Revert 6257 "Rename neteq4 folder to neteq"

> Rename neteq4 folder to neteq
> 
> BUG=2996
> R=turaj@webrtc.org
> 
> Review URL: https://webrtc-codereview.appspot.com/12569005

TBR=henrik.lundin@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/13549004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6259 4adac7df-926f-26a2-2b94-8c16560cd09d
diff --git a/webrtc/modules/audio_coding/neteq4/neteq_unittest.cc b/webrtc/modules/audio_coding/neteq4/neteq_unittest.cc
new file mode 100644
index 0000000..f66a3cf
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq4/neteq_unittest.cc
@@ -0,0 +1,1429 @@
+/*
+ *  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.
+ */
+
+/*
+ * This file includes unit tests for NetEQ.
+ */
+
+#include "webrtc/modules/audio_coding/neteq4/interface/neteq.h"
+
+#include <math.h>
+#include <stdlib.h>
+#include <string.h>  // memset
+
+#include <algorithm>
+#include <set>
+#include <string>
+#include <vector>
+
+#include "gflags/gflags.h"
+#include "gtest/gtest.h"
+#include "webrtc/modules/audio_coding/neteq4/test/NETEQTEST_RTPpacket.h"
+#include "webrtc/modules/audio_coding/codecs/pcm16b/include/pcm16b.h"
+#include "webrtc/test/testsupport/fileutils.h"
+#include "webrtc/test/testsupport/gtest_disable.h"
+#include "webrtc/typedefs.h"
+
+DEFINE_bool(gen_ref, false, "Generate reference files.");
+
+namespace webrtc {
+
+static bool IsAllZero(const int16_t* buf, int buf_length) {
+  bool all_zero = true;
+  for (int n = 0; n < buf_length && all_zero; ++n)
+    all_zero = buf[n] == 0;
+  return all_zero;
+}
+
+static bool IsAllNonZero(const int16_t* buf, int buf_length) {
+  bool all_non_zero = true;
+  for (int n = 0; n < buf_length && all_non_zero; ++n)
+    all_non_zero = buf[n] != 0;
+  return all_non_zero;
+}
+
+class RefFiles {
+ public:
+  RefFiles(const std::string& input_file, const std::string& output_file);
+  ~RefFiles();
+  template<class T> void ProcessReference(const T& test_results);
+  template<typename T, size_t n> void ProcessReference(
+      const T (&test_results)[n],
+      size_t length);
+  template<typename T, size_t n> void WriteToFile(
+      const T (&test_results)[n],
+      size_t length);
+  template<typename T, size_t n> void ReadFromFileAndCompare(
+      const T (&test_results)[n],
+      size_t length);
+  void WriteToFile(const NetEqNetworkStatistics& stats);
+  void ReadFromFileAndCompare(const NetEqNetworkStatistics& stats);
+  void WriteToFile(const RtcpStatistics& stats);
+  void ReadFromFileAndCompare(const RtcpStatistics& stats);
+
+  FILE* input_fp_;
+  FILE* output_fp_;
+};
+
+RefFiles::RefFiles(const std::string &input_file,
+                   const std::string &output_file)
+    : input_fp_(NULL),
+      output_fp_(NULL) {
+  if (!input_file.empty()) {
+    input_fp_ = fopen(input_file.c_str(), "rb");
+    EXPECT_TRUE(input_fp_ != NULL);
+  }
+  if (!output_file.empty()) {
+    output_fp_ = fopen(output_file.c_str(), "wb");
+    EXPECT_TRUE(output_fp_ != NULL);
+  }
+}
+
+RefFiles::~RefFiles() {
+  if (input_fp_) {
+    EXPECT_EQ(EOF, fgetc(input_fp_));  // Make sure that we reached the end.
+    fclose(input_fp_);
+  }
+  if (output_fp_) fclose(output_fp_);
+}
+
+template<class T>
+void RefFiles::ProcessReference(const T& test_results) {
+  WriteToFile(test_results);
+  ReadFromFileAndCompare(test_results);
+}
+
+template<typename T, size_t n>
+void RefFiles::ProcessReference(const T (&test_results)[n], size_t length) {
+  WriteToFile(test_results, length);
+  ReadFromFileAndCompare(test_results, length);
+}
+
+template<typename T, size_t n>
+void RefFiles::WriteToFile(const T (&test_results)[n], size_t length) {
+  if (output_fp_) {
+    ASSERT_EQ(length, fwrite(&test_results, sizeof(T), length, output_fp_));
+  }
+}
+
+template<typename T, size_t n>
+void RefFiles::ReadFromFileAndCompare(const T (&test_results)[n],
+                                      size_t length) {
+  if (input_fp_) {
+    // Read from ref file.
+    T* ref = new T[length];
+    ASSERT_EQ(length, fread(ref, sizeof(T), length, input_fp_));
+    // Compare
+    ASSERT_EQ(0, memcmp(&test_results, ref, sizeof(T) * length));
+    delete [] ref;
+  }
+}
+
+void RefFiles::WriteToFile(const NetEqNetworkStatistics& stats) {
+  if (output_fp_) {
+    ASSERT_EQ(1u, fwrite(&stats, sizeof(NetEqNetworkStatistics), 1,
+                         output_fp_));
+  }
+}
+
+void RefFiles::ReadFromFileAndCompare(
+    const NetEqNetworkStatistics& stats) {
+  if (input_fp_) {
+    // Read from ref file.
+    size_t stat_size = sizeof(NetEqNetworkStatistics);
+    NetEqNetworkStatistics ref_stats;
+    ASSERT_EQ(1u, fread(&ref_stats, stat_size, 1, input_fp_));
+    // Compare
+    ASSERT_EQ(0, memcmp(&stats, &ref_stats, stat_size));
+  }
+}
+
+void RefFiles::WriteToFile(const RtcpStatistics& stats) {
+  if (output_fp_) {
+    ASSERT_EQ(1u, fwrite(&(stats.fraction_lost), sizeof(stats.fraction_lost), 1,
+                         output_fp_));
+    ASSERT_EQ(1u, fwrite(&(stats.cumulative_lost),
+                         sizeof(stats.cumulative_lost), 1, output_fp_));
+    ASSERT_EQ(1u, fwrite(&(stats.extended_max_sequence_number),
+                         sizeof(stats.extended_max_sequence_number), 1,
+                         output_fp_));
+    ASSERT_EQ(1u, fwrite(&(stats.jitter), sizeof(stats.jitter), 1,
+                         output_fp_));
+  }
+}
+
+void RefFiles::ReadFromFileAndCompare(
+    const RtcpStatistics& stats) {
+  if (input_fp_) {
+    // Read from ref file.
+    RtcpStatistics ref_stats;
+    ASSERT_EQ(1u, fread(&(ref_stats.fraction_lost),
+                        sizeof(ref_stats.fraction_lost), 1, input_fp_));
+    ASSERT_EQ(1u, fread(&(ref_stats.cumulative_lost),
+                        sizeof(ref_stats.cumulative_lost), 1, input_fp_));
+    ASSERT_EQ(1u, fread(&(ref_stats.extended_max_sequence_number),
+                        sizeof(ref_stats.extended_max_sequence_number), 1,
+                        input_fp_));
+    ASSERT_EQ(1u, fread(&(ref_stats.jitter), sizeof(ref_stats.jitter), 1,
+                        input_fp_));
+    // Compare
+    ASSERT_EQ(ref_stats.fraction_lost, stats.fraction_lost);
+    ASSERT_EQ(ref_stats.cumulative_lost, stats.cumulative_lost);
+    ASSERT_EQ(ref_stats.extended_max_sequence_number,
+              stats.extended_max_sequence_number);
+    ASSERT_EQ(ref_stats.jitter, stats.jitter);
+  }
+}
+
+class NetEqDecodingTest : public ::testing::Test {
+ protected:
+  // NetEQ must be polled for data once every 10 ms. Thus, neither of the
+  // constants below can be changed.
