Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

24 files changed, 4482 insertions, 0 deletions

diff --git a/third_party/libwebrtc/modules/audio_coding/test/Channel.cc b/third_party/libwebrtc/modules/audio_coding/test/Channel.cc
new file mode 100644
index 0000000000..35aa6cb6b4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/Channel.cc
@@ -0,0 +1,274 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/Channel.h"
+
+#include <iostream>
+
+#include "rtc_base/strings/string_builder.h"
+#include "rtc_base/time_utils.h"
+
+namespace webrtc {
+
+int32_t Channel::SendData(AudioFrameType frameType,
+                          uint8_t payloadType,
+                          uint32_t timeStamp,
+                          const uint8_t* payloadData,
+                          size_t payloadSize,
+                          int64_t absolute_capture_timestamp_ms) {
+  RTPHeader rtp_header;
+  int32_t status;
+  size_t payloadDataSize = payloadSize;
+
+  rtp_header.markerBit = false;
+  rtp_header.ssrc = 0;
+  rtp_header.sequenceNumber =
+      (external_sequence_number_ < 0)
+          ? _seqNo++
+          : static_cast<uint16_t>(external_sequence_number_);
+  rtp_header.payloadType = payloadType;
+  rtp_header.timestamp = (external_send_timestamp_ < 0)
+                             ? timeStamp
+                             : static_cast<uint32_t>(external_send_timestamp_);
+
+  if (frameType == AudioFrameType::kEmptyFrame) {
+    // When frame is empty, we should not transmit it. The frame size of the
+    // next non-empty frame will be based on the previous frame size.
+    _useLastFrameSize = _lastFrameSizeSample > 0;
+    return 0;
+  }
+
+  memcpy(_payloadData, payloadData, payloadDataSize);
+  if (_isStereo) {
+    if (_leftChannel) {
+      _rtp_header = rtp_header;
+      _leftChannel = false;
+    } else {
+      rtp_header = _rtp_header;
+      _leftChannel = true;
+    }
+  }
+
+  _channelCritSect.Lock();
+  if (_saveBitStream) {
+    // fwrite(payloadData, sizeof(uint8_t), payloadSize, _bitStreamFile);
+  }
+
+  if (!_isStereo) {
+    CalcStatistics(rtp_header, payloadSize);
+  }
+  _useLastFrameSize = false;
+  _lastInTimestamp = timeStamp;
+  _totalBytes += payloadDataSize;
+  _channelCritSect.Unlock();
+
+  if (_useFECTestWithPacketLoss) {
+    _packetLoss += 1;
+    if (_packetLoss == 3) {
+      _packetLoss = 0;
+      return 0;
+    }
+  }
+
+  if (num_packets_to_drop_ > 0) {
+    num_packets_to_drop_--;
+    return 0;
+  }
+
+  status =
+      _receiverACM->IncomingPacket(_payloadData, payloadDataSize, rtp_header);
+
+  return status;
+}
+
+// TODO(turajs): rewite this method.
+void Channel::CalcStatistics(const RTPHeader& rtp_header, size_t payloadSize) {
+  int n;
+  if ((rtp_header.payloadType != _lastPayloadType) &&
+      (_lastPayloadType != -1)) {
+    // payload-type is changed.
+    // we have to terminate the calculations on the previous payload type
+    // we ignore the last packet in that payload type just to make things
+    // easier.
+    for (n = 0; n < MAX_NUM_PAYLOADS; n++) {
+      if (_lastPayloadType == _payloadStats[n].payloadType) {
+        _payloadStats[n].newPacket = true;
+        break;
+      }
+    }
+  }
+  _lastPayloadType = rtp_header.payloadType;
+
+  bool newPayload = true;
+  ACMTestPayloadStats* currentPayloadStr = NULL;
+  for (n = 0; n < MAX_NUM_PAYLOADS; n++) {
+    if (rtp_header.payloadType == _payloadStats[n].payloadType) {
+      newPayload = false;
+      currentPayloadStr = &_payloadStats[n];
+      break;
+    }
+  }
+
+  if (!newPayload) {
+    if (!currentPayloadStr->newPacket) {
+      if (!_useLastFrameSize) {
+        _lastFrameSizeSample =
+            (uint32_t)((uint32_t)rtp_header.timestamp -
+                       (uint32_t)currentPayloadStr->lastTimestamp);
+      }
+      RTC_DCHECK_GT(_lastFrameSizeSample, 0);
+      int k = 0;
+      for (; k < MAX_NUM_FRAMESIZES; ++k) {
+        if ((currentPayloadStr->frameSizeStats[k].frameSizeSample ==
+             _lastFrameSizeSample) ||
+            (currentPayloadStr->frameSizeStats[k].frameSizeSample == 0)) {
+          break;
+        }
+      }
+      if (k == MAX_NUM_FRAMESIZES) {
+        // New frame size found but no space to count statistics on it. Skip it.
+        printf("No memory to store statistics for payload %d : frame size %d\n",
+               _lastPayloadType, _lastFrameSizeSample);
+        return;
+      }
+      ACMTestFrameSizeStats* currentFrameSizeStats =
+          &(currentPayloadStr->frameSizeStats[k]);
+      currentFrameSizeStats->frameSizeSample = (int16_t)_lastFrameSizeSample;
+
+      // increment the number of encoded samples.
+      currentFrameSizeStats->totalEncodedSamples += _lastFrameSizeSample;
+      // increment the number of recveived packets
+      currentFrameSizeStats->numPackets++;
+      // increment the total number of bytes (this is based on
+      // the previous payload we don't know the frame-size of
+      // the current payload.
+      currentFrameSizeStats->totalPayloadLenByte +=
+          currentPayloadStr->lastPayloadLenByte;
+      // store the maximum payload-size (this is based on
+      // the previous payload we don't know the frame-size of
+      // the current payload.
+      if (currentFrameSizeStats->maxPayloadLen <
+          currentPayloadStr->lastPayloadLenByte) {
+        currentFrameSizeStats->maxPayloadLen =
+            currentPayloadStr->lastPayloadLenByte;
+      }
+      // store the current values for the next time
+      currentPayloadStr->lastTimestamp = rtp_header.timestamp;
+      currentPayloadStr->lastPayloadLenByte = payloadSize;
+    } else {
+      currentPayloadStr->newPacket = false;
+      currentPayloadStr->lastPayloadLenByte = payloadSize;
+      currentPayloadStr->lastTimestamp = rtp_header.timestamp;
+      currentPayloadStr->payloadType = rtp_header.payloadType;
+      memset(currentPayloadStr->frameSizeStats, 0,
+             MAX_NUM_FRAMESIZES * sizeof(ACMTestFrameSizeStats));
+    }
+  } else {
+    n = 0;
+    while (_payloadStats[n].payloadType != -1) {
+      n++;
+    }
+    // first packet
+    _payloadStats[n].newPacket = false;
+    _payloadStats[n].lastPayloadLenByte = payloadSize;
+    _payloadStats[n].lastTimestamp = rtp_header.timestamp;
+    _payloadStats[n].payloadType = rtp_header.payloadType;
+    memset(_payloadStats[n].frameSizeStats, 0,
+           MAX_NUM_FRAMESIZES * sizeof(ACMTestFrameSizeStats));
+  }
+}
+
+Channel::Channel(int16_t chID)
+    : _receiverACM(NULL),
+      _seqNo(0),
+      _bitStreamFile(NULL),
+      _saveBitStream(false),
+      _lastPayloadType(-1),
+      _isStereo(false),
+      _leftChannel(true),
+      _lastInTimestamp(0),
+      _useLastFrameSize(false),
+      _lastFrameSizeSample(0),
+      _packetLoss(0),
+      _useFECTestWithPacketLoss(false),
+      _beginTime(rtc::TimeMillis()),
+      _totalBytes(0),
+      external_send_timestamp_(-1),
+      external_sequence_number_(-1),
+      num_packets_to_drop_(0) {
+  int n;
+  int k;
+  for (n = 0; n < MAX_NUM_PAYLOADS; n++) {
+    _payloadStats[n].payloadType = -1;
+    _payloadStats[n].newPacket = true;
+    for (k = 0; k < MAX_NUM_FRAMESIZES; k++) {
+      _payloadStats[n].frameSizeStats[k].frameSizeSample = 0;
+      _payloadStats[n].frameSizeStats[k].maxPayloadLen = 0;
+      _payloadStats[n].frameSizeStats[k].numPackets = 0;
+      _payloadStats[n].frameSizeStats[k].totalPayloadLenByte = 0;
+      _payloadStats[n].frameSizeStats[k].totalEncodedSamples = 0;
+    }
+  }
+  if (chID >= 0) {
+    _saveBitStream = true;
+    rtc::StringBuilder ss;
+    ss.AppendFormat("bitStream_%d.dat", chID);
+    _bitStreamFile = fopen(ss.str().c_str(), "wb");
+  } else {
+    _saveBitStream = false;
+  }
+}
+
+Channel::~Channel() {}
+
+void Channel::RegisterReceiverACM(AudioCodingModule* acm) {
+  _receiverACM = acm;
+  return;
+}
+
+void Channel::ResetStats() {
+  int n;
+  int k;
+  _channelCritSect.Lock();
+  _lastPayloadType = -1;
+  for (n = 0; n < MAX_NUM_PAYLOADS; n++) {
+    _payloadStats[n].payloadType = -1;
+    _payloadStats[n].newPacket = true;
+    for (k = 0; k < MAX_NUM_FRAMESIZES; k++) {
+      _payloadStats[n].frameSizeStats[k].frameSizeSample = 0;
+      _payloadStats[n].frameSizeStats[k].maxPayloadLen = 0;
+      _payloadStats[n].frameSizeStats[k].numPackets = 0;
+      _payloadStats[n].frameSizeStats[k].totalPayloadLenByte = 0;
+      _payloadStats[n].frameSizeStats[k].totalEncodedSamples = 0;
+    }
+  }
+  _beginTime = rtc::TimeMillis();
+  _totalBytes = 0;
+  _channelCritSect.Unlock();
+}
+
+uint32_t Channel::LastInTimestamp() {
+  uint32_t timestamp;
+  _channelCritSect.Lock();
+  timestamp = _lastInTimestamp;
+  _channelCritSect.Unlock();
+  return timestamp;
+}
+
+double Channel::BitRate() {
+  double rate;
+  uint64_t currTime = rtc::TimeMillis();
+  _channelCritSect.Lock();
+  rate = ((double)_totalBytes * 8.0) / (double)(currTime - _beginTime);
+  _channelCritSect.Unlock();
+  return rate;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/Channel.h b/third_party/libwebrtc/modules/audio_coding/test/Channel.h
new file mode 100644
index 0000000000..7a8829e1d2
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/Channel.h
@@ -0,0 +1,117 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_CHANNEL_H_
+#define MODULES_AUDIO_CODING_TEST_CHANNEL_H_
+
+#include <stdio.h>
+
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/include/module_common_types.h"
+#include "rtc_base/synchronization/mutex.h"
+
+namespace webrtc {
+
+#define MAX_NUM_PAYLOADS 50
+#define MAX_NUM_FRAMESIZES 6
+
+// TODO(turajs): Write constructor for this structure.
+struct ACMTestFrameSizeStats {
+  uint16_t frameSizeSample;
+  size_t maxPayloadLen;
+  uint32_t numPackets;
+  uint64_t totalPayloadLenByte;
+  uint64_t totalEncodedSamples;
+  double rateBitPerSec;
+  double usageLenSec;
+};
+
+// TODO(turajs): Write constructor for this structure.
+struct ACMTestPayloadStats {
+  bool newPacket;
+  int16_t payloadType;
+  size_t lastPayloadLenByte;
+  uint32_t lastTimestamp;
+  ACMTestFrameSizeStats frameSizeStats[MAX_NUM_FRAMESIZES];
+};
+
+class Channel : public AudioPacketizationCallback {
+ public:
+  Channel(int16_t chID = -1);
+  ~Channel() override;
+
+  int32_t SendData(AudioFrameType frameType,
+                   uint8_t payloadType,
+                   uint32_t timeStamp,
+                   const uint8_t* payloadData,
+                   size_t payloadSize,
+                   int64_t absolute_capture_timestamp_ms) override;
+
+  void RegisterReceiverACM(AudioCodingModule* acm);
+
+  void ResetStats();
+
+  void SetIsStereo(bool isStereo) { _isStereo = isStereo; }
+
+  uint32_t LastInTimestamp();
+
+  void SetFECTestWithPacketLoss(bool usePacketLoss) {
+    _useFECTestWithPacketLoss = usePacketLoss;
+  }
+
+  double BitRate();
+
+  void set_send_timestamp(uint32_t new_send_ts) {
+    external_send_timestamp_ = new_send_ts;
+  }
+
+  void set_sequence_number(uint16_t new_sequence_number) {
+    external_sequence_number_ = new_sequence_number;
+  }
+
+  void set_num_packets_to_drop(int new_num_packets_to_drop) {
+    num_packets_to_drop_ = new_num_packets_to_drop;
+  }
+
+ private:
+  void CalcStatistics(const RTPHeader& rtp_header, size_t payloadSize);
+
+  AudioCodingModule* _receiverACM;
+  uint16_t _seqNo;
+  // 60msec * 32 sample(max)/msec * 2 description (maybe) * 2 bytes/sample
+  uint8_t _payloadData[60 * 32 * 2 * 2];
+
+  Mutex _channelCritSect;
+  FILE* _bitStreamFile;
+  bool _saveBitStream;
+  int16_t _lastPayloadType;
+  ACMTestPayloadStats _payloadStats[MAX_NUM_PAYLOADS];
+  bool _isStereo;
+  RTPHeader _rtp_header;
+  bool _leftChannel;
+  uint32_t _lastInTimestamp;
+  bool _useLastFrameSize;
+  uint32_t _lastFrameSizeSample;
+  // FEC Test variables
+  int16_t _packetLoss;
+  bool _useFECTestWithPacketLoss;
+  uint64_t _beginTime;
+  uint64_t _totalBytes;
+
+  // External timing info, defaulted to -1. Only used if they are
+  // non-negative.
+  int64_t external_send_timestamp_;
+  int32_t external_sequence_number_;
+  int num_packets_to_drop_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_CHANNEL_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.cc b/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.cc
new file mode 100644
index 0000000000..9f9c4aa74c
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.cc
@@ -0,0 +1,269 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/EncodeDecodeTest.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "api/audio_codecs/builtin_audio_encoder_factory.h"
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+namespace {
+// Buffer size for stereo 48 kHz audio.
+constexpr size_t kWebRtc10MsPcmAudio = 960;
+
+}  // namespace
+
+TestPacketization::TestPacketization(RTPStream* rtpStream, uint16_t frequency)
+    : _rtpStream(rtpStream), _frequency(frequency), _seqNo(0) {}
+
+TestPacketization::~TestPacketization() {}
+
+int32_t TestPacketization::SendData(const AudioFrameType /* frameType */,
+                                    const uint8_t payloadType,
+                                    const uint32_t timeStamp,
+                                    const uint8_t* payloadData,
+                                    const size_t payloadSize,
+                                    int64_t absolute_capture_timestamp_ms) {
+  _rtpStream->Write(payloadType, timeStamp, _seqNo++, payloadData, payloadSize,
+                    _frequency);
+  return 1;
+}
+
+Sender::Sender()
+    : _acm(NULL), _pcmFile(), _audioFrame(), _packetization(NULL) {}
+
+void Sender::Setup(AudioCodingModule* acm,
+                   RTPStream* rtpStream,
+                   absl::string_view in_file_name,
+                   int in_sample_rate,
+                   int payload_type,
+                   SdpAudioFormat format) {
+  // Open input file
+  const std::string file_name = webrtc::test::ResourcePath(in_file_name, "pcm");
+  _pcmFile.Open(file_name, in_sample_rate, "rb");
+  if (format.num_channels == 2) {
+    _pcmFile.ReadStereo(true);
+  }
+  // Set test length to 500 ms (50 blocks of 10 ms each).
+  _pcmFile.SetNum10MsBlocksToRead(50);
+  // Fast-forward 1 second (100 blocks) since the file starts with silence.
