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_impl.cc b/webrtc/modules/audio_coding/neteq4/neteq_impl.cc
new file mode 100644
index 0000000..38a5456
--- /dev/null
+++ b/webrtc/modules/audio_coding/neteq4/neteq_impl.cc
@@ -0,0 +1,1941 @@
+/*
+ *  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 "webrtc/modules/audio_coding/neteq4/neteq_impl.h"
+
+#include <assert.h>
+#include <memory.h>  // memset
+
+#include <algorithm>
+
+#include "webrtc/common_audio/signal_processing/include/signal_processing_library.h"
+#include "webrtc/modules/audio_coding/neteq4/accelerate.h"
+#include "webrtc/modules/audio_coding/neteq4/background_noise.h"
+#include "webrtc/modules/audio_coding/neteq4/buffer_level_filter.h"
+#include "webrtc/modules/audio_coding/neteq4/comfort_noise.h"
+#include "webrtc/modules/audio_coding/neteq4/decision_logic.h"
+#include "webrtc/modules/audio_coding/neteq4/decoder_database.h"
+#include "webrtc/modules/audio_coding/neteq4/defines.h"
+#include "webrtc/modules/audio_coding/neteq4/delay_manager.h"
+#include "webrtc/modules/audio_coding/neteq4/delay_peak_detector.h"
+#include "webrtc/modules/audio_coding/neteq4/dtmf_buffer.h"
+#include "webrtc/modules/audio_coding/neteq4/dtmf_tone_generator.h"
+#include "webrtc/modules/audio_coding/neteq4/expand.h"
+#include "webrtc/modules/audio_coding/neteq4/interface/audio_decoder.h"
+#include "webrtc/modules/audio_coding/neteq4/merge.h"
+#include "webrtc/modules/audio_coding/neteq4/normal.h"
+#include "webrtc/modules/audio_coding/neteq4/packet_buffer.h"
+#include "webrtc/modules/audio_coding/neteq4/packet.h"
+#include "webrtc/modules/audio_coding/neteq4/payload_splitter.h"
+#include "webrtc/modules/audio_coding/neteq4/post_decode_vad.h"
+#include "webrtc/modules/audio_coding/neteq4/preemptive_expand.h"
+#include "webrtc/modules/audio_coding/neteq4/sync_buffer.h"
+#include "webrtc/modules/audio_coding/neteq4/timestamp_scaler.h"
+#include "webrtc/modules/interface/module_common_types.h"
+#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
+#include "webrtc/system_wrappers/interface/logging.h"
+
+// Modify the code to obtain backwards bit-exactness. Once bit-exactness is no
+// longer required, this #define should be removed (and the code that it
+// enables).
+#define LEGACY_BITEXACT
+
+namespace webrtc {
+
+NetEqImpl::NetEqImpl(int fs,
+                     BufferLevelFilter* buffer_level_filter,
+                     DecoderDatabase* decoder_database,
+                     DelayManager* delay_manager,
+                     DelayPeakDetector* delay_peak_detector,
+                     DtmfBuffer* dtmf_buffer,
+                     DtmfToneGenerator* dtmf_tone_generator,
+                     PacketBuffer* packet_buffer,
+                     PayloadSplitter* payload_splitter,
+                     TimestampScaler* timestamp_scaler,
+                     AccelerateFactory* accelerate_factory,
+                     ExpandFactory* expand_factory,
+                     PreemptiveExpandFactory* preemptive_expand_factory,
+                     bool create_components)
+    : buffer_level_filter_(buffer_level_filter),
+      decoder_database_(decoder_database),
+      delay_manager_(delay_manager),
+      delay_peak_detector_(delay_peak_detector),
+      dtmf_buffer_(dtmf_buffer),
+      dtmf_tone_generator_(dtmf_tone_generator),
+      packet_buffer_(packet_buffer),
+      payload_splitter_(payload_splitter),
+      timestamp_scaler_(timestamp_scaler),
+      vad_(new PostDecodeVad()),
+      expand_factory_(expand_factory),
+      accelerate_factory_(accelerate_factory),
+      preemptive_expand_factory_(preemptive_expand_factory),
+      last_mode_(kModeNormal),
+      decoded_buffer_length_(kMaxFrameSize),
+      decoded_buffer_(new int16_t[decoded_buffer_length_]),
+      playout_timestamp_(0),
+      new_codec_(false),
+      timestamp_(0),
+      reset_decoder_(false),
+      current_rtp_payload_type_(0xFF),  // Invalid RTP payload type.
+      current_cng_rtp_payload_type_(0xFF),  // Invalid RTP payload type.
+      ssrc_(0),
+      first_packet_(true),
+      error_code_(0),
+      decoder_error_code_(0),
+      crit_sect_(CriticalSectionWrapper::CreateCriticalSection()),
+      decoded_packet_sequence_number_(-1),
+      decoded_packet_timestamp_(0) {
+  if (fs != 8000 && fs != 16000 && fs != 32000 && fs != 48000) {
+    LOG(LS_ERROR) << "Sample rate " << fs << " Hz not supported. " <<
+        "Changing to 8000 Hz.";
+    fs = 8000;
+  }
+  LOG(LS_VERBOSE) << "Create NetEqImpl object with fs = " << fs << ".";
+  fs_hz_ = fs;
+  fs_mult_ = fs / 8000;
+  output_size_samples_ = kOutputSizeMs * 8 * fs_mult_;
+  decoder_frame_length_ = 3 * output_size_samples_;
+  WebRtcSpl_Init();
+  if (create_components) {
+    SetSampleRateAndChannels(fs, 1);  // Default is 1 channel.
+  }
+}
+
+NetEqImpl::~NetEqImpl() {
+  LOG(LS_INFO) << "Deleting NetEqImpl object.";
+}
+
+int NetEqImpl::InsertPacket(const WebRtcRTPHeader& rtp_header,
+                            const uint8_t* payload,
+                            int length_bytes,
+                            uint32_t receive_timestamp) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG(LS_VERBOSE) << "InsertPacket: ts=" << rtp_header.header.timestamp <<
+      ", sn=" << rtp_header.header.sequenceNumber <<
+      ", pt=" << static_cast<int>(rtp_header.header.payloadType) <<
+      ", ssrc=" << rtp_header.header.ssrc <<
+      ", len=" << length_bytes;
+  int error = InsertPacketInternal(rtp_header, payload, length_bytes,
+                                   receive_timestamp, false);
+  if (error != 0) {
+    LOG_FERR1(LS_WARNING, InsertPacketInternal, error);
+    error_code_ = error;
+    return kFail;
+  }
+  return kOK;
+}
+
+int NetEqImpl::InsertSyncPacket(const WebRtcRTPHeader& rtp_header,
+                                uint32_t receive_timestamp) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG(LS_VERBOSE) << "InsertPacket-Sync: ts="
+      << rtp_header.header.timestamp <<
+      ", sn=" << rtp_header.header.sequenceNumber <<
+      ", pt=" << static_cast<int>(rtp_header.header.payloadType) <<
+      ", ssrc=" << rtp_header.header.ssrc;
+
+  const uint8_t kSyncPayload[] = { 's', 'y', 'n', 'c' };
+  int error = InsertPacketInternal(
+      rtp_header, kSyncPayload, sizeof(kSyncPayload), receive_timestamp, true);
+
+  if (error != 0) {
+    LOG_FERR1(LS_WARNING, InsertPacketInternal, error);
+    error_code_ = error;
+    return kFail;
+  }
+  return kOK;
+}
+
+int NetEqImpl::GetAudio(size_t max_length, int16_t* output_audio,
+                        int* samples_per_channel, int* num_channels,
+                        NetEqOutputType* type) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG(LS_VERBOSE) << "GetAudio";
+  int error = GetAudioInternal(max_length, output_audio, samples_per_channel,
+                               num_channels);
+  LOG(LS_VERBOSE) << "Produced " << *samples_per_channel <<
+      " samples/channel for " << *num_channels << " channel(s)";
+  if (error != 0) {
+    LOG_FERR1(LS_WARNING, GetAudioInternal, error);
+    error_code_ = error;
+    return kFail;
+  }
+  if (type) {
+    *type = LastOutputType();
+  }
+  return kOK;
+}
+
+int NetEqImpl::RegisterPayloadType(enum NetEqDecoder codec,
+                                   uint8_t rtp_payload_type) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG_API2(static_cast<int>(rtp_payload_type), codec);
+  int ret = decoder_database_->RegisterPayload(rtp_payload_type, codec);
+  if (ret != DecoderDatabase::kOK) {
+    LOG_FERR2(LS_WARNING, RegisterPayload, rtp_payload_type, codec);
+    switch (ret) {
+      case DecoderDatabase::kInvalidRtpPayloadType:
+        error_code_ = kInvalidRtpPayloadType;
+        break;
+      case DecoderDatabase::kCodecNotSupported:
+        error_code_ = kCodecNotSupported;
+        break;
+      case DecoderDatabase::kDecoderExists:
+        error_code_ = kDecoderExists;
+        break;
+      default:
+        error_code_ = kOtherError;
+    }
+    return kFail;
+  }
+  return kOK;
+}
+
+int NetEqImpl::RegisterExternalDecoder(AudioDecoder* decoder,
+                                       enum NetEqDecoder codec,
+                                       uint8_t rtp_payload_type) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG_API2(static_cast<int>(rtp_payload_type), codec);
+  if (!decoder) {
+    LOG(LS_ERROR) << "Cannot register external decoder with NULL pointer";
+    assert(false);
+    return kFail;
+  }
+  const int sample_rate_hz = AudioDecoder::CodecSampleRateHz(codec);
+  int ret = decoder_database_->InsertExternal(rtp_payload_type, codec,
+                                              sample_rate_hz, decoder);
+  if (ret != DecoderDatabase::kOK) {
+    LOG_FERR2(LS_WARNING, InsertExternal, rtp_payload_type, codec);
+    switch (ret) {
+      case DecoderDatabase::kInvalidRtpPayloadType:
+        error_code_ = kInvalidRtpPayloadType;
+        break;
+      case DecoderDatabase::kCodecNotSupported:
+        error_code_ = kCodecNotSupported;
+        break;
+      case DecoderDatabase::kDecoderExists:
+        error_code_ = kDecoderExists;
+        break;
+      case DecoderDatabase::kInvalidSampleRate:
+        error_code_ = kInvalidSampleRate;
+        break;
+      case DecoderDatabase::kInvalidPointer:
+        error_code_ = kInvalidPointer;
+        break;
+      default:
+        error_code_ = kOtherError;
+    }
+    return kFail;
+  }
+  return kOK;
+}
+
+int NetEqImpl::RemovePayloadType(uint8_t rtp_payload_type) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG_API1(static_cast<int>(rtp_payload_type));
+  int ret = decoder_database_->Remove(rtp_payload_type);
+  if (ret == DecoderDatabase::kOK) {
+    return kOK;
+  } else if (ret == DecoderDatabase::kDecoderNotFound) {
+    error_code_ = kDecoderNotFound;
+  } else {
+    error_code_ = kOtherError;
+  }
+  LOG_FERR1(LS_WARNING, Remove, rtp_payload_type);
+  return kFail;
+}
+
+bool NetEqImpl::SetMinimumDelay(int delay_ms) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (delay_ms >= 0 && delay_ms < 10000) {
+    assert(delay_manager_.get());
+    return delay_manager_->SetMinimumDelay(delay_ms);
+  }
+  return false;
+}
+
+bool NetEqImpl::SetMaximumDelay(int delay_ms) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (delay_ms >= 0 && delay_ms < 10000) {
+    assert(delay_manager_.get());
+    return delay_manager_->SetMaximumDelay(delay_ms);
+  }
+  return false;
+}
+
+int NetEqImpl::LeastRequiredDelayMs() const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(delay_manager_.get());
+  return delay_manager_->least_required_delay_ms();
+}
+
+void NetEqImpl::SetPlayoutMode(NetEqPlayoutMode mode) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (!decision_logic_.get() || mode != decision_logic_->playout_mode()) {
+    // The reset() method calls delete for the old object.