+  static const int kTimeStepMs = 10;
+  static const int kBlockSize8kHz = kTimeStepMs * 8;
+  static const int kBlockSize16kHz = kTimeStepMs * 16;
+  static const int kBlockSize32kHz = kTimeStepMs * 32;
+  static const int kMaxBlockSize = kBlockSize32kHz;
+  static const int kInitSampleRateHz = 8000;
+
+  NetEqDecodingTest();
+  virtual void SetUp();
+  virtual void TearDown();
+  void SelectDecoders(NetEqDecoder* used_codec);
+  void LoadDecoders();
+  void OpenInputFile(const std::string &rtp_file);
+  void Process(NETEQTEST_RTPpacket* rtp_ptr, int* out_len);
+  void DecodeAndCompare(const std::string &rtp_file,
+                        const std::string &ref_file);
+  void DecodeAndCheckStats(const std::string &rtp_file,
+                           const std::string &stat_ref_file,
+                           const std::string &rtcp_ref_file);
+  static void PopulateRtpInfo(int frame_index,
+                              int timestamp,
+                              WebRtcRTPHeader* rtp_info);
+  static void PopulateCng(int frame_index,
+                          int timestamp,
+                          WebRtcRTPHeader* rtp_info,
+                          uint8_t* payload,
+                          int* payload_len);
+
+  void CheckBgnOff(int sampling_rate, NetEqBackgroundNoiseMode bgn_mode);
+
+  void WrapTest(uint16_t start_seq_no, uint32_t start_timestamp,
+                const std::set<uint16_t>& drop_seq_numbers,
+                bool expect_seq_no_wrap, bool expect_timestamp_wrap);
+
+  void LongCngWithClockDrift(double drift_factor,
+                             double network_freeze_ms,
+                             bool pull_audio_during_freeze,
+                             int delay_tolerance_ms,
+                             int max_time_to_speech_ms);
+
+  void DuplicateCng();
+
+  NetEq* neteq_;
+  FILE* rtp_fp_;
+  unsigned int sim_clock_;
+  int16_t out_data_[kMaxBlockSize];
+  int output_sample_rate_;
+  int algorithmic_delay_ms_;
+};
+
+// Allocating the static const so that it can be passed by reference.
+const int NetEqDecodingTest::kTimeStepMs;
+const int NetEqDecodingTest::kBlockSize8kHz;
+const int NetEqDecodingTest::kBlockSize16kHz;
+const int NetEqDecodingTest::kBlockSize32kHz;
+const int NetEqDecodingTest::kMaxBlockSize;
+const int NetEqDecodingTest::kInitSampleRateHz;
+
+NetEqDecodingTest::NetEqDecodingTest()
+    : neteq_(NULL),
+      rtp_fp_(NULL),
+      sim_clock_(0),
+      output_sample_rate_(kInitSampleRateHz),
+      algorithmic_delay_ms_(0) {
+  memset(out_data_, 0, sizeof(out_data_));
+}
+
+void NetEqDecodingTest::SetUp() {
+  NetEq::Config config;
+  config.sample_rate_hz = kInitSampleRateHz;
+  neteq_ = NetEq::Create(config);
+  NetEqNetworkStatistics stat;
+  ASSERT_EQ(0, neteq_->NetworkStatistics(&stat));
+  algorithmic_delay_ms_ = stat.current_buffer_size_ms;
+  ASSERT_TRUE(neteq_);
+  LoadDecoders();
+}
+
+void NetEqDecodingTest::TearDown() {
+  delete neteq_;
+  if (rtp_fp_)
+    fclose(rtp_fp_);
+}
+
+void NetEqDecodingTest::LoadDecoders() {
+  // Load PCMu.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCMu, 0));
+  // Load PCMa.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCMa, 8));
+#ifndef WEBRTC_ANDROID
+  // Load iLBC.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderILBC, 102));
+#endif  // WEBRTC_ANDROID
+  // Load iSAC.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderISAC, 103));
+#ifndef WEBRTC_ANDROID
+  // Load iSAC SWB.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderISACswb, 104));
+  // Load iSAC FB.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderISACfb, 105));
+#endif  // WEBRTC_ANDROID
+  // Load PCM16B nb.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCM16B, 93));
+  // Load PCM16B wb.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCM16Bwb, 94));
+  // Load PCM16B swb32.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCM16Bswb32kHz, 95));
+  // Load CNG 8 kHz.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGnb, 13));
+  // Load CNG 16 kHz.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGwb, 98));
+}
+
+void NetEqDecodingTest::OpenInputFile(const std::string &rtp_file) {
+  rtp_fp_ = fopen(rtp_file.c_str(), "rb");
+  ASSERT_TRUE(rtp_fp_ != NULL);
+  ASSERT_EQ(0, NETEQTEST_RTPpacket::skipFileHeader(rtp_fp_));
+}
+
+void NetEqDecodingTest::Process(NETEQTEST_RTPpacket* rtp, int* out_len) {
+  // Check if time to receive.
+  while ((sim_clock_ >= rtp->time()) &&
+         (rtp->dataLen() >= 0)) {
+    if (rtp->dataLen() > 0) {
+      WebRtcRTPHeader rtpInfo;
+      rtp->parseHeader(&rtpInfo);
+      ASSERT_EQ(0, neteq_->InsertPacket(
+          rtpInfo,
+          rtp->payload(),
+          rtp->payloadLen(),
+          rtp->time() * (output_sample_rate_ / 1000)));
+    }
+    // Get next packet.
+    ASSERT_NE(-1, rtp->readFromFile(rtp_fp_));
+  }
+
+  // Get audio from NetEq.
+  NetEqOutputType type;
+  int num_channels;
+  ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, out_len,
+                                &num_channels, &type));
+  ASSERT_TRUE((*out_len == kBlockSize8kHz) ||
+              (*out_len == kBlockSize16kHz) ||
+              (*out_len == kBlockSize32kHz));
+  output_sample_rate_ = *out_len / 10 * 1000;
+
+  // Increase time.
+  sim_clock_ += kTimeStepMs;
+}
+
+void NetEqDecodingTest::DecodeAndCompare(const std::string &rtp_file,
+                                         const std::string &ref_file) {
+  OpenInputFile(rtp_file);
+
+  std::string ref_out_file = "";
+  if (ref_file.empty()) {
+    ref_out_file = webrtc::test::OutputPath() + "neteq_universal_ref.pcm";
+  }
+  RefFiles ref_files(ref_file, ref_out_file);
+
+  NETEQTEST_RTPpacket rtp;
+  ASSERT_GT(rtp.readFromFile(rtp_fp_), 0);
+  int i = 0;
+  while (rtp.dataLen() >= 0) {
+    std::ostringstream ss;
+    ss << "Lap number " << i++ << " in DecodeAndCompare while loop";
+    SCOPED_TRACE(ss.str());  // Print out the parameter values on failure.