+  _pcmFile.FastForward(100);
+
+  acm->SetEncoder(CreateBuiltinAudioEncoderFactory()->MakeAudioEncoder(
+      payload_type, format, absl::nullopt));
+  _packetization = new TestPacketization(rtpStream, format.clockrate_hz);
+  EXPECT_EQ(0, acm->RegisterTransportCallback(_packetization));
+
+  _acm = acm;
+}
+
+void Sender::Teardown() {
+  _pcmFile.Close();
+  delete _packetization;
+}
+
+bool Sender::Add10MsData() {
+  if (!_pcmFile.EndOfFile()) {
+    EXPECT_GT(_pcmFile.Read10MsData(_audioFrame), 0);
+    int32_t ok = _acm->Add10MsData(_audioFrame);
+    EXPECT_GE(ok, 0);
+    return ok >= 0 ? true : false;
+  }
+  return false;
+}
+
+void Sender::Run() {
+  while (true) {
+    if (!Add10MsData()) {
+      break;
+    }
+  }
+}
+
+Receiver::Receiver()
+    : _playoutLengthSmpls(kWebRtc10MsPcmAudio),
+      _payloadSizeBytes(MAX_INCOMING_PAYLOAD) {}
+
+void Receiver::Setup(AudioCodingModule* acm,
+                     RTPStream* rtpStream,
+                     absl::string_view out_file_name,
+                     size_t channels,
+                     int file_num) {
+  EXPECT_EQ(0, acm->InitializeReceiver());
+
+  if (channels == 1) {
+    acm->SetReceiveCodecs({{107, {"L16", 8000, 1}},
+                           {108, {"L16", 16000, 1}},
+                           {109, {"L16", 32000, 1}},
+                           {0, {"PCMU", 8000, 1}},
+                           {8, {"PCMA", 8000, 1}},
+                           {102, {"ILBC", 8000, 1}},
+                           {9, {"G722", 8000, 1}},
+                           {120, {"OPUS", 48000, 2}},
+                           {13, {"CN", 8000, 1}},
+                           {98, {"CN", 16000, 1}},
+                           {99, {"CN", 32000, 1}}});
+  } else {
+    ASSERT_EQ(channels, 2u);
+    acm->SetReceiveCodecs({{111, {"L16", 8000, 2}},
+                           {112, {"L16", 16000, 2}},
+                           {113, {"L16", 32000, 2}},
+                           {110, {"PCMU", 8000, 2}},
+                           {118, {"PCMA", 8000, 2}},
+                           {119, {"G722", 8000, 2}},
+                           {120, {"OPUS", 48000, 2, {{"stereo", "1"}}}}});
+  }
+
+  int playSampFreq;
+  std::string file_name;
+  rtc::StringBuilder file_stream;
+  file_stream << webrtc::test::OutputPath() << out_file_name << file_num
+              << ".pcm";
+  file_name = file_stream.str();
+  _rtpStream = rtpStream;
+
+  playSampFreq = 32000;
+  _pcmFile.Open(file_name, 32000, "wb+");
+
+  _realPayloadSizeBytes = 0;
+  _playoutBuffer = new int16_t[kWebRtc10MsPcmAudio];
+  _frequency = playSampFreq;
+  _acm = acm;
+  _firstTime = true;
+}
+
+void Receiver::Teardown() {
+  delete[] _playoutBuffer;
+  _pcmFile.Close();
+}
+
+bool Receiver::IncomingPacket() {
+  if (!_rtpStream->EndOfFile()) {
+    if (_firstTime) {
+      _firstTime = false;
+      _realPayloadSizeBytes = _rtpStream->Read(&_rtpHeader, _incomingPayload,
+                                               _payloadSizeBytes, &_nextTime);
+      if (_realPayloadSizeBytes == 0) {
+        if (_rtpStream->EndOfFile()) {
+          _firstTime = true;
+          return true;
+        } else {
+          return false;
+        }
+      }
+    }
+
+    EXPECT_EQ(0, _acm->IncomingPacket(_incomingPayload, _realPayloadSizeBytes,
+                                      _rtpHeader));
+    _realPayloadSizeBytes = _rtpStream->Read(&_rtpHeader, _incomingPayload,
+                                             _payloadSizeBytes, &_nextTime);
+    if (_realPayloadSizeBytes == 0 && _rtpStream->EndOfFile()) {
+      _firstTime = true;
+    }
+  }
+  return true;
+}
+
+bool Receiver::PlayoutData() {
+  AudioFrame audioFrame;
+  bool muted;
+  int32_t ok = _acm->PlayoutData10Ms(_frequency, &audioFrame, &muted);
+  if (muted) {
+    ADD_FAILURE();
+    return false;
+  }
+  EXPECT_EQ(0, ok);
+  if (ok < 0) {
+    return false;
+  }
+  if (_playoutLengthSmpls == 0) {
+    return false;
+  }
+  _pcmFile.Write10MsData(audioFrame.data(), audioFrame.samples_per_channel_ *
+                                                audioFrame.num_channels_);
+  return true;
+}
+
+void Receiver::Run() {
+  uint8_t counter500Ms = 50;
+  uint32_t clock = 0;
+
+  while (counter500Ms > 0) {
+    if (clock == 0 || clock >= _nextTime) {
+      EXPECT_TRUE(IncomingPacket());
+      if (clock == 0) {
+        clock = _nextTime;
+      }
+    }
+    if ((clock % 10) == 0) {
+      if (!PlayoutData()) {
+        clock++;
+        continue;
+      }
+    }
+    if (_rtpStream->EndOfFile()) {
+      counter500Ms--;
+    }
+    clock++;
+  }
+}
+
+EncodeDecodeTest::EncodeDecodeTest() = default;
+
+void EncodeDecodeTest::Perform() {
+  const std::map<int, SdpAudioFormat> send_codecs = {
+      {107, {"L16", 8000, 1}},   {108, {"L16", 16000, 1}},
+      {109, {"L16", 32000, 1}},  {0, {"PCMU", 8000, 1}},
+      {8, {"PCMA", 8000, 1}},
+#ifdef WEBRTC_CODEC_ILBC
+      {102, {"ILBC", 8000, 1}},
+#endif
+      {9, {"G722", 8000, 1}}};
+  int file_num = 0;
+  for (const auto& send_codec : send_codecs) {
+    RTPFile rtpFile;
+    std::unique_ptr<AudioCodingModule> acm(AudioCodingModule::Create(
+        AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory())));
+
+    std::string fileName = webrtc::test::TempFilename(
+        webrtc::test::OutputPath(), "encode_decode_rtp");
+    rtpFile.Open(fileName.c_str(), "wb+");
+    rtpFile.WriteHeader();
+    Sender sender;
+    sender.Setup(acm.get(), &rtpFile, "audio_coding/testfile32kHz", 32000,
+                 send_codec.first, send_codec.second);
+    sender.Run();
+    sender.Teardown();
+    rtpFile.Close();
+
+    rtpFile.Open(fileName.c_str(), "rb");
+    rtpFile.ReadHeader();
+    Receiver receiver;
+    receiver.Setup(acm.get(), &rtpFile, "encodeDecode_out", 1, file_num);
+    receiver.Run();
+    receiver.Teardown();
+    rtpFile.Close();
+
+    file_num++;
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.h b/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.h
new file mode 100644
index 0000000000..89b76440ef
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/EncodeDecodeTest.h
@@ -0,0 +1,111 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_ENCODEDECODETEST_H_
+#define MODULES_AUDIO_CODING_TEST_ENCODEDECODETEST_H_
+
+#include <stdio.h>
+#include <string.h>
+
+#include "absl/strings/string_view.h"
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/test/PCMFile.h"
+#include "modules/audio_coding/test/RTPFile.h"
+#include "modules/include/module_common_types.h"
+
+namespace webrtc {
+
+#define MAX_INCOMING_PAYLOAD 8096
+
+// TestPacketization callback which writes the encoded payloads to file
+class TestPacketization : public AudioPacketizationCallback {
+ public:
+  TestPacketization(RTPStream* rtpStream, uint16_t frequency);
+  ~TestPacketization();
+  int32_t SendData(AudioFrameType frameType,
+                   uint8_t payloadType,
+                   uint32_t timeStamp,
+                   const uint8_t* payloadData,
+                   size_t payloadSize,
+                   int64_t absolute_capture_timestamp_ms) override;
+
+ private:
+  static void MakeRTPheader(uint8_t* rtpHeader,
+                            uint8_t payloadType,
+                            int16_t seqNo,
+                            uint32_t timeStamp,
+                            uint32_t ssrc);
+  RTPStream* _rtpStream;
+  int32_t _frequency;
+  int16_t _seqNo;
+};
+
+class Sender {
+ public:
+  Sender();
+  void Setup(AudioCodingModule* acm,
+             RTPStream* rtpStream,
+             absl::string_view in_file_name,
+             int in_sample_rate,
+             int payload_type,
+             SdpAudioFormat format);
+  void Teardown();
+  void Run();
+  bool Add10MsData();
+
+ protected:
+  AudioCodingModule* _acm;
+
+ private:
+  PCMFile _pcmFile;
+  AudioFrame _audioFrame;
+  TestPacketization* _packetization;
+};
+
+class Receiver {
+ public:
+  Receiver();
+  virtual ~Receiver() {}
+  void Setup(AudioCodingModule* acm,
+             RTPStream* rtpStream,
+             absl::string_view out_file_name,
+             size_t channels,
+             int file_num);
+  void Teardown();
+  void Run();
+  virtual bool IncomingPacket();
+  bool PlayoutData();
+
+ private:
+  PCMFile _pcmFile;
+  int16_t* _playoutBuffer;
+  uint16_t _playoutLengthSmpls;
+  int32_t _frequency;
+  bool _firstTime;
+
+ protected:
+  AudioCodingModule* _acm;
+  uint8_t _incomingPayload[MAX_INCOMING_PAYLOAD];
+  RTPStream* _rtpStream;
+  RTPHeader _rtpHeader;
+  size_t _realPayloadSizeBytes;
+  size_t _payloadSizeBytes;
+  uint32_t _nextTime;
+};
+
+class EncodeDecodeTest {
+ public:
+  EncodeDecodeTest();
+  void Perform();
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_ENCODEDECODETEST_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/PCMFile.cc b/third_party/libwebrtc/modules/audio_coding/test/PCMFile.cc
new file mode 100644
index 0000000000..e069a42de1
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/PCMFile.cc
@@ -0,0 +1,240 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/PCMFile.h"
+
+#include <ctype.h>
+#include <stdio.h>
+#include <string.h>
+
+#include "absl/strings/string_view.h"
+#include "rtc_base/checks.h"
+#include "test/gtest.h"
+
+namespace webrtc {
+
+#define MAX_FILE_NAME_LENGTH_BYTE 500
+
+PCMFile::PCMFile()
+    : pcm_file_(NULL),
+      samples_10ms_(160),
+      frequency_(16000),
+      end_of_file_(false),
+      auto_rewind_(false),
+      rewinded_(false),
+      read_stereo_(false),
+      save_stereo_(false) {
+  timestamp_ =
+      (((uint32_t)rand() & 0x0000FFFF) << 16) | ((uint32_t)rand() & 0x0000FFFF);
+}
+
+PCMFile::PCMFile(uint32_t timestamp)
+    : pcm_file_(NULL),
+      samples_10ms_(160),
+      frequency_(16000),
+      end_of_file_(false),
+      auto_rewind_(false),
+      rewinded_(false),
+      read_stereo_(false),
+      save_stereo_(false) {
+  timestamp_ = timestamp;
+}
+
+PCMFile::~PCMFile() {
+  if (pcm_file_) {
+    fclose(pcm_file_);
+  }
+}
+
+int16_t PCMFile::ChooseFile(std::string* file_name,
+                            int16_t max_len,
+                            uint16_t* frequency_hz) {
+  char tmp_name[MAX_FILE_NAME_LENGTH_BYTE];
+
+  EXPECT_TRUE(fgets(tmp_name, MAX_FILE_NAME_LENGTH_BYTE, stdin) != NULL);
+  tmp_name[MAX_FILE_NAME_LENGTH_BYTE - 1] = '\0';
+  int16_t n = 0;
+
+  // Removing trailing spaces.
+  while ((isspace(static_cast<unsigned char>(tmp_name[n])) ||
+          iscntrl(static_cast<unsigned char>(tmp_name[n]))) &&
+         (static_cast<unsigned char>(tmp_name[n]) != 0) &&
+         (n < MAX_FILE_NAME_LENGTH_BYTE)) {
+    n++;
+  }
+  if (n > 0) {
+    memmove(tmp_name, &tmp_name[n], MAX_FILE_NAME_LENGTH_BYTE - n);
+  }
+
+  // Removing trailing spaces.
+  n = (int16_t)(strlen(tmp_name) - 1);
+  if (n >= 0) {
+    while ((isspace(static_cast<unsigned char>(tmp_name[n])) ||
+            iscntrl(static_cast<unsigned char>(tmp_name[n]))) &&
+           (n >= 0)) {
+      n--;
+    }
+  }
+  if (n >= 0) {
+    tmp_name[n + 1] = '\0';
+  }
+
+  int16_t len = (int16_t)strlen(tmp_name);
+  if (len > max_len) {
+    return -1;
+  }
+  if (len > 0) {
+    std::string tmp_string(tmp_name, len + 1);
+    *file_name = tmp_string;
+  }
+  printf("Enter the sampling frequency (in Hz) of the above file [%u]: ",
+         *frequency_hz);
+  EXPECT_TRUE(fgets(tmp_name, 10, stdin) != NULL);
+  uint16_t tmp_frequency = (uint16_t)atoi(tmp_name);
+  if (tmp_frequency > 0) {
+    *frequency_hz = tmp_frequency;
+  }
+  return 0;
+}
+
+void PCMFile::Open(absl::string_view file_name,
+                   uint16_t frequency,
+                   absl::string_view mode,
+                   bool auto_rewind) {
+  if ((pcm_file_ = fopen(std::string(file_name).c_str(),
+                         std::string(mode).c_str())) == NULL) {
+    printf("Cannot open file %s.\n", std::string(file_name).c_str());
+    ADD_FAILURE() << "Unable to read file";
+  }
+  frequency_ = frequency;
+  samples_10ms_ = (uint16_t)(frequency_ / 100);
+  auto_rewind_ = auto_rewind;
+  end_of_file_ = false;
+  rewinded_ = false;
+}
+
+int32_t PCMFile::SamplingFrequency() const {
+  return frequency_;
+}
+
+uint16_t PCMFile::PayloadLength10Ms() const {
+  return samples_10ms_;
+}
+
+int32_t PCMFile::Read10MsData(AudioFrame& audio_frame) {
+  uint16_t channels = 1;
+  if (read_stereo_) {
+    channels = 2;
+  }
+
+  int32_t payload_size =
+      (int32_t)fread(audio_frame.mutable_data(), sizeof(uint16_t),
+                     samples_10ms_ * channels, pcm_file_);
+  if (payload_size < samples_10ms_ * channels) {
+    int16_t* frame_data = audio_frame.mutable_data();
+    for (int k = payload_size; k < samples_10ms_ * channels; k++) {
+      frame_data[k] = 0;
+    }
+    if (auto_rewind_) {
+      rewind(pcm_file_);
+      rewinded_ = true;
+    } else {
+      end_of_file_ = true;
+    }
+  }
+  audio_frame.samples_per_channel_ = samples_10ms_;
+  audio_frame.sample_rate_hz_ = frequency_;
+  audio_frame.num_channels_ = channels;
+  audio_frame.timestamp_ = timestamp_;
+  timestamp_ += samples_10ms_;
+  ++blocks_read_;
+  if (num_10ms_blocks_to_read_ && blocks_read_ >= *num_10ms_blocks_to_read_)
+    end_of_file_ = true;
+  return samples_10ms_;
+}
+
+void PCMFile::Write10MsData(const AudioFrame& audio_frame) {
+  if (audio_frame.num_channels_ == 1) {
+    if (!save_stereo_) {
+      if (fwrite(audio_frame.data(), sizeof(uint16_t),
+                 audio_frame.samples_per_channel_, pcm_file_) !=
+          static_cast<size_t>(audio_frame.samples_per_channel_)) {
+        return;
+      }
+    } else {
+      const int16_t* frame_data = audio_frame.data();
+      int16_t* stereo_audio = new int16_t[2 * audio_frame.samples_per_channel_];
+      for (size_t k = 0; k < audio_frame.samples_per_channel_; k++) {
+        stereo_audio[k << 1] = frame_data[k];
+        stereo_audio[(k << 1) + 1] = frame_data[k];
+      }
+      if (fwrite(stereo_audio, sizeof(int16_t),
+                 2 * audio_frame.samples_per_channel_, pcm_file_) !=
+          static_cast<size_t>(2 * audio_frame.samples_per_channel_)) {
+        return;
+      }
+      delete[] stereo_audio;
+    }
+  } else {
+    if (fwrite(audio_frame.data(), sizeof(int16_t),
+               audio_frame.num_channels_ * audio_frame.samples_per_channel_,
+               pcm_file_) !=
+        static_cast<size_t>(audio_frame.num_channels_ *
+                            audio_frame.samples_per_channel_)) {
+      return;
+    }
+  }
+}
+
+void PCMFile::Write10MsData(const int16_t* playout_buffer,
+                            size_t length_smpls) {
+  if (fwrite(playout_buffer, sizeof(uint16_t), length_smpls, pcm_file_) !=
+      length_smpls) {
+    return;
+  }
+}
+
+void PCMFile::Close() {
+  fclose(pcm_file_);
+  pcm_file_ = NULL;
+  blocks_read_ = 0;
+}
+
+void PCMFile::FastForward(int num_10ms_blocks) {
+  const int channels = read_stereo_ ? 2 : 1;
+  long num_bytes_to_move =
+      num_10ms_blocks * sizeof(int16_t) * samples_10ms_ * channels;
+  int error = fseek(pcm_file_, num_bytes_to_move, SEEK_CUR);
+  RTC_DCHECK_EQ(error, 0);
+}
+
+void PCMFile::Rewind() {
+  rewind(pcm_file_);
+  end_of_file_ = false;
+  blocks_read_ = 0;
+}
+
+bool PCMFile::Rewinded() {
+  return rewinded_;
+}
+
+void PCMFile::SaveStereo(bool is_stereo) {
+  save_stereo_ = is_stereo;
+}
+
+void PCMFile::ReadStereo(bool is_stereo) {
+  read_stereo_ = is_stereo;
+}
+
+void PCMFile::SetNum10MsBlocksToRead(int value) {
+  num_10ms_blocks_to_read_ = value;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/PCMFile.h b/third_party/libwebrtc/modules/audio_coding/test/PCMFile.h
new file mode 100644
index 0000000000..5320aa63d0
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/PCMFile.h
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_PCMFILE_H_
+#define MODULES_AUDIO_CODING_TEST_PCMFILE_H_
+
+#include <stdio.h>
+#include <stdlib.h>
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "absl/types/optional.h"
+#include "api/audio/audio_frame.h"
+
+namespace webrtc {
+
+class PCMFile {
+ public:
+  PCMFile();
+  PCMFile(uint32_t timestamp);
+  ~PCMFile();
+
+  void Open(absl::string_view filename,
+            uint16_t frequency,
+            absl::string_view mode,
+            bool auto_rewind = false);
+
+  int32_t Read10MsData(AudioFrame& audio_frame);
+
+  void Write10MsData(const int16_t* playout_buffer, size_t length_smpls);
+  void Write10MsData(const AudioFrame& audio_frame);
+
+  uint16_t PayloadLength10Ms() const;
+  int32_t SamplingFrequency() const;
+  void Close();
+  bool EndOfFile() const { return end_of_file_; }
+  // Moves forward the specified number of 10 ms blocks. If a limit has been set
+  // with SetNum10MsBlocksToRead, fast-forwarding does not count towards this
+  // limit.
+  void FastForward(int num_10ms_blocks);
+  void Rewind();
+  static int16_t ChooseFile(std::string* file_name,
+                            int16_t max_len,
+                            uint16_t* frequency_hz);
+  bool Rewinded();
+  void SaveStereo(bool is_stereo = true);
+  void ReadStereo(bool is_stereo = true);
+  // If set, the reading will stop after the specified number of blocks have
+  // been read. When that has happened, EndOfFile() will return true. Calling
+  // Rewind() will reset the counter and start over.
+  void SetNum10MsBlocksToRead(int value);
+
+ private:
+  FILE* pcm_file_;
+  uint16_t samples_10ms_;
+  int32_t frequency_;
+  bool end_of_file_;
+  bool auto_rewind_;
+  bool rewinded_;
+  uint32_t timestamp_;
+  bool read_stereo_;
+  bool save_stereo_;
+  absl::optional<int> num_10ms_blocks_to_read_;
+  int blocks_read_ = 0;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_PCMFILE_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.cc b/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.cc
new file mode 100644
index 0000000000..799e9c5b1f
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.cc
@@ -0,0 +1,167 @@
+/*
+ *  Copyright (c) 2014 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/audio_coding/test/PacketLossTest.h"
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+ReceiverWithPacketLoss::ReceiverWithPacketLoss()
+    : loss_rate_(0),
+      burst_length_(1),
+      packet_counter_(0),
+      lost_packet_counter_(0),
+      burst_lost_counter_(burst_length_) {}
+
+void ReceiverWithPacketLoss::Setup(AudioCodingModule* acm,
+                                   RTPStream* rtpStream,
+                                   absl::string_view out_file_name,
+                                   int channels,
+                                   int file_num,
+                                   int loss_rate,
+                                   int burst_length) {
+  loss_rate_ = loss_rate;
+  burst_length_ = burst_length;
+  burst_lost_counter_ = burst_length_;  // To prevent first packet gets lost.