+    CreateDecisionLogic(mode);
+  }
+}
+
+NetEqPlayoutMode NetEqImpl::PlayoutMode() const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(decision_logic_.get());
+  return decision_logic_->playout_mode();
+}
+
+int NetEqImpl::NetworkStatistics(NetEqNetworkStatistics* stats) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(decoder_database_.get());
+  const int total_samples_in_buffers = packet_buffer_->NumSamplesInBuffer(
+      decoder_database_.get(), decoder_frame_length_) +
+          static_cast<int>(sync_buffer_->FutureLength());
+  assert(delay_manager_.get());
+  assert(decision_logic_.get());
+  stats_.GetNetworkStatistics(fs_hz_, total_samples_in_buffers,
+                              decoder_frame_length_, *delay_manager_.get(),
+                              *decision_logic_.get(), stats);
+  return 0;
+}
+
+void NetEqImpl::WaitingTimes(std::vector<int>* waiting_times) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  stats_.WaitingTimes(waiting_times);
+}
+
+void NetEqImpl::GetRtcpStatistics(RtcpStatistics* stats) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (stats) {
+    rtcp_.GetStatistics(false, stats);
+  }
+}
+
+void NetEqImpl::GetRtcpStatisticsNoReset(RtcpStatistics* stats) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (stats) {
+    rtcp_.GetStatistics(true, stats);
+  }
+}
+
+void NetEqImpl::EnableVad() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(vad_.get());
+  vad_->Enable();
+}
+
+void NetEqImpl::DisableVad() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(vad_.get());
+  vad_->Disable();
+}
+
+uint32_t NetEqImpl::PlayoutTimestamp() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  return timestamp_scaler_->ToExternal(playout_timestamp_);
+}
+
+int NetEqImpl::LastError() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  return error_code_;
+}
+
+int NetEqImpl::LastDecoderError() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  return decoder_error_code_;
+}
+
+void NetEqImpl::FlushBuffers() {
+  CriticalSectionScoped lock(crit_sect_.get());
+  LOG_API0();
+  packet_buffer_->Flush();
+  assert(sync_buffer_.get());
+  assert(expand_.get());
+  sync_buffer_->Flush();
+  sync_buffer_->set_next_index(sync_buffer_->next_index() -
+                               expand_->overlap_length());
+  // Set to wait for new codec.
+  first_packet_ = true;
+}
+
+void NetEqImpl::PacketBufferStatistics(int* current_num_packets,
+                                       int* max_num_packets) const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  packet_buffer_->BufferStat(current_num_packets, max_num_packets);
+}
+
+int NetEqImpl::DecodedRtpInfo(int* sequence_number, uint32_t* timestamp) const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  if (decoded_packet_sequence_number_ < 0)
+    return -1;
+  *sequence_number = decoded_packet_sequence_number_;
+  *timestamp = decoded_packet_timestamp_;
+  return 0;
+}
+
+void NetEqImpl::SetBackgroundNoiseMode(NetEqBackgroundNoiseMode mode) {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(background_noise_.get());
+  background_noise_->set_mode(mode);
+}
+
+NetEqBackgroundNoiseMode NetEqImpl::BackgroundNoiseMode() const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  assert(background_noise_.get());
+  return background_noise_->mode();
+}
+
+const SyncBuffer* NetEqImpl::sync_buffer_for_test() const {
+  CriticalSectionScoped lock(crit_sect_.get());
+  return sync_buffer_.get();
+}
+
+// Methods below this line are private.
+
+int NetEqImpl::InsertPacketInternal(const WebRtcRTPHeader& rtp_header,
+                                    const uint8_t* payload,
+                                    int length_bytes,
+                                    uint32_t receive_timestamp,
+                                    bool is_sync_packet) {
+  if (!payload) {
+    LOG_F(LS_ERROR) << "payload == NULL";
+    return kInvalidPointer;
+  }
+  // Sanity checks for sync-packets.
+  if (is_sync_packet) {
+    if (decoder_database_->IsDtmf(rtp_header.header.payloadType) ||
+        decoder_database_->IsRed(rtp_header.header.payloadType) ||
+        decoder_database_->IsComfortNoise(rtp_header.header.payloadType)) {
+      LOG_F(LS_ERROR) << "Sync-packet with an unacceptable payload type "
+          << rtp_header.header.payloadType;
+      return kSyncPacketNotAccepted;
+    }
+    if (first_packet_ ||
+        rtp_header.header.payloadType != current_rtp_payload_type_ ||
+        rtp_header.header.ssrc != ssrc_) {
+      // Even if |current_rtp_payload_type_| is 0xFF, sync-packet isn't
+      // accepted.
+      LOG_F(LS_ERROR) << "Changing codec, SSRC or first packet "
+          "with sync-packet.";
+      return kSyncPacketNotAccepted;
+    }
+  }
+  PacketList packet_list;
+  RTPHeader main_header;
+  {
+    // Convert to Packet.
+    // Create |packet| within this separate scope, since it should not be used
+    // directly once it's been inserted in the packet list. This way, |packet|
+    // is not defined outside of this block.
+    Packet* packet = new Packet;
+    packet->header.markerBit = false;
+    packet->header.payloadType = rtp_header.header.payloadType;
+    packet->header.sequenceNumber = rtp_header.header.sequenceNumber;
+    packet->header.timestamp = rtp_header.header.timestamp;
+    packet->header.ssrc = rtp_header.header.ssrc;
+    packet->header.numCSRCs = 0;
+    packet->payload_length = length_bytes;
+    packet->primary = true;
+    packet->waiting_time = 0;
+    packet->payload = new uint8_t[packet->payload_length];
+    packet->sync_packet = is_sync_packet;
+    if (!packet->payload) {
+      LOG_F(LS_ERROR) << "Payload pointer is NULL.";
+    }
+    assert(payload);  // Already checked above.
+    memcpy(packet->payload, payload, packet->payload_length);
+    // Insert packet in a packet list.
+    packet_list.push_back(packet);
+    // Save main payloads header for later.
+    memcpy(&main_header, &packet->header, sizeof(main_header));
+  }
+
+  bool update_sample_rate_and_channels = false;
+  // Reinitialize NetEq if it's needed (changed SSRC or first call).
+  if ((main_header.ssrc != ssrc_) || first_packet_) {
+    rtcp_.Init(main_header.sequenceNumber);
+    first_packet_ = false;
+
+    // Flush the packet buffer and DTMF buffer.
+    packet_buffer_->Flush();
+    dtmf_buffer_->Flush();
+
+    // Store new SSRC.
+    ssrc_ = main_header.ssrc;
+
+    // Update audio buffer timestamp.
+    sync_buffer_->IncreaseEndTimestamp(main_header.timestamp - timestamp_);
+
+    // Update codecs.
+    timestamp_ = main_header.timestamp;
+    current_rtp_payload_type_ = main_header.payloadType;
+
+    // Set MCU to update codec on next SignalMCU call.
+    new_codec_ = true;
+
+    // Reset timestamp scaling.
+    timestamp_scaler_->Reset();
+
+    // Triger an update of sampling rate and the number of channels.
+    update_sample_rate_and_channels = true;
+  }
+
+  // Update RTCP statistics, only for regular packets.
+  if (!is_sync_packet)
+    rtcp_.Update(main_header, receive_timestamp);
+
+  // Check for RED payload type, and separate payloads into several packets.
+  if (decoder_database_->IsRed(main_header.payloadType)) {
+    assert(!is_sync_packet);  // We had a sanity check for this.
+    if (payload_splitter_->SplitRed(&packet_list) != PayloadSplitter::kOK) {
+      LOG_FERR1(LS_WARNING, SplitRed, packet_list.size());
+      PacketBuffer::DeleteAllPackets(&packet_list);
+      return kRedundancySplitError;
+    }
+    // Only accept a few RED payloads of the same type as the main data,
+    // DTMF events and CNG.
+    payload_splitter_->CheckRedPayloads(&packet_list, *decoder_database_);
+    // Update the stored main payload header since the main payload has now
+    // changed.
+    memcpy(&main_header, &packet_list.front()->header, sizeof(main_header));
+  }
+
+  // Check payload types.
