc/modules/video_coding/frame_object.h

@@ -0,0 +1,50 @@
+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_VIDEO_CODING_FRAME_OBJECT_H_
+#define WEBRTC_MODULES_VIDEO_CODING_FRAME_OBJECT_H_
+
+#include "webrtc/modules/video_coding/packet.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class FrameObject {
+ public:
+  virtual uint16_t picture_id() const = 0;
+  virtual bool GetBitstream(uint8_t* destination) const = 0;
+  virtual ~FrameObject() {}
+};
+
+class PacketBuffer;
+
+class RtpFrameObject : public FrameObject {
+ public:
+  RtpFrameObject(PacketBuffer* packet_buffer,
+                 uint16_t picture_id,
+                 uint16_t first_packet,
+                 uint16_t last_packet);
+  ~RtpFrameObject();
+  uint16_t first_packet() const;
+  uint16_t last_packet() const;
+  uint16_t picture_id() const override;
+  bool GetBitstream(uint8_t* destination) const override;
+
+ private:
+  PacketBuffer* packet_buffer_;
+  uint16_t picture_id_;
+  uint16_t first_packet_;
+  uint16_t last_packet_;
+};
+
+}  // namespace video_coding
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_CODING_FRAME_OBJECT_H_

webrtc/modules/video_coding/packet_buffer.cc

@@ -0,0 +1,204 @@
+/*
+ *  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 "webrtc/modules/video_coding/packet_buffer.h"
+
+#include <algorithm>
+#include <limits>
+
+#include "webrtc/base/checks.h"
+#include "webrtc/modules/video_coding/frame_object.h"
+#include "webrtc/modules/video_coding/sequence_number_util.h"
+
+namespace webrtc {
+namespace video_coding {
+
+PacketBuffer::PacketBuffer(size_t start_buffer_size,
+                           size_t max_buffer_size,
+                           OnCompleteFrameCallback* frame_callback)
+    : size_(start_buffer_size),
+      max_size_(max_buffer_size),
+      last_seq_num_(0),
+      first_seq_num_(0),
+      initialized_(false),
+      data_buffer_(start_buffer_size),
+      sequence_buffer_(start_buffer_size),
+      frame_callback_(frame_callback) {
+  RTC_DCHECK_LE(start_buffer_size, max_buffer_size);
+  // Buffer size must always be a power of 2.
+  RTC_DCHECK((start_buffer_size & (start_buffer_size - 1)) == 0);
+  RTC_DCHECK((max_buffer_size & (max_buffer_size - 1)) == 0);
+}
+
+bool PacketBuffer::InsertPacket(const VCMPacket& packet) {
+  rtc::CritScope lock(&crit_);
+  uint16_t seq_num = packet.seqNum;
+  int index = seq_num % size_;
+
+  if (!initialized_) {
+    first_seq_num_ = seq_num - 1;
+    last_seq_num_ = seq_num;
+    initialized_ = true;
+  }
+
+  if (sequence_buffer_[index].used) {
+    // Duplicate packet, do nothing.
+    if (data_buffer_[index].seqNum == packet.seqNum)
+      return true;
+
+    // The packet buffer is full, try to expand the buffer.
+    while (ExpandBufferSize() && sequence_buffer_[seq_num % size_].used) {
+    }
+    index = seq_num % size_;
+
+    // Packet buffer is still full.
+    if (sequence_buffer_[index].used)
+      return false;
+  }
+
+  if (AheadOf(seq_num, last_seq_num_))
+    last_seq_num_ = seq_num;
+
+  sequence_buffer_[index].frame_begin = packet.isFirstPacket;
+  sequence_buffer_[index].frame_end = packet.markerBit;
+  sequence_buffer_[index].seq_num = packet.seqNum;
+  sequence_buffer_[index].continuous = false;
+  sequence_buffer_[index].used = true;
+  data_buffer_[index] = packet;
+
+  FindCompleteFrames(seq_num);
+  return true;
+}
+
+void PacketBuffer::ClearTo(uint16_t seq_num) {
+  rtc::CritScope lock(&crit_);
+  int index = first_seq_num_ % size_;
+  while (AheadOf<uint16_t>(seq_num, first_seq_num_ + 1)) {
+    index = (index + 1) % size_;