+    int out_len = 0;
+    ASSERT_NO_FATAL_FAILURE(Process(&rtp, &out_len));
+    ASSERT_NO_FATAL_FAILURE(ref_files.ProcessReference(out_data_, out_len));
+  }
+}
+
+void NetEqDecodingTest::DecodeAndCheckStats(const std::string &rtp_file,
+                                            const std::string &stat_ref_file,
+                                            const std::string &rtcp_ref_file) {
+  OpenInputFile(rtp_file);
+  std::string stat_out_file = "";
+  if (stat_ref_file.empty()) {
+    stat_out_file = webrtc::test::OutputPath() +
+        "neteq_network_stats.dat";
+  }
+  RefFiles network_stat_files(stat_ref_file, stat_out_file);
+
+  std::string rtcp_out_file = "";
+  if (rtcp_ref_file.empty()) {
+    rtcp_out_file = webrtc::test::OutputPath() +
+        "neteq_rtcp_stats.dat";
+  }
+  RefFiles rtcp_stat_files(rtcp_ref_file, rtcp_out_file);
+
+  NETEQTEST_RTPpacket rtp;
+  ASSERT_GT(rtp.readFromFile(rtp_fp_), 0);
+  while (rtp.dataLen() >= 0) {
+    int out_len;
+    ASSERT_NO_FATAL_FAILURE(Process(&rtp, &out_len));
+
+    // Query the network statistics API once per second
+    if (sim_clock_ % 1000 == 0) {
+      // Process NetworkStatistics.
+      NetEqNetworkStatistics network_stats;
+      ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+      ASSERT_NO_FATAL_FAILURE(
+          network_stat_files.ProcessReference(network_stats));
+
+      // Process RTCPstat.
+      RtcpStatistics rtcp_stats;
+      neteq_->GetRtcpStatistics(&rtcp_stats);
+      ASSERT_NO_FATAL_FAILURE(rtcp_stat_files.ProcessReference(rtcp_stats));
+    }
+  }
+}
+
+void NetEqDecodingTest::PopulateRtpInfo(int frame_index,
+                                        int timestamp,
+                                        WebRtcRTPHeader* rtp_info) {
+  rtp_info->header.sequenceNumber = frame_index;
+  rtp_info->header.timestamp = timestamp;
+  rtp_info->header.ssrc = 0x1234;  // Just an arbitrary SSRC.
+  rtp_info->header.payloadType = 94;  // PCM16b WB codec.
+  rtp_info->header.markerBit = 0;
+}
+
+void NetEqDecodingTest::PopulateCng(int frame_index,
+                                    int timestamp,
+                                    WebRtcRTPHeader* rtp_info,
+                                    uint8_t* payload,
+                                    int* payload_len) {
+  rtp_info->header.sequenceNumber = frame_index;
+  rtp_info->header.timestamp = timestamp;
+  rtp_info->header.ssrc = 0x1234;  // Just an arbitrary SSRC.
+  rtp_info->header.payloadType = 98;  // WB CNG.
+  rtp_info->header.markerBit = 0;
+  payload[0] = 64;  // Noise level -64 dBov, quite arbitrarily chosen.
+  *payload_len = 1;  // Only noise level, no spectral parameters.
+}
+
+void NetEqDecodingTest::CheckBgnOff(int sampling_rate_hz,
+                                    NetEqBackgroundNoiseMode bgn_mode) {
+  int expected_samples_per_channel = 0;
+  uint8_t payload_type = 0xFF;  // Invalid.
+  if (sampling_rate_hz == 8000) {
+    expected_samples_per_channel = kBlockSize8kHz;
+    payload_type = 93;  // PCM 16, 8 kHz.
+  } else if (sampling_rate_hz == 16000) {
+    expected_samples_per_channel = kBlockSize16kHz;
+    payload_type = 94;  // PCM 16, 16 kHZ.
+  } else if (sampling_rate_hz == 32000) {
+    expected_samples_per_channel = kBlockSize32kHz;
+    payload_type = 95;  // PCM 16, 32 kHz.
+  } else {
+    ASSERT_TRUE(false);  // Unsupported test case.
+  }
+
+  NetEqOutputType type;
+  int16_t output[kBlockSize32kHz];  // Maximum size is chosen.
+  int16_t input[kBlockSize32kHz];  // Maximum size is chosen.
+
+  // Payload of 10 ms of PCM16 32 kHz.
+  uint8_t payload[kBlockSize32kHz * sizeof(int16_t)];
+
+  // Random payload.
+  for (int n = 0; n < expected_samples_per_channel; ++n) {
+    input[n] = (rand() & ((1 << 10) - 1)) - ((1 << 5) - 1);
+  }
+  int enc_len_bytes = WebRtcPcm16b_EncodeW16(
+      input, expected_samples_per_channel, reinterpret_cast<int16_t*>(payload));
+  ASSERT_EQ(enc_len_bytes, expected_samples_per_channel * 2);
+
+  WebRtcRTPHeader rtp_info;
+  PopulateRtpInfo(0, 0, &rtp_info);
+  rtp_info.header.payloadType = payload_type;
+
+  int number_channels = 0;
+  int samples_per_channel = 0;
+
+  uint32_t receive_timestamp = 0;
+  for (int n = 0; n < 10; ++n) {  // Insert few packets and get audio.
+    number_channels = 0;
+    samples_per_channel = 0;
+    ASSERT_EQ(0, neteq_->InsertPacket(
+        rtp_info, payload, enc_len_bytes, receive_timestamp));
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize32kHz, output, &samples_per_channel,
+                                  &number_channels, &type));
+    ASSERT_EQ(1, number_channels);
+    ASSERT_EQ(expected_samples_per_channel, samples_per_channel);
+    ASSERT_EQ(kOutputNormal, type);
+
+    // Next packet.
+    rtp_info.header.timestamp += expected_samples_per_channel;
+    rtp_info.header.sequenceNumber++;
+    receive_timestamp += expected_samples_per_channel;
+  }
+
+  number_channels = 0;
+  samples_per_channel = 0;
+
+  // Get audio without inserting packets, expecting PLC and PLC-to-CNG. Pull one
+  // frame without checking speech-type. This is the first frame pulled without
+  // inserting any packet, and might not be labeled as PCL.
+  ASSERT_EQ(0, neteq_->GetAudio(kBlockSize32kHz, output, &samples_per_channel,
+                                &number_channels, &type));
+  ASSERT_EQ(1, number_channels);
+  ASSERT_EQ(expected_samples_per_channel, samples_per_channel);
+
+  // To be able to test the fading of background noise we need at lease to pull
+  // 611 frames.
+  const int kFadingThreshold = 611;
+
+  // Test several CNG-to-PLC packet for the expected behavior. The number 20 is
+  // arbitrary, but sufficiently large to test enough number of frames.
+  const int kNumPlcToCngTestFrames = 20;
+  bool plc_to_cng = false;
+  for (int n = 0; n < kFadingThreshold + kNumPlcToCngTestFrames; ++n) {
+    number_channels = 0;
+    samples_per_channel = 0;
+    memset(output, 1, sizeof(output));  // Set to non-zero.
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize32kHz, output, &samples_per_channel,
+                                  &number_channels, &type));
+    ASSERT_EQ(1, number_channels);
+    ASSERT_EQ(expected_samples_per_channel, samples_per_channel);
+    if (type == kOutputPLCtoCNG) {
+      plc_to_cng = true;
+      double sum_squared = 0;
+      for (int k = 0; k < number_channels * samples_per_channel; ++k)
+        sum_squared += output[k] * output[k];
+      if (bgn_mode == kBgnOn) {
+        EXPECT_NE(0, sum_squared);
+      } else if (bgn_mode == kBgnOff || n > kFadingThreshold) {
+        EXPECT_EQ(0, sum_squared);
+      }
+    } else {
+      EXPECT_EQ(kOutputPLC, type);
+    }
+  }
+  EXPECT_TRUE(plc_to_cng);  // Just to be sure that PLC-to-CNG has occurred.