+  if (decoder_database_->CheckPayloadTypes(packet_list) ==
+      DecoderDatabase::kDecoderNotFound) {
+    LOG_FERR1(LS_WARNING, CheckPayloadTypes, packet_list.size());
+    PacketBuffer::DeleteAllPackets(&packet_list);
+    return kUnknownRtpPayloadType;
+  }
+
+  // Scale timestamp to internal domain (only for some codecs).
+  timestamp_scaler_->ToInternal(&packet_list);
+
+  // Process DTMF payloads. Cycle through the list of packets, and pick out any
+  // DTMF payloads found.
+  PacketList::iterator it = packet_list.begin();
+  while (it != packet_list.end()) {
+    Packet* current_packet = (*it);
+    assert(current_packet);
+    assert(current_packet->payload);
+    if (decoder_database_->IsDtmf(current_packet->header.payloadType)) {
+      assert(!current_packet->sync_packet);  // We had a sanity check for this.
+      DtmfEvent event;
+      int ret = DtmfBuffer::ParseEvent(
+          current_packet->header.timestamp,
+          current_packet->payload,
+          current_packet->payload_length,
+          &event);
+      if (ret != DtmfBuffer::kOK) {
+        LOG_FERR2(LS_WARNING, ParseEvent, ret,
+                  current_packet->payload_length);
+        PacketBuffer::DeleteAllPackets(&packet_list);
+        return kDtmfParsingError;
+      }
+      if (dtmf_buffer_->InsertEvent(event) != DtmfBuffer::kOK) {
+        LOG_FERR0(LS_WARNING, InsertEvent);
+        PacketBuffer::DeleteAllPackets(&packet_list);
+        return kDtmfInsertError;
+      }
+      // TODO(hlundin): Let the destructor of Packet handle the payload.
+      delete [] current_packet->payload;
+      delete current_packet;
+      it = packet_list.erase(it);
+    } else {
+      ++it;
+    }
+  }
+
+  // Check for FEC in packets, and separate payloads into several packets.
+  int ret = payload_splitter_->SplitFec(&packet_list, decoder_database_.get());
+  if (ret != PayloadSplitter::kOK) {
+    LOG_FERR1(LS_WARNING, SplitFec, packet_list.size());
+    PacketBuffer::DeleteAllPackets(&packet_list);
+    switch (ret) {
+      case PayloadSplitter::kUnknownPayloadType:
+        return kUnknownRtpPayloadType;
+      default:
+        return kOtherError;
+    }
+  }
+
+  // Split payloads into smaller chunks. This also verifies that all payloads
+  // are of a known payload type. SplitAudio() method is protected against
+  // sync-packets.
+  ret = payload_splitter_->SplitAudio(&packet_list, *decoder_database_);
+  if (ret != PayloadSplitter::kOK) {
+    LOG_FERR1(LS_WARNING, SplitAudio, packet_list.size());
+    PacketBuffer::DeleteAllPackets(&packet_list);
+    switch (ret) {
+      case PayloadSplitter::kUnknownPayloadType:
+        return kUnknownRtpPayloadType;
+      case PayloadSplitter::kFrameSplitError:
+        return kFrameSplitError;
+      default:
+        return kOtherError;
+    }
+  }
+
+  // Update bandwidth estimate, if the packet is not sync-packet.
+  if (!packet_list.empty() && !packet_list.front()->sync_packet) {
+    // The list can be empty here if we got nothing but DTMF payloads.
+    AudioDecoder* decoder =
+        decoder_database_->GetDecoder(main_header.payloadType);
+    assert(decoder);  // Should always get a valid object, since we have
+                      // already checked that the payload types are known.
+    decoder->IncomingPacket(packet_list.front()->payload,
+                            packet_list.front()->payload_length,
+                            packet_list.front()->header.sequenceNumber,
+                            packet_list.front()->header.timestamp,
+                            receive_timestamp);
+  }
+
+  // Insert packets in buffer.
+  int temp_bufsize = packet_buffer_->NumPacketsInBuffer();
+  ret = packet_buffer_->InsertPacketList(
+      &packet_list,
+      *decoder_database_,
+      &current_rtp_payload_type_,
+      &current_cng_rtp_payload_type_);
+  if (ret == PacketBuffer::kFlushed) {
+    // Reset DSP timestamp etc. if packet buffer flushed.
+    new_codec_ = true;
+    update_sample_rate_and_channels = true;
+    LOG_F(LS_WARNING) << "Packet buffer flushed";
+  } else if (ret != PacketBuffer::kOK) {
+    LOG_FERR1(LS_WARNING, InsertPacketList, packet_list.size());
+    PacketBuffer::DeleteAllPackets(&packet_list);
+    return kOtherError;
+  }
+  if (current_rtp_payload_type_ != 0xFF) {
+    const DecoderDatabase::DecoderInfo* dec_info =
+        decoder_database_->GetDecoderInfo(current_rtp_payload_type_);
+    if (!dec_info) {
+      assert(false);  // Already checked that the payload type is known.
+    }
+  }
+
+  if (update_sample_rate_and_channels && !packet_buffer_->Empty()) {
+    // We do not use |current_rtp_payload_type_| to |set payload_type|, but
+    // get the next RTP header from |packet_buffer_| to obtain the payload type.
+    // The reason for it is the following corner case. If NetEq receives a
+    // CNG packet with a sample rate different than the current CNG then it
+    // flushes its buffer, assuming send codec must have been changed. However,
+    // payload type of the hypothetically new send codec is not known.
+    const RTPHeader* rtp_header = packet_buffer_->NextRtpHeader();
+    assert(rtp_header);
+    int payload_type = rtp_header->payloadType;
+    AudioDecoder* decoder = decoder_database_->GetDecoder(payload_type);
+    assert(decoder);  // Payloads are already checked to be valid.
+    const DecoderDatabase::DecoderInfo* decoder_info =
+        decoder_database_->GetDecoderInfo(payload_type);
+    assert(decoder_info);
+    if (decoder_info->fs_hz != fs_hz_ ||
+        decoder->channels() != algorithm_buffer_->Channels())
+      SetSampleRateAndChannels(decoder_info->fs_hz, decoder->channels());
+  }
+
+  // TODO(hlundin): Move this code to DelayManager class.
+  const DecoderDatabase::DecoderInfo* dec_info =
+          decoder_database_->GetDecoderInfo(main_header.payloadType);
+  assert(dec_info);  // Already checked that the payload type is known.
+  delay_manager_->LastDecoderType(dec_info->codec_type);
+  if (delay_manager_->last_pack_cng_or_dtmf() == 0) {
+    // Calculate the total speech length carried in each packet.
+    temp_bufsize = packet_buffer_->NumPacketsInBuffer() - temp_bufsize;
+    temp_bufsize *= decoder_frame_length_;
+
+    if ((temp_bufsize > 0) &&
+        (temp_bufsize != decision_logic_->packet_length_samples())) {
+      decision_logic_->set_packet_length_samples(temp_bufsize);
+      delay_manager_->SetPacketAudioLength((1000 * temp_bufsize) / fs_hz_);
+    }
+
+    // Update statistics.
+    if ((int32_t) (main_header.timestamp - timestamp_) >= 0 &&
+        !new_codec_) {
+      // Only update statistics if incoming packet is not older than last played
+      // out packet, and if new codec flag is not set.
+      delay_manager_->Update(main_header.sequenceNumber, main_header.timestamp,
+                             fs_hz_);
+    }
+  } else if (delay_manager_->last_pack_cng_or_dtmf() == -1) {
+    // This is first "normal" packet after CNG or DTMF.
+    // Reset packet time counter and measure time until next packet,
+    // but don't update statistics.
+    delay_manager_->set_last_pack_cng_or_dtmf(0);
+    delay_manager_->ResetPacketIatCount();
+  }
+  return 0;
+}
+
+int NetEqImpl::GetAudioInternal(size_t max_length, int16_t* output,
+                                int* samples_per_channel, int* num_channels) {
+  PacketList packet_list;
+  DtmfEvent dtmf_event;
+  Operations operation;
+  bool play_dtmf;
+  int return_value = GetDecision(&operation, &packet_list, &dtmf_event,
+                                 &play_dtmf);
+  if (return_value != 0) {
+    LOG_FERR1(LS_WARNING, GetDecision, return_value);
+    assert(false);
+    last_mode_ = kModeError;
+    return return_value;
+  }
+  LOG(LS_VERBOSE) << "GetDecision returned operation=" << operation <<
+      " and " << packet_list.size() << " packet(s)";
+
+  AudioDecoder::SpeechType speech_type;
+  int length = 0;
+  int decode_return_value = Decode(&packet_list, &operation,
+                                   &length, &speech_type);
+
+  assert(vad_.get());
+  bool sid_frame_available =
+      (operation == kRfc3389Cng && !packet_list.empty());
+  vad_->Update(decoded_buffer_.get(), length, speech_type,
+               sid_frame_available, fs_hz_);
+
+  algorithm_buffer_->Clear();
+  switch (operation) {
+    case kNormal: {
+      DoNormal(decoded_buffer_.get(), length, speech_type, play_dtmf);
+      break;
+    }
+    case kMerge: {
+      DoMerge(decoded_buffer_.get(), length, speech_type, play_dtmf);
+      break;
+    }
+    case kExpand: {
+      return_value = DoExpand(play_dtmf);
+      break;
+    }
+    case kAccelerate: {
+      return_value = DoAccelerate(decoded_buffer_.get(), length, speech_type,
+                                  play_dtmf);
+      break;
+    }
+    case kPreemptiveExpand: {
+      return_value = DoPreemptiveExpand(decoded_buffer_.get(), length,
+                                        speech_type, play_dtmf);
+      break;
+    }
+    case kRfc3389Cng:
+    case kRfc3389CngNoPacket: {
+      return_value = DoRfc3389Cng(&packet_list, play_dtmf);
+      break;
+    }
+    case kCodecInternalCng: {
+      // This handles the case when there is no transmission and the decoder
+      // should produce internal comfort noise.
+      // TODO(hlundin): Write test for codec-internal CNG.
+      DoCodecInternalCng();
+      break;
+    }
+    case kDtmf: {
+      // TODO(hlundin): Write test for this.
+      return_value = DoDtmf(dtmf_event, &play_dtmf);
+      break;
+    }
+    case kAlternativePlc: {
+      // TODO(hlundin): Write test for this.