+    first_seq_num_ = Add<1 << 16>(first_seq_num_, 1);
+    sequence_buffer_[index].used = false;
+  }
+}
+
+bool PacketBuffer::ExpandBufferSize() {
+  if (size_ == max_size_)
+    return false;
+
+  size_t new_size = std::min(max_size_, 2 * size_);
+  std::vector<VCMPacket> new_data_buffer(new_size);
+  std::vector<ContinuityInfo> new_sequence_buffer(new_size);
+  for (size_t i = 0; i < size_; ++i) {
+    if (sequence_buffer_[i].used) {
+      int index = sequence_buffer_[i].seq_num % new_size;
+      new_sequence_buffer[index] = sequence_buffer_[i];
+      new_data_buffer[index] = data_buffer_[i];
+    }
+  }
+  size_ = new_size;
+  sequence_buffer_ = std::move(new_sequence_buffer);
+  data_buffer_ = std::move(new_data_buffer);
+  return true;
+}
+
+bool PacketBuffer::IsContinuous(uint16_t seq_num) const {
+  int index = seq_num % size_;
+  int prev_index = index > 0 ? index - 1 : size_ - 1;
+  if (!sequence_buffer_[index].used)
+    return false;
+  if (sequence_buffer_[index].frame_begin)
+    return true;
+  if (!sequence_buffer_[prev_index].used)
+    return false;
+  if (sequence_buffer_[prev_index].continuous)
+    return true;
+
+  return false;
+}
+
+void PacketBuffer::FindCompleteFrames(uint16_t seq_num) {
+  int index = seq_num % size_;
+  while (IsContinuous(seq_num)) {
+    sequence_buffer_[index].continuous = true;
+
+    // If the frame is complete, find the first packet of the frame and
+    // create a FrameObject.
+    if (sequence_buffer_[index].frame_end) {
+      int rindex = index;
+      uint16_t start_seq_num = seq_num;
+      while (!sequence_buffer_[rindex].frame_begin) {
+        rindex = rindex > 0 ? rindex - 1 : size_ - 1;
+        start_seq_num--;
+      }
+
+      std::unique_ptr<FrameObject> frame(
+          new RtpFrameObject(this, 1, start_seq_num, seq_num));
+      frame_callback_->OnCompleteFrame(std::move(frame));
+    }
+
+    index = (index + 1) % size_;
+    ++seq_num;
+  }
+}
+
+void PacketBuffer::ReturnFrame(RtpFrameObject* frame) {
+  rtc::CritScope lock(&crit_);
+  int index = frame->first_packet() % size_;
+  int end = (frame->last_packet() + 1) % size_;
+  uint16_t seq_num = frame->first_packet();
+  while (index != end) {
+    if (sequence_buffer_[index].seq_num == seq_num) {
+      sequence_buffer_[index].used = false;
+      sequence_buffer_[index].continuous = false;
+    }
+    index = (index + 1) % size_;
+    ++seq_num;
+  }
+
+  index = first_seq_num_ % size_;
+  while (AheadOf<uint16_t>(last_seq_num_, first_seq_num_) &&
+         !sequence_buffer_[index].used) {
+    ++first_seq_num_;
+    index = (index + 1) % size_;
+  }
+}
+
+bool PacketBuffer::GetBitstream(const RtpFrameObject& frame,
+                                uint8_t* destination) {
+  rtc::CritScope lock(&crit_);
+
+  int index = frame.first_packet() % size_;
+  int end = (frame.last_packet() + 1) % size_;
+  uint16_t seq_num = frame.first_packet();
+  while (index != end) {
+    if (!sequence_buffer_[index].used ||
+        sequence_buffer_[index].seq_num != seq_num) {
+      return false;
+    }
+
+    const uint8_t* source = data_buffer_[index].dataPtr;
+    size_t length = data_buffer_[index].sizeBytes;
+    memcpy(destination, source, length);
+    destination += length;
+    index = (index + 1) % size_;
+    ++seq_num;
+  }
+  return true;
+}
+
+void PacketBuffer::Flush() {
+  rtc::CritScope lock(&crit_);
+  for (size_t i = 0; i < size_; ++i) {
+    sequence_buffer_[i].used = false;
+    sequence_buffer_[i].continuous = false;
+  }
+}
+
+}  // namespace video_coding
+}  // namespace webrtc