+  rtc::StringBuilder ss;
+  ss << out_file_name << "_" << loss_rate_ << "_" << burst_length_ << "_";
+  Receiver::Setup(acm, rtpStream, ss.str(), channels, file_num);
+}
+
+bool ReceiverWithPacketLoss::IncomingPacket() {
+  if (!_rtpStream->EndOfFile()) {
+    if (packet_counter_ == 0) {
+      _realPayloadSizeBytes = _rtpStream->Read(&_rtpHeader, _incomingPayload,
+                                               _payloadSizeBytes, &_nextTime);
+      if (_realPayloadSizeBytes == 0) {
+        if (_rtpStream->EndOfFile()) {
+          packet_counter_ = 0;
+          return true;
+        } else {
+          return false;
+        }
+      }
+    }
+
+    if (!PacketLost()) {
+      _acm->IncomingPacket(_incomingPayload, _realPayloadSizeBytes, _rtpHeader);
+    }
+    packet_counter_++;
+    _realPayloadSizeBytes = _rtpStream->Read(&_rtpHeader, _incomingPayload,
+                                             _payloadSizeBytes, &_nextTime);
+    if (_realPayloadSizeBytes == 0 && _rtpStream->EndOfFile()) {
+      packet_counter_ = 0;
+      lost_packet_counter_ = 0;
+    }
+  }
+  return true;
+}
+
+bool ReceiverWithPacketLoss::PacketLost() {
+  if (burst_lost_counter_ < burst_length_) {
+    lost_packet_counter_++;
+    burst_lost_counter_++;
+    return true;
+  }
+
+  if (lost_packet_counter_ * 100 < loss_rate_ * packet_counter_) {
+    lost_packet_counter_++;
+    burst_lost_counter_ = 1;
+    return true;
+  }
+  return false;
+}
+
+SenderWithFEC::SenderWithFEC() : expected_loss_rate_(0) {}
+
+void SenderWithFEC::Setup(AudioCodingModule* acm,
+                          RTPStream* rtpStream,
+                          absl::string_view in_file_name,
+                          int payload_type,
+                          SdpAudioFormat format,
+                          int expected_loss_rate) {
+  Sender::Setup(acm, rtpStream, in_file_name, format.clockrate_hz, payload_type,
+                format);
+  EXPECT_TRUE(SetFEC(true));
+  EXPECT_TRUE(SetPacketLossRate(expected_loss_rate));
+}
+
+bool SenderWithFEC::SetFEC(bool enable_fec) {
+  bool success = false;
+  _acm->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* enc) {
+    if (*enc && (*enc)->SetFec(enable_fec)) {
+      success = true;
+    }
+  });
+  return success;
+}
+
+bool SenderWithFEC::SetPacketLossRate(int expected_loss_rate) {
+  if (_acm->SetPacketLossRate(expected_loss_rate) == 0) {
+    expected_loss_rate_ = expected_loss_rate;
+    return true;
+  }
+  return false;
+}
+
+PacketLossTest::PacketLossTest(int channels,
+                               int expected_loss_rate,
+                               int actual_loss_rate,
+                               int burst_length)
+    : channels_(channels),
+      in_file_name_(channels_ == 1 ? "audio_coding/testfile32kHz"
+                                   : "audio_coding/teststereo32kHz"),
+      sample_rate_hz_(32000),
+      expected_loss_rate_(expected_loss_rate),
+      actual_loss_rate_(actual_loss_rate),
+      burst_length_(burst_length) {}
+
+void PacketLossTest::Perform() {
+#ifndef WEBRTC_CODEC_OPUS
+  return;
+#else
+  RTPFile rtpFile;
+  std::unique_ptr<AudioCodingModule> acm(AudioCodingModule::Create(
+      AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory())));
+  SdpAudioFormat send_format = SdpAudioFormat("opus", 48000, 2);
+  if (channels_ == 2) {
+    send_format.parameters = {{"stereo", "1"}};
+  }
+
+  std::string fileName = webrtc::test::TempFilename(webrtc::test::OutputPath(),
+                                                    "packet_loss_test");
+  rtpFile.Open(fileName.c_str(), "wb+");
+  rtpFile.WriteHeader();
+  SenderWithFEC sender;
+  sender.Setup(acm.get(), &rtpFile, in_file_name_, 120, send_format,
+               expected_loss_rate_);
+  sender.Run();
+  sender.Teardown();
+  rtpFile.Close();
+
+  rtpFile.Open(fileName.c_str(), "rb");
+  rtpFile.ReadHeader();
+  ReceiverWithPacketLoss receiver;
+  receiver.Setup(acm.get(), &rtpFile, "packetLoss_out", channels_, 15,
+                 actual_loss_rate_, burst_length_);
+  receiver.Run();
+  receiver.Teardown();
+  rtpFile.Close();
+#endif
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.h b/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.h
new file mode 100644
index 0000000000..d841d65a1b
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/PacketLossTest.h
@@ -0,0 +1,77 @@
+/*
+ *  Copyright (c) 2014 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 MODULES_AUDIO_CODING_TEST_PACKETLOSSTEST_H_
+#define MODULES_AUDIO_CODING_TEST_PACKETLOSSTEST_H_
+
+#include <string>
+
+#include "absl/strings/string_view.h"
+#include "modules/audio_coding/test/EncodeDecodeTest.h"
+
+namespace webrtc {
+
+class ReceiverWithPacketLoss : public Receiver {
+ public:
+  ReceiverWithPacketLoss();
+  void Setup(AudioCodingModule* acm,
+             RTPStream* rtpStream,
+             absl::string_view out_file_name,
+             int channels,
+             int file_num,
+             int loss_rate,
+             int burst_length);
+  bool IncomingPacket() override;
+
+ protected:
+  bool PacketLost();
+  int loss_rate_;
+  int burst_length_;
+  int packet_counter_;
+  int lost_packet_counter_;
+  int burst_lost_counter_;
+};
+
+class SenderWithFEC : public Sender {
+ public:
+  SenderWithFEC();
+  void Setup(AudioCodingModule* acm,
+             RTPStream* rtpStream,
+             absl::string_view in_file_name,
+             int payload_type,
+             SdpAudioFormat format,
+             int expected_loss_rate);
+  bool SetPacketLossRate(int expected_loss_rate);
+  bool SetFEC(bool enable_fec);
+
+ protected:
+  int expected_loss_rate_;
+};
+
+class PacketLossTest {
+ public:
+  PacketLossTest(int channels,
+                 int expected_loss_rate_,
+                 int actual_loss_rate,
+                 int burst_length);
+  void Perform();
+
+ protected:
+  int channels_;
+  std::string in_file_name_;
+  int sample_rate_hz_;
+  int expected_loss_rate_;
+  int actual_loss_rate_;
+  int burst_length_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_PACKETLOSSTEST_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/RTPFile.cc b/third_party/libwebrtc/modules/audio_coding/test/RTPFile.cc
new file mode 100644
index 0000000000..0c2ab3c443
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/RTPFile.cc
@@ -0,0 +1,235 @@
+/*
+ *  Copyright (c) 2012 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 "RTPFile.h"
+
+#include <stdlib.h>
+
+#include <limits>
+
+#include "absl/strings/string_view.h"
+
+#ifdef WIN32
+#include <Winsock2.h>
+#else
+#include <arpa/inet.h>
+#endif
+
+// TODO(tlegrand): Consider removing usage of gtest.
+#include "test/gtest.h"
+
+namespace webrtc {
+
+void RTPStream::ParseRTPHeader(RTPHeader* rtp_header,
+                               const uint8_t* rtpHeader) {
+  rtp_header->payloadType = rtpHeader[1];
+  rtp_header->sequenceNumber =
+      (static_cast<uint16_t>(rtpHeader[2]) << 8) | rtpHeader[3];
+  rtp_header->timestamp = (static_cast<uint32_t>(rtpHeader[4]) << 24) |
+                          (static_cast<uint32_t>(rtpHeader[5]) << 16) |
+                          (static_cast<uint32_t>(rtpHeader[6]) << 8) |
+                          rtpHeader[7];
+  rtp_header->ssrc = (static_cast<uint32_t>(rtpHeader[8]) << 24) |
+                     (static_cast<uint32_t>(rtpHeader[9]) << 16) |
+                     (static_cast<uint32_t>(rtpHeader[10]) << 8) |
+                     rtpHeader[11];
+}
+
+void RTPStream::MakeRTPheader(uint8_t* rtpHeader,
+                              uint8_t payloadType,
+                              int16_t seqNo,
+                              uint32_t timeStamp,
+                              uint32_t ssrc) {
+  rtpHeader[0] = 0x80;
+  rtpHeader[1] = payloadType;
+  rtpHeader[2] = (seqNo >> 8) & 0xFF;
+  rtpHeader[3] = seqNo & 0xFF;
+  rtpHeader[4] = timeStamp >> 24;
+  rtpHeader[5] = (timeStamp >> 16) & 0xFF;
+  rtpHeader[6] = (timeStamp >> 8) & 0xFF;
+  rtpHeader[7] = timeStamp & 0xFF;
+  rtpHeader[8] = ssrc >> 24;
+  rtpHeader[9] = (ssrc >> 16) & 0xFF;
+  rtpHeader[10] = (ssrc >> 8) & 0xFF;
+  rtpHeader[11] = ssrc & 0xFF;
+}
+
+RTPPacket::RTPPacket(uint8_t payloadType,
+                     uint32_t timeStamp,
+                     int16_t seqNo,
+                     const uint8_t* payloadData,
+                     size_t payloadSize,
+                     uint32_t frequency)
+    : payloadType(payloadType),
+      timeStamp(timeStamp),
+      seqNo(seqNo),
+      payloadSize(payloadSize),
+      frequency(frequency) {
+  if (payloadSize > 0) {
+    this->payloadData = new uint8_t[payloadSize];
+    memcpy(this->payloadData, payloadData, payloadSize);
+  }
+}
+
+RTPPacket::~RTPPacket() {
+  delete[] payloadData;
+}
+
+void RTPBuffer::Write(const uint8_t payloadType,
+                      const uint32_t timeStamp,
+                      const int16_t seqNo,
+                      const uint8_t* payloadData,
+                      const size_t payloadSize,
+                      uint32_t frequency) {
+  RTPPacket* packet = new RTPPacket(payloadType, timeStamp, seqNo, payloadData,
+                                    payloadSize, frequency);
+  MutexLock lock(&mutex_);
+  _rtpQueue.push(packet);
+}
+
+size_t RTPBuffer::Read(RTPHeader* rtp_header,
+                       uint8_t* payloadData,
+                       size_t payloadSize,
+                       uint32_t* offset) {
+  RTPPacket* packet;
+  {
+    MutexLock lock(&mutex_);
+    packet = _rtpQueue.front();
+    _rtpQueue.pop();
+  }
+  rtp_header->markerBit = 1;
+  rtp_header->payloadType = packet->payloadType;
+  rtp_header->sequenceNumber = packet->seqNo;
+  rtp_header->ssrc = 0;
+  rtp_header->timestamp = packet->timeStamp;
+  if (packet->payloadSize > 0 && payloadSize >= packet->payloadSize) {
+    memcpy(payloadData, packet->payloadData, packet->payloadSize);
+  } else {
+    return 0;
+  }
+  *offset = (packet->timeStamp / (packet->frequency / 1000));
+
+  return packet->payloadSize;
+}
+
+bool RTPBuffer::EndOfFile() const {
+  MutexLock lock(&mutex_);
+  return _rtpQueue.empty();
+}
+
+void RTPFile::Open(absl::string_view filename, absl::string_view mode) {
+  std::string filename_str = std::string(filename);
+  if ((_rtpFile = fopen(filename_str.c_str(), std::string(mode).c_str())) ==
+      NULL) {
+    printf("Cannot write file %s.\n", filename_str.c_str());
+    ADD_FAILURE() << "Unable to write file";
+    exit(1);
+  }
+}
+
+void RTPFile::Close() {
+  if (_rtpFile != NULL) {
+    fclose(_rtpFile);
+    _rtpFile = NULL;
+  }
+}
+
+void RTPFile::WriteHeader() {
+  // Write data in a format that NetEQ and RTP Play can parse
+  fprintf(_rtpFile, "#!RTPencode%s\n", "1.0");
+  uint32_t dummy_variable = 0;
+  // should be converted to network endian format, but does not matter when 0
+  EXPECT_EQ(1u, fwrite(&dummy_variable, 4, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&dummy_variable, 4, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&dummy_variable, 4, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&dummy_variable, 2, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&dummy_variable, 2, 1, _rtpFile));
+  fflush(_rtpFile);
+}
+
+void RTPFile::ReadHeader() {
+  uint32_t start_sec, start_usec, source;
+  uint16_t port, padding;
+  char fileHeader[40];
+  EXPECT_TRUE(fgets(fileHeader, 40, _rtpFile) != 0);
+  EXPECT_EQ(1u, fread(&start_sec, 4, 1, _rtpFile));
+  start_sec = ntohl(start_sec);
+  EXPECT_EQ(1u, fread(&start_usec, 4, 1, _rtpFile));
+  start_usec = ntohl(start_usec);
+  EXPECT_EQ(1u, fread(&source, 4, 1, _rtpFile));
+  source = ntohl(source);
+  EXPECT_EQ(1u, fread(&port, 2, 1, _rtpFile));
+  port = ntohs(port);
+  EXPECT_EQ(1u, fread(&padding, 2, 1, _rtpFile));
+  padding = ntohs(padding);
+}
+
+void RTPFile::Write(const uint8_t payloadType,
+                    const uint32_t timeStamp,
+                    const int16_t seqNo,
+                    const uint8_t* payloadData,
+                    const size_t payloadSize,
+                    uint32_t frequency) {
+  /* write RTP packet to file */
+  uint8_t rtpHeader[12];
+  MakeRTPheader(rtpHeader, payloadType, seqNo, timeStamp, 0);
+  ASSERT_LE(12 + payloadSize + 8, std::numeric_limits<u_short>::max());
+  uint16_t lengthBytes = htons(static_cast<u_short>(12 + payloadSize + 8));
+  uint16_t plen = htons(static_cast<u_short>(12 + payloadSize));
+  uint32_t offsetMs;
+
+  offsetMs = (timeStamp / (frequency / 1000));
+  offsetMs = htonl(offsetMs);
+  EXPECT_EQ(1u, fwrite(&lengthBytes, 2, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&plen, 2, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&offsetMs, 4, 1, _rtpFile));
+  EXPECT_EQ(1u, fwrite(&rtpHeader, 12, 1, _rtpFile));
+  EXPECT_EQ(payloadSize, fwrite(payloadData, 1, payloadSize, _rtpFile));
+}
+
+size_t RTPFile::Read(RTPHeader* rtp_header,
+                     uint8_t* payloadData,
+                     size_t payloadSize,
+                     uint32_t* offset) {
+  uint16_t lengthBytes;
+  uint16_t plen;
+  uint8_t rtpHeader[12];
+  size_t read_len = fread(&lengthBytes, 2, 1, _rtpFile);
+  /* Check if we have reached end of file. */
+  if ((read_len == 0) && feof(_rtpFile)) {
+    _rtpEOF = true;
+    return 0;
+  }
+  EXPECT_EQ(1u, fread(&plen, 2, 1, _rtpFile));
+  EXPECT_EQ(1u, fread(offset, 4, 1, _rtpFile));
+  lengthBytes = ntohs(lengthBytes);
+  plen = ntohs(plen);
+  *offset = ntohl(*offset);
+  EXPECT_GT(plen, 11);
+
+  EXPECT_EQ(1u, fread(rtpHeader, 12, 1, _rtpFile));
+  ParseRTPHeader(rtp_header, rtpHeader);
+  EXPECT_EQ(lengthBytes, plen + 8);
+
+  if (plen == 0) {
+    return 0;
+  }
+  if (lengthBytes < 20) {
+    return 0;
+  }
+  if (payloadSize < static_cast<size_t>((lengthBytes - 20))) {
+    return 0;
+  }
+  lengthBytes -= 20;
+  EXPECT_EQ(lengthBytes, fread(payloadData, 1, lengthBytes, _rtpFile));
+  return lengthBytes;
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/RTPFile.h b/third_party/libwebrtc/modules/audio_coding/test/RTPFile.h
new file mode 100644
index 0000000000..b796491da9
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/RTPFile.h
@@ -0,0 +1,133 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_RTPFILE_H_
+#define MODULES_AUDIO_CODING_TEST_RTPFILE_H_
+
+#include <stdio.h>
+
+#include <queue>
+
+#include "absl/strings/string_view.h"
+#include "api/rtp_headers.h"
+#include "rtc_base/synchronization/mutex.h"
+#include "rtc_base/thread_annotations.h"
+
+namespace webrtc {
+
+class RTPStream {
+ public:
+  virtual ~RTPStream() {}
+
+  virtual void Write(uint8_t payloadType,
+                     uint32_t timeStamp,
+                     int16_t seqNo,
+                     const uint8_t* payloadData,
+                     size_t payloadSize,
+                     uint32_t frequency) = 0;
+
+  // Returns the packet's payload size. Zero should be treated as an
+  // end-of-stream (in the case that EndOfFile() is true) or an error.