+      DoAlternativePlc(false);
+      break;
+    }
+    case kAlternativePlcIncreaseTimestamp: {
+      // TODO(hlundin): Write test for this.
+      DoAlternativePlc(true);
+      break;
+    }
+    case kAudioRepetitionIncreaseTimestamp: {
+      // TODO(hlundin): Write test for this.
+      sync_buffer_->IncreaseEndTimestamp(output_size_samples_);
+      // Skipping break on purpose. Execution should move on into the
+      // next case.
+    }
+    case kAudioRepetition: {
+      // TODO(hlundin): Write test for this.
+      // Copy last |output_size_samples_| from |sync_buffer_| to
+      // |algorithm_buffer|.
+      algorithm_buffer_->PushBackFromIndex(
+          *sync_buffer_, sync_buffer_->Size() - output_size_samples_);
+      expand_->Reset();
+      break;
+    }
+    case kUndefined: {
+      LOG_F(LS_ERROR) << "Invalid operation kUndefined.";
+      assert(false);  // This should not happen.
+      last_mode_ = kModeError;
+      return kInvalidOperation;
+    }
+  }  // End of switch.
+  if (return_value < 0) {
+    return return_value;
+  }
+
+  if (last_mode_ != kModeRfc3389Cng) {
+    comfort_noise_->Reset();
+  }
+
+  // Copy from |algorithm_buffer| to |sync_buffer_|.
+  sync_buffer_->PushBack(*algorithm_buffer_);
+
+  // Extract data from |sync_buffer_| to |output|.
+  size_t num_output_samples_per_channel = output_size_samples_;
+  size_t num_output_samples = output_size_samples_ * sync_buffer_->Channels();
+  if (num_output_samples > max_length) {
+    LOG(LS_WARNING) << "Output array is too short. " << max_length << " < " <<
+        output_size_samples_ << " * " << sync_buffer_->Channels();
+    num_output_samples = max_length;
+    num_output_samples_per_channel = static_cast<int>(
+        max_length / sync_buffer_->Channels());
+  }
+  int samples_from_sync = static_cast<int>(
+      sync_buffer_->GetNextAudioInterleaved(num_output_samples_per_channel,
+                                            output));
+  *num_channels = static_cast<int>(sync_buffer_->Channels());
+  LOG(LS_VERBOSE) << "Sync buffer (" << *num_channels << " channel(s)):" <<
+      " insert " << algorithm_buffer_->Size() << " samples, extract " <<
+      samples_from_sync << " samples";
+  if (samples_from_sync != output_size_samples_) {
+    LOG_F(LS_ERROR) << "samples_from_sync != output_size_samples_";
+    // TODO(minyue): treatment of under-run, filling zeros
+    memset(output, 0, num_output_samples * sizeof(int16_t));
+    *samples_per_channel = output_size_samples_;
+    return kSampleUnderrun;
+  }
+  *samples_per_channel = output_size_samples_;
+
+  // Should always have overlap samples left in the |sync_buffer_|.
+  assert(sync_buffer_->FutureLength() >= expand_->overlap_length());
+
+  if (play_dtmf) {
+    return_value = DtmfOverdub(dtmf_event, sync_buffer_->Channels(), output);
+  }
+
+  // Update the background noise parameters if last operation wrote data
+  // straight from the decoder to the |sync_buffer_|. That is, none of the
+  // operations that modify the signal can be followed by a parameter update.
+  if ((last_mode_ == kModeNormal) ||
+      (last_mode_ == kModeAccelerateFail) ||
+      (last_mode_ == kModePreemptiveExpandFail) ||
+      (last_mode_ == kModeRfc3389Cng) ||
+      (last_mode_ == kModeCodecInternalCng)) {
+    background_noise_->Update(*sync_buffer_, *vad_.get());
+  }
+
+  if (operation == kDtmf) {
+    // DTMF data was written the end of |sync_buffer_|.
+    // Update index to end of DTMF data in |sync_buffer_|.
+    sync_buffer_->set_dtmf_index(sync_buffer_->Size());
+  }
+
+  if (last_mode_ != kModeExpand) {
+    // If last operation was not expand, calculate the |playout_timestamp_| from
+    // the |sync_buffer_|. However, do not update the |playout_timestamp_| if it
+    // would be moved "backwards".
+    uint32_t temp_timestamp = sync_buffer_->end_timestamp() -
+        static_cast<uint32_t>(sync_buffer_->FutureLength());
+    if (static_cast<int32_t>(temp_timestamp - playout_timestamp_) > 0) {
+      playout_timestamp_ = temp_timestamp;
+    }
+  } else {
+    // Use dead reckoning to estimate the |playout_timestamp_|.
+    playout_timestamp_ += output_size_samples_;
+  }
+
+  if (decode_return_value) return decode_return_value;
+  return return_value;
+}
+
+int NetEqImpl::GetDecision(Operations* operation,
+                           PacketList* packet_list,
+                           DtmfEvent* dtmf_event,
+                           bool* play_dtmf) {
+  // Initialize output variables.
+  *play_dtmf = false;
+  *operation = kUndefined;
+
+  // Increment time counters.
+  packet_buffer_->IncrementWaitingTimes();
+  stats_.IncreaseCounter(output_size_samples_, fs_hz_);
+
+  assert(sync_buffer_.get());
+  uint32_t end_timestamp = sync_buffer_->end_timestamp();
+  if (!new_codec_) {
+    packet_buffer_->DiscardOldPackets(end_timestamp);
+  }
+  const RTPHeader* header = packet_buffer_->NextRtpHeader();
+
+  if (decision_logic_->CngRfc3389On() || last_mode_ == kModeRfc3389Cng) {
+    // Because of timestamp peculiarities, we have to "manually" disallow using
+    // a CNG packet with the same timestamp as the one that was last played.
+    // This can happen when using redundancy and will cause the timing to shift.
+    while (header && decoder_database_->IsComfortNoise(header->payloadType) &&
+           (end_timestamp >= header->timestamp ||
+            end_timestamp + decision_logic_->generated_noise_samples() >
+                header->timestamp)) {
+      // Don't use this packet, discard it.
+      if (packet_buffer_->DiscardNextPacket() != PacketBuffer::kOK) {
+        assert(false);  // Must be ok by design.
+      }
+      // Check buffer again.
+      if (!new_codec_) {
+        packet_buffer_->DiscardOldPackets(end_timestamp);
+      }
+      header = packet_buffer_->NextRtpHeader();
+    }
+  }
+
+  assert(expand_.get());
+  const int samples_left = static_cast<int>(sync_buffer_->FutureLength() -
+      expand_->overlap_length());
+  if (last_mode_ == kModeAccelerateSuccess ||
+      last_mode_ == kModeAccelerateLowEnergy ||
+      last_mode_ == kModePreemptiveExpandSuccess ||
+      last_mode_ == kModePreemptiveExpandLowEnergy) {
+    // Subtract (samples_left + output_size_samples_) from sampleMemory.
+    decision_logic_->AddSampleMemory(-(samples_left + output_size_samples_));
+  }
+
+  // Check if it is time to play a DTMF event.
+  if (dtmf_buffer_->GetEvent(end_timestamp +
+                             decision_logic_->generated_noise_samples(),
+                             dtmf_event)) {
+    *play_dtmf = true;
+  }
+
+  // Get instruction.
+  assert(sync_buffer_.get());
+  assert(expand_.get());
+  *operation = decision_logic_->GetDecision(*sync_buffer_,
+                                            *expand_,
+                                            decoder_frame_length_,
+                                            header,
+                                            last_mode_,
+                                            *play_dtmf,
+                                            &reset_decoder_);
+
+  // Check if we already have enough samples in the |sync_buffer_|. If so,
+  // change decision to normal, unless the decision was merge, accelerate, or
+  // preemptive expand.
+  if (samples_left >= output_size_samples_ &&
+      *operation != kMerge &&
+      *operation != kAccelerate &&
+      *operation != kPreemptiveExpand) {
+    *operation = kNormal;
+    return 0;
+  }
+
+  decision_logic_->ExpandDecision(*operation);
+
+  // Check conditions for reset.
+  if (new_codec_ || *operation == kUndefined) {
+    // The only valid reason to get kUndefined is that new_codec_ is set.
+    assert(new_codec_);
+    if (*play_dtmf && !header) {
+      timestamp_ = dtmf_event->timestamp;
+    } else {
+      assert(header);
+      if (!header) {
+        LOG_F(LS_ERROR) << "Packet missing where it shouldn't.";
+        return -1;
+      }
+      timestamp_ = header->timestamp;
+      if (*operation == kRfc3389CngNoPacket
+#ifndef LEGACY_BITEXACT
+          // Without this check, it can happen that a non-CNG packet is sent to
+          // the CNG decoder as if it was a SID frame. This is clearly a bug,
+          // but is kept for now to maintain bit-exactness with the test
+          // vectors.
+          && decoder_database_->IsComfortNoise(header->payloadType)
+#endif
+      ) {
+        // Change decision to CNG packet, since we do have a CNG packet, but it
+        // was considered too early to use. Now, use it anyway.
+        *operation = kRfc3389Cng;
+      } else if (*operation != kRfc3389Cng) {
+        *operation = kNormal;
+      }
+    }
+    // Adjust |sync_buffer_| timestamp before setting |end_timestamp| to the
+    // new value.
+    sync_buffer_->IncreaseEndTimestamp(timestamp_ - end_timestamp);
+    end_timestamp = timestamp_;
+    new_codec_ = false;
+    decision_logic_->SoftReset();
+    buffer_level_filter_->Reset();
+    delay_manager_->Reset();
+    stats_.ResetMcu();
+  }
+
+  int required_samples = output_size_samples_;
+  const int samples_10_ms = 80 * fs_mult_;
+  const int samples_20_ms = 2 * samples_10_ms;
+  const int samples_30_ms = 3 * samples_10_ms;
+
+  switch (*operation) {
+    case kExpand: {
+      timestamp_ = end_timestamp;
+      return 0;
+    }
+    case kRfc3389CngNoPacket:
+    case kCodecInternalCng: {
+      return 0;
+    }
+    case kDtmf: {
+      // TODO(hlundin): Write test for this.