webrtc/modules/video_coding/packet_buffer.h

@@ -0,0 +1,81 @@
+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
+#define WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_
+
+#include <vector>
+
+#include "webrtc/base/criticalsection.h"
+#include "webrtc/base/scoped_ptr.h"
+#include "webrtc/base/thread_annotations.h"
+#include "webrtc/modules/video_coding/packet.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class FrameObject;
+class RtpFrameObject;
+
+class OnCompleteFrameCallback {
+ public:
+  virtual ~OnCompleteFrameCallback() {}
+  virtual void OnCompleteFrame(std::unique_ptr<FrameObject> frame) = 0;
+};
+
+class PacketBuffer {
+ public:
+  // Both |start_buffer_size| and |max_buffer_size| must be a power of 2.
+  PacketBuffer(size_t start_buffer_size,
+               size_t max_buffer_size,
+               OnCompleteFrameCallback* frame_callback);
+
+  bool InsertPacket(const VCMPacket& packet);
+  void ClearTo(uint16_t seq_num);
+  void Flush();
+
+ private:
+  friend RtpFrameObject;
+  // Since we want the packet buffer to be as packet type agnostic
+  // as possible we extract only the information needed in order
+  // to determin whether a sequence of packets is continuous or not.
+  struct ContinuityInfo {
+    uint16_t seq_num = 0;
+    bool frame_begin = false;
+    bool frame_end = false;
+    bool used = false;
+    bool continuous = false;
+  };
+
+  bool ExpandBufferSize() EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  bool IsContinuous(uint16_t seq_num) const EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  void FindCompleteFrames(uint16_t seq_num) EXCLUSIVE_LOCKS_REQUIRED(crit_);
+  bool GetBitstream(const RtpFrameObject& frame, uint8_t* destination);
+  void ReturnFrame(RtpFrameObject* frame);
+
+  rtc::CriticalSection crit_;
+
+  // Buffer size_ and max_size_ must always be a power of two.
+  size_t size_ GUARDED_BY(crit_);
+  const size_t max_size_;
+
+  uint16_t last_seq_num_ GUARDED_BY(crit_);
+  uint16_t first_seq_num_ GUARDED_BY(crit_);
+  bool initialized_ GUARDED_BY(crit_);
+  std::vector<VCMPacket> data_buffer_ GUARDED_BY(crit_);
+  std::vector<ContinuityInfo> sequence_buffer_ GUARDED_BY(crit_);
+
+  OnCompleteFrameCallback* const frame_callback_;
+};
+
+}  // namespace video_coding
+}  // namespace webrtc
+
+#endif  // WEBRTC_MODULES_VIDEO_CODING_PACKET_BUFFER_H_