+  virtual size_t Read(RTPHeader* rtp_Header,
+                      uint8_t* payloadData,
+                      size_t payloadSize,
+                      uint32_t* offset) = 0;
+  virtual bool EndOfFile() const = 0;
+
+ protected:
+  void MakeRTPheader(uint8_t* rtpHeader,
+                     uint8_t payloadType,
+                     int16_t seqNo,
+                     uint32_t timeStamp,
+                     uint32_t ssrc);
+
+  void ParseRTPHeader(RTPHeader* rtp_header, const uint8_t* rtpHeader);
+};
+
+class RTPPacket {
+ public:
+  RTPPacket(uint8_t payloadType,
+            uint32_t timeStamp,
+            int16_t seqNo,
+            const uint8_t* payloadData,
+            size_t payloadSize,
+            uint32_t frequency);
+
+  ~RTPPacket();
+
+  uint8_t payloadType;
+  uint32_t timeStamp;
+  int16_t seqNo;
+  uint8_t* payloadData;
+  size_t payloadSize;
+  uint32_t frequency;
+};
+
+class RTPBuffer : public RTPStream {
+ public:
+  RTPBuffer() = default;
+
+  ~RTPBuffer() = default;
+
+  void Write(uint8_t payloadType,
+             uint32_t timeStamp,
+             int16_t seqNo,
+             const uint8_t* payloadData,
+             size_t payloadSize,
+             uint32_t frequency) override;
+
+  size_t Read(RTPHeader* rtp_header,
+              uint8_t* payloadData,
+              size_t payloadSize,
+              uint32_t* offset) override;
+
+  bool EndOfFile() const override;
+
+ private:
+  mutable Mutex mutex_;
+  std::queue<RTPPacket*> _rtpQueue RTC_GUARDED_BY(&mutex_);
+};
+
+class RTPFile : public RTPStream {
+ public:
+  ~RTPFile() {}
+
+  RTPFile() : _rtpFile(NULL), _rtpEOF(false) {}
+
+  void Open(absl::string_view outFilename, absl::string_view mode);
+
+  void Close();
+
+  void WriteHeader();
+
+  void ReadHeader();
+
+  void Write(uint8_t payloadType,
+             uint32_t timeStamp,
+             int16_t seqNo,
+             const uint8_t* payloadData,
+             size_t payloadSize,
+             uint32_t frequency) override;
+
+  size_t Read(RTPHeader* rtp_header,
+              uint8_t* payloadData,
+              size_t payloadSize,
+              uint32_t* offset) override;
+
+  bool EndOfFile() const override { return _rtpEOF; }
+
+ private:
+  FILE* _rtpFile;
+  bool _rtpEOF;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_RTPFILE_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.cc b/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.cc
new file mode 100644
index 0000000000..b44037d732
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.cc
@@ -0,0 +1,412 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/TestAllCodecs.h"
+
+#include <cstdio>
+#include <limits>
+#include <string>
+
+#include "absl/strings/match.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "api/audio_codecs/builtin_audio_encoder_factory.h"
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
+#include "modules/include/module_common_types.h"
+#include "rtc_base/logging.h"
+#include "rtc_base/string_encode.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+// Description of the test:
+// In this test we set up a one-way communication channel from a participant
+// called "a" to a participant called "b".
+// a -> channel_a_to_b -> b
+//
+// The test loops through all available mono codecs, encode at "a" sends over
+// the channel, and decodes at "b".
+
+#define CHECK_ERROR(f)                      \
+  do {                                      \
+    EXPECT_GE(f, 0) << "Error Calling API"; \
+  } while (0)
+
+namespace {
+const size_t kVariableSize = std::numeric_limits<size_t>::max();
+}
+
+namespace webrtc {
+
+// Class for simulating packet handling.
+TestPack::TestPack()
+    : receiver_acm_(NULL),
+      sequence_number_(0),
+      timestamp_diff_(0),
+      last_in_timestamp_(0),
+      total_bytes_(0),
+      payload_size_(0) {}
+
+TestPack::~TestPack() {}
+
+void TestPack::RegisterReceiverACM(AudioCodingModule* acm) {
+  receiver_acm_ = acm;
+  return;
+}
+
+int32_t TestPack::SendData(AudioFrameType frame_type,
+                           uint8_t payload_type,
+                           uint32_t timestamp,
+                           const uint8_t* payload_data,
+                           size_t payload_size,
+                           int64_t absolute_capture_timestamp_ms) {
+  RTPHeader rtp_header;
+  int32_t status;
+
+  rtp_header.markerBit = false;
+  rtp_header.ssrc = 0;
+  rtp_header.sequenceNumber = sequence_number_++;
+  rtp_header.payloadType = payload_type;
+  rtp_header.timestamp = timestamp;
+
+  if (frame_type == AudioFrameType::kEmptyFrame) {
+    // Skip this frame.
+    return 0;
+  }
+
+  // Only run mono for all test cases.
+  memcpy(payload_data_, payload_data, payload_size);
+
+  status =
+      receiver_acm_->IncomingPacket(payload_data_, payload_size, rtp_header);
+
+  payload_size_ = payload_size;
+  timestamp_diff_ = timestamp - last_in_timestamp_;
+  last_in_timestamp_ = timestamp;
+  total_bytes_ += payload_size;
+  return status;
+}
+
+size_t TestPack::payload_size() {
+  return payload_size_;
+}
+
+uint32_t TestPack::timestamp_diff() {
+  return timestamp_diff_;
+}
+
+void TestPack::reset_payload_size() {
+  payload_size_ = 0;
+}
+
+TestAllCodecs::TestAllCodecs()
+    : acm_a_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      acm_b_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      channel_a_to_b_(NULL),
+      test_count_(0),
+      packet_size_samples_(0),
+      packet_size_bytes_(0) {}
+
+TestAllCodecs::~TestAllCodecs() {
+  if (channel_a_to_b_ != NULL) {
+    delete channel_a_to_b_;
+    channel_a_to_b_ = NULL;
+  }
+}
+
+void TestAllCodecs::Perform() {
+  const std::string file_name =
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
+  infile_a_.Open(file_name, 32000, "rb");
+
+  acm_a_->InitializeReceiver();
+  acm_b_->InitializeReceiver();
+
+  acm_b_->SetReceiveCodecs({{107, {"L16", 8000, 1}},
+                            {108, {"L16", 16000, 1}},
+                            {109, {"L16", 32000, 1}},
+                            {111, {"L16", 8000, 2}},
+                            {112, {"L16", 16000, 2}},
+                            {113, {"L16", 32000, 2}},
+                            {0, {"PCMU", 8000, 1}},
+                            {110, {"PCMU", 8000, 2}},
+                            {8, {"PCMA", 8000, 1}},
+                            {118, {"PCMA", 8000, 2}},
+                            {102, {"ILBC", 8000, 1}},
+                            {9, {"G722", 8000, 1}},
+                            {119, {"G722", 8000, 2}},
+                            {120, {"OPUS", 48000, 2, {{"stereo", "1"}}}},
+                            {13, {"CN", 8000, 1}},
+                            {98, {"CN", 16000, 1}},
+                            {99, {"CN", 32000, 1}}});
+
+  // Create and connect the channel
+  channel_a_to_b_ = new TestPack;
+  acm_a_->RegisterTransportCallback(channel_a_to_b_);
+  channel_a_to_b_->RegisterReceiverACM(acm_b_.get());
+
+  // All codecs are tested for all allowed sampling frequencies, rates and
+  // packet sizes.
+  test_count_++;
+  OpenOutFile(test_count_);
+  char codec_g722[] = "G722";
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 320, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 480, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 640, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 800, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 960, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+#ifdef WEBRTC_CODEC_ILBC
+  test_count_++;
+  OpenOutFile(test_count_);
+  char codec_ilbc[] = "ILBC";
+  RegisterSendCodec('A', codec_ilbc, 8000, 13300, 240, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_ilbc, 8000, 13300, 480, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_ilbc, 8000, 15200, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_ilbc, 8000, 15200, 320, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+#endif
+  test_count_++;
+  OpenOutFile(test_count_);
+  char codec_l16[] = "L16";
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 80, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 240, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 320, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+
+  test_count_++;
+  OpenOutFile(test_count_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 320, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 480, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 640, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+
+  test_count_++;
+  OpenOutFile(test_count_);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 320, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 640, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+
+  test_count_++;
+  OpenOutFile(test_count_);
+  char codec_pcma[] = "PCMA";
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 80, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 240, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 320, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 400, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 480, 0);
+  Run(channel_a_to_b_);
+
+  char codec_pcmu[] = "PCMU";
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 80, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 160, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 240, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 320, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 400, 0);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 480, 0);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+#ifdef WEBRTC_CODEC_OPUS
+  test_count_++;
+  OpenOutFile(test_count_);
+  char codec_opus[] = "OPUS";
+  RegisterSendCodec('A', codec_opus, 48000, 6000, 480, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 20000, 480 * 2, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 32000, 480 * 4, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 48000, 480, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 480 * 4, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 96000, 480 * 6, kVariableSize);
+  Run(channel_a_to_b_);
+  RegisterSendCodec('A', codec_opus, 48000, 500000, 480 * 2, kVariableSize);
+  Run(channel_a_to_b_);
+  outfile_b_.Close();
+#endif
+}
+
+// Register Codec to use in the test
+//
+// Input:  side             - which ACM to use, 'A' or 'B'
+//         codec_name       - name to use when register the codec
+//         sampling_freq_hz - sampling frequency in Herz
+//         rate             - bitrate in bytes
+//         packet_size      - packet size in samples
+//         extra_byte       - if extra bytes needed compared to the bitrate
+//                            used when registering, can be an internal header
+//                            set to kVariableSize if the codec is a variable
+//                            rate codec
+void TestAllCodecs::RegisterSendCodec(char side,
+                                      char* codec_name,
+                                      int32_t sampling_freq_hz,
+                                      int rate,
+                                      int packet_size,
+                                      size_t extra_byte) {
+  // Store packet-size in samples, used to validate the received packet.
+  // If G.722, store half the size to compensate for the timestamp bug in the
+  // RFC for G.722.
+  int clockrate_hz = sampling_freq_hz;
+  size_t num_channels = 1;
+  if (absl::EqualsIgnoreCase(codec_name, "G722")) {
+    packet_size_samples_ = packet_size / 2;
+    clockrate_hz = sampling_freq_hz / 2;
+  } else if (absl::EqualsIgnoreCase(codec_name, "OPUS")) {
+    packet_size_samples_ = packet_size;
+    num_channels = 2;
+  } else {
+    packet_size_samples_ = packet_size;
+  }
+
+  // Store the expected packet size in bytes, used to validate the received
+  // packet. If variable rate codec (extra_byte == -1), set to -1.
+  if (extra_byte != kVariableSize) {
+    // Add 0.875 to always round up to a whole byte
+    packet_size_bytes_ =
+        static_cast<size_t>(static_cast<float>(packet_size * rate) /
+                                static_cast<float>(sampling_freq_hz * 8) +
+                            0.875) +
+        extra_byte;
+  } else {
+    // Packets will have a variable size.
+    packet_size_bytes_ = kVariableSize;
+  }
+
+  // Set pointer to the ACM where to register the codec.
+  AudioCodingModule* my_acm = NULL;
+  switch (side) {
+    case 'A': {
+      my_acm = acm_a_.get();
+      break;
+    }
+    case 'B': {
+      my_acm = acm_b_.get();
+      break;
+    }
+    default: {
+      break;
+    }
+  }
+  ASSERT_TRUE(my_acm != NULL);
+
+  auto factory = CreateBuiltinAudioEncoderFactory();
+  constexpr int payload_type = 17;
+  SdpAudioFormat format = {codec_name, clockrate_hz, num_channels};
+  format.parameters["ptime"] = rtc::ToString(rtc::CheckedDivExact(
+      packet_size, rtc::CheckedDivExact(sampling_freq_hz, 1000)));
+  my_acm->SetEncoder(
+      factory->MakeAudioEncoder(payload_type, format, absl::nullopt));
+}
+
+void TestAllCodecs::Run(TestPack* channel) {
+  AudioFrame audio_frame;
+
+  int32_t out_freq_hz = outfile_b_.SamplingFrequency();
+  size_t receive_size;
+  uint32_t timestamp_diff;
+  channel->reset_payload_size();
+  int error_count = 0;
+  int counter = 0;
+  // Set test length to 500 ms (50 blocks of 10 ms each).
+  infile_a_.SetNum10MsBlocksToRead(50);
+  // Fast-forward 1 second (100 blocks) since the file starts with silence.
+  infile_a_.FastForward(100);
+
+  while (!infile_a_.EndOfFile()) {
+    // Add 10 msec to ACM.
+    infile_a_.Read10MsData(audio_frame);
+    CHECK_ERROR(acm_a_->Add10MsData(audio_frame));
+
+    // Verify that the received packet size matches the settings.
+    receive_size = channel->payload_size();
+    if (receive_size) {
+      if ((receive_size != packet_size_bytes_) &&
+          (packet_size_bytes_ != kVariableSize)) {
+        error_count++;
+      }
+
+      // Verify that the timestamp is updated with expected length. The counter
+      // is used to avoid problems when switching codec or frame size in the
+      // test.
+      timestamp_diff = channel->timestamp_diff();
+      if ((counter > 10) &&
+          (static_cast<int>(timestamp_diff) != packet_size_samples_) &&
+          (packet_size_samples_ > -1))
+        error_count++;
+    }
+
+    // Run received side of ACM.
+    bool muted;
+    CHECK_ERROR(acm_b_->PlayoutData10Ms(out_freq_hz, &audio_frame, &muted));
+    ASSERT_FALSE(muted);
+
+    // Write output speech to file.
+    outfile_b_.Write10MsData(audio_frame.data(),
+                             audio_frame.samples_per_channel_);
+
+    // Update loop counter
+    counter++;
+  }
+
+  EXPECT_EQ(0, error_count);
+
+  if (infile_a_.EndOfFile()) {
+    infile_a_.Rewind();
+  }
+}
+
+void TestAllCodecs::OpenOutFile(int test_number) {
+  std::string filename = webrtc::test::OutputPath();
+  rtc::StringBuilder test_number_str;
+  test_number_str << test_number;
+  filename += "testallcodecs_out_";
+  filename += test_number_str.str();
+  filename += ".pcm";
+  outfile_b_.Open(filename, 32000, "wb");
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.h b/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.h
new file mode 100644
index 0000000000..0c276414e4
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestAllCodecs.h
@@ -0,0 +1,83 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_TESTALLCODECS_H_
+#define MODULES_AUDIO_CODING_TEST_TESTALLCODECS_H_
+
+#include <memory>
+
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/test/PCMFile.h"
+
+namespace webrtc {
+
+class TestPack : public AudioPacketizationCallback {
+ public:
+  TestPack();
+  ~TestPack();
+
+  void RegisterReceiverACM(AudioCodingModule* acm);
+
+  int32_t SendData(AudioFrameType frame_type,
+                   uint8_t payload_type,
+                   uint32_t timestamp,
+                   const uint8_t* payload_data,
+                   size_t payload_size,
+                   int64_t absolute_capture_timestamp_ms) override;
+
+  size_t payload_size();
+  uint32_t timestamp_diff();
+  void reset_payload_size();
+
+ private:
+  AudioCodingModule* receiver_acm_;
+  uint16_t sequence_number_;
+  uint8_t payload_data_[60 * 32 * 2 * 2];
+  uint32_t timestamp_diff_;
+  uint32_t last_in_timestamp_;
+  uint64_t total_bytes_;
+  size_t payload_size_;
+};
+
+class TestAllCodecs {
+ public:
+  TestAllCodecs();
+  ~TestAllCodecs();
+
+  void Perform();
+
+ private:
+  // The default value of '-1' indicates that the registration is based only on
+  // codec name, and a sampling frequency matching is not required.
+  // This is useful for codecs which support several sampling frequency.
+  // Note! Only mono mode is tested in this test.
+  void RegisterSendCodec(char side,
+                         char* codec_name,
+                         int32_t sampling_freq_hz,
+                         int rate,
+                         int packet_size,
+                         size_t extra_byte);
+
+  void Run(TestPack* channel);
+  void OpenOutFile(int test_number);
+
+  std::unique_ptr<AudioCodingModule> acm_a_;
+  std::unique_ptr<AudioCodingModule> acm_b_;
+  TestPack* channel_a_to_b_;
+  PCMFile infile_a_;
+  PCMFile outfile_b_;
+  int test_count_;
+  int packet_size_samples_;
+  size_t packet_size_bytes_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_TESTALLCODECS_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.cc b/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.cc
new file mode 100644
index 0000000000..fff48b27bc
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.cc
@@ -0,0 +1,200 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/TestRedFec.h"
+
+#include <memory>
+#include <utility>
+
+#include "absl/strings/match.h"
+#include "api/audio_codecs/L16/audio_decoder_L16.h"
+#include "api/audio_codecs/L16/audio_encoder_L16.h"
+#include "api/audio_codecs/audio_decoder_factory_template.h"
+#include "api/audio_codecs/audio_encoder_factory_template.h"
+#include "api/audio_codecs/g711/audio_decoder_g711.h"
+#include "api/audio_codecs/g711/audio_encoder_g711.h"
+#include "api/audio_codecs/g722/audio_decoder_g722.h"
+#include "api/audio_codecs/g722/audio_encoder_g722.h"
+#include "api/audio_codecs/opus/audio_decoder_opus.h"
+#include "api/audio_codecs/opus/audio_encoder_opus.h"
+#include "modules/audio_coding/codecs/cng/audio_encoder_cng.h"
+#include "modules/audio_coding/codecs/red/audio_encoder_copy_red.h"
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+TestRedFec::TestRedFec()
+    : encoder_factory_(CreateAudioEncoderFactory<AudioEncoderG711,
+                                                 AudioEncoderG722,
+                                                 AudioEncoderL16,
+                                                 AudioEncoderOpus>()),
+      decoder_factory_(CreateAudioDecoderFactory<AudioDecoderG711,
+                                                 AudioDecoderG722,
+                                                 AudioDecoderL16,
+                                                 AudioDecoderOpus>()),
+      _acmA(AudioCodingModule::Create(
+          AudioCodingModule::Config(decoder_factory_))),
+      _acmB(AudioCodingModule::Create(
+          AudioCodingModule::Config(decoder_factory_))),
+      _channelA2B(NULL),
+      _testCntr(0) {}
+
+TestRedFec::~TestRedFec() {
+  if (_channelA2B != NULL) {
+    delete _channelA2B;
+    _channelA2B = NULL;
+  }
+}
+
+void TestRedFec::Perform() {
+  const std::string file_name =
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
+  _inFileA.Open(file_name, 32000, "rb");
+
+  ASSERT_EQ(0, _acmA->InitializeReceiver());
+  ASSERT_EQ(0, _acmB->InitializeReceiver());
+
+  // Create and connect the channel
+  _channelA2B = new Channel;
+  _acmA->RegisterTransportCallback(_channelA2B);
+  _channelA2B->RegisterReceiverACM(_acmB.get());
+
+  RegisterSendCodec(_acmA, {"L16", 8000, 1}, Vad::kVadAggressive, true);
+
+  OpenOutFile(_testCntr);
+  Run();
+  _outFileB.Close();
+
+  // Switch to another 8 kHz codec; RED should remain switched on.
+  RegisterSendCodec(_acmA, {"PCMU", 8000, 1}, Vad::kVadAggressive, true);
+  OpenOutFile(_testCntr);
+  Run();
+  _outFileB.Close();
+
+  // Switch to a 16 kHz codec; RED should be switched off.
+  RegisterSendCodec(_acmA, {"G722", 8000, 1}, Vad::kVadAggressive, false);
+
+  OpenOutFile(_testCntr);
+  RegisterSendCodec(_acmA, {"G722", 8000, 1}, Vad::kVadAggressive, false);
+  Run();
+  RegisterSendCodec(_acmA, {"G722", 8000, 1}, Vad::kVadAggressive, false);
+  Run();
+  _outFileB.Close();
+
+  _channelA2B->SetFECTestWithPacketLoss(true);
+  // Following tests are under packet losses.
+
+  // Switch to a 16 kHz codec; RED should be switched off.