+      // Update timestamp.
+      timestamp_ = end_timestamp;
+      if (decision_logic_->generated_noise_samples() > 0 &&
+          last_mode_ != kModeDtmf) {
+        // Make a jump in timestamp due to the recently played comfort noise.
+        uint32_t timestamp_jump = decision_logic_->generated_noise_samples();
+        sync_buffer_->IncreaseEndTimestamp(timestamp_jump);
+        timestamp_ += timestamp_jump;
+      }
+      decision_logic_->set_generated_noise_samples(0);
+      return 0;
+    }
+    case kAccelerate: {
+      // In order to do a accelerate we need at least 30 ms of audio data.
+      if (samples_left >= samples_30_ms) {
+        // Already have enough data, so we do not need to extract any more.
+        decision_logic_->set_sample_memory(samples_left);
+        decision_logic_->set_prev_time_scale(true);
+        return 0;
+      } else if (samples_left >= samples_10_ms &&
+          decoder_frame_length_ >= samples_30_ms) {
+        // Avoid decoding more data as it might overflow the playout buffer.
+        *operation = kNormal;
+        return 0;
+      } else if (samples_left < samples_20_ms &&
+          decoder_frame_length_ < samples_30_ms) {
+        // Build up decoded data by decoding at least 20 ms of audio data. Do
+        // not perform accelerate yet, but wait until we only need to do one
+        // decoding.
+        required_samples = 2 * output_size_samples_;
+        *operation = kNormal;
+      }
+      // If none of the above is true, we have one of two possible situations:
+      // (1) 20 ms <= samples_left < 30 ms and decoder_frame_length_ < 30 ms; or
+      // (2) samples_left < 10 ms and decoder_frame_length_ >= 30 ms.
+      // In either case, we move on with the accelerate decision, and decode one
+      // frame now.
+      break;
+    }
+    case kPreemptiveExpand: {
+      // In order to do a preemptive expand we need at least 30 ms of decoded
+      // audio data.
+      if ((samples_left >= samples_30_ms) ||
+          (samples_left >= samples_10_ms &&
+              decoder_frame_length_ >= samples_30_ms)) {
+        // Already have enough data, so we do not need to extract any more.
+        // Or, avoid decoding more data as it might overflow the playout buffer.
+        // Still try preemptive expand, though.
+        decision_logic_->set_sample_memory(samples_left);
+        decision_logic_->set_prev_time_scale(true);
+        return 0;
+      }
+      if (samples_left < samples_20_ms &&
+          decoder_frame_length_ < samples_30_ms) {
+        // Build up decoded data by decoding at least 20 ms of audio data.
+        // Still try to perform preemptive expand.
+        required_samples = 2 * output_size_samples_;
+      }
+      // Move on with the preemptive expand decision.
+      break;
+    }
+    case kMerge: {
+      required_samples =
+          std::max(merge_->RequiredFutureSamples(), required_samples);
+      break;
+    }
+    default: {
+      // Do nothing.
+    }
+  }
+
+  // Get packets from buffer.
+  int extracted_samples = 0;
+  if (header &&
+      *operation != kAlternativePlc &&
+      *operation != kAlternativePlcIncreaseTimestamp &&
+      *operation != kAudioRepetition &&
+      *operation != kAudioRepetitionIncreaseTimestamp) {
+    sync_buffer_->IncreaseEndTimestamp(header->timestamp - end_timestamp);
+    if (decision_logic_->CngOff()) {
+      // Adjustment of timestamp only corresponds to an actual packet loss
+      // if comfort noise is not played. If comfort noise was just played,
+      // this adjustment of timestamp is only done to get back in sync with the
+      // stream timestamp; no loss to report.
+      stats_.LostSamples(header->timestamp - end_timestamp);
+    }
+
+    if (*operation != kRfc3389Cng) {
+      // We are about to decode and use a non-CNG packet.
+      decision_logic_->SetCngOff();
+    }
+    // Reset CNG timestamp as a new packet will be delivered.
+    // (Also if this is a CNG packet, since playedOutTS is updated.)
+    decision_logic_->set_generated_noise_samples(0);
+
+    extracted_samples = ExtractPackets(required_samples, packet_list);
+    if (extracted_samples < 0) {
+      LOG_F(LS_WARNING) << "Failed to extract packets from buffer.";
+      return kPacketBufferCorruption;
+    }
+  }
+
+  if (*operation == kAccelerate ||
+      *operation == kPreemptiveExpand) {
+    decision_logic_->set_sample_memory(samples_left + extracted_samples);
+    decision_logic_->set_prev_time_scale(true);
+  }
+
+  if (*operation == kAccelerate) {
+    // Check that we have enough data (30ms) to do accelerate.
+    if (extracted_samples + samples_left < samples_30_ms) {
+      // TODO(hlundin): Write test for this.
+      // Not enough, do normal operation instead.
+      *operation = kNormal;
+    }
+  }
+
+  timestamp_ = end_timestamp;
+  return 0;
+}
+
+int NetEqImpl::Decode(PacketList* packet_list, Operations* operation,
+                      int* decoded_length,
+                      AudioDecoder::SpeechType* speech_type) {
+  *speech_type = AudioDecoder::kSpeech;
+  AudioDecoder* decoder = NULL;
+  if (!packet_list->empty()) {
+    const Packet* packet = packet_list->front();
+    int payload_type = packet->header.payloadType;
+    if (!decoder_database_->IsComfortNoise(payload_type)) {
+      decoder = decoder_database_->GetDecoder(payload_type);
+      assert(decoder);
+      if (!decoder) {
+        LOG_FERR1(LS_WARNING, GetDecoder, payload_type);
+        PacketBuffer::DeleteAllPackets(packet_list);
+        return kDecoderNotFound;
+      }
+      bool decoder_changed;
+      decoder_database_->SetActiveDecoder(payload_type, &decoder_changed);
+      if (decoder_changed) {
+        // We have a new decoder. Re-init some values.
+        const DecoderDatabase::DecoderInfo* decoder_info = decoder_database_
+            ->GetDecoderInfo(payload_type);
+        assert(decoder_info);
+        if (!decoder_info) {
+          LOG_FERR1(LS_WARNING, GetDecoderInfo, payload_type);
+          PacketBuffer::DeleteAllPackets(packet_list);
+          return kDecoderNotFound;
+        }
+        // If sampling rate or number of channels has changed, we need to make
+        // a reset.
+        if (decoder_info->fs_hz != fs_hz_ ||
+            decoder->channels() != algorithm_buffer_->Channels()) {
+          // TODO(tlegrand): Add unittest to cover this event.
+          SetSampleRateAndChannels(decoder_info->fs_hz, decoder->channels());
+        }
+        sync_buffer_->set_end_timestamp(timestamp_);
+        playout_timestamp_ = timestamp_;
+      }
+    }
+  }
+
+  if (reset_decoder_) {
+    // TODO(hlundin): Write test for this.
+    // Reset decoder.
+    if (decoder) {
+      decoder->Init();
+    }
+    // Reset comfort noise decoder.
+    AudioDecoder* cng_decoder = decoder_database_->GetActiveCngDecoder();
+    if (cng_decoder) {
+      cng_decoder->Init();
+    }
+    reset_decoder_ = false;
+  }
+
+#ifdef LEGACY_BITEXACT
+  // Due to a bug in old SignalMCU, it could happen that CNG operation was
+  // decided, but a speech packet was provided. The speech packet will be used
+  // to update the comfort noise decoder, as if it was a SID frame, which is
+  // clearly wrong.
+  if (*operation == kRfc3389Cng) {
+    return 0;
+  }
+#endif
+
+  *decoded_length = 0;
+  // Update codec-internal PLC state.
+  if ((*operation == kMerge) && decoder && decoder->HasDecodePlc()) {
+    decoder->DecodePlc(1, &decoded_buffer_[*decoded_length]);
+  }
+
+  int return_value = DecodeLoop(packet_list, operation, decoder,
+                                decoded_length, speech_type);
+
+  if (*decoded_length < 0) {
+    // Error returned from the decoder.
+    *decoded_length = 0;
+    sync_buffer_->IncreaseEndTimestamp(decoder_frame_length_);
+    int error_code = 0;
+    if (decoder)
+      error_code = decoder->ErrorCode();
+    if (error_code != 0) {
+      // Got some error code from the decoder.
+      decoder_error_code_ = error_code;
+      return_value = kDecoderErrorCode;
+    } else {
+      // Decoder does not implement error codes. Return generic error.
+      return_value = kOtherDecoderError;
+    }
+    LOG_FERR2(LS_WARNING, DecodeLoop, error_code, packet_list->size());
+    *operation = kExpand;  // Do expansion to get data instead.
+  }
+  if (*speech_type != AudioDecoder::kComfortNoise) {
+    // Don't increment timestamp if codec returned CNG speech type
+    // since in this case, the we will increment the CNGplayedTS counter.
+    // Increase with number of samples per channel.
+    assert(*decoded_length == 0 ||
+           (decoder && decoder->channels() == sync_buffer_->Channels()));
+    sync_buffer_->IncreaseEndTimestamp(
+        *decoded_length / static_cast<int>(sync_buffer_->Channels()));
+  }
+  return return_value;
+}
+
+int NetEqImpl::DecodeLoop(PacketList* packet_list, Operations* operation,
+                          AudioDecoder* decoder, int* decoded_length,
+                          AudioDecoder::SpeechType* speech_type) {
+  Packet* packet = NULL;
+  if (!packet_list->empty()) {
+    packet = packet_list->front();
+  }
+  // Do decoding.
+  while (packet &&
+      !decoder_database_->IsComfortNoise(packet->header.payloadType)) {
+    assert(decoder);  // At this point, we must have a decoder object.
+    // The number of channels in the |sync_buffer_| should be the same as the
+    // number decoder channels.
+    assert(sync_buffer_->Channels() == decoder->channels());
+    assert(decoded_buffer_length_ >= kMaxFrameSize * decoder->channels());
+    assert(*operation == kNormal || *operation == kAccelerate ||
+           *operation == kMerge || *operation == kPreemptiveExpand);
+    packet_list->pop_front();
+    int payload_length = packet->payload_length;
+    int16_t decode_length;
+    if (packet->sync_packet) {
+      // Decode to silence with the same frame size as the last decode.