+}
+
+TEST_F(NetEqDecodingTest, DISABLED_ON_ANDROID(TestBitExactness)) {
+  const std::string input_rtp_file = webrtc::test::ProjectRootPath() +
+      "resources/audio_coding/neteq_universal_new.rtp";
+  // Note that neteq4_universal_ref.pcm and neteq4_universal_ref_win_32.pcm
+  // are identical. The latter could have been removed, but if clients still
+  // have a copy of the file, the test will fail.
+  const std::string input_ref_file =
+      webrtc::test::ResourcePath("audio_coding/neteq4_universal_ref", "pcm");
+
+  if (FLAGS_gen_ref) {
+    DecodeAndCompare(input_rtp_file, "");
+  } else {
+    DecodeAndCompare(input_rtp_file, input_ref_file);
+  }
+}
+
+TEST_F(NetEqDecodingTest, DISABLED_ON_ANDROID(TestNetworkStatistics)) {
+  const std::string input_rtp_file = webrtc::test::ProjectRootPath() +
+      "resources/audio_coding/neteq_universal_new.rtp";
+#if defined(_MSC_VER) && (_MSC_VER >= 1700)
+  // For Visual Studio 2012 and later, we will have to use the generic reference
+  // file, rather than the windows-specific one.
+  const std::string network_stat_ref_file = webrtc::test::ProjectRootPath() +
+      "resources/audio_coding/neteq4_network_stats.dat";
+#else
+  const std::string network_stat_ref_file =
+      webrtc::test::ResourcePath("audio_coding/neteq4_network_stats", "dat");
+#endif
+  const std::string rtcp_stat_ref_file =
+      webrtc::test::ResourcePath("audio_coding/neteq4_rtcp_stats", "dat");
+  if (FLAGS_gen_ref) {
+    DecodeAndCheckStats(input_rtp_file, "", "");
+  } else {
+    DecodeAndCheckStats(input_rtp_file, network_stat_ref_file,
+                        rtcp_stat_ref_file);
+  }
+}
+
+// TODO(hlundin): Re-enable test once the statistics interface is up and again.
+TEST_F(NetEqDecodingTest, TestFrameWaitingTimeStatistics) {
+  // Use fax mode to avoid time-scaling. This is to simplify the testing of
+  // packet waiting times in the packet buffer.
+  neteq_->SetPlayoutMode(kPlayoutFax);
+  ASSERT_EQ(kPlayoutFax, neteq_->PlayoutMode());
+  // Insert 30 dummy packets at once. Each packet contains 10 ms 16 kHz audio.
+  size_t num_frames = 30;
+  const int kSamples = 10 * 16;
+  const int kPayloadBytes = kSamples * 2;
+  for (size_t i = 0; i < num_frames; ++i) {
+    uint16_t payload[kSamples] = {0};
+    WebRtcRTPHeader rtp_info;
+    rtp_info.header.sequenceNumber = i;
+    rtp_info.header.timestamp = i * kSamples;
+    rtp_info.header.ssrc = 0x1234;  // Just an arbitrary SSRC.
+    rtp_info.header.payloadType = 94;  // PCM16b WB codec.
+    rtp_info.header.markerBit = 0;
+    ASSERT_EQ(0, neteq_->InsertPacket(
+        rtp_info,
+        reinterpret_cast<uint8_t*>(payload),
+        kPayloadBytes, 0));
+  }
+  // Pull out all data.
+  for (size_t i = 0; i < num_frames; ++i) {
+    int out_len;
+    int num_channels;
+    NetEqOutputType type;
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  std::vector<int> waiting_times;
+  neteq_->WaitingTimes(&waiting_times);
+  EXPECT_EQ(num_frames, waiting_times.size());
+  // Since all frames are dumped into NetEQ at once, but pulled out with 10 ms
+  // spacing (per definition), we expect the delay to increase with 10 ms for
+  // each packet.
+  for (size_t i = 0; i < waiting_times.size(); ++i) {
+    EXPECT_EQ(static_cast<int>(i + 1) * 10, waiting_times[i]);
+  }
+
+  // Check statistics again and make sure it's been reset.
+  neteq_->WaitingTimes(&waiting_times);
+  int len = waiting_times.size();
+  EXPECT_EQ(0, len);
+
+  // Process > 100 frames, and make sure that that we get statistics
+  // only for 100 frames. Note the new SSRC, causing NetEQ to reset.
+  num_frames = 110;
+  for (size_t i = 0; i < num_frames; ++i) {
+    uint16_t payload[kSamples] = {0};
+    WebRtcRTPHeader rtp_info;
+    rtp_info.header.sequenceNumber = i;
+    rtp_info.header.timestamp = i * kSamples;
+    rtp_info.header.ssrc = 0x1235;  // Just an arbitrary SSRC.
+    rtp_info.header.payloadType = 94;  // PCM16b WB codec.
+    rtp_info.header.markerBit = 0;
+    ASSERT_EQ(0, neteq_->InsertPacket(
+        rtp_info,
+        reinterpret_cast<uint8_t*>(payload),
+        kPayloadBytes, 0));
+    int out_len;
+    int num_channels;
+    NetEqOutputType type;
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  neteq_->WaitingTimes(&waiting_times);
+  EXPECT_EQ(100u, waiting_times.size());
+}
+
+TEST_F(NetEqDecodingTest, TestAverageInterArrivalTimeNegative) {
+  const int kNumFrames = 3000;  // Needed for convergence.
+  int frame_index = 0;
+  const int kSamples = 10 * 16;
+  const int kPayloadBytes = kSamples * 2;
+  while (frame_index < kNumFrames) {
+    // Insert one packet each time, except every 10th time where we insert two
+    // packets at once. This will create a negative clock-drift of approx. 10%.
+    int num_packets = (frame_index % 10 == 0 ? 2 : 1);
+    for (int n = 0; n < num_packets; ++n) {
+      uint8_t payload[kPayloadBytes] = {0};
+      WebRtcRTPHeader rtp_info;
+      PopulateRtpInfo(frame_index, frame_index * kSamples, &rtp_info);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+      ++frame_index;
+    }
+
+    // Pull out data once.
+    int out_len;
+    int num_channels;
+    NetEqOutputType type;
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  NetEqNetworkStatistics network_stats;
+  ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+  EXPECT_EQ(-103196, network_stats.clockdrift_ppm);
+}
+
+TEST_F(NetEqDecodingTest, TestAverageInterArrivalTimePositive) {
+  const int kNumFrames = 5000;  // Needed for convergence.
+  int frame_index = 0;
+  const int kSamples = 10 * 16;
+  const int kPayloadBytes = kSamples * 2;
+  for (int i = 0; i < kNumFrames; ++i) {
+    // Insert one packet each time, except every 10th time where we don't insert
+    // any packet. This will create a positive clock-drift of approx. 11%.
+    int num_packets = (i % 10 == 9 ? 0 : 1);
+    for (int n = 0; n < num_packets; ++n) {
+      uint8_t payload[kPayloadBytes] = {0};
+      WebRtcRTPHeader rtp_info;
+      PopulateRtpInfo(frame_index, frame_index * kSamples, &rtp_info);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+      ++frame_index;
+    }
+
+    // Pull out data once.