+  RegisterSendCodec(_acmA, {"G722", 8000, 1}, Vad::kVadAggressive, false);
+
+  OpenOutFile(_testCntr);
+  Run();
+  _outFileB.Close();
+
+  RegisterSendCodec(_acmA, {"opus", 48000, 2}, absl::nullopt, false);
+
+  // _channelA2B imposes 25% packet loss rate.
+  EXPECT_EQ(0, _acmA->SetPacketLossRate(25));
+
+  _acmA->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* enc) {
+    EXPECT_EQ(true, (*enc)->SetFec(true));
+  });
+
+  OpenOutFile(_testCntr);
+  Run();
+
+  // Switch to L16 with RED.
+  RegisterSendCodec(_acmA, {"L16", 8000, 1}, absl::nullopt, true);
+  Run();
+
+  // Switch to Opus again.
+  RegisterSendCodec(_acmA, {"opus", 48000, 2}, absl::nullopt, false);
+  _acmA->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* enc) {
+    EXPECT_EQ(true, (*enc)->SetFec(false));
+  });
+  Run();
+
+  _acmA->ModifyEncoder([&](std::unique_ptr<AudioEncoder>* enc) {
+    EXPECT_EQ(true, (*enc)->SetFec(true));
+  });
+  _outFileB.Close();
+}
+
+void TestRedFec::RegisterSendCodec(
+    const std::unique_ptr<AudioCodingModule>& acm,
+    const SdpAudioFormat& codec_format,
+    absl::optional<Vad::Aggressiveness> vad_mode,
+    bool use_red) {
+  constexpr int payload_type = 17, cn_payload_type = 27, red_payload_type = 37;
+  const auto& other_acm = &acm == &_acmA ? _acmB : _acmA;
+
+  auto encoder = encoder_factory_->MakeAudioEncoder(payload_type, codec_format,
+                                                    absl::nullopt);
+  EXPECT_NE(encoder, nullptr);
+  std::map<int, SdpAudioFormat> receive_codecs = {{payload_type, codec_format}};
+  if (!absl::EqualsIgnoreCase(codec_format.name, "opus")) {
+    if (vad_mode.has_value()) {
+      AudioEncoderCngConfig config;
+      config.speech_encoder = std::move(encoder);
+      config.num_channels = 1;
+      config.payload_type = cn_payload_type;
+      config.vad_mode = vad_mode.value();
+      encoder = CreateComfortNoiseEncoder(std::move(config));
+      receive_codecs.emplace(std::make_pair(
+          cn_payload_type, SdpAudioFormat("CN", codec_format.clockrate_hz, 1)));
+    }
+    if (use_red) {
+      AudioEncoderCopyRed::Config config;
+      config.payload_type = red_payload_type;
+      config.speech_encoder = std::move(encoder);
+      encoder = std::make_unique<AudioEncoderCopyRed>(std::move(config),
+                                                      field_trials_);
+      receive_codecs.emplace(
+          std::make_pair(red_payload_type,
+                         SdpAudioFormat("red", codec_format.clockrate_hz, 1)));
+    }
+  }
+  acm->SetEncoder(std::move(encoder));
+  other_acm->SetReceiveCodecs(receive_codecs);
+}
+
+void TestRedFec::Run() {
+  AudioFrame audioFrame;
+  int32_t outFreqHzB = _outFileB.SamplingFrequency();
+  // Set test length to 500 ms (50 blocks of 10 ms each).
+  _inFileA.SetNum10MsBlocksToRead(50);
+  // Fast-forward 1 second (100 blocks) since the file starts with silence.
+  _inFileA.FastForward(100);
+
+  while (!_inFileA.EndOfFile()) {
+    EXPECT_GT(_inFileA.Read10MsData(audioFrame), 0);
+    EXPECT_GE(_acmA->Add10MsData(audioFrame), 0);
+    bool muted;
+    EXPECT_EQ(0, _acmB->PlayoutData10Ms(outFreqHzB, &audioFrame, &muted));
+    ASSERT_FALSE(muted);
+    _outFileB.Write10MsData(audioFrame.data(), audioFrame.samples_per_channel_);
+  }
+  _inFileA.Rewind();
+}
+
+void TestRedFec::OpenOutFile(int16_t test_number) {
+  std::string file_name;
+  rtc::StringBuilder file_stream;
+  file_stream << webrtc::test::OutputPath();
+  file_stream << "TestRedFec_outFile_";
+  file_stream << test_number << ".pcm";
+  file_name = file_stream.str();
+  _outFileB.Open(file_name, 16000, "wb");
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.h b/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.h
new file mode 100644
index 0000000000..dbadd88487
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestRedFec.h
@@ -0,0 +1,56 @@
+/*
+ *  Copyright (c) 2011 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 MODULES_AUDIO_CODING_TEST_TESTREDFEC_H_
+#define MODULES_AUDIO_CODING_TEST_TESTREDFEC_H_
+
+#include <memory>
+#include <string>
+
+#include "api/audio_codecs/audio_decoder_factory.h"
+#include "api/audio_codecs/audio_encoder_factory.h"
+#include "common_audio/vad/include/vad.h"
+#include "modules/audio_coding/test/Channel.h"
+#include "modules/audio_coding/test/PCMFile.h"
+#include "test/scoped_key_value_config.h"
+
+namespace webrtc {
+
+class TestRedFec {
+ public:
+  explicit TestRedFec();
+  ~TestRedFec();
+
+  void Perform();
+
+ private:
+  void RegisterSendCodec(const std::unique_ptr<AudioCodingModule>& acm,
+                         const SdpAudioFormat& codec_format,
+                         absl::optional<Vad::Aggressiveness> vad_mode,
+                         bool use_red);
+  void Run();
+  void OpenOutFile(int16_t testNumber);
+
+  test::ScopedKeyValueConfig field_trials_;
+  const rtc::scoped_refptr<AudioEncoderFactory> encoder_factory_;
+  const rtc::scoped_refptr<AudioDecoderFactory> decoder_factory_;
+  std::unique_ptr<AudioCodingModule> _acmA;
+  std::unique_ptr<AudioCodingModule> _acmB;
+
+  Channel* _channelA2B;
+
+  PCMFile _inFileA;
+  PCMFile _outFileB;
+  int16_t _testCntr;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_TESTREDFEC_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestStereo.cc b/third_party/libwebrtc/modules/audio_coding/test/TestStereo.cc
new file mode 100644
index 0000000000..599fafb602
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestStereo.cc
@@ -0,0 +1,599 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/TestStereo.h"
+
+#include <string>
+
+#include "absl/strings/match.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "api/audio_codecs/builtin_audio_encoder_factory.h"
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
+#include "modules/include/module_common_types.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+// Class for simulating packet handling
+TestPackStereo::TestPackStereo()
+    : receiver_acm_(NULL),
+      seq_no_(0),
+      timestamp_diff_(0),
+      last_in_timestamp_(0),
+      total_bytes_(0),
+      payload_size_(0),
+      lost_packet_(false) {}
+
+TestPackStereo::~TestPackStereo() {}
+
+void TestPackStereo::RegisterReceiverACM(AudioCodingModule* acm) {
+  receiver_acm_ = acm;
+  return;
+}
+
+int32_t TestPackStereo::SendData(const AudioFrameType frame_type,
+                                 const uint8_t payload_type,
+                                 const uint32_t timestamp,
+                                 const uint8_t* payload_data,
+                                 const size_t payload_size,
+                                 int64_t absolute_capture_timestamp_ms) {
+  RTPHeader rtp_header;
+  int32_t status = 0;
+
+  rtp_header.markerBit = false;
+  rtp_header.ssrc = 0;
+  rtp_header.sequenceNumber = seq_no_++;
+  rtp_header.payloadType = payload_type;
+  rtp_header.timestamp = timestamp;
+  if (frame_type == AudioFrameType::kEmptyFrame) {
+    // Skip this frame
+    return 0;
+  }
+
+  if (lost_packet_ == false) {
+    status =
+        receiver_acm_->IncomingPacket(payload_data, payload_size, rtp_header);
+
+    if (frame_type != AudioFrameType::kAudioFrameCN) {
+      payload_size_ = static_cast<int>(payload_size);
+    } else {
+      payload_size_ = -1;
+    }
+
+    timestamp_diff_ = timestamp - last_in_timestamp_;
+    last_in_timestamp_ = timestamp;
+    total_bytes_ += payload_size;
+  }
+  return status;
+}
+
+uint16_t TestPackStereo::payload_size() {
+  return static_cast<uint16_t>(payload_size_);
+}
+
+uint32_t TestPackStereo::timestamp_diff() {
+  return timestamp_diff_;
+}
+
+void TestPackStereo::reset_payload_size() {
+  payload_size_ = 0;
+}
+
+void TestPackStereo::set_codec_mode(enum StereoMonoMode mode) {
+  codec_mode_ = mode;
+}
+
+void TestPackStereo::set_lost_packet(bool lost) {
+  lost_packet_ = lost;
+}
+
+TestStereo::TestStereo()
+    : acm_a_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      acm_b_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      channel_a2b_(NULL),
+      test_cntr_(0),
+      pack_size_samp_(0),
+      pack_size_bytes_(0),
+      counter_(0) {}
+
+TestStereo::~TestStereo() {
+  if (channel_a2b_ != NULL) {
+    delete channel_a2b_;
+    channel_a2b_ = NULL;
+  }
+}
+
+void TestStereo::Perform() {
+  uint16_t frequency_hz;
+  int audio_channels;
+  int codec_channels;
+
+  // Open both mono and stereo test files in 32 kHz.
+  const std::string file_name_stereo =
+      webrtc::test::ResourcePath("audio_coding/teststereo32kHz", "pcm");
+  const std::string file_name_mono =
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
+  frequency_hz = 32000;
+  in_file_stereo_ = new PCMFile();
+  in_file_mono_ = new PCMFile();
+  in_file_stereo_->Open(file_name_stereo, frequency_hz, "rb");
+  in_file_stereo_->ReadStereo(true);
+  in_file_mono_->Open(file_name_mono, frequency_hz, "rb");
+  in_file_mono_->ReadStereo(false);
+
+  // Create and initialize two ACMs, one for each side of a one-to-one call.
+  ASSERT_TRUE((acm_a_.get() != NULL) && (acm_b_.get() != NULL));
+  EXPECT_EQ(0, acm_a_->InitializeReceiver());
+  EXPECT_EQ(0, acm_b_->InitializeReceiver());
+
+  acm_b_->SetReceiveCodecs({{103, {"ISAC", 16000, 1}},
+                            {104, {"ISAC", 32000, 1}},
+                            {107, {"L16", 8000, 1}},
+                            {108, {"L16", 16000, 1}},
+                            {109, {"L16", 32000, 1}},
+                            {111, {"L16", 8000, 2}},
+                            {112, {"L16", 16000, 2}},
+                            {113, {"L16", 32000, 2}},
+                            {0, {"PCMU", 8000, 1}},
+                            {110, {"PCMU", 8000, 2}},
+                            {8, {"PCMA", 8000, 1}},
+                            {118, {"PCMA", 8000, 2}},
+                            {102, {"ILBC", 8000, 1}},
+                            {9, {"G722", 8000, 1}},
+                            {119, {"G722", 8000, 2}},
+                            {120, {"OPUS", 48000, 2, {{"stereo", "1"}}}},
+                            {13, {"CN", 8000, 1}},
+                            {98, {"CN", 16000, 1}},
+                            {99, {"CN", 32000, 1}}});
+
+  // Create and connect the channel.
+  channel_a2b_ = new TestPackStereo;
+  EXPECT_EQ(0, acm_a_->RegisterTransportCallback(channel_a2b_));
+  channel_a2b_->RegisterReceiverACM(acm_b_.get());
+
+  char codec_pcma_temp[] = "PCMA";
+  RegisterSendCodec('A', codec_pcma_temp, 8000, 64000, 80, 2);
+
+  //
+  // Test Stereo-To-Stereo for all codecs.
+  //
+  audio_channels = 2;
+  codec_channels = 2;
+
+  // All codecs are tested for all allowed sampling frequencies, rates and
+  // packet sizes.
+  channel_a2b_->set_codec_mode(kStereo);
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  char codec_g722[] = "G722";
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 480, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 640, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 800, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 960, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  channel_a2b_->set_codec_mode(kStereo);
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  char codec_l16[] = "L16";
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 240, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 480, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 640, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 640, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#ifdef PCMA_AND_PCMU
+  channel_a2b_->set_codec_mode(kStereo);
+  audio_channels = 2;
+  codec_channels = 2;
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  char codec_pcma[] = "PCMA";
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 240, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 400, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 480, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  char codec_pcmu[] = "PCMU";
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 240, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 400, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 480, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+#ifdef WEBRTC_CODEC_OPUS
+  channel_a2b_->set_codec_mode(kStereo);
+  audio_channels = 2;
+  codec_channels = 2;
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+
+  char codec_opus[] = "opus";
+  // Run Opus with 10 ms frame size.
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 480, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  // Run Opus with 20 ms frame size.
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 480 * 2, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  // Run Opus with 40 ms frame size.
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 480 * 4, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  // Run Opus with 60 ms frame size.
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 480 * 6, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  // Run Opus with 20 ms frame size and different bitrates.
+  RegisterSendCodec('A', codec_opus, 48000, 40000, 960, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_opus, 48000, 510000, 960, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+  //
+  // Test Mono-To-Stereo for all codecs.
+  //
+  audio_channels = 1;
+  codec_channels = 2;
+
+  test_cntr_++;
+  channel_a2b_->set_codec_mode(kStereo);
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  channel_a2b_->set_codec_mode(kStereo);
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#ifdef PCMA_AND_PCMU
+  test_cntr_++;
+  channel_a2b_->set_codec_mode(kStereo);
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+#ifdef WEBRTC_CODEC_OPUS
+  // Keep encode and decode in stereo.
+  test_cntr_++;
+  channel_a2b_->set_codec_mode(kStereo);
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 960, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+
+  // Encode in mono, decode in stereo mode.
+  RegisterSendCodec('A', codec_opus, 48000, 64000, 960, 1);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+
+  //
+  // Test Stereo-To-Mono for all codecs.
+  //
+  audio_channels = 2;
+  codec_channels = 1;
+  channel_a2b_->set_codec_mode(kMono);
+
+  // Run stereo audio and mono codec.
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_g722, 16000, 64000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 8000, 128000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 16000, 256000, 160, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_l16, 32000, 512000, 320, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#ifdef PCMA_AND_PCMU
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  RegisterSendCodec('A', codec_pcmu, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  RegisterSendCodec('A', codec_pcma, 8000, 64000, 80, codec_channels);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+#ifdef WEBRTC_CODEC_OPUS
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  // Encode and decode in mono.
+  RegisterSendCodec('A', codec_opus, 48000, 32000, 960, codec_channels);
+  acm_b_->SetReceiveCodecs({{120, {"OPUS", 48000, 2}}});
+  Run(channel_a2b_, audio_channels, codec_channels);
+
+  // Encode in stereo, decode in mono.
+  RegisterSendCodec('A', codec_opus, 48000, 32000, 960, 2);
+  Run(channel_a2b_, audio_channels, codec_channels);
+
+  out_file_.Close();
+
+  // Test switching between decoding mono and stereo for Opus.
+
+  // Decode in mono.
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+  // Decode in stereo.
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  acm_b_->SetReceiveCodecs({{120, {"OPUS", 48000, 2, {{"stereo", "1"}}}}});
+  Run(channel_a2b_, audio_channels, 2);
+  out_file_.Close();
+  // Decode in mono.
+  test_cntr_++;
+  OpenOutFile(test_cntr_);
+  acm_b_->SetReceiveCodecs({{120, {"OPUS", 48000, 2}}});
+  Run(channel_a2b_, audio_channels, codec_channels);
+  out_file_.Close();
+#endif
+
+  // Delete the file pointers.
+  delete in_file_stereo_;
+  delete in_file_mono_;
+}
+
+// Register Codec to use in the test
+//
+// Input:   side             - which ACM to use, 'A' or 'B'
+//          codec_name       - name to use when register the codec
+//          sampling_freq_hz - sampling frequency in Herz
+//          rate             - bitrate in bytes
+//          pack_size        - packet size in samples
+//          channels         - number of channels; 1 for mono, 2 for stereo
+void TestStereo::RegisterSendCodec(char side,
+                                   char* codec_name,
+                                   int32_t sampling_freq_hz,
+                                   int rate,
+                                   int pack_size,
+                                   int channels) {
+  // Store packet size in samples, used to validate the received packet
+  pack_size_samp_ = pack_size;
+
+  // Store the expected packet size in bytes, used to validate the received
+  // packet. Add 0.875 to always round up to a whole byte.
+  pack_size_bytes_ = (uint16_t)(static_cast<float>(pack_size * rate) /
+                                    static_cast<float>(sampling_freq_hz * 8) +
+                                0.875);
+
+  // Set pointer to the ACM where to register the codec
+  AudioCodingModule* my_acm = NULL;
+  switch (side) {
+    case 'A': {
+      my_acm = acm_a_.get();
+      break;
+    }
+    case 'B': {
+      my_acm = acm_b_.get();
+      break;
+    }
+    default:
+      break;
+  }
+  ASSERT_TRUE(my_acm != NULL);
+
+  auto encoder_factory = CreateBuiltinAudioEncoderFactory();
+  const int clockrate_hz = absl::EqualsIgnoreCase(codec_name, "g722")
+                               ? sampling_freq_hz / 2
+                               : sampling_freq_hz;
+  const std::string ptime = rtc::ToString(rtc::CheckedDivExact(
+      pack_size, rtc::CheckedDivExact(sampling_freq_hz, 1000)));
+  SdpAudioFormat::Parameters params = {{"ptime", ptime}};
+  RTC_CHECK(channels == 1 || channels == 2);
+  if (absl::EqualsIgnoreCase(codec_name, "opus")) {
+    if (channels == 2) {
+      params["stereo"] = "1";
+    }
+    channels = 2;
+    params["maxaveragebitrate"] = rtc::ToString(rate);
+  }
+  constexpr int payload_type = 17;
+  auto encoder = encoder_factory->MakeAudioEncoder(
+      payload_type, SdpAudioFormat(codec_name, clockrate_hz, channels, params),
+      absl::nullopt);
+  EXPECT_NE(nullptr, encoder);
+  my_acm->SetEncoder(std::move(encoder));
+
+  send_codec_name_ = codec_name;
+}
+
+void TestStereo::Run(TestPackStereo* channel,
+                     int in_channels,
+                     int out_channels,
+                     int percent_loss) {
+  AudioFrame audio_frame;
+
+  int32_t out_freq_hz_b = out_file_.SamplingFrequency();
+  uint16_t rec_size;
+  uint32_t time_stamp_diff;
+  channel->reset_payload_size();
+  int error_count = 0;
+  int variable_bytes = 0;
+  int variable_packets = 0;
+  // Set test length to 500 ms (50 blocks of 10 ms each).