+      LOG(LS_VERBOSE) << "Decoding sync-packet: " <<
+          " ts=" << packet->header.timestamp <<
+          ", sn=" << packet->header.sequenceNumber <<
+          ", pt=" << static_cast<int>(packet->header.payloadType) <<
+          ", ssrc=" << packet->header.ssrc <<
+          ", len=" << packet->payload_length;
+      memset(&decoded_buffer_[*decoded_length], 0, decoder_frame_length_ *
+             decoder->channels() * sizeof(decoded_buffer_[0]));
+      decode_length = decoder_frame_length_;
+    } else if (!packet->primary) {
+      // This is a redundant payload; call the special decoder method.
+      LOG(LS_VERBOSE) << "Decoding packet (redundant):" <<
+          " ts=" << packet->header.timestamp <<
+          ", sn=" << packet->header.sequenceNumber <<
+          ", pt=" << static_cast<int>(packet->header.payloadType) <<
+          ", ssrc=" << packet->header.ssrc <<
+          ", len=" << packet->payload_length;
+      decode_length = decoder->DecodeRedundant(
+          packet->payload, packet->payload_length,
+          &decoded_buffer_[*decoded_length], speech_type);
+    } else {
+      LOG(LS_VERBOSE) << "Decoding packet: ts=" << packet->header.timestamp <<
+          ", sn=" << packet->header.sequenceNumber <<
+          ", pt=" << static_cast<int>(packet->header.payloadType) <<
+          ", ssrc=" << packet->header.ssrc <<
+          ", len=" << packet->payload_length;
+      decode_length = decoder->Decode(packet->payload,
+                                      packet->payload_length,
+                                      &decoded_buffer_[*decoded_length],
+                                      speech_type);
+    }
+
+    delete[] packet->payload;
+    delete packet;
+    packet = NULL;
+    if (decode_length > 0) {
+      *decoded_length += decode_length;
+      // Update |decoder_frame_length_| with number of samples per channel.
+      decoder_frame_length_ = decode_length /
+          static_cast<int>(decoder->channels());
+      LOG(LS_VERBOSE) << "Decoded " << decode_length << " samples (" <<
+          decoder->channels() << " channel(s) -> " << decoder_frame_length_ <<
+          " samples per channel)";
+    } else if (decode_length < 0) {
+      // Error.
+      LOG_FERR2(LS_WARNING, Decode, decode_length, payload_length);
+      *decoded_length = -1;
+      PacketBuffer::DeleteAllPackets(packet_list);
+      break;
+    }
+    if (*decoded_length > static_cast<int>(decoded_buffer_length_)) {
+      // Guard against overflow.
+      LOG_F(LS_WARNING) << "Decoded too much.";
+      PacketBuffer::DeleteAllPackets(packet_list);
+      return kDecodedTooMuch;
+    }
+    if (!packet_list->empty()) {
+      packet = packet_list->front();
+    } else {
+      packet = NULL;
+    }
+  }  // End of decode loop.
+
+  // If the list is not empty at this point, either a decoding error terminated
+  // the while-loop, or list must hold exactly one CNG packet.
+  assert(packet_list->empty() || *decoded_length < 0 ||
+         (packet_list->size() == 1 && packet &&
+             decoder_database_->IsComfortNoise(packet->header.payloadType)));
+  return 0;
+}
+
+void NetEqImpl::DoNormal(const int16_t* decoded_buffer, size_t decoded_length,
+                         AudioDecoder::SpeechType speech_type, bool play_dtmf) {
+  assert(normal_.get());
+  assert(mute_factor_array_.get());
+  normal_->Process(decoded_buffer, decoded_length, last_mode_,
+                   mute_factor_array_.get(), algorithm_buffer_.get());
+  if (decoded_length != 0) {
+    last_mode_ = kModeNormal;
+  }
+
+  // If last packet was decoded as an inband CNG, set mode to CNG instead.
+  if ((speech_type == AudioDecoder::kComfortNoise)
+      || ((last_mode_ == kModeCodecInternalCng)
+          && (decoded_length == 0))) {
+    // TODO(hlundin): Remove second part of || statement above.
+    last_mode_ = kModeCodecInternalCng;
+  }
+
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+}
+
+void NetEqImpl::DoMerge(int16_t* decoded_buffer, size_t decoded_length,
+                        AudioDecoder::SpeechType speech_type, bool play_dtmf) {
+  assert(mute_factor_array_.get());
+  assert(merge_.get());
+  int new_length = merge_->Process(decoded_buffer, decoded_length,
+                                   mute_factor_array_.get(),
+                                   algorithm_buffer_.get());
+
+  // Update in-call and post-call statistics.
+  if (expand_->MuteFactor(0) == 0) {
+    // Expand generates only noise.
+    stats_.ExpandedNoiseSamples(new_length - static_cast<int>(decoded_length));
+  } else {
+    // Expansion generates more than only noise.
+    stats_.ExpandedVoiceSamples(new_length - static_cast<int>(decoded_length));
+  }
+
+  last_mode_ = kModeMerge;
+  // If last packet was decoded as an inband CNG, set mode to CNG instead.
+  if (speech_type == AudioDecoder::kComfortNoise) {
+    last_mode_ = kModeCodecInternalCng;
+  }
+  expand_->Reset();
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+}
+
+int NetEqImpl::DoExpand(bool play_dtmf) {
+  while ((sync_buffer_->FutureLength() - expand_->overlap_length()) <
+      static_cast<size_t>(output_size_samples_)) {
+    algorithm_buffer_->Clear();
+    int return_value = expand_->Process(algorithm_buffer_.get());
+    int length = static_cast<int>(algorithm_buffer_->Size());
+
+    // Update in-call and post-call statistics.
+    if (expand_->MuteFactor(0) == 0) {
+      // Expand operation generates only noise.
+      stats_.ExpandedNoiseSamples(length);
+    } else {
+      // Expand operation generates more than only noise.
+      stats_.ExpandedVoiceSamples(length);
+    }
+
+    last_mode_ = kModeExpand;
+
+    if (return_value < 0) {
+      return return_value;
+    }
+
+    sync_buffer_->PushBack(*algorithm_buffer_);
+    algorithm_buffer_->Clear();
+  }
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+  return 0;
+}
+
+int NetEqImpl::DoAccelerate(int16_t* decoded_buffer, size_t decoded_length,
+                            AudioDecoder::SpeechType speech_type,
+                            bool play_dtmf) {
+  const size_t required_samples = 240 * fs_mult_;  // Must have 30 ms.
+  size_t borrowed_samples_per_channel = 0;
+  size_t num_channels = algorithm_buffer_->Channels();
+  size_t decoded_length_per_channel = decoded_length / num_channels;
+  if (decoded_length_per_channel < required_samples) {
+    // Must move data from the |sync_buffer_| in order to get 30 ms.
+    borrowed_samples_per_channel = static_cast<int>(required_samples -
+        decoded_length_per_channel);
+    memmove(&decoded_buffer[borrowed_samples_per_channel * num_channels],
+            decoded_buffer,
+            sizeof(int16_t) * decoded_length);
+    sync_buffer_->ReadInterleavedFromEnd(borrowed_samples_per_channel,
+                                         decoded_buffer);
+    decoded_length = required_samples * num_channels;
+  }
+
+  int16_t samples_removed;
+  Accelerate::ReturnCodes return_code = accelerate_->Process(
+      decoded_buffer, decoded_length, algorithm_buffer_.get(),
+      &samples_removed);
+  stats_.AcceleratedSamples(samples_removed);
+  switch (return_code) {
+    case Accelerate::kSuccess:
+      last_mode_ = kModeAccelerateSuccess;
+      break;
+    case Accelerate::kSuccessLowEnergy:
+      last_mode_ = kModeAccelerateLowEnergy;
+      break;
+    case Accelerate::kNoStretch:
+      last_mode_ = kModeAccelerateFail;
+      break;
+    case Accelerate::kError:
+      // TODO(hlundin): Map to kModeError instead?
+      last_mode_ = kModeAccelerateFail;
+      return kAccelerateError;
+  }
+
+  if (borrowed_samples_per_channel > 0) {
+    // Copy borrowed samples back to the |sync_buffer_|.
+    size_t length = algorithm_buffer_->Size();
+    if (length < borrowed_samples_per_channel) {
+      // This destroys the beginning of the buffer, but will not cause any
+      // problems.
+      sync_buffer_->ReplaceAtIndex(*algorithm_buffer_,
+                                   sync_buffer_->Size() -
+                                   borrowed_samples_per_channel);
+      sync_buffer_->PushFrontZeros(borrowed_samples_per_channel - length);
+      algorithm_buffer_->PopFront(length);
+      assert(algorithm_buffer_->Empty());
+    } else {
+      sync_buffer_->ReplaceAtIndex(*algorithm_buffer_,
+                                   borrowed_samples_per_channel,
+                                   sync_buffer_->Size() -
+                                   borrowed_samples_per_channel);
+      algorithm_buffer_->PopFront(borrowed_samples_per_channel);
+    }
+  }
+
+  // If last packet was decoded as an inband CNG, set mode to CNG instead.
+  if (speech_type == AudioDecoder::kComfortNoise) {
+    last_mode_ = kModeCodecInternalCng;
+  }
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+  expand_->Reset();
+  return 0;
+}
+
+int NetEqImpl::DoPreemptiveExpand(int16_t* decoded_buffer,
+                                  size_t decoded_length,
+                                  AudioDecoder::SpeechType speech_type,
+                                  bool play_dtmf) {
+  const size_t required_samples = 240 * fs_mult_;  // Must have 30 ms.
+  size_t num_channels = algorithm_buffer_->Channels();
+  int borrowed_samples_per_channel = 0;
+  int old_borrowed_samples_per_channel = 0;
+  size_t decoded_length_per_channel = decoded_length / num_channels;
+  if (decoded_length_per_channel < required_samples) {
+    // Must move data from the |sync_buffer_| in order to get 30 ms.
+    borrowed_samples_per_channel = static_cast<int>(required_samples -
+        decoded_length_per_channel);
+    // Calculate how many of these were already played out.
