video_engine/vie_channel.cc

/*
 *  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/video_engine/vie_channel.h"

#include <algorithm>
#include <vector>

#include "webrtc/common.h"
#include "webrtc/common_video/libyuv/include/webrtc_libyuv.h"
#include "webrtc/experiments.h"
#include "webrtc/modules/pacing/include/paced_sender.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_receiver.h"
#include "webrtc/modules/rtp_rtcp/interface/rtp_rtcp.h"
#include "webrtc/modules/utility/interface/process_thread.h"
#include "webrtc/modules/video_coding/main/interface/video_coding.h"
#include "webrtc/modules/video_processing/main/interface/video_processing.h"
#include "webrtc/modules/video_render/include/video_render_defines.h"
#include "webrtc/system_wrappers/interface/critical_section_wrapper.h"
#include "webrtc/system_wrappers/interface/logging.h"
#include "webrtc/system_wrappers/interface/thread_wrapper.h"
#include "webrtc/video_engine/call_stats.h"
#include "webrtc/video_engine/include/vie_codec.h"
#include "webrtc/video_engine/include/vie_errors.h"
#include "webrtc/video_engine/include/vie_image_process.h"
#include "webrtc/video_engine/include/vie_rtp_rtcp.h"
#include "webrtc/frame_callback.h"
#include "webrtc/video_engine/vie_defines.h"

namespace webrtc {

const int kMaxDecodeWaitTimeMs = 50;
const int kInvalidRtpExtensionId = 0;
static const int kMaxTargetDelayMs = 10000;
static const float kMaxIncompleteTimeMultiplier = 3.5f;

namespace {

RTCPReportBlock AggregateReportBlocks(
    const std::vector<RTCPReportBlock>& report_blocks,
    std::map<uint32_t, RTCPReportBlock>* prev_report_blocks) {
  int fraction_lost_sum = 0;
  int fl_seq_num_sum = 0;
  int jitter_sum = 0;
  int number_of_report_blocks = 0;
  RTCPReportBlock aggregate;
  std::vector<RTCPReportBlock>::const_iterator report_block =
      report_blocks.begin();
  for (; report_block != report_blocks.end(); ++report_block) {
    aggregate.cumulativeLost += report_block->cumulativeLost;
    std::map<uint32_t, RTCPReportBlock>::iterator prev_report_block =
        prev_report_blocks->find(report_block->sourceSSRC);
    if (prev_report_block != prev_report_blocks->end()) {
      // Skip the first report block since we won't be able to get a correct
      // weight for it.
      int seq_num_diff = report_block->extendedHighSeqNum -
                         prev_report_block->second.extendedHighSeqNum;
      if (seq_num_diff > 0) {
        fraction_lost_sum += report_block->fractionLost * seq_num_diff;
        fl_seq_num_sum += seq_num_diff;
      }
    }
    jitter_sum += report_block->jitter;
    ++number_of_report_blocks;
    (*prev_report_blocks)[report_block->sourceSSRC] = *report_block;
  }
  if (fl_seq_num_sum > 0) {
    aggregate.fractionLost =
        (fraction_lost_sum + fl_seq_num_sum / 2) / fl_seq_num_sum;
  }
  if (number_of_report_blocks > 0) {
    aggregate.jitter =
        (jitter_sum + number_of_report_blocks / 2) / number_of_report_blocks;
  }
  // Not well defined for aggregated report blocks.
  aggregate.extendedHighSeqNum = 0;
  return aggregate;
}
}  // namespace

// Helper class receiving statistics callbacks.
class ChannelStatsObserver : public CallStatsObserver {
 public:
  explicit ChannelStatsObserver(ViEChannel* owner) : owner_(owner) {}
  virtual ~ChannelStatsObserver() {}

  // Implements StatsObserver.
  virtual void OnRttUpdate(uint32_t rtt) {
    owner_->OnRttUpdate(rtt);
  }

 private:
  ViEChannel* owner_;
};

ViEChannel::ViEChannel(int32_t channel_id,
                       int32_t engine_id,
                       uint32_t number_of_cores,
                       const Config& config,
                       ProcessThread& module_process_thread,
                       RtcpIntraFrameObserver* intra_frame_observer,
                       RtcpBandwidthObserver* bandwidth_observer,
                       RemoteBitrateEstimator* remote_bitrate_estimator,
                       RtcpRttStats* rtt_stats,
                       PacedSender* paced_sender,
                       RtpRtcp* default_rtp_rtcp,
                       bool sender)
    : ViEFrameProviderBase(channel_id, engine_id),
      channel_id_(channel_id),
      engine_id_(engine_id),
      number_of_cores_(number_of_cores),
      num_socket_threads_(kViESocketThreads),
      callback_cs_(CriticalSectionWrapper::CreateCriticalSection()),
      rtp_rtcp_cs_(CriticalSectionWrapper::CreateCriticalSection()),
      default_rtp_rtcp_(default_rtp_rtcp),
      vcm_(VideoCodingModule::Create()),
      vie_receiver_(channel_id, vcm_, remote_bitrate_estimator, this),
      vie_sender_(channel_id),
      vie_sync_(vcm_, this),
      stats_observer_(new ChannelStatsObserver(this)),
      module_process_thread_(module_process_thread),
      codec_observer_(NULL),
      do_key_frame_callbackRequest_(false),
      rtp_observer_(NULL),
      rtcp_observer_(NULL),
      intra_frame_observer_(intra_frame_observer),
      rtt_stats_(rtt_stats),
      paced_sender_(paced_sender),
      pad_with_redundant_payloads_(false),
      bandwidth_observer_(bandwidth_observer),
      send_timestamp_extension_id_(kInvalidRtpExtensionId),
      absolute_send_time_extension_id_(kInvalidRtpExtensionId),
      external_transport_(NULL),
      decoder_reset_(true),
      wait_for_key_frame_(false),
      decode_thread_(NULL),
      effect_filter_(NULL),
      color_enhancement_(false),
      mtu_(0),
      sender_(sender),
      nack_history_size_sender_(kSendSidePacketHistorySize),
      max_nack_reordering_threshold_(kMaxPacketAgeToNack),
      pre_render_callback_(NULL) {
  RtpRtcp::Configuration configuration;
  configuration.id = ViEModuleId(engine_id, channel_id);
  configuration.audio = false;
  configuration.default_module = default_rtp_rtcp;
  configuration.outgoing_transport = &vie_sender_;
  configuration.rtcp_feedback = this;
  configuration.intra_frame_callback = intra_frame_observer;
  configuration.bandwidth_callback = bandwidth_observer;
  configuration.rtt_stats = rtt_stats;
  configuration.remote_bitrate_estimator = remote_bitrate_estimator;
  configuration.paced_sender = paced_sender;
  configuration.receive_statistics = vie_receiver_.GetReceiveStatistics();
  configuration.send_bitrate_observer = &send_bitrate_observer_;
  configuration.send_frame_count_observer = &send_frame_count_observer_;
  configuration.send_side_delay_observer = &send_side_delay_observer_;