+  in_file_mono_->SetNum10MsBlocksToRead(50);
+  in_file_stereo_->SetNum10MsBlocksToRead(50);
+  // Fast-forward 1 second (100 blocks) since the files start with silence.
+  in_file_stereo_->FastForward(100);
+  in_file_mono_->FastForward(100);
+
+  while (true) {
+    // Simulate packet loss by setting `packet_loss_` to "true" in
+    // `percent_loss` percent of the loops.
+    if (percent_loss > 0) {
+      if (counter_ == floor((100 / percent_loss) + 0.5)) {
+        counter_ = 0;
+        channel->set_lost_packet(true);
+      } else {
+        channel->set_lost_packet(false);
+      }
+      counter_++;
+    }
+
+    // Add 10 msec to ACM
+    if (in_channels == 1) {
+      if (in_file_mono_->EndOfFile()) {
+        break;
+      }
+      in_file_mono_->Read10MsData(audio_frame);
+    } else {
+      if (in_file_stereo_->EndOfFile()) {
+        break;
+      }
+      in_file_stereo_->Read10MsData(audio_frame);
+    }
+    EXPECT_GE(acm_a_->Add10MsData(audio_frame), 0);
+
+    // Verify that the received packet size matches the settings.
+    rec_size = channel->payload_size();
+    if ((0 < rec_size) & (rec_size < 65535)) {
+      if (strcmp(send_codec_name_, "opus") == 0) {
+        // Opus is a variable rate codec, hence calculate the average packet
+        // size, and later make sure the average is in the right range.
+        variable_bytes += rec_size;
+        variable_packets++;
+      } else {
+        // For fixed rate codecs, check that packet size is correct.
+        if ((rec_size != pack_size_bytes_ * out_channels) &&
+            (pack_size_bytes_ < 65535)) {
+          error_count++;
+        }
+      }
+      // Verify that the timestamp is updated with expected length
+      time_stamp_diff = channel->timestamp_diff();
+      if ((counter_ > 10) && (time_stamp_diff != pack_size_samp_)) {
+        error_count++;
+      }
+    }
+
+    // Run receive side of ACM
+    bool muted;
+    EXPECT_EQ(0, acm_b_->PlayoutData10Ms(out_freq_hz_b, &audio_frame, &muted));
+    ASSERT_FALSE(muted);
+
+    // Write output speech to file
+    out_file_.Write10MsData(
+        audio_frame.data(),
+        audio_frame.samples_per_channel_ * audio_frame.num_channels_);
+  }
+
+  EXPECT_EQ(0, error_count);
+
+  // Check that packet size is in the right range for variable rate codecs,
+  // such as Opus.
+  if (variable_packets > 0) {
+    variable_bytes /= variable_packets;
+    EXPECT_NEAR(variable_bytes, pack_size_bytes_, 18);
+  }
+
+  if (in_file_mono_->EndOfFile()) {
+    in_file_mono_->Rewind();
+  }
+  if (in_file_stereo_->EndOfFile()) {
+    in_file_stereo_->Rewind();
+  }
+  // Reset in case we ended with a lost packet
+  channel->set_lost_packet(false);
+}
+
+void TestStereo::OpenOutFile(int16_t test_number) {
+  std::string file_name;
+  rtc::StringBuilder file_stream;
+  file_stream << webrtc::test::OutputPath() << "teststereo_out_" << test_number
+              << ".pcm";
+  file_name = file_stream.str();
+  out_file_.Open(file_name, 32000, "wb");
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestStereo.h b/third_party/libwebrtc/modules/audio_coding/test/TestStereo.h
new file mode 100644
index 0000000000..4c50a4b555
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestStereo.h
@@ -0,0 +1,100 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_TESTSTEREO_H_
+#define MODULES_AUDIO_CODING_TEST_TESTSTEREO_H_
+
+#include <math.h>
+
+#include <memory>
+
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/test/PCMFile.h"
+
+#define PCMA_AND_PCMU
+
+namespace webrtc {
+
+enum StereoMonoMode { kNotSet, kMono, kStereo };
+
+class TestPackStereo : public AudioPacketizationCallback {
+ public:
+  TestPackStereo();
+  ~TestPackStereo();
+
+  void RegisterReceiverACM(AudioCodingModule* acm);
+
+  int32_t SendData(AudioFrameType frame_type,
+                   uint8_t payload_type,
+                   uint32_t timestamp,
+                   const uint8_t* payload_data,
+                   size_t payload_size,
+                   int64_t absolute_capture_timestamp_ms) override;
+
+  uint16_t payload_size();
+  uint32_t timestamp_diff();
+  void reset_payload_size();
+  void set_codec_mode(StereoMonoMode mode);
+  void set_lost_packet(bool lost);
+
+ private:
+  AudioCodingModule* receiver_acm_;
+  int16_t seq_no_;
+  uint32_t timestamp_diff_;
+  uint32_t last_in_timestamp_;
+  uint64_t total_bytes_;
+  int payload_size_;
+  StereoMonoMode codec_mode_;
+  // Simulate packet losses
+  bool lost_packet_;
+};
+
+class TestStereo {
+ public:
+  TestStereo();
+  ~TestStereo();
+
+  void Perform();
+
+ private:
+  // The default value of '-1' indicates that the registration is based only on
+  // codec name and a sampling frequncy matching is not required. This is useful
+  // for codecs which support several sampling frequency.
+  void RegisterSendCodec(char side,
+                         char* codec_name,
+                         int32_t samp_freq_hz,
+                         int rate,
+                         int pack_size,
+                         int channels);
+
+  void Run(TestPackStereo* channel,
+           int in_channels,
+           int out_channels,
+           int percent_loss = 0);
+  void OpenOutFile(int16_t test_number);
+
+  std::unique_ptr<AudioCodingModule> acm_a_;
+  std::unique_ptr<AudioCodingModule> acm_b_;
+
+  TestPackStereo* channel_a2b_;
+
+  PCMFile* in_file_stereo_;
+  PCMFile* in_file_mono_;
+  PCMFile out_file_;
+  int16_t test_cntr_;
+  uint16_t pack_size_samp_;
+  uint16_t pack_size_bytes_;
+  int counter_;
+  char* send_codec_name_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_TESTSTEREO_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.cc b/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.cc
new file mode 100644
index 0000000000..de26cafb68
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.cc
@@ -0,0 +1,240 @@
+/*
+ *  Copyright (c) 2012 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/audio_coding/test/TestVADDTX.h"
+
+#include <string>
+
+#include "absl/strings/match.h"
+#include "absl/strings/string_view.h"
+#include "api/audio_codecs/audio_decoder_factory_template.h"
+#include "api/audio_codecs/audio_encoder_factory_template.h"
+#include "api/audio_codecs/ilbc/audio_decoder_ilbc.h"
+#include "api/audio_codecs/ilbc/audio_encoder_ilbc.h"
+#include "api/audio_codecs/opus/audio_decoder_opus.h"
+#include "api/audio_codecs/opus/audio_encoder_opus.h"
+#include "modules/audio_coding/codecs/cng/audio_encoder_cng.h"
+#include "modules/audio_coding/test/PCMFile.h"
+#include "rtc_base/strings/string_builder.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+MonitoringAudioPacketizationCallback::MonitoringAudioPacketizationCallback(
+    AudioPacketizationCallback* next)
+    : next_(next) {
+  ResetStatistics();
+}
+
+int32_t MonitoringAudioPacketizationCallback::SendData(
+    AudioFrameType frame_type,
+    uint8_t payload_type,
+    uint32_t timestamp,
+    const uint8_t* payload_data,
+    size_t payload_len_bytes,
+    int64_t absolute_capture_timestamp_ms) {
+  counter_[static_cast<int>(frame_type)]++;
+  return next_->SendData(frame_type, payload_type, timestamp, payload_data,
+                         payload_len_bytes, absolute_capture_timestamp_ms);
+}
+
+void MonitoringAudioPacketizationCallback::PrintStatistics() {
+  printf("\n");
+  printf("kEmptyFrame       %u\n",
+         counter_[static_cast<int>(AudioFrameType::kEmptyFrame)]);
+  printf("kAudioFrameSpeech %u\n",
+         counter_[static_cast<int>(AudioFrameType::kAudioFrameSpeech)]);
+  printf("kAudioFrameCN     %u\n",
+         counter_[static_cast<int>(AudioFrameType::kAudioFrameCN)]);
+  printf("\n\n");
+}
+
+void MonitoringAudioPacketizationCallback::ResetStatistics() {
+  memset(counter_, 0, sizeof(counter_));
+}
+
+void MonitoringAudioPacketizationCallback::GetStatistics(uint32_t* counter) {
+  memcpy(counter, counter_, sizeof(counter_));
+}
+
+TestVadDtx::TestVadDtx()
+    : encoder_factory_(
+          CreateAudioEncoderFactory<AudioEncoderIlbc, AudioEncoderOpus>()),
+      decoder_factory_(
+          CreateAudioDecoderFactory<AudioDecoderIlbc, AudioDecoderOpus>()),
+      acm_send_(AudioCodingModule::Create(
+          AudioCodingModule::Config(decoder_factory_))),
+      acm_receive_(AudioCodingModule::Create(
+          AudioCodingModule::Config(decoder_factory_))),
+      channel_(std::make_unique<Channel>()),
+      packetization_callback_(
+          std::make_unique<MonitoringAudioPacketizationCallback>(
+              channel_.get())) {
+  EXPECT_EQ(
+      0, acm_send_->RegisterTransportCallback(packetization_callback_.get()));
+  channel_->RegisterReceiverACM(acm_receive_.get());
+}
+
+bool TestVadDtx::RegisterCodec(const SdpAudioFormat& codec_format,
+                               absl::optional<Vad::Aggressiveness> vad_mode) {
+  constexpr int payload_type = 17, cn_payload_type = 117;
+  bool added_comfort_noise = false;
+
+  auto encoder = encoder_factory_->MakeAudioEncoder(payload_type, codec_format,
+                                                    absl::nullopt);
+  if (vad_mode.has_value() &&
+      !absl::EqualsIgnoreCase(codec_format.name, "opus")) {
+    AudioEncoderCngConfig config;
+    config.speech_encoder = std::move(encoder);
+    config.num_channels = 1;
+    config.payload_type = cn_payload_type;
+    config.vad_mode = vad_mode.value();
+    encoder = CreateComfortNoiseEncoder(std::move(config));
+    added_comfort_noise = true;
+  }
+  channel_->SetIsStereo(encoder->NumChannels() > 1);
+  acm_send_->SetEncoder(std::move(encoder));
+
+  std::map<int, SdpAudioFormat> receive_codecs = {{payload_type, codec_format}};
+  acm_receive_->SetReceiveCodecs(receive_codecs);
+
+  return added_comfort_noise;
+}
+
+// Encoding a file and see if the numbers that various packets occur follow
+// the expectation.
+void TestVadDtx::Run(absl::string_view in_filename,
+                     int frequency,
+                     int channels,
+                     absl::string_view out_filename,
+                     bool append,
+                     const int* expects) {
+  packetization_callback_->ResetStatistics();
+
+  PCMFile in_file;
+  in_file.Open(in_filename, frequency, "rb");
+  in_file.ReadStereo(channels > 1);
+  // Set test length to 1000 ms (100 blocks of 10 ms each).
+  in_file.SetNum10MsBlocksToRead(100);
+  // Fast-forward both files 500 ms (50 blocks). The first second of the file is
+  // silence, but we want to keep half of that to test silence periods.
+  in_file.FastForward(50);
+
+  PCMFile out_file;
+  if (append) {
+    out_file.Open(out_filename, kOutputFreqHz, "ab");
+  } else {
+    out_file.Open(out_filename, kOutputFreqHz, "wb");
+  }
+
+  uint16_t frame_size_samples = in_file.PayloadLength10Ms();
+  AudioFrame audio_frame;
+  while (!in_file.EndOfFile()) {
+    in_file.Read10MsData(audio_frame);
+    audio_frame.timestamp_ = time_stamp_;
+    time_stamp_ += frame_size_samples;
+    EXPECT_GE(acm_send_->Add10MsData(audio_frame), 0);
+    bool muted;
+    acm_receive_->PlayoutData10Ms(kOutputFreqHz, &audio_frame, &muted);
+    ASSERT_FALSE(muted);
+    out_file.Write10MsData(audio_frame);
+  }
+
+  in_file.Close();
+  out_file.Close();
+
+#ifdef PRINT_STAT
+  packetization_callback_->PrintStatistics();
+#endif
+
+  uint32_t stats[3];
+  packetization_callback_->GetStatistics(stats);
+  packetization_callback_->ResetStatistics();
+
+  for (const auto& st : stats) {
+    int i = &st - stats;  // Calculate the current position in stats.
+    switch (expects[i]) {
+      case 0: {
+        EXPECT_EQ(0u, st) << "stats[" << i << "] error.";
+        break;
+      }
+      case 1: {
+        EXPECT_GT(st, 0u) << "stats[" << i << "] error.";
+        break;
+      }
+    }
+  }
+}
+
+// Following is the implementation of TestWebRtcVadDtx.
+TestWebRtcVadDtx::TestWebRtcVadDtx() : output_file_num_(0) {}
+
+void TestWebRtcVadDtx::Perform() {
+  RunTestCases({"ILBC", 8000, 1});
+  RunTestCases({"opus", 48000, 2});
+}
+
+// Test various configurations on VAD/DTX.
+void TestWebRtcVadDtx::RunTestCases(const SdpAudioFormat& codec_format) {
+  Test(/*new_outfile=*/true,
+       /*expect_dtx_enabled=*/RegisterCodec(codec_format, absl::nullopt));
+
+  Test(/*new_outfile=*/false,
+       /*expect_dtx_enabled=*/RegisterCodec(codec_format, Vad::kVadAggressive));
+
+  Test(/*new_outfile=*/false,
+       /*expect_dtx_enabled=*/RegisterCodec(codec_format, Vad::kVadLowBitrate));
+
+  Test(/*new_outfile=*/false, /*expect_dtx_enabled=*/RegisterCodec(
+           codec_format, Vad::kVadVeryAggressive));
+
+  Test(/*new_outfile=*/false,
+       /*expect_dtx_enabled=*/RegisterCodec(codec_format, Vad::kVadNormal));
+}
+
+// Set the expectation and run the test.
+void TestWebRtcVadDtx::Test(bool new_outfile, bool expect_dtx_enabled) {
+  int expects[] = {-1, 1, expect_dtx_enabled, 0, 0};
+  if (new_outfile) {
+    output_file_num_++;
+  }
+  rtc::StringBuilder out_filename;
+  out_filename << webrtc::test::OutputPath() << "testWebRtcVadDtx_outFile_"
+               << output_file_num_ << ".pcm";
+  Run(webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm"), 32000, 1,
+      out_filename.str(), !new_outfile, expects);
+}
+
+// Following is the implementation of TestOpusDtx.
+void TestOpusDtx::Perform() {
+  int expects[] = {0, 1, 0, 0, 0};
+
+  // Register Opus as send codec
+  std::string out_filename =
+      webrtc::test::OutputPath() + "testOpusDtx_outFile_mono.pcm";
+  RegisterCodec({"opus", 48000, 2}, absl::nullopt);
+  acm_send_->ModifyEncoder([](std::unique_ptr<AudioEncoder>* encoder_ptr) {
+    (*encoder_ptr)->SetDtx(false);
+  });
+
+  Run(webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm"), 32000, 1,
+      out_filename, false, expects);
+
+  acm_send_->ModifyEncoder([](std::unique_ptr<AudioEncoder>* encoder_ptr) {
+    (*encoder_ptr)->SetDtx(true);
+  });
+  expects[static_cast<int>(AudioFrameType::kEmptyFrame)] = 1;
+  expects[static_cast<int>(AudioFrameType::kAudioFrameCN)] = 1;
+  Run(webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm"), 32000, 1,
+      out_filename, true, expects);
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.h b/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.h
new file mode 100644
index 0000000000..d81ae28beb
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TestVADDTX.h
@@ -0,0 +1,115 @@
+/*
+ *  Copyright (c) 2011 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 MODULES_AUDIO_CODING_TEST_TESTVADDTX_H_
+#define MODULES_AUDIO_CODING_TEST_TESTVADDTX_H_
+
+#include <memory>
+
+#include "absl/strings/string_view.h"
+#include "api/audio_codecs/audio_decoder_factory.h"
+#include "api/audio_codecs/audio_encoder_factory.h"
+#include "common_audio/vad/include/vad.h"
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
+#include "modules/audio_coding/test/Channel.h"
+
+namespace webrtc {
+
+// This class records the frame type, and delegates actual sending to the
+// `next_` AudioPacketizationCallback.
+class MonitoringAudioPacketizationCallback : public AudioPacketizationCallback {
+ public:
+  explicit MonitoringAudioPacketizationCallback(
+      AudioPacketizationCallback* next);
+
+  int32_t SendData(AudioFrameType frame_type,
+                   uint8_t payload_type,
+                   uint32_t timestamp,
+                   const uint8_t* payload_data,
+                   size_t payload_len_bytes,
+                   int64_t absolute_capture_timestamp_ms) override;
+
+  void PrintStatistics();
+  void ResetStatistics();
+  void GetStatistics(uint32_t* stats);
+
+ private:
+  // 0 - kEmptyFrame
+  // 1 - kAudioFrameSpeech
+  // 2 - kAudioFrameCN
+  uint32_t counter_[3];
+  AudioPacketizationCallback* const next_;
+};
+
+// TestVadDtx is to verify that VAD/DTX perform as they should. It runs through
+// an audio file and check if the occurrence of various packet types follows
+// expectation. TestVadDtx needs its derived class to implement the Perform()
+// to put the test together.
+class TestVadDtx {
+ public:
+  static const int kOutputFreqHz = 16000;
+
+  TestVadDtx();
+
+ protected:
+  // Returns true iff CN was added.
+  bool RegisterCodec(const SdpAudioFormat& codec_format,
+                     absl::optional<Vad::Aggressiveness> vad_mode);
+
+  // Encoding a file and see if the numbers that various packets occur follow
+  // the expectation. Saves result to a file.
+  // expects[x] means
+  // -1 : do not care,
+  // 0  : there have been no packets of type `x`,
+  // 1  : there have been packets of type `x`,
+  // with `x` indicates the following packet types
+  // 0 - kEmptyFrame
+  // 1 - kAudioFrameSpeech
+  // 2 - kAudioFrameCN
+  void Run(absl::string_view in_filename,
+           int frequency,
+           int channels,
+           absl::string_view out_filename,
+           bool append,
+           const int* expects);
+
+  const rtc::scoped_refptr<AudioEncoderFactory> encoder_factory_;
+  const rtc::scoped_refptr<AudioDecoderFactory> decoder_factory_;
+  std::unique_ptr<AudioCodingModule> acm_send_;
+  std::unique_ptr<AudioCodingModule> acm_receive_;
+  std::unique_ptr<Channel> channel_;
+  std::unique_ptr<MonitoringAudioPacketizationCallback> packetization_callback_;
+  uint32_t time_stamp_ = 0x12345678;
+};
+
+// TestWebRtcVadDtx is to verify that the WebRTC VAD/DTX perform as they should.