+    old_borrowed_samples_per_channel = static_cast<int>(
+        borrowed_samples_per_channel - sync_buffer_->FutureLength());
+    old_borrowed_samples_per_channel = std::max(
+        0, old_borrowed_samples_per_channel);
+    memmove(&decoded_buffer[borrowed_samples_per_channel * num_channels],
+            decoded_buffer,
+            sizeof(int16_t) * decoded_length);
+    sync_buffer_->ReadInterleavedFromEnd(borrowed_samples_per_channel,
+                                         decoded_buffer);
+    decoded_length = required_samples * num_channels;
+  }
+
+  int16_t samples_added;
+  PreemptiveExpand::ReturnCodes return_code = preemptive_expand_->Process(
+      decoded_buffer, static_cast<int>(decoded_length),
+      old_borrowed_samples_per_channel,
+      algorithm_buffer_.get(), &samples_added);
+  stats_.PreemptiveExpandedSamples(samples_added);
+  switch (return_code) {
+    case PreemptiveExpand::kSuccess:
+      last_mode_ = kModePreemptiveExpandSuccess;
+      break;
+    case PreemptiveExpand::kSuccessLowEnergy:
+      last_mode_ = kModePreemptiveExpandLowEnergy;
+      break;
+    case PreemptiveExpand::kNoStretch:
+      last_mode_ = kModePreemptiveExpandFail;
+      break;
+    case PreemptiveExpand::kError:
+      // TODO(hlundin): Map to kModeError instead?
+      last_mode_ = kModePreemptiveExpandFail;
+      return kPreemptiveExpandError;
+  }
+
+  if (borrowed_samples_per_channel > 0) {
+    // Copy borrowed samples back to the |sync_buffer_|.
+    sync_buffer_->ReplaceAtIndex(
+        *algorithm_buffer_, borrowed_samples_per_channel,
+        sync_buffer_->Size() - borrowed_samples_per_channel);
+    algorithm_buffer_->PopFront(borrowed_samples_per_channel);
+  }
+
+  // If last packet was decoded as an inband CNG, set mode to CNG instead.
+  if (speech_type == AudioDecoder::kComfortNoise) {
+    last_mode_ = kModeCodecInternalCng;
+  }
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+  expand_->Reset();
+  return 0;
+}
+
+int NetEqImpl::DoRfc3389Cng(PacketList* packet_list, bool play_dtmf) {
+  if (!packet_list->empty()) {
+    // Must have exactly one SID frame at this point.
+    assert(packet_list->size() == 1);
+    Packet* packet = packet_list->front();
+    packet_list->pop_front();
+    if (!decoder_database_->IsComfortNoise(packet->header.payloadType)) {
+#ifdef LEGACY_BITEXACT
+      // This can happen due to a bug in GetDecision. Change the payload type
+      // to a CNG type, and move on. Note that this means that we are in fact
+      // sending a non-CNG payload to the comfort noise decoder for decoding.
+      // Clearly wrong, but will maintain bit-exactness with legacy.
+      if (fs_hz_ == 8000) {
+        packet->header.payloadType =
+            decoder_database_->GetRtpPayloadType(kDecoderCNGnb);
+      } else if (fs_hz_ == 16000) {
+        packet->header.payloadType =
+            decoder_database_->GetRtpPayloadType(kDecoderCNGwb);
+      } else if (fs_hz_ == 32000) {
+        packet->header.payloadType =
+            decoder_database_->GetRtpPayloadType(kDecoderCNGswb32kHz);
+      } else if (fs_hz_ == 48000) {
+        packet->header.payloadType =
+            decoder_database_->GetRtpPayloadType(kDecoderCNGswb48kHz);
+      }
+      assert(decoder_database_->IsComfortNoise(packet->header.payloadType));
+#else
+      LOG(LS_ERROR) << "Trying to decode non-CNG payload as CNG.";
+      return kOtherError;
+#endif
+    }
+    // UpdateParameters() deletes |packet|.
+    if (comfort_noise_->UpdateParameters(packet) ==
+        ComfortNoise::kInternalError) {
+      LOG_FERR0(LS_WARNING, UpdateParameters);
+      algorithm_buffer_->Zeros(output_size_samples_);
+      return -comfort_noise_->internal_error_code();
+    }
+  }
+  int cn_return = comfort_noise_->Generate(output_size_samples_,
+                                           algorithm_buffer_.get());
+  expand_->Reset();
+  last_mode_ = kModeRfc3389Cng;
+  if (!play_dtmf) {
+    dtmf_tone_generator_->Reset();
+  }
+  if (cn_return == ComfortNoise::kInternalError) {
+    LOG_FERR1(LS_WARNING, comfort_noise_->Generate, cn_return);
+    decoder_error_code_ = comfort_noise_->internal_error_code();
+    return kComfortNoiseErrorCode;
+  } else if (cn_return == ComfortNoise::kUnknownPayloadType) {
+    LOG_FERR1(LS_WARNING, comfort_noise_->Generate, cn_return);
+    return kUnknownRtpPayloadType;
+  }
+  return 0;
+}
+
+void NetEqImpl::DoCodecInternalCng() {
+  int length = 0;
+  // TODO(hlundin): Will probably need a longer buffer for multi-channel.
+  int16_t decoded_buffer[kMaxFrameSize];
+  AudioDecoder* decoder = decoder_database_->GetActiveDecoder();
+  if (decoder) {
+    const uint8_t* dummy_payload = NULL;
+    AudioDecoder::SpeechType speech_type;
+    length = decoder->Decode(dummy_payload, 0, decoded_buffer, &speech_type);
+  }
+  assert(mute_factor_array_.get());
+  normal_->Process(decoded_buffer, length, last_mode_, mute_factor_array_.get(),
+                   algorithm_buffer_.get());
+  last_mode_ = kModeCodecInternalCng;
+  expand_->Reset();
+}
+
+int NetEqImpl::DoDtmf(const DtmfEvent& dtmf_event, bool* play_dtmf) {
+  // This block of the code and the block further down, handling |dtmf_switch|
+  // are commented out. Otherwise playing out-of-band DTMF would fail in VoE
+  // test, DtmfTest.ManualSuccessfullySendsOutOfBandTelephoneEvents. This is
+  // equivalent to |dtmf_switch| always be false.
+  //
+  // See http://webrtc-codereview.appspot.com/1195004/ for discussion
+  // On this issue. This change might cause some glitches at the point of
+  // switch from audio to DTMF. Issue 1545 is filed to track this.
+  //
+  //  bool dtmf_switch = false;
+  //  if ((last_mode_ != kModeDtmf) && dtmf_tone_generator_->initialized()) {
+  //    // Special case; see below.
+  //    // We must catch this before calling Generate, since |initialized| is
+  //    // modified in that call.
+  //    dtmf_switch = true;
+  //  }
+
+  int dtmf_return_value = 0;
+  if (!dtmf_tone_generator_->initialized()) {
+    // Initialize if not already done.
+    dtmf_return_value = dtmf_tone_generator_->Init(fs_hz_, dtmf_event.event_no,
+                                                   dtmf_event.volume);
+  }
+
+  if (dtmf_return_value == 0) {
+    // Generate DTMF signal.
+    dtmf_return_value = dtmf_tone_generator_->Generate(output_size_samples_,
+                                                       algorithm_buffer_.get());
+  }
+
+  if (dtmf_return_value < 0) {
+    algorithm_buffer_->Zeros(output_size_samples_);
+    return dtmf_return_value;
+  }
+
+  //  if (dtmf_switch) {
+  //    // This is the special case where the previous operation was DTMF
+  //    // overdub, but the current instruction is "regular" DTMF. We must make
+  //    // sure that the DTMF does not have any discontinuities. The first DTMF
+  //    // sample that we generate now must be played out immediately, therefore
+  //    // it must be copied to the speech buffer.
+  //    // TODO(hlundin): This code seems incorrect. (Legacy.) Write test and
+  //    // verify correct operation.
+  //    assert(false);
+  //    // Must generate enough data to replace all of the |sync_buffer_|
+  //    // "future".
+  //    int required_length = sync_buffer_->FutureLength();
+  //    assert(dtmf_tone_generator_->initialized());
+  //    dtmf_return_value = dtmf_tone_generator_->Generate(required_length,
+  //                                                       algorithm_buffer_);
+  //    assert((size_t) required_length == algorithm_buffer_->Size());
+  //    if (dtmf_return_value < 0) {
+  //      algorithm_buffer_->Zeros(output_size_samples_);
+  //      return dtmf_return_value;
+  //    }
+  //
+  //    // Overwrite the "future" part of the speech buffer with the new DTMF
+  //    // data.
+  //    // TODO(hlundin): It seems that this overwriting has gone lost.
+  //    // Not adapted for multi-channel yet.
+  //    assert(algorithm_buffer_->Channels() == 1);
+  //    if (algorithm_buffer_->Channels() != 1) {
+  //      LOG(LS_WARNING) << "DTMF not supported for more than one channel";
+  //      return kStereoNotSupported;
+  //    }
+  //    // Shuffle the remaining data to the beginning of algorithm buffer.
+  //    algorithm_buffer_->PopFront(sync_buffer_->FutureLength());
+  //  }
+
+  sync_buffer_->IncreaseEndTimestamp(output_size_samples_);
+  expand_->Reset();
+  last_mode_ = kModeDtmf;
+
+  // Set to false because the DTMF is already in the algorithm buffer.
+  *play_dtmf = false;
+  return 0;
+}
+
+void NetEqImpl::DoAlternativePlc(bool increase_timestamp) {
+  AudioDecoder* decoder = decoder_database_->GetActiveDecoder();
+  int length;
+  if (decoder && decoder->HasDecodePlc()) {
+    // Use the decoder's packet-loss concealment.
+    // TODO(hlundin): Will probably need a longer buffer for multi-channel.
+    int16_t decoded_buffer[kMaxFrameSize];
+    length = decoder->DecodePlc(1, decoded_buffer);
+    if (length > 0) {
+      algorithm_buffer_->PushBackInterleaved(decoded_buffer, length);
+    } else {
+      length = 0;
+    }
+  } else {
+    // Do simple zero-stuffing.