+    int out_len;
+    int num_channels;
+    NetEqOutputType type;
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  NetEqNetworkStatistics network_stats;
+  ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+  EXPECT_EQ(110946, network_stats.clockdrift_ppm);
+}
+
+void NetEqDecodingTest::LongCngWithClockDrift(double drift_factor,
+                                              double network_freeze_ms,
+                                              bool pull_audio_during_freeze,
+                                              int delay_tolerance_ms,
+                                              int max_time_to_speech_ms) {
+  uint16_t seq_no = 0;
+  uint32_t timestamp = 0;
+  const int kFrameSizeMs = 30;
+  const int kSamples = kFrameSizeMs * 16;
+  const int kPayloadBytes = kSamples * 2;
+  double next_input_time_ms = 0.0;
+  double t_ms;
+  int out_len;
+  int num_channels;
+  NetEqOutputType type;
+
+  // Insert speech for 5 seconds.
+  const int kSpeechDurationMs = 5000;
+  for (t_ms = 0; t_ms < kSpeechDurationMs; t_ms += 10) {
+    // Each turn in this for loop is 10 ms.
+    while (next_input_time_ms <= t_ms) {
+      // Insert one 30 ms speech frame.
+      uint8_t payload[kPayloadBytes] = {0};
+      WebRtcRTPHeader rtp_info;
+      PopulateRtpInfo(seq_no, timestamp, &rtp_info);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+      ++seq_no;
+      timestamp += kSamples;
+      next_input_time_ms += static_cast<double>(kFrameSizeMs) * drift_factor;
+    }
+    // Pull out data once.
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  EXPECT_EQ(kOutputNormal, type);
+  int32_t delay_before = timestamp - neteq_->PlayoutTimestamp();
+
+  // Insert CNG for 1 minute (= 60000 ms).
+  const int kCngPeriodMs = 100;
+  const int kCngPeriodSamples = kCngPeriodMs * 16;  // Period in 16 kHz samples.
+  const int kCngDurationMs = 60000;
+  for (; t_ms < kSpeechDurationMs + kCngDurationMs; t_ms += 10) {
+    // Each turn in this for loop is 10 ms.
+    while (next_input_time_ms <= t_ms) {
+      // Insert one CNG frame each 100 ms.
+      uint8_t payload[kPayloadBytes];
+      int payload_len;
+      WebRtcRTPHeader rtp_info;
+      PopulateCng(seq_no, timestamp, &rtp_info, payload, &payload_len);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, payload_len, 0));
+      ++seq_no;
+      timestamp += kCngPeriodSamples;
+      next_input_time_ms += static_cast<double>(kCngPeriodMs) * drift_factor;
+    }
+    // Pull out data once.
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+
+  EXPECT_EQ(kOutputCNG, type);
+
+  if (network_freeze_ms > 0) {
+    // First keep pulling audio for |network_freeze_ms| without inserting
+    // any data, then insert CNG data corresponding to |network_freeze_ms|
+    // without pulling any output audio.
+    const double loop_end_time = t_ms + network_freeze_ms;
+    for (; t_ms < loop_end_time; t_ms += 10) {
+      // Pull out data once.
+      ASSERT_EQ(0,
+                neteq_->GetAudio(
+                    kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+      ASSERT_EQ(kBlockSize16kHz, out_len);
+      EXPECT_EQ(kOutputCNG, type);
+    }
+    bool pull_once = pull_audio_during_freeze;
+    // If |pull_once| is true, GetAudio will be called once half-way through
+    // the network recovery period.
+    double pull_time_ms = (t_ms + next_input_time_ms) / 2;
+    while (next_input_time_ms <= t_ms) {
+      if (pull_once && next_input_time_ms >= pull_time_ms) {
+        pull_once = false;
+        // Pull out data once.
+        ASSERT_EQ(
+            0,
+            neteq_->GetAudio(
+                kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+        ASSERT_EQ(kBlockSize16kHz, out_len);
+        EXPECT_EQ(kOutputCNG, type);
+        t_ms += 10;
+      }
+      // Insert one CNG frame each 100 ms.
+      uint8_t payload[kPayloadBytes];
+      int payload_len;
+      WebRtcRTPHeader rtp_info;
+      PopulateCng(seq_no, timestamp, &rtp_info, payload, &payload_len);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, payload_len, 0));
+      ++seq_no;
+      timestamp += kCngPeriodSamples;
+      next_input_time_ms += kCngPeriodMs * drift_factor;
+    }
+  }
+
+  // Insert speech again until output type is speech.
+  double speech_restart_time_ms = t_ms;
+  while (type != kOutputNormal) {
+    // Each turn in this for loop is 10 ms.
+    while (next_input_time_ms <= t_ms) {
+      // Insert one 30 ms speech frame.
+      uint8_t payload[kPayloadBytes] = {0};
+      WebRtcRTPHeader rtp_info;
+      PopulateRtpInfo(seq_no, timestamp, &rtp_info);
+      ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+      ++seq_no;
+      timestamp += kSamples;
+      next_input_time_ms += kFrameSizeMs * drift_factor;
+    }
+    // Pull out data once.
+    ASSERT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_, &out_len,
+                                  &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+    // Increase clock.
+    t_ms += 10;
+  }
+
+  // Check that the speech starts again within reasonable time.
+  double time_until_speech_returns_ms = t_ms - speech_restart_time_ms;
+  EXPECT_LT(time_until_speech_returns_ms, max_time_to_speech_ms);
+  int32_t delay_after = timestamp - neteq_->PlayoutTimestamp();
+  // Compare delay before and after, and make sure it differs less than 20 ms.
+  EXPECT_LE(delay_after, delay_before + delay_tolerance_ms * 16);
+  EXPECT_GE(delay_after, delay_before - delay_tolerance_ms * 16);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithNegativeClockDrift) {
+  // Apply a clock drift of -25 ms / s (sender faster than receiver).
+  const double kDriftFactor = 1000.0 / (1000.0 + 25.0);
+  const double kNetworkFreezeTimeMs = 0.0;
+  const bool kGetAudioDuringFreezeRecovery = false;
+  const int kDelayToleranceMs = 20;
+  const int kMaxTimeToSpeechMs = 100;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithPositiveClockDrift) {
+  // Apply a clock drift of +25 ms / s (sender slower than receiver).
+  const double kDriftFactor = 1000.0 / (1000.0 - 25.0);
+  const double kNetworkFreezeTimeMs = 0.0;
+  const bool kGetAudioDuringFreezeRecovery = false;
+  const int kDelayToleranceMs = 20;
+  const int kMaxTimeToSpeechMs = 100;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithNegativeClockDriftNetworkFreeze) {
+  // Apply a clock drift of -25 ms / s (sender faster than receiver).
+  const double kDriftFactor = 1000.0 / (1000.0 + 25.0);
+  const double kNetworkFreezeTimeMs = 5000.0;
+  const bool kGetAudioDuringFreezeRecovery = false;
+  const int kDelayToleranceMs = 50;
+  const int kMaxTimeToSpeechMs = 200;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithPositiveClockDriftNetworkFreeze) {
+  // Apply a clock drift of +25 ms / s (sender slower than receiver).
+  const double kDriftFactor = 1000.0 / (1000.0 - 25.0);
+  const double kNetworkFreezeTimeMs = 5000.0;
+  const bool kGetAudioDuringFreezeRecovery = false;
+  const int kDelayToleranceMs = 20;
+  const int kMaxTimeToSpeechMs = 100;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithPositiveClockDriftNetworkFreezeExtraPull) {
+  // Apply a clock drift of +25 ms / s (sender slower than receiver).
+  const double kDriftFactor = 1000.0 / (1000.0 - 25.0);
+  const double kNetworkFreezeTimeMs = 5000.0;
+  const bool kGetAudioDuringFreezeRecovery = true;
+  const int kDelayToleranceMs = 20;
+  const int kMaxTimeToSpeechMs = 100;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, LongCngWithoutClockDrift) {
+  const double kDriftFactor = 1.0;  // No drift.