webrtc/modules/video_coding/packet_buffer_unittest.cc

@@ -0,0 +1,305 @@
+/*
+ *  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 <cstring>
+#include <limits>
+
+#include "webrtc/modules/video_coding/frame_object.h"
+#include "webrtc/modules/video_coding/packet_buffer.h"
+
+#include "testing/gtest/include/gtest/gtest.h"
+#include "webrtc/base/random.h"
+
+namespace webrtc {
+namespace video_coding {
+
+class TestPacketBuffer : public ::testing::Test,
+                         public OnCompleteFrameCallback {
+ protected:
+  TestPacketBuffer()
+      : rand_(0x8739211), packet_buffer_(kStartSize, kMaxSize, this) {}
+
+  uint16_t Rand() { return rand_.Rand(std::numeric_limits<uint16_t>::max()); }
+
+  void OnCompleteFrame(std::unique_ptr<FrameObject> frame) override {
+    frames_from_callback_.emplace_back(std::move(frame));
+  }
+
+  void TearDown() override {
+    // All FrameObjects must be destroyed before the PacketBuffer since
+    // a FrameObject will try to remove itself from the packet buffer
+    // upon destruction.
+    frames_from_callback_.clear();
+  }
+
+  const int kStartSize = 16;
+  const int kMaxSize = 64;
+
+  Random rand_;
+  PacketBuffer packet_buffer_;
+  std::vector<std::unique_ptr<FrameObject>> frames_from_callback_;
+};
+
+TEST_F(TestPacketBuffer, InsertOnePacket) {
+  VCMPacket packet;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+}
+
+TEST_F(TestPacketBuffer, InsertMultiplePackets) {
+  VCMPacket packet;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+}
+
+TEST_F(TestPacketBuffer, InsertDuplicatePacket) {
+  VCMPacket packet;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+}
+
+TEST_F(TestPacketBuffer, ExpandBuffer) {
+  VCMPacket packet;
+  packet.seqNum = Rand();
+
+  for (int i = 0; i < kStartSize + 1; ++i) {
+    EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+    ++packet.seqNum;
+  }
+}
+
+TEST_F(TestPacketBuffer, ExpandBufferOverflow) {
+  VCMPacket packet;
+  packet.seqNum = Rand();
+
+  for (int i = 0; i < kMaxSize; ++i) {
+    EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+    ++packet.seqNum;
+  }
+
+  EXPECT_FALSE(packet_buffer_.InsertPacket(packet));
+}
+
+TEST_F(TestPacketBuffer, OnePacketOneFrame) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.markerBit = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, TwoPacketsTwoFrames) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.markerBit = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(2UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, TwoPacketsOneFrames) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet.markerBit = true;
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, ThreePacketReorderingOneFrame) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.isFirstPacket = false;
+  packet.markerBit = true;
+  packet.seqNum += 2;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.markerBit = false;
+  packet.seqNum -= 1;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, IndexWrapOneFrame) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.seqNum = kStartSize - 1;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.isFirstPacket = false;
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.markerBit = true;
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, DiscardOldPacket) {
+  uint16_t seq_num = Rand();
+  VCMPacket packet;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet.seqNum += 2;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+
+  for (int i = 3; i < kMaxSize; ++i) {
+    ++packet.seqNum;
+    EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  }
+
+  ++packet.seqNum;
+  EXPECT_FALSE(packet_buffer_.InsertPacket(packet));
+  packet_buffer_.ClearTo(seq_num + 1);
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+}
+
+TEST_F(TestPacketBuffer, DiscardMultipleOldPackets) {
+  uint16_t seq_num = Rand();
+  VCMPacket packet;
+  packet.seqNum = seq_num;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet.seqNum += 2;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+
+  for (int i = 3; i < kMaxSize; ++i) {
+    ++packet.seqNum;
+    EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  }
+
+  packet_buffer_.ClearTo(seq_num + 15);
+  for (int i = 0; i < 15; ++i) {
+    ++packet.seqNum;
+    EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  }
+  for (int i = 15; i < kMaxSize; ++i) {
+    ++packet.seqNum;
+    EXPECT_FALSE(packet_buffer_.InsertPacket(packet));
+  }
+}
+
+TEST_F(TestPacketBuffer, GetBitstreamFromFrame) {
+  // "many bitstream, such data" with null termination.
+  uint8_t many[] = {0x6d, 0x61, 0x6e, 0x79, 0x20};
+  uint8_t bitstream[] = {0x62, 0x69, 0x74, 0x73, 0x74, 0x72,
+                         0x65, 0x61, 0x6d, 0x2c, 0x20};
+  uint8_t such[] = {0x73, 0x75, 0x63, 0x68, 0x20};
+  uint8_t data[] = {0x64, 0x61, 0x74, 0x61, 0x0};
+  uint8_t
+      result[sizeof(many) + sizeof(bitstream) + sizeof(such) + sizeof(data)];
+
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.seqNum = 0xfffe;
+  packet.dataPtr = many;
+  packet.sizeBytes = sizeof(many);
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet.isFirstPacket = false;
+  ++packet.seqNum;
+  packet.dataPtr = bitstream;
+  packet.sizeBytes = sizeof(bitstream);
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ++packet.seqNum;
+  packet.dataPtr = such;
+  packet.sizeBytes = sizeof(such);
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet.markerBit = true;
+  ++packet.seqNum;
+  packet.dataPtr = data;
+  packet.sizeBytes = sizeof(data);
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ASSERT_EQ(1UL, frames_from_callback_.size());
+
+  EXPECT_TRUE(frames_from_callback_[0]->GetBitstream(result));
+  EXPECT_EQ(
+      std::strcmp("many bitstream, such data", reinterpret_cast<char*>(result)),
+      0);
+}
+
+TEST_F(TestPacketBuffer, FreeSlotsOnFrameDestruction) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.isFirstPacket = false;
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  ++packet.seqNum;
+  packet.markerBit = true;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+
+  frames_from_callback_.clear();
+
+  packet.isFirstPacket = true;
+  packet.markerBit = false;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  packet.isFirstPacket = false;
+  ++packet.seqNum;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(0UL, frames_from_callback_.size());
+  ++packet.seqNum;
+  packet.markerBit = true;
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(1UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, Flush) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.markerBit = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  packet_buffer_.Flush();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  EXPECT_EQ(2UL, frames_from_callback_.size());
+}
+
+TEST_F(TestPacketBuffer, InvalidateFrameByFlushing) {
+  VCMPacket packet;
+  packet.isFirstPacket = true;
+  packet.markerBit = true;
+  packet.seqNum = Rand();
+  EXPECT_TRUE(packet_buffer_.InsertPacket(packet));
+  ASSERT_EQ(1UL, frames_from_callback_.size());
+
+  packet_buffer_.Flush();
+  EXPECT_FALSE(frames_from_callback_[0]->GetBitstream(nullptr));
+}
+
+}  // namespace video_coding
+}  // namespace webrtc

webrtc/modules/video_coding/video_coding.gypi

@@ -34,6 +34,7 @@
         'encoded_frame.h',
         'fec_tables_xor.h',
         'frame_buffer.h',
+        'frame_object.h',
         'generic_decoder.h',
         'generic_encoder.h',
         'histogram.h',
@@ -47,6 +48,7 @@
         'nack_fec_tables.h',
         'nack_module.h',
         'packet.h',
+        'packet_buffer.h',
         'percentile_filter.h',
         'qm_select_data.h',
         'qm_select.h',
@@ -65,6 +67,7 @@
         'decoding_state.cc',
         'encoded_frame.cc',
         'frame_buffer.cc',
+        'frame_object.cc',
         'generic_decoder.cc',
         'generic_encoder.cc',
         'inter_frame_delay.cc',
@@ -75,6 +78,7 @@
         'media_optimization.cc',
         'nack_module.cc',
         'packet.cc',
+        'packet_buffer.cc',
         'percentile_filter.cc',
         'qm_select.cc',
         'receiver.cc',