+    length = output_size_samples_;
+    algorithm_buffer_->Zeros(length);
+    // By not advancing the timestamp, NetEq inserts samples.
+    stats_.AddZeros(length);
+  }
+  if (increase_timestamp) {
+    sync_buffer_->IncreaseEndTimestamp(length);
+  }
+  expand_->Reset();
+}
+
+int NetEqImpl::DtmfOverdub(const DtmfEvent& dtmf_event, size_t num_channels,
+                           int16_t* output) const {
+  size_t out_index = 0;
+  int overdub_length = output_size_samples_;  // Default value.
+
+  if (sync_buffer_->dtmf_index() > sync_buffer_->next_index()) {
+    // Special operation for transition from "DTMF only" to "DTMF overdub".
+    out_index = std::min(
+        sync_buffer_->dtmf_index() - sync_buffer_->next_index(),
+        static_cast<size_t>(output_size_samples_));
+    overdub_length = output_size_samples_ - static_cast<int>(out_index);
+  }
+
+  AudioMultiVector dtmf_output(num_channels);
+  int dtmf_return_value = 0;
+  if (!dtmf_tone_generator_->initialized()) {
+    dtmf_return_value = dtmf_tone_generator_->Init(fs_hz_, dtmf_event.event_no,
+                                                   dtmf_event.volume);
+  }
+  if (dtmf_return_value == 0) {
+    dtmf_return_value = dtmf_tone_generator_->Generate(overdub_length,
+                                                       &dtmf_output);
+    assert((size_t) overdub_length == dtmf_output.Size());
+  }
+  dtmf_output.ReadInterleaved(overdub_length, &output[out_index]);
+  return dtmf_return_value < 0 ? dtmf_return_value : 0;
+}
+
+int NetEqImpl::ExtractPackets(int required_samples, PacketList* packet_list) {
+  bool first_packet = true;
+  uint8_t prev_payload_type = 0;
+  uint32_t prev_timestamp = 0;
+  uint16_t prev_sequence_number = 0;
+  bool next_packet_available = false;
+
+  const RTPHeader* header = packet_buffer_->NextRtpHeader();
+  assert(header);
+  if (!header) {
+    return -1;
+  }
+  uint32_t first_timestamp = header->timestamp;
+  int extracted_samples = 0;
+
+  // Packet extraction loop.
+  do {
+    timestamp_ = header->timestamp;
+    int discard_count = 0;
+    Packet* packet = packet_buffer_->GetNextPacket(&discard_count);
+    // |header| may be invalid after the |packet_buffer_| operation.
+    header = NULL;
+    if (!packet) {
+      LOG_FERR1(LS_ERROR, GetNextPacket, discard_count) <<
+          "Should always be able to extract a packet here";
+      assert(false);  // Should always be able to extract a packet here.
+      return -1;
+    }
+    stats_.PacketsDiscarded(discard_count);
+    // Store waiting time in ms; packets->waiting_time is in "output blocks".
+    stats_.StoreWaitingTime(packet->waiting_time * kOutputSizeMs);
+    assert(packet->payload_length > 0);
+    packet_list->push_back(packet);  // Store packet in list.
+
+    if (first_packet) {
+      first_packet = false;
+      decoded_packet_sequence_number_ = prev_sequence_number =
+          packet->header.sequenceNumber;
+      decoded_packet_timestamp_ = prev_timestamp = packet->header.timestamp;
+      prev_payload_type = packet->header.payloadType;
+    }
+
+    // Store number of extracted samples.
+    int packet_duration = 0;
+    AudioDecoder* decoder = decoder_database_->GetDecoder(
+        packet->header.payloadType);
+    if (decoder) {
+      if (packet->sync_packet) {
+        packet_duration = decoder_frame_length_;
+      } else {
+        packet_duration = packet->primary ?
+            decoder->PacketDuration(packet->payload, packet->payload_length) :
+            decoder->PacketDurationRedundant(packet->payload,
+                                             packet->payload_length);
+      }
+    } else {
+      LOG_FERR1(LS_WARNING, GetDecoder, packet->header.payloadType) <<
+          "Could not find a decoder for a packet about to be extracted.";
+      assert(false);
+    }
+    if (packet_duration <= 0) {
+      // Decoder did not return a packet duration. Assume that the packet
+      // contains the same number of samples as the previous one.
+      packet_duration = decoder_frame_length_;
+    }
+    extracted_samples = packet->header.timestamp - first_timestamp +
+        packet_duration;
+
+    // Check what packet is available next.
+    header = packet_buffer_->NextRtpHeader();
+    next_packet_available = false;
+    if (header && prev_payload_type == header->payloadType) {
+      int16_t seq_no_diff = header->sequenceNumber - prev_sequence_number;
+      int32_t ts_diff = header->timestamp - prev_timestamp;
+      if (seq_no_diff == 1 ||
+          (seq_no_diff == 0 && ts_diff == decoder_frame_length_)) {
+        // The next sequence number is available, or the next part of a packet
+        // that was split into pieces upon insertion.
+        next_packet_available = true;
+      }
+      prev_sequence_number = header->sequenceNumber;
+    }
+  } while (extracted_samples < required_samples && next_packet_available);
+
+  return extracted_samples;
+}
+
+void NetEqImpl::UpdatePlcComponents(int fs_hz, size_t channels) {
+  // Delete objects and create new ones.
+  expand_.reset(expand_factory_->Create(background_noise_.get(),
+                                        sync_buffer_.get(), &random_vector_,
+                                        fs_hz, channels));
+  merge_.reset(new Merge(fs_hz, channels, expand_.get(), sync_buffer_.get()));
+}
+
+void NetEqImpl::SetSampleRateAndChannels(int fs_hz, size_t channels) {
+  LOG_API2(fs_hz, channels);
+  // TODO(hlundin): Change to an enumerator and skip assert.
+  assert(fs_hz == 8000 || fs_hz == 16000 || fs_hz ==  32000 || fs_hz == 48000);
+  assert(channels > 0);
+
+  fs_hz_ = fs_hz;
+  fs_mult_ = fs_hz / 8000;
+  output_size_samples_ = kOutputSizeMs * 8 * fs_mult_;
+  decoder_frame_length_ = 3 * output_size_samples_;  // Initialize to 30ms.
+
+  last_mode_ = kModeNormal;
+
+  // Create a new array of mute factors and set all to 1.
+  mute_factor_array_.reset(new int16_t[channels]);
+  for (size_t i = 0; i < channels; ++i) {
+    mute_factor_array_[i] = 16384;  // 1.0 in Q14.
+  }
+
+  // Reset comfort noise decoder, if there is one active.
+  AudioDecoder* cng_decoder = decoder_database_->GetActiveCngDecoder();
+  if (cng_decoder) {
+    cng_decoder->Init();
+  }
+
+  // Reinit post-decode VAD with new sample rate.
+  assert(vad_.get());  // Cannot be NULL here.
+  vad_->Init();
+
+  // Delete algorithm buffer and create a new one.
+  algorithm_buffer_.reset(new AudioMultiVector(channels));
+
+  // Delete sync buffer and create a new one.
+  sync_buffer_.reset(new SyncBuffer(channels, kSyncBufferSize * fs_mult_));
+
+
+  // Delete BackgroundNoise object and create a new one, while preserving its
+  // mode.
+  NetEqBackgroundNoiseMode current_mode = kBgnOn;
+  if (background_noise_.get())
+    current_mode = background_noise_->mode();
+  background_noise_.reset(new BackgroundNoise(channels));
+  background_noise_->set_mode(current_mode);
+
+  // Reset random vector.
+  random_vector_.Reset();
+
+  UpdatePlcComponents(fs_hz, channels);
+
+  // Move index so that we create a small set of future samples (all 0).
+  sync_buffer_->set_next_index(sync_buffer_->next_index() -
+      expand_->overlap_length());
+
+  normal_.reset(new Normal(fs_hz, decoder_database_.get(), *background_noise_,
+                           expand_.get()));
+  accelerate_.reset(
+      accelerate_factory_->Create(fs_hz, channels, *background_noise_));
+  preemptive_expand_.reset(preemptive_expand_factory_->Create(
+      fs_hz, channels,
+      *background_noise_,
+      static_cast<int>(expand_->overlap_length())));
+
+  // Delete ComfortNoise object and create a new one.
+  comfort_noise_.reset(new ComfortNoise(fs_hz, decoder_database_.get(),
+                                        sync_buffer_.get()));
+
+  // Verify that |decoded_buffer_| is long enough.
+  if (decoded_buffer_length_ < kMaxFrameSize * channels) {
+    // Reallocate to larger size.
+    decoded_buffer_length_ = kMaxFrameSize * channels;
+    decoded_buffer_.reset(new int16_t[decoded_buffer_length_]);
+  }
+
+  // Create DecisionLogic if it is not created yet, then communicate new sample
+  // rate and output size to DecisionLogic object.
+  if (!decision_logic_.get()) {
+    CreateDecisionLogic(kPlayoutOn);
+  }
+  decision_logic_->SetSampleRate(fs_hz_, output_size_samples_);
+}
+
+NetEqOutputType NetEqImpl::LastOutputType() {
+  assert(vad_.get());
+  assert(expand_.get());
+  if (last_mode_ == kModeCodecInternalCng || last_mode_ == kModeRfc3389Cng) {
+    return kOutputCNG;
+  } else if (last_mode_ == kModeExpand && expand_->MuteFactor(0) == 0) {
+    // Expand mode has faded down to background noise only (very long expand).
+    return kOutputPLCtoCNG;
+  } else if (last_mode_ == kModeExpand) {
+    return kOutputPLC;
+  } else if (vad_->running() && !vad_->active_speech()) {
+    return kOutputVADPassive;
+  } else {
+    return kOutputNormal;
+  }
+}
+
+void NetEqImpl::CreateDecisionLogic(NetEqPlayoutMode mode) {
+  decision_logic_.reset(DecisionLogic::Create(fs_hz_, output_size_samples_,
+                                              mode,
+                                              decoder_database_.get(),
+                                              *packet_buffer_.get(),
+                                              delay_manager_.get(),
+                                              buffer_level_filter_.get()));
+}
+}  // namespace webrtc