+  const double kNetworkFreezeTimeMs = 0.0;
+  const bool kGetAudioDuringFreezeRecovery = false;
+  const int kDelayToleranceMs = 10;
+  const int kMaxTimeToSpeechMs = 50;
+  LongCngWithClockDrift(kDriftFactor,
+                        kNetworkFreezeTimeMs,
+                        kGetAudioDuringFreezeRecovery,
+                        kDelayToleranceMs,
+                        kMaxTimeToSpeechMs);
+}
+
+TEST_F(NetEqDecodingTest, UnknownPayloadType) {
+  const int kPayloadBytes = 100;
+  uint8_t payload[kPayloadBytes] = {0};
+  WebRtcRTPHeader rtp_info;
+  PopulateRtpInfo(0, 0, &rtp_info);
+  rtp_info.header.payloadType = 1;  // Not registered as a decoder.
+  EXPECT_EQ(NetEq::kFail,
+            neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+  EXPECT_EQ(NetEq::kUnknownRtpPayloadType, neteq_->LastError());
+}
+
+TEST_F(NetEqDecodingTest, DISABLED_ON_ANDROID(DecoderError)) {
+  const int kPayloadBytes = 100;
+  uint8_t payload[kPayloadBytes] = {0};
+  WebRtcRTPHeader rtp_info;
+  PopulateRtpInfo(0, 0, &rtp_info);
+  rtp_info.header.payloadType = 103;  // iSAC, but the payload is invalid.
+  EXPECT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+  NetEqOutputType type;
+  // Set all of |out_data_| to 1, and verify that it was set to 0 by the call
+  // to GetAudio.
+  for (int i = 0; i < kMaxBlockSize; ++i) {
+    out_data_[i] = 1;
+  }
+  int num_channels;
+  int samples_per_channel;
+  EXPECT_EQ(NetEq::kFail,
+            neteq_->GetAudio(kMaxBlockSize, out_data_,
+                             &samples_per_channel, &num_channels, &type));
+  // Verify that there is a decoder error to check.
+  EXPECT_EQ(NetEq::kDecoderErrorCode, neteq_->LastError());
+  // Code 6730 is an iSAC error code.
+  EXPECT_EQ(6730, neteq_->LastDecoderError());
+  // Verify that the first 160 samples are set to 0, and that the remaining
+  // samples are left unmodified.
+  static const int kExpectedOutputLength = 160;  // 10 ms at 16 kHz sample rate.
+  for (int i = 0; i < kExpectedOutputLength; ++i) {
+    std::ostringstream ss;
+    ss << "i = " << i;
+    SCOPED_TRACE(ss.str());  // Print out the parameter values on failure.
+    EXPECT_EQ(0, out_data_[i]);
+  }
+  for (int i = kExpectedOutputLength; i < kMaxBlockSize; ++i) {
+    std::ostringstream ss;
+    ss << "i = " << i;
+    SCOPED_TRACE(ss.str());  // Print out the parameter values on failure.
+    EXPECT_EQ(1, out_data_[i]);
+  }
+}
+
+TEST_F(NetEqDecodingTest, GetAudioBeforeInsertPacket) {
+  NetEqOutputType type;
+  // Set all of |out_data_| to 1, and verify that it was set to 0 by the call
+  // to GetAudio.
+  for (int i = 0; i < kMaxBlockSize; ++i) {
+    out_data_[i] = 1;
+  }
+  int num_channels;
+  int samples_per_channel;
+  EXPECT_EQ(0, neteq_->GetAudio(kMaxBlockSize, out_data_,
+                                &samples_per_channel,
+                                &num_channels, &type));
+  // Verify that the first block of samples is set to 0.
+  static const int kExpectedOutputLength =
+      kInitSampleRateHz / 100;  // 10 ms at initial sample rate.
+  for (int i = 0; i < kExpectedOutputLength; ++i) {
+    std::ostringstream ss;
+    ss << "i = " << i;
+    SCOPED_TRACE(ss.str());  // Print out the parameter values on failure.
+    EXPECT_EQ(0, out_data_[i]);
+  }
+}
+
+TEST_F(NetEqDecodingTest, BackgroundNoise) {
+  neteq_->SetBackgroundNoiseMode(kBgnOn);
+  CheckBgnOff(8000, kBgnOn);
+  CheckBgnOff(16000, kBgnOn);
+  CheckBgnOff(32000, kBgnOn);
+  EXPECT_EQ(kBgnOn, neteq_->BackgroundNoiseMode());
+
+  neteq_->SetBackgroundNoiseMode(kBgnOff);
+  CheckBgnOff(8000, kBgnOff);
+  CheckBgnOff(16000, kBgnOff);
+  CheckBgnOff(32000, kBgnOff);
+  EXPECT_EQ(kBgnOff, neteq_->BackgroundNoiseMode());
+
+  neteq_->SetBackgroundNoiseMode(kBgnFade);
+  CheckBgnOff(8000, kBgnFade);
+  CheckBgnOff(16000, kBgnFade);
+  CheckBgnOff(32000, kBgnFade);
+  EXPECT_EQ(kBgnFade, neteq_->BackgroundNoiseMode());
+}
+
+TEST_F(NetEqDecodingTest, SyncPacketInsert) {
+  WebRtcRTPHeader rtp_info;
+  uint32_t receive_timestamp = 0;
+  // For the readability use the following payloads instead of the defaults of
+  // this test.
+  uint8_t kPcm16WbPayloadType = 1;
+  uint8_t kCngNbPayloadType = 2;
+  uint8_t kCngWbPayloadType = 3;
+  uint8_t kCngSwb32PayloadType = 4;
+  uint8_t kCngSwb48PayloadType = 5;
+  uint8_t kAvtPayloadType = 6;
+  uint8_t kRedPayloadType = 7;
+  uint8_t kIsacPayloadType = 9;  // Payload type 8 is already registered.
+
+  // Register decoders.
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderPCM16Bwb,
+                                           kPcm16WbPayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGnb, kCngNbPayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGwb, kCngWbPayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGswb32kHz,
+                                           kCngSwb32PayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderCNGswb48kHz,
+                                           kCngSwb48PayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderAVT, kAvtPayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderRED, kRedPayloadType));
+  ASSERT_EQ(0, neteq_->RegisterPayloadType(kDecoderISAC, kIsacPayloadType));
+
+  PopulateRtpInfo(0, 0, &rtp_info);
+  rtp_info.header.payloadType = kPcm16WbPayloadType;
+
+  // The first packet injected cannot be sync-packet.
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  // Payload length of 10 ms PCM16 16 kHz.
+  const int kPayloadBytes = kBlockSize16kHz * sizeof(int16_t);
+  uint8_t payload[kPayloadBytes] = {0};
+  ASSERT_EQ(0, neteq_->InsertPacket(
+      rtp_info, payload, kPayloadBytes, receive_timestamp));
+
+  // Next packet. Last packet contained 10 ms audio.
+  rtp_info.header.sequenceNumber++;
+  rtp_info.header.timestamp += kBlockSize16kHz;
+  receive_timestamp += kBlockSize16kHz;
+
+  // Unacceptable payload types CNG, AVT (DTMF), RED.
+  rtp_info.header.payloadType = kCngNbPayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  rtp_info.header.payloadType = kCngWbPayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  rtp_info.header.payloadType = kCngSwb32PayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  rtp_info.header.payloadType = kCngSwb48PayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  rtp_info.header.payloadType = kAvtPayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  rtp_info.header.payloadType = kRedPayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  // Change of codec cannot be initiated with a sync packet.