+class TestWebRtcVadDtx final : public TestVadDtx {
+ public:
+  TestWebRtcVadDtx();
+
+  void Perform();
+
+ private:
+  void RunTestCases(const SdpAudioFormat& codec_format);
+  void Test(bool new_outfile, bool expect_dtx_enabled);
+
+  int output_file_num_;
+};
+
+// TestOpusDtx is to verify that the Opus DTX performs as it should.
+class TestOpusDtx final : public TestVadDtx {
+ public:
+  void Perform();
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_TESTVADDTX_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/Tester.cc b/third_party/libwebrtc/modules/audio_coding/test/Tester.cc
new file mode 100644
index 0000000000..7612aa43a3
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/Tester.cc
@@ -0,0 +1,102 @@
+/*
+ *  Copyright (c) 2012 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 <stdio.h>
+
+#include <string>
+#include <vector>
+
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/test/EncodeDecodeTest.h"
+#include "modules/audio_coding/test/PacketLossTest.h"
+#include "modules/audio_coding/test/TestAllCodecs.h"
+#include "modules/audio_coding/test/TestRedFec.h"
+#include "modules/audio_coding/test/TestStereo.h"
+#include "modules/audio_coding/test/TestVADDTX.h"
+#include "modules/audio_coding/test/TwoWayCommunication.h"
+#include "modules/audio_coding/test/opus_test.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+TEST(AudioCodingModuleTest, TestAllCodecs) {
+  webrtc::TestAllCodecs().Perform();
+}
+
+#if defined(WEBRTC_ANDROID)
+TEST(AudioCodingModuleTest, DISABLED_TestEncodeDecode) {
+#else
+TEST(AudioCodingModuleTest, TestEncodeDecode) {
+#endif
+  webrtc::EncodeDecodeTest().Perform();
+}
+
+TEST(AudioCodingModuleTest, TestRedFec) {
+  webrtc::TestRedFec().Perform();
+}
+
+// Disabled on ios as flaky, see https://crbug.com/webrtc/7057
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS)
+TEST(AudioCodingModuleTest, DISABLED_TestStereo) {
+#else
+TEST(AudioCodingModuleTest, TestStereo) {
+#endif
+  webrtc::TestStereo().Perform();
+}
+
+TEST(AudioCodingModuleTest, TestWebRtcVadDtx) {
+  webrtc::TestWebRtcVadDtx().Perform();
+}
+
+TEST(AudioCodingModuleTest, TestOpusDtx) {
+  webrtc::TestOpusDtx().Perform();
+}
+
+// Disabled on ios as flaky, see https://crbug.com/webrtc/7057
+#if defined(WEBRTC_IOS)
+TEST(AudioCodingModuleTest, DISABLED_TestOpus) {
+#else
+TEST(AudioCodingModuleTest, TestOpus) {
+#endif
+  webrtc::OpusTest().Perform();
+}
+
+TEST(AudioCodingModuleTest, TestPacketLoss) {
+  webrtc::PacketLossTest(1, 10, 10, 1).Perform();
+}
+
+TEST(AudioCodingModuleTest, TestPacketLossBurst) {
+  webrtc::PacketLossTest(1, 10, 10, 2).Perform();
+}
+
+// Disabled on ios as flake, see https://crbug.com/webrtc/7057
+#if defined(WEBRTC_IOS)
+TEST(AudioCodingModuleTest, DISABLED_TestPacketLossStereo) {
+#else
+TEST(AudioCodingModuleTest, TestPacketLossStereo) {
+#endif
+  webrtc::PacketLossTest(2, 10, 10, 1).Perform();
+}
+
+// Disabled on ios as flake, see https://crbug.com/webrtc/7057
+#if defined(WEBRTC_IOS)
+TEST(AudioCodingModuleTest, DISABLED_TestPacketLossStereoBurst) {
+#else
+TEST(AudioCodingModuleTest, TestPacketLossStereoBurst) {
+#endif
+  webrtc::PacketLossTest(2, 10, 10, 2).Perform();
+}
+
+// The full API test is too long to run automatically on bots, but can be used
+// for offline testing. User interaction is needed.
+#ifdef ACM_TEST_FULL_API
+TEST(AudioCodingModuleTest, TestAPI) {
+  webrtc::APITest().Perform();
+}
+#endif
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.cc b/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.cc
new file mode 100644
index 0000000000..b42415a21a
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.cc
@@ -0,0 +1,191 @@
+/*
+ *  Copyright (c) 2012 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 "TwoWayCommunication.h"
+
+#include <stdio.h>
+#include <string.h>
+
+#include <memory>
+
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "api/audio_codecs/builtin_audio_encoder_factory.h"
+#include "modules/audio_coding/test/PCMFile.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+#define MAX_FILE_NAME_LENGTH_BYTE 500
+
+TwoWayCommunication::TwoWayCommunication()
+    : _acmA(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      _acmRefA(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))) {
+  AudioCodingModule::Config config;
+  // The clicks will be more obvious if time-stretching is not allowed.
+  // TODO(henrik.lundin) Really?
+  config.neteq_config.for_test_no_time_stretching = true;
+  config.decoder_factory = CreateBuiltinAudioDecoderFactory();
+  _acmB.reset(AudioCodingModule::Create(config));
+  _acmRefB.reset(AudioCodingModule::Create(config));
+}
+
+TwoWayCommunication::~TwoWayCommunication() {
+  delete _channel_A2B;
+  delete _channel_B2A;
+  delete _channelRef_A2B;
+  delete _channelRef_B2A;
+  _inFileA.Close();
+  _inFileB.Close();
+  _outFileA.Close();
+  _outFileB.Close();
+  _outFileRefA.Close();
+  _outFileRefB.Close();
+}
+
+void TwoWayCommunication::SetUpAutotest(
+    AudioEncoderFactory* const encoder_factory,
+    const SdpAudioFormat& format1,
+    const int payload_type1,
+    const SdpAudioFormat& format2,
+    const int payload_type2) {
+  //--- Set A codecs
+  _acmA->SetEncoder(
+      encoder_factory->MakeAudioEncoder(payload_type1, format1, absl::nullopt));
+  _acmA->SetReceiveCodecs({{payload_type2, format2}});
+
+  //--- Set ref-A codecs
+  _acmRefA->SetEncoder(
+      encoder_factory->MakeAudioEncoder(payload_type1, format1, absl::nullopt));
+  _acmRefA->SetReceiveCodecs({{payload_type2, format2}});
+
+  //--- Set B codecs
+  _acmB->SetEncoder(
+      encoder_factory->MakeAudioEncoder(payload_type2, format2, absl::nullopt));
+  _acmB->SetReceiveCodecs({{payload_type1, format1}});
+
+  //--- Set ref-B codecs
+  _acmRefB->SetEncoder(
+      encoder_factory->MakeAudioEncoder(payload_type2, format2, absl::nullopt));
+  _acmRefB->SetReceiveCodecs({{payload_type1, format1}});
+
+  uint16_t frequencyHz;
+
+  //--- Input A and B
+  std::string in_file_name =
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
+  frequencyHz = 16000;
+  _inFileA.Open(in_file_name, frequencyHz, "rb");
+  _inFileB.Open(in_file_name, frequencyHz, "rb");
+
+  //--- Output A
+  std::string output_file_a = webrtc::test::OutputPath() + "outAutotestA.pcm";
+  frequencyHz = 16000;
+  _outFileA.Open(output_file_a, frequencyHz, "wb");
+  std::string output_ref_file_a =
+      webrtc::test::OutputPath() + "ref_outAutotestA.pcm";
+  _outFileRefA.Open(output_ref_file_a, frequencyHz, "wb");
+
+  //--- Output B
+  std::string output_file_b = webrtc::test::OutputPath() + "outAutotestB.pcm";
+  frequencyHz = 16000;
+  _outFileB.Open(output_file_b, frequencyHz, "wb");
+  std::string output_ref_file_b =
+      webrtc::test::OutputPath() + "ref_outAutotestB.pcm";
+  _outFileRefB.Open(output_ref_file_b, frequencyHz, "wb");
+
+  //--- Set A-to-B channel
+  _channel_A2B = new Channel;
+  _acmA->RegisterTransportCallback(_channel_A2B);
+  _channel_A2B->RegisterReceiverACM(_acmB.get());
+  //--- Do the same for the reference
+  _channelRef_A2B = new Channel;
+  _acmRefA->RegisterTransportCallback(_channelRef_A2B);
+  _channelRef_A2B->RegisterReceiverACM(_acmRefB.get());
+
+  //--- Set B-to-A channel
+  _channel_B2A = new Channel;
+  _acmB->RegisterTransportCallback(_channel_B2A);
+  _channel_B2A->RegisterReceiverACM(_acmA.get());
+  //--- Do the same for reference
+  _channelRef_B2A = new Channel;
+  _acmRefB->RegisterTransportCallback(_channelRef_B2A);
+  _channelRef_B2A->RegisterReceiverACM(_acmRefA.get());
+}
+
+void TwoWayCommunication::Perform() {
+  const SdpAudioFormat format1("ISAC", 16000, 1);
+  const SdpAudioFormat format2("L16", 8000, 1);
+  constexpr int payload_type1 = 17, payload_type2 = 18;
+
+  auto encoder_factory = CreateBuiltinAudioEncoderFactory();
+
+  SetUpAutotest(encoder_factory.get(), format1, payload_type1, format2,
+                payload_type2);
+
+  unsigned int msecPassed = 0;
+  unsigned int secPassed = 0;
+
+  int32_t outFreqHzA = _outFileA.SamplingFrequency();
+  int32_t outFreqHzB = _outFileB.SamplingFrequency();
+
+  AudioFrame audioFrame;
+
+  // In the following loop we tests that the code can handle misuse of the APIs.
+  // In the middle of a session with data flowing between two sides, called A
+  // and B, APIs will be called, and the code should continue to run, and be
+  // able to recover.
+  while (!_inFileA.EndOfFile() && !_inFileB.EndOfFile()) {
+    msecPassed += 10;
+    EXPECT_GT(_inFileA.Read10MsData(audioFrame), 0);
+    EXPECT_GE(_acmA->Add10MsData(audioFrame), 0);
+    EXPECT_GE(_acmRefA->Add10MsData(audioFrame), 0);
+
+    EXPECT_GT(_inFileB.Read10MsData(audioFrame), 0);
+
+    EXPECT_GE(_acmB->Add10MsData(audioFrame), 0);
+    EXPECT_GE(_acmRefB->Add10MsData(audioFrame), 0);
+    bool muted;
+    EXPECT_EQ(0, _acmA->PlayoutData10Ms(outFreqHzA, &audioFrame, &muted));
+    ASSERT_FALSE(muted);
+    _outFileA.Write10MsData(audioFrame);
+    EXPECT_EQ(0, _acmRefA->PlayoutData10Ms(outFreqHzA, &audioFrame, &muted));
+    ASSERT_FALSE(muted);
+    _outFileRefA.Write10MsData(audioFrame);
+    EXPECT_EQ(0, _acmB->PlayoutData10Ms(outFreqHzB, &audioFrame, &muted));
+    ASSERT_FALSE(muted);
+    _outFileB.Write10MsData(audioFrame);
+    EXPECT_EQ(0, _acmRefB->PlayoutData10Ms(outFreqHzB, &audioFrame, &muted));
+    ASSERT_FALSE(muted);
+    _outFileRefB.Write10MsData(audioFrame);
+
+    // Update time counters each time a second of data has passed.
+    if (msecPassed >= 1000) {
+      msecPassed = 0;
+      secPassed++;
+    }
+    // Re-register send codec on side B.
+    if (((secPassed % 5) == 4) && (msecPassed >= 990)) {
+      _acmB->SetEncoder(encoder_factory->MakeAudioEncoder(
+          payload_type2, format2, absl::nullopt));
+    }
+    // Initialize receiver on side A.
+    if (((secPassed % 7) == 6) && (msecPassed == 0))
+      EXPECT_EQ(0, _acmA->InitializeReceiver());
+    // Re-register codec on side A.
+    if (((secPassed % 7) == 6) && (msecPassed >= 990)) {
+      _acmA->SetReceiveCodecs({{payload_type2, format2}});
+    }
+  }
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.h b/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.h
new file mode 100644
index 0000000000..b7eb9e5583
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/TwoWayCommunication.h
@@ -0,0 +1,62 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_TWOWAYCOMMUNICATION_H_
+#define MODULES_AUDIO_CODING_TEST_TWOWAYCOMMUNICATION_H_
+
+#include <memory>
+
+#include "api/audio_codecs/audio_encoder_factory.h"
+#include "api/audio_codecs/audio_format.h"
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "modules/audio_coding/test/Channel.h"
+#include "modules/audio_coding/test/PCMFile.h"
+
+namespace webrtc {
+
+class TwoWayCommunication {
+ public:
+  TwoWayCommunication();
+  ~TwoWayCommunication();
+
+  void Perform();
+
+ private:
+  void SetUpAutotest(AudioEncoderFactory* const encoder_factory,
+                     const SdpAudioFormat& format1,
+                     int payload_type1,
+                     const SdpAudioFormat& format2,
+                     int payload_type2);
+
+  std::unique_ptr<AudioCodingModule> _acmA;
+  std::unique_ptr<AudioCodingModule> _acmB;
+
+  std::unique_ptr<AudioCodingModule> _acmRefA;
+  std::unique_ptr<AudioCodingModule> _acmRefB;
+
+  Channel* _channel_A2B;
+  Channel* _channel_B2A;
+
+  Channel* _channelRef_A2B;
+  Channel* _channelRef_B2A;
+
+  PCMFile _inFileA;
+  PCMFile _inFileB;
+
+  PCMFile _outFileA;
+  PCMFile _outFileB;
+
+  PCMFile _outFileRefA;
+  PCMFile _outFileRefB;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_TWOWAYCOMMUNICATION_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/opus_test.cc b/third_party/libwebrtc/modules/audio_coding/test/opus_test.cc
new file mode 100644
index 0000000000..6822bc3d72
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/opus_test.cc
@@ -0,0 +1,402 @@
+/*
+ *  Copyright (c) 2013 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/audio_coding/test/opus_test.h"
+
+#include <string>
+
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "modules/audio_coding/codecs/opus/opus_interface.h"
+#include "modules/audio_coding/include/audio_coding_module_typedefs.h"
+#include "modules/audio_coding/test/TestStereo.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+OpusTest::OpusTest()
+    : acm_receiver_(AudioCodingModule::Create(
+          AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory()))),
+      channel_a2b_(NULL),
+      counter_(0),
+      payload_type_(255),
+      rtp_timestamp_(0) {}
+
+OpusTest::~OpusTest() {
+  if (channel_a2b_ != NULL) {
+    delete channel_a2b_;
+    channel_a2b_ = NULL;
+  }
+  if (opus_mono_encoder_ != NULL) {
+    WebRtcOpus_EncoderFree(opus_mono_encoder_);
+    opus_mono_encoder_ = NULL;
+  }
+  if (opus_stereo_encoder_ != NULL) {
+    WebRtcOpus_EncoderFree(opus_stereo_encoder_);
+    opus_stereo_encoder_ = NULL;
+  }
+  if (opus_mono_decoder_ != NULL) {
+    WebRtcOpus_DecoderFree(opus_mono_decoder_);
+    opus_mono_decoder_ = NULL;
+  }
+  if (opus_stereo_decoder_ != NULL) {
+    WebRtcOpus_DecoderFree(opus_stereo_decoder_);
+    opus_stereo_decoder_ = NULL;
+  }
+}
+
+void OpusTest::Perform() {
+#ifndef WEBRTC_CODEC_OPUS
+  // Opus isn't defined, exit.
+  return;
+#else
+  uint16_t frequency_hz;
+  size_t audio_channels;
+  int16_t test_cntr = 0;
+
+  // Open both mono and stereo test files in 32 kHz.
+  const std::string file_name_stereo =
+      webrtc::test::ResourcePath("audio_coding/teststereo32kHz", "pcm");
+  const std::string file_name_mono =
+      webrtc::test::ResourcePath("audio_coding/testfile32kHz", "pcm");
+  frequency_hz = 32000;
+  in_file_stereo_.Open(file_name_stereo, frequency_hz, "rb");
+  in_file_stereo_.ReadStereo(true);
+  in_file_mono_.Open(file_name_mono, frequency_hz, "rb");
+  in_file_mono_.ReadStereo(false);
+
+  // Create Opus encoders for mono and stereo.
+  ASSERT_GT(WebRtcOpus_EncoderCreate(&opus_mono_encoder_, 1, 0, 48000), -1);
+  ASSERT_GT(WebRtcOpus_EncoderCreate(&opus_stereo_encoder_, 2, 1, 48000), -1);
+
+  // Create Opus decoders for mono and stereo for stand-alone testing of Opus.
+  ASSERT_GT(WebRtcOpus_DecoderCreate(&opus_mono_decoder_, 1, 48000), -1);
+  ASSERT_GT(WebRtcOpus_DecoderCreate(&opus_stereo_decoder_, 2, 48000), -1);
+  WebRtcOpus_DecoderInit(opus_mono_decoder_);
+  WebRtcOpus_DecoderInit(opus_stereo_decoder_);
+
+  ASSERT_TRUE(acm_receiver_.get() != NULL);
+  EXPECT_EQ(0, acm_receiver_->InitializeReceiver());
+
+  // Register Opus stereo as receiving codec.
+  constexpr int kOpusPayloadType = 120;
+  const SdpAudioFormat kOpusFormatStereo("opus", 48000, 2, {{"stereo", "1"}});
+  payload_type_ = kOpusPayloadType;
+  acm_receiver_->SetReceiveCodecs({{kOpusPayloadType, kOpusFormatStereo}});
+
+  // Create and connect the channel.
+  channel_a2b_ = new TestPackStereo;
+  channel_a2b_->RegisterReceiverACM(acm_receiver_.get());
+
+  //
+  // Test Stereo.
+  //
+
+  channel_a2b_->set_codec_mode(kStereo);
+  audio_channels = 2;
+  test_cntr++;
+  OpenOutFile(test_cntr);
+
+  // Run Opus with 2.5 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 120);
+
+  // Run Opus with 5 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 240);
+
+  // Run Opus with 10 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 480);
+
+  // Run Opus with 20 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 960);
+
+  // Run Opus with 40 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 1920);
+
+  // Run Opus with 60 ms frame size.