+  rtp_info.header.payloadType = kIsacPayloadType;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  // Change of SSRC is not allowed with a sync packet.
+  rtp_info.header.payloadType = kPcm16WbPayloadType;
+  ++rtp_info.header.ssrc;
+  EXPECT_EQ(-1, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+
+  --rtp_info.header.ssrc;
+  EXPECT_EQ(0, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+}
+
+// First insert several noise like packets, then sync-packets. Decoding all
+// packets should not produce error, statistics should not show any packet loss
+// and sync-packets should decode to zero.
+// TODO(turajs) we will have a better test if we have a referece NetEq, and
+// when Sync packets are inserted in "test" NetEq we insert all-zero payload
+// in reference NetEq and compare the output of those two.
+TEST_F(NetEqDecodingTest, SyncPacketDecode) {
+  WebRtcRTPHeader rtp_info;
+  PopulateRtpInfo(0, 0, &rtp_info);
+  const int kPayloadBytes = kBlockSize16kHz * sizeof(int16_t);
+  uint8_t payload[kPayloadBytes];
+  int16_t decoded[kBlockSize16kHz];
+  int algorithmic_frame_delay = algorithmic_delay_ms_ / 10 + 1;
+  for (int n = 0; n < kPayloadBytes; ++n) {
+    payload[n] = (rand() & 0xF0) + 1;  // Non-zero random sequence.
+  }
+  // Insert some packets which decode to noise. We are not interested in
+  // actual decoded values.
+  NetEqOutputType output_type;
+  int num_channels;
+  int samples_per_channel;
+  uint32_t receive_timestamp = 0;
+  for (int n = 0; n < 100; ++n) {
+    ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes,
+                                      receive_timestamp));
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    ASSERT_EQ(kBlockSize16kHz, samples_per_channel);
+    ASSERT_EQ(1, num_channels);
+
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+  const int kNumSyncPackets = 10;
+
+  // Make sure sufficient number of sync packets are inserted that we can
+  // conduct a test.
+  ASSERT_GT(kNumSyncPackets, algorithmic_frame_delay);
+  // Insert sync-packets, the decoded sequence should be all-zero.
+  for (int n = 0; n < kNumSyncPackets; ++n) {
+    ASSERT_EQ(0, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    ASSERT_EQ(kBlockSize16kHz, samples_per_channel);
+    ASSERT_EQ(1, num_channels);
+    if (n > algorithmic_frame_delay) {
+      EXPECT_TRUE(IsAllZero(decoded, samples_per_channel * num_channels));
+    }
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+
+  // We insert regular packets, if sync packet are not correctly buffered then
+  // network statistics would show some packet loss.
+  for (int n = 0; n <= algorithmic_frame_delay + 10; ++n) {
+    ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes,
+                                      receive_timestamp));
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    if (n >= algorithmic_frame_delay + 1) {
+      // Expect that this frame contain samples from regular RTP.
+      EXPECT_TRUE(IsAllNonZero(decoded, samples_per_channel * num_channels));
+    }
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+  NetEqNetworkStatistics network_stats;
+  ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+  // Expecting a "clean" network.
+  EXPECT_EQ(0, network_stats.packet_loss_rate);
+  EXPECT_EQ(0, network_stats.expand_rate);
+  EXPECT_EQ(0, network_stats.accelerate_rate);
+  EXPECT_LE(network_stats.preemptive_rate, 150);
+}
+
+// Test if the size of the packet buffer reported correctly when containing
+// sync packets. Also, test if network packets override sync packets. That is to
+// prefer decoding a network packet to a sync packet, if both have same sequence
+// number and timestamp.
+TEST_F(NetEqDecodingTest, SyncPacketBufferSizeAndOverridenByNetworkPackets) {
+  WebRtcRTPHeader rtp_info;
+  PopulateRtpInfo(0, 0, &rtp_info);
+  const int kPayloadBytes = kBlockSize16kHz * sizeof(int16_t);
+  uint8_t payload[kPayloadBytes];
+  int16_t decoded[kBlockSize16kHz];
+  for (int n = 0; n < kPayloadBytes; ++n) {
+    payload[n] = (rand() & 0xF0) + 1;  // Non-zero random sequence.
+  }
+  // Insert some packets which decode to noise. We are not interested in
+  // actual decoded values.
+  NetEqOutputType output_type;
+  int num_channels;
+  int samples_per_channel;
+  uint32_t receive_timestamp = 0;
+  int algorithmic_frame_delay = algorithmic_delay_ms_ / 10 + 1;
+  for (int n = 0; n < algorithmic_frame_delay; ++n) {
+    ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes,
+                                      receive_timestamp));
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    ASSERT_EQ(kBlockSize16kHz, samples_per_channel);
+    ASSERT_EQ(1, num_channels);
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+  const int kNumSyncPackets = 10;
+
+  WebRtcRTPHeader first_sync_packet_rtp_info;
+  memcpy(&first_sync_packet_rtp_info, &rtp_info, sizeof(rtp_info));
+
+  // Insert sync-packets, but no decoding.
+  for (int n = 0; n < kNumSyncPackets; ++n) {
+    ASSERT_EQ(0, neteq_->InsertSyncPacket(rtp_info, receive_timestamp));
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+  NetEqNetworkStatistics network_stats;
+  ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+  EXPECT_EQ(kNumSyncPackets * 10 + algorithmic_delay_ms_,
+            network_stats.current_buffer_size_ms);
+
+  // Rewind |rtp_info| to that of the first sync packet.
+  memcpy(&rtp_info, &first_sync_packet_rtp_info, sizeof(rtp_info));
+
+  // Insert.
+  for (int n = 0; n < kNumSyncPackets; ++n) {
+    ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes,
+                                      receive_timestamp));
+    rtp_info.header.sequenceNumber++;
+    rtp_info.header.timestamp += kBlockSize16kHz;
+    receive_timestamp += kBlockSize16kHz;
+  }
+
+  // Decode.
+  for (int n = 0; n < kNumSyncPackets; ++n) {
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    ASSERT_EQ(kBlockSize16kHz, samples_per_channel);
+    ASSERT_EQ(1, num_channels);
+    EXPECT_TRUE(IsAllNonZero(decoded, samples_per_channel * num_channels));
+  }
+}
+
+void NetEqDecodingTest::WrapTest(uint16_t start_seq_no,
+                                 uint32_t start_timestamp,
+                                 const std::set<uint16_t>& drop_seq_numbers,
+                                 bool expect_seq_no_wrap,
+                                 bool expect_timestamp_wrap) {
+  uint16_t seq_no = start_seq_no;
+  uint32_t timestamp = start_timestamp;
+  const int kBlocksPerFrame = 3;  // Number of 10 ms blocks per frame.
+  const int kFrameSizeMs = kBlocksPerFrame * kTimeStepMs;
+  const int kSamples = kBlockSize16kHz * kBlocksPerFrame;
+  const int kPayloadBytes = kSamples * sizeof(int16_t);
+  double next_input_time_ms = 0.0;
+  int16_t decoded[kBlockSize16kHz];
+  int num_channels;
+  int samples_per_channel;
+  NetEqOutputType output_type;
+  uint32_t receive_timestamp = 0;
+
+  // Insert speech for 2 seconds.
+  const int kSpeechDurationMs = 2000;
+  int packets_inserted = 0;
+  uint16_t last_seq_no;
+  uint32_t last_timestamp;
+  bool timestamp_wrapped = false;
+  bool seq_no_wrapped = false;
+  for (double t_ms = 0; t_ms < kSpeechDurationMs; t_ms += 10) {
+    // Each turn in this for loop is 10 ms.
+    while (next_input_time_ms <= t_ms) {
+      // Insert one 30 ms speech frame.
+      uint8_t payload[kPayloadBytes] = {0};
+      WebRtcRTPHeader rtp_info;
+      PopulateRtpInfo(seq_no, timestamp, &rtp_info);
+      if (drop_seq_numbers.find(seq_no) == drop_seq_numbers.end()) {
+        // This sequence number was not in the set to drop. Insert it.
+        ASSERT_EQ(0,
+                  neteq_->InsertPacket(rtp_info, payload, kPayloadBytes,
+                                       receive_timestamp));
+        ++packets_inserted;
+      }
+      NetEqNetworkStatistics network_stats;
+      ASSERT_EQ(0, neteq_->NetworkStatistics(&network_stats));
+
+      // Due to internal NetEq logic, preferred buffer-size is about 4 times the
+      // packet size for first few packets. Therefore we refrain from checking
+      // the criteria.
+      if (packets_inserted > 4) {
+        // Expect preferred and actual buffer size to be no more than 2 frames.
+        EXPECT_LE(network_stats.preferred_buffer_size_ms, kFrameSizeMs * 2);
+        EXPECT_LE(network_stats.current_buffer_size_ms, kFrameSizeMs * 2 +
+                  algorithmic_delay_ms_);
+      }
+      last_seq_no = seq_no;
+      last_timestamp = timestamp;
+
+      ++seq_no;
+      timestamp += kSamples;
+      receive_timestamp += kSamples;
+      next_input_time_ms += static_cast<double>(kFrameSizeMs);
+
+      seq_no_wrapped |= seq_no < last_seq_no;
+      timestamp_wrapped |= timestamp < last_timestamp;
+    }
+    // Pull out data once.
+    ASSERT_EQ(0, neteq_->GetAudio(kBlockSize16kHz, decoded,
+                                  &samples_per_channel, &num_channels,
+                                  &output_type));
+    ASSERT_EQ(kBlockSize16kHz, samples_per_channel);
+    ASSERT_EQ(1, num_channels);
+
+    // Expect delay (in samples) to be less than 2 packets.
+    EXPECT_LE(timestamp - neteq_->PlayoutTimestamp(),
+              static_cast<uint32_t>(kSamples * 2));
+  }
+  // Make sure we have actually tested wrap-around.
+  ASSERT_EQ(expect_seq_no_wrap, seq_no_wrapped);
+  ASSERT_EQ(expect_timestamp_wrap, timestamp_wrapped);
+}
+
+TEST_F(NetEqDecodingTest, SequenceNumberWrap) {
+  // Start with a sequence number that will soon wrap.
+  std::set<uint16_t> drop_seq_numbers;  // Don't drop any packets.
+  WrapTest(0xFFFF - 10, 0, drop_seq_numbers, true, false);
+}
+
+TEST_F(NetEqDecodingTest, SequenceNumberWrapAndDrop) {
+  // Start with a sequence number that will soon wrap.
+  std::set<uint16_t> drop_seq_numbers;
+  drop_seq_numbers.insert(0xFFFF);
+  drop_seq_numbers.insert(0x0);
+  WrapTest(0xFFFF - 10, 0, drop_seq_numbers, true, false);
+}
+
+TEST_F(NetEqDecodingTest, TimestampWrap) {
+  // Start with a timestamp that will soon wrap.
+  std::set<uint16_t> drop_seq_numbers;
+  WrapTest(0, 0xFFFFFFFF - 3000, drop_seq_numbers, false, true);
+}
+
+TEST_F(NetEqDecodingTest, TimestampAndSequenceNumberWrap) {
+  // Start with a timestamp and a sequence number that will wrap at the same
+  // time.
+  std::set<uint16_t> drop_seq_numbers;
+  WrapTest(0xFFFF - 10, 0xFFFFFFFF - 5000, drop_seq_numbers, true, true);
+}
+
+void NetEqDecodingTest::DuplicateCng() {
+  uint16_t seq_no = 0;
+  uint32_t timestamp = 0;
+  const int kFrameSizeMs = 10;
+  const int kSampleRateKhz = 16;
+  const int kSamples = kFrameSizeMs * kSampleRateKhz;
+  const int kPayloadBytes = kSamples * 2;
+
+  const int algorithmic_delay_samples = std::max(
+      algorithmic_delay_ms_ * kSampleRateKhz, 5 * kSampleRateKhz / 8);
+  // Insert three speech packet. Three are needed to get the frame length
+  // correct.
+  int out_len;
+  int num_channels;
+  NetEqOutputType type;
+  uint8_t payload[kPayloadBytes] = {0};
+  WebRtcRTPHeader rtp_info;
+  for (int i = 0; i < 3; ++i) {
+    PopulateRtpInfo(seq_no, timestamp, &rtp_info);
+    ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+    ++seq_no;
+    timestamp += kSamples;
+
+    // Pull audio once.
+    ASSERT_EQ(0,
+              neteq_->GetAudio(
+                  kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+  }
+  // Verify speech output.
+  EXPECT_EQ(kOutputNormal, type);
+
+  // Insert same CNG packet twice.
+  const int kCngPeriodMs = 100;
+  const int kCngPeriodSamples = kCngPeriodMs * kSampleRateKhz;
+  int payload_len;
+  PopulateCng(seq_no, timestamp, &rtp_info, payload, &payload_len);
+  // This is the first time this CNG packet is inserted.
+  ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, payload_len, 0));
+
+  // Pull audio once and make sure CNG is played.
+  ASSERT_EQ(0,
+            neteq_->GetAudio(
+                kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+  ASSERT_EQ(kBlockSize16kHz, out_len);
+  EXPECT_EQ(kOutputCNG, type);
+  EXPECT_EQ(timestamp - algorithmic_delay_samples, neteq_->PlayoutTimestamp());
+
+  // Insert the same CNG packet again. Note that at this point it is old, since
+  // we have already decoded the first copy of it.
+  ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, payload_len, 0));
+
+  // Pull audio until we have played |kCngPeriodMs| of CNG. Start at 10 ms since
+  // we have already pulled out CNG once.
+  for (int cng_time_ms = 10; cng_time_ms < kCngPeriodMs; cng_time_ms += 10) {
+    ASSERT_EQ(0,
+              neteq_->GetAudio(
+                  kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+    ASSERT_EQ(kBlockSize16kHz, out_len);
+    EXPECT_EQ(kOutputCNG, type);
+    EXPECT_EQ(timestamp - algorithmic_delay_samples,
+              neteq_->PlayoutTimestamp());
+  }
+
+  // Insert speech again.
+  ++seq_no;
+  timestamp += kCngPeriodSamples;
+  PopulateRtpInfo(seq_no, timestamp, &rtp_info);
+  ASSERT_EQ(0, neteq_->InsertPacket(rtp_info, payload, kPayloadBytes, 0));
+
+  // Pull audio once and verify that the output is speech again.
+  ASSERT_EQ(0,
+            neteq_->GetAudio(
+                kMaxBlockSize, out_data_, &out_len, &num_channels, &type));
+  ASSERT_EQ(kBlockSize16kHz, out_len);
+  EXPECT_EQ(kOutputNormal, type);
+  EXPECT_EQ(timestamp + kSamples - algorithmic_delay_samples,
+            neteq_->PlayoutTimestamp());
+}
+
+TEST_F(NetEqDecodingTest, DiscardDuplicateCng) { DuplicateCng(); }
+}  // namespace webrtc