+  Run(channel_a2b_, audio_channels, 64000, 2880);
+
+  out_file_.Close();
+  out_file_standalone_.Close();
+
+  //
+  // Test Opus stereo with packet-losses.
+  //
+
+  test_cntr++;
+  OpenOutFile(test_cntr);
+
+  // Run Opus with 20 ms frame size, 1% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 1);
+
+  // Run Opus with 20 ms frame size, 5% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 5);
+
+  // Run Opus with 20 ms frame size, 10% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 10);
+
+  out_file_.Close();
+  out_file_standalone_.Close();
+
+  //
+  // Test Mono.
+  //
+  channel_a2b_->set_codec_mode(kMono);
+  audio_channels = 1;
+  test_cntr++;
+  OpenOutFile(test_cntr);
+
+  // Register Opus mono as receiving codec.
+  const SdpAudioFormat kOpusFormatMono("opus", 48000, 2);
+  acm_receiver_->SetReceiveCodecs({{kOpusPayloadType, kOpusFormatMono}});
+
+  // Run Opus with 2.5 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 120);
+
+  // Run Opus with 5 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 240);
+
+  // Run Opus with 10 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 480);
+
+  // Run Opus with 20 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 960);
+
+  // Run Opus with 40 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 1920);
+
+  // Run Opus with 60 ms frame size.
+  Run(channel_a2b_, audio_channels, 32000, 2880);
+
+  out_file_.Close();
+  out_file_standalone_.Close();
+
+  //
+  // Test Opus mono with packet-losses.
+  //
+  test_cntr++;
+  OpenOutFile(test_cntr);
+
+  // Run Opus with 20 ms frame size, 1% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 1);
+
+  // Run Opus with 20 ms frame size, 5% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 5);
+
+  // Run Opus with 20 ms frame size, 10% packet loss.
+  Run(channel_a2b_, audio_channels, 64000, 960, 10);
+
+  // Close the files.
+  in_file_stereo_.Close();
+  in_file_mono_.Close();
+  out_file_.Close();
+  out_file_standalone_.Close();
+#endif
+}
+
+void OpusTest::Run(TestPackStereo* channel,
+                   size_t channels,
+                   int bitrate,
+                   size_t frame_length,
+                   int percent_loss) {
+  AudioFrame audio_frame;
+  int32_t out_freq_hz_b = out_file_.SamplingFrequency();
+  const size_t kBufferSizeSamples = 480 * 12 * 2;  // 120 ms stereo audio.
+  int16_t audio[kBufferSizeSamples];
+  int16_t out_audio[kBufferSizeSamples];
+  int16_t audio_type;
+  size_t written_samples = 0;
+  size_t read_samples = 0;
+  size_t decoded_samples = 0;
+  bool first_packet = true;
+  uint32_t start_time_stamp = 0;
+
+  channel->reset_payload_size();
+  counter_ = 0;
+
+  // Set encoder rate.
+  EXPECT_EQ(0, WebRtcOpus_SetBitRate(opus_mono_encoder_, bitrate));
+  EXPECT_EQ(0, WebRtcOpus_SetBitRate(opus_stereo_encoder_, bitrate));
+
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS) || defined(WEBRTC_ARCH_ARM)
+  // If we are on Android, iOS and/or ARM, use a lower complexity setting as
+  // default.
+  const int kOpusComplexity5 = 5;
+  EXPECT_EQ(0, WebRtcOpus_SetComplexity(opus_mono_encoder_, kOpusComplexity5));
+  EXPECT_EQ(0,
+            WebRtcOpus_SetComplexity(opus_stereo_encoder_, kOpusComplexity5));
+#endif
+
+  // Fast-forward 1 second (100 blocks) since the files start with silence.
+  in_file_stereo_.FastForward(100);
+  in_file_mono_.FastForward(100);
+
+  // Limit the runtime to 1000 blocks of 10 ms each.
+  for (size_t audio_length = 0; audio_length < 1000; audio_length += 10) {
+    bool lost_packet = false;
+
+    // Get 10 msec of audio.
+    if (channels == 1) {
+      if (in_file_mono_.EndOfFile()) {
+        break;
+      }
+      in_file_mono_.Read10MsData(audio_frame);
+    } else {
+      if (in_file_stereo_.EndOfFile()) {
+        break;
+      }
+      in_file_stereo_.Read10MsData(audio_frame);
+    }
+
+    // If input audio is sampled at 32 kHz, resampling to 48 kHz is required.
+    EXPECT_EQ(480, resampler_.Resample10Msec(
+                       audio_frame.data(), audio_frame.sample_rate_hz_, 48000,
+                       channels, kBufferSizeSamples - written_samples,
+                       &audio[written_samples]));
+    written_samples += 480 * channels;
+
+    // Sometimes we need to loop over the audio vector to produce the right
+    // number of packets.
+    size_t loop_encode =
+        (written_samples - read_samples) / (channels * frame_length);
+
+    if (loop_encode > 0) {
+      const size_t kMaxBytes = 1000;  // Maximum number of bytes for one packet.
+      size_t bitstream_len_byte;
+      uint8_t bitstream[kMaxBytes];
+      for (size_t i = 0; i < loop_encode; i++) {
+        int bitstream_len_byte_int = WebRtcOpus_Encode(
+            (channels == 1) ? opus_mono_encoder_ : opus_stereo_encoder_,
+            &audio[read_samples], frame_length, kMaxBytes, bitstream);
+        ASSERT_GE(bitstream_len_byte_int, 0);
+        bitstream_len_byte = static_cast<size_t>(bitstream_len_byte_int);
+
+        // Simulate packet loss by setting `packet_loss_` to "true" in
+        // `percent_loss` percent of the loops.
+        // TODO(tlegrand): Move handling of loss simulation to TestPackStereo.
+        if (percent_loss > 0) {
+          if (counter_ == floor((100 / percent_loss) + 0.5)) {
+            counter_ = 0;
+            lost_packet = true;
+            channel->set_lost_packet(true);
+          } else {
+            lost_packet = false;
+            channel->set_lost_packet(false);
+          }
+          counter_++;
+        }
+
+        // Run stand-alone Opus decoder, or decode PLC.
+        if (channels == 1) {
+          if (!lost_packet) {
+            decoded_samples += WebRtcOpus_Decode(
+                opus_mono_decoder_, bitstream, bitstream_len_byte,
+                &out_audio[decoded_samples * channels], &audio_type);
+          } else {
+            // Call decoder PLC.
+            constexpr int kPlcDurationMs = 10;
+            constexpr int kPlcSamples = 48 * kPlcDurationMs;
+            size_t total_plc_samples = 0;
+            while (total_plc_samples < frame_length) {
+              int ret = WebRtcOpus_Decode(
+                  opus_mono_decoder_, NULL, 0,
+                  &out_audio[decoded_samples * channels], &audio_type);
+              EXPECT_EQ(ret, kPlcSamples);
+              decoded_samples += ret;
+              total_plc_samples += ret;
+            }
+            EXPECT_EQ(total_plc_samples, frame_length);
+          }
+        } else {
+          if (!lost_packet) {
+            decoded_samples += WebRtcOpus_Decode(
+                opus_stereo_decoder_, bitstream, bitstream_len_byte,
+                &out_audio[decoded_samples * channels], &audio_type);
+          } else {
+            // Call decoder PLC.
+            constexpr int kPlcDurationMs = 10;
+            constexpr int kPlcSamples = 48 * kPlcDurationMs;
+            size_t total_plc_samples = 0;
+            while (total_plc_samples < frame_length) {
+              int ret = WebRtcOpus_Decode(
+                  opus_stereo_decoder_, NULL, 0,
+                  &out_audio[decoded_samples * channels], &audio_type);
+              EXPECT_EQ(ret, kPlcSamples);
+              decoded_samples += ret;
+              total_plc_samples += ret;
+            }
+            EXPECT_EQ(total_plc_samples, frame_length);
+          }
+        }
+
+        // Send data to the channel. "channel" will handle the loss simulation.
+        channel->SendData(AudioFrameType::kAudioFrameSpeech, payload_type_,
+                          rtp_timestamp_, bitstream, bitstream_len_byte, 0);
+        if (first_packet) {
+          first_packet = false;
+          start_time_stamp = rtp_timestamp_;
+        }
+        rtp_timestamp_ += static_cast<uint32_t>(frame_length);
+        read_samples += frame_length * channels;
+      }
+      if (read_samples == written_samples) {
+        read_samples = 0;
+        written_samples = 0;
+      }
+    }
+
+    // Run received side of ACM.
+    bool muted;
+    ASSERT_EQ(
+        0, acm_receiver_->PlayoutData10Ms(out_freq_hz_b, &audio_frame, &muted));
+    ASSERT_FALSE(muted);
+
+    // Write output speech to file.
+    out_file_.Write10MsData(
+        audio_frame.data(),
+        audio_frame.samples_per_channel_ * audio_frame.num_channels_);
+
+    // Write stand-alone speech to file.
+    out_file_standalone_.Write10MsData(out_audio, decoded_samples * channels);
+
+    if (audio_frame.timestamp_ > start_time_stamp) {
+      // Number of channels should be the same for both stand-alone and
+      // ACM-decoding.
+      EXPECT_EQ(audio_frame.num_channels_, channels);
+    }
+
+    decoded_samples = 0;
+  }
+
+  if (in_file_mono_.EndOfFile()) {
+    in_file_mono_.Rewind();
+  }
+  if (in_file_stereo_.EndOfFile()) {
+    in_file_stereo_.Rewind();
+  }
+  // Reset in case we ended with a lost packet.
+  channel->set_lost_packet(false);
+}
+
+void OpusTest::OpenOutFile(int test_number) {
+  std::string file_name;
+  std::stringstream file_stream;
+  file_stream << webrtc::test::OutputPath() << "opustest_out_" << test_number
+              << ".pcm";
+  file_name = file_stream.str();
+  out_file_.Open(file_name, 48000, "wb");
+  file_stream.str("");
+  file_name = file_stream.str();
+  file_stream << webrtc::test::OutputPath() << "opusstandalone_out_"
+              << test_number << ".pcm";
+  file_name = file_stream.str();
+  out_file_standalone_.Open(file_name, 48000, "wb");
+}
+
+}  // namespace webrtc
diff --git a/third_party/libwebrtc/modules/audio_coding/test/opus_test.h b/third_party/libwebrtc/modules/audio_coding/test/opus_test.h
new file mode 100644
index 0000000000..c69f922adb
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/opus_test.h
@@ -0,0 +1,59 @@
+/*
+ *  Copyright (c) 2012 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 MODULES_AUDIO_CODING_TEST_OPUS_TEST_H_
+#define MODULES_AUDIO_CODING_TEST_OPUS_TEST_H_
+
+#include <math.h>
+
+#include <memory>
+
+#include "modules/audio_coding/acm2/acm_resampler.h"
+#include "modules/audio_coding/codecs/opus/opus_interface.h"
+#include "modules/audio_coding/test/PCMFile.h"
+#include "modules/audio_coding/test/TestStereo.h"
+
+namespace webrtc {
+
+class OpusTest {
+ public:
+  OpusTest();
+  ~OpusTest();
+
+  void Perform();
+
+ private:
+  void Run(TestPackStereo* channel,
+           size_t channels,
+           int bitrate,
+           size_t frame_length,
+           int percent_loss = 0);
+
+  void OpenOutFile(int test_number);
+
+  std::unique_ptr<AudioCodingModule> acm_receiver_;
+  TestPackStereo* channel_a2b_;
+  PCMFile in_file_stereo_;
+  PCMFile in_file_mono_;
+  PCMFile out_file_;
+  PCMFile out_file_standalone_;
+  int counter_;
+  uint8_t payload_type_;
+  uint32_t rtp_timestamp_;
+  acm2::ACMResampler resampler_;
+  WebRtcOpusEncInst* opus_mono_encoder_;
+  WebRtcOpusEncInst* opus_stereo_encoder_;
+  WebRtcOpusDecInst* opus_mono_decoder_;
+  WebRtcOpusDecInst* opus_stereo_decoder_;
+};
+
+}  // namespace webrtc
+
+#endif  // MODULES_AUDIO_CODING_TEST_OPUS_TEST_H_
diff --git a/third_party/libwebrtc/modules/audio_coding/test/target_delay_unittest.cc b/third_party/libwebrtc/modules/audio_coding/test/target_delay_unittest.cc
new file mode 100644
index 0000000000..5eccdcf8eb
--- /dev/null
+++ b/third_party/libwebrtc/modules/audio_coding/test/target_delay_unittest.cc
@@ -0,0 +1,161 @@
+/*
+ *  Copyright (c) 2013 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 <memory>
+
+#include "api/audio/audio_frame.h"
+#include "api/audio_codecs/builtin_audio_decoder_factory.h"
+#include "api/rtp_headers.h"
+#include "modules/audio_coding/acm2/acm_receiver.h"
+#include "modules/audio_coding/codecs/pcm16b/pcm16b.h"
+#include "modules/audio_coding/include/audio_coding_module.h"
+#include "test/gtest.h"
+#include "test/testsupport/file_utils.h"
+
+namespace webrtc {
+
+class TargetDelayTest : public ::testing::Test {
+ protected:
+  TargetDelayTest()
+      : receiver_(
+            AudioCodingModule::Config(CreateBuiltinAudioDecoderFactory())) {}
+
+  ~TargetDelayTest() {}
+
+  void SetUp() {
+    constexpr int pltype = 108;
+    std::map<int, SdpAudioFormat> receive_codecs = {
+        {pltype, {"L16", kSampleRateHz, 1}}};
+    receiver_.SetCodecs(receive_codecs);
+
+    rtp_header_.payloadType = pltype;
+    rtp_header_.timestamp = 0;
+    rtp_header_.ssrc = 0x12345678;
+    rtp_header_.markerBit = false;
+    rtp_header_.sequenceNumber = 0;
+
+    int16_t audio[kFrameSizeSamples];
+    const int kRange = 0x7FF;  // 2047, easy for masking.
+    for (size_t n = 0; n < kFrameSizeSamples; ++n)
+      audio[n] = (rand() & kRange) - kRange / 2;
+    WebRtcPcm16b_Encode(audio, kFrameSizeSamples, payload_);
+  }
+
+  void OutOfRangeInput() {
+    EXPECT_EQ(-1, SetMinimumDelay(-1));
+    EXPECT_EQ(-1, SetMinimumDelay(10001));
+  }
+
+  void TargetDelayBufferMinMax() {
+    const int kTargetMinDelayMs = kNum10msPerFrame * 10;
+    ASSERT_EQ(0, SetMinimumDelay(kTargetMinDelayMs));
+    for (int m = 0; m < 30; ++m)  // Run enough iterations to fill the buffer.
+      Run(true);
+    int clean_optimal_delay = GetCurrentOptimalDelayMs();
+    EXPECT_EQ(kTargetMinDelayMs, clean_optimal_delay);
+
+    const int kTargetMaxDelayMs = 2 * (kNum10msPerFrame * 10);
+    ASSERT_EQ(0, SetMaximumDelay(kTargetMaxDelayMs));
+    for (int n = 0; n < 30; ++n)  // Run enough iterations to fill the buffer.
+      Run(false);
+
+    int capped_optimal_delay = GetCurrentOptimalDelayMs();
+    EXPECT_EQ(kTargetMaxDelayMs, capped_optimal_delay);
+  }
+
+ private:
+  static const int kSampleRateHz = 16000;
+  static const int kNum10msPerFrame = 2;
+  static const size_t kFrameSizeSamples = 320;  // 20 ms @ 16 kHz.
+  // payload-len = frame-samples * 2 bytes/sample.
+  static const int kPayloadLenBytes = 320 * 2;
+  // Inter-arrival time in number of packets in a jittery channel. One is no
+  // jitter.
+  static const int kInterarrivalJitterPacket = 2;
+
+  void Push() {
+    rtp_header_.timestamp += kFrameSizeSamples;
+    rtp_header_.sequenceNumber++;
+    ASSERT_EQ(0, receiver_.InsertPacket(rtp_header_,
+                                        rtc::ArrayView<const uint8_t>(
+                                            payload_, kFrameSizeSamples * 2)));
+  }
+
+  // Pull audio equivalent to the amount of audio in one RTP packet.
+  void Pull() {
+    AudioFrame frame;
+    bool muted;
+    for (int k = 0; k < kNum10msPerFrame; ++k) {  // Pull one frame.
+      ASSERT_EQ(0, receiver_.GetAudio(-1, &frame, &muted));
+      ASSERT_FALSE(muted);
+      // Had to use ASSERT_TRUE, ASSERT_EQ generated error.
+      ASSERT_TRUE(kSampleRateHz == frame.sample_rate_hz_);
+      ASSERT_EQ(1u, frame.num_channels_);
+      ASSERT_TRUE(kSampleRateHz / 100 == frame.samples_per_channel_);
+    }
+  }
+
+  void Run(bool clean) {
+    for (int n = 0; n < 10; ++n) {
+      for (int m = 0; m < 5; ++m) {
+        Push();
+        Pull();
+      }
+
+      if (!clean) {
+        for (int m = 0; m < 10; ++m) {  // Long enough to trigger delay change.
+          Push();
+          for (int n = 0; n < kInterarrivalJitterPacket; ++n)
+            Pull();
+        }
+      }
+    }
+  }
+
+  int SetMinimumDelay(int delay_ms) {
+    return receiver_.SetMinimumDelay(delay_ms);
+  }
+
+  int SetMaximumDelay(int delay_ms) {
+    return receiver_.SetMaximumDelay(delay_ms);
+  }
+
+  int GetCurrentOptimalDelayMs() {
+    NetworkStatistics stats;
+    receiver_.GetNetworkStatistics(&stats);
+    return stats.preferredBufferSize;
+  }
+
+  acm2::AcmReceiver receiver_;
+  RTPHeader rtp_header_;
+  uint8_t payload_[kPayloadLenBytes];
+};
+
+// Flaky on iOS: webrtc:7057.
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS)
+#define MAYBE_OutOfRangeInput DISABLED_OutOfRangeInput
+#else
+#define MAYBE_OutOfRangeInput OutOfRangeInput
+#endif
+TEST_F(TargetDelayTest, MAYBE_OutOfRangeInput) {
+  OutOfRangeInput();
+}
+
+// Flaky on iOS: webrtc:7057.
+#if defined(WEBRTC_ANDROID) || defined(WEBRTC_IOS)
+#define MAYBE_TargetDelayBufferMinMax DISABLED_TargetDelayBufferMinMax
+#else
+#define MAYBE_TargetDelayBufferMinMax TargetDelayBufferMinMax
+#endif
+TEST_F(TargetDelayTest, MAYBE_TargetDelayBufferMinMax) {
+  TargetDelayBufferMinMax();
+}
+
+}  // namespace webrtc