  rtp_rtcp_.reset(RtpRtcp::CreateRtpRtcp(configuration));
  vie_receiver_.SetRtpRtcpModule(rtp_rtcp_.get());
  vcm_->SetNackSettings(kMaxNackListSize, max_nack_reordering_threshold_, 0);
}

int32_t ViEChannel::Init() {
  if (module_process_thread_.RegisterModule(
      vie_receiver_.GetReceiveStatistics()) != 0) {
    return -1;
  }
  // RTP/RTCP initialization.
  if (rtp_rtcp_->SetSendingMediaStatus(false) != 0) {
    return -1;
  }
  if (module_process_thread_.RegisterModule(rtp_rtcp_.get()) != 0) {
    return -1;
  }
  rtp_rtcp_->SetKeyFrameRequestMethod(kKeyFrameReqFirRtp);
  rtp_rtcp_->SetRTCPStatus(kRtcpCompound);
  if (paced_sender_) {
    rtp_rtcp_->SetStorePacketsStatus(true, nack_history_size_sender_);
  }
  if (vcm_->InitializeReceiver() != 0) {
    return -1;
  }
  if (vcm_->SetVideoProtection(kProtectionKeyOnLoss, true)) {
    return -1;
  }
  if (vcm_->RegisterReceiveCallback(this) != 0) {
    return -1;
  }
  vcm_->RegisterFrameTypeCallback(this);
  vcm_->RegisterReceiveStatisticsCallback(this);
  vcm_->RegisterDecoderTimingCallback(this);
  vcm_->SetRenderDelay(kViEDefaultRenderDelayMs);
  if (module_process_thread_.RegisterModule(vcm_) != 0) {
    return -1;
  }
#ifdef VIDEOCODEC_VP8
  VideoCodec video_codec;
  if (vcm_->Codec(kVideoCodecVP8, &video_codec) == VCM_OK) {
    rtp_rtcp_->RegisterSendPayload(video_codec);
    // TODO(holmer): Can we call SetReceiveCodec() here instead?
    if (!vie_receiver_.RegisterPayload(video_codec)) {
      return -1;
    }
    vcm_->RegisterReceiveCodec(&video_codec, number_of_cores_);
    vcm_->RegisterSendCodec(&video_codec, number_of_cores_,
                           rtp_rtcp_->MaxDataPayloadLength());
  } else {
    assert(false);
  }
#endif

  return 0;
}

ViEChannel::~ViEChannel() {
  // Make sure we don't get more callbacks from the RTP module.
  module_process_thread_.DeRegisterModule(vie_receiver_.GetReceiveStatistics());
  module_process_thread_.DeRegisterModule(rtp_rtcp_.get());
  module_process_thread_.DeRegisterModule(vcm_);
  module_process_thread_.DeRegisterModule(&vie_sync_);
  while (simulcast_rtp_rtcp_.size() > 0) {
    std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
    RtpRtcp* rtp_rtcp = *it;
    module_process_thread_.DeRegisterModule(rtp_rtcp);
    delete rtp_rtcp;
    simulcast_rtp_rtcp_.erase(it);
  }
  while (removed_rtp_rtcp_.size() > 0) {
    std::list<RtpRtcp*>::iterator it = removed_rtp_rtcp_.begin();
    delete *it;
    removed_rtp_rtcp_.erase(it);
  }
  if (decode_thread_) {
    StopDecodeThread();
  }
  // Release modules.
  VideoCodingModule::Destroy(vcm_);
}

int32_t ViEChannel::SetSendCodec(const VideoCodec& video_codec,
                                 bool new_stream) {
  if (!sender_) {
    return 0;
  }
  if (video_codec.codecType == kVideoCodecRED ||
      video_codec.codecType == kVideoCodecULPFEC) {
    LOG_F(LS_ERROR) << "Not a valid send codec " << video_codec.codecType;
    return -1;
  }
  if (kMaxSimulcastStreams < video_codec.numberOfSimulcastStreams) {
    LOG_F(LS_ERROR) << "Incorrect config "
                    << video_codec.numberOfSimulcastStreams;
    return -1;
  }
  // Update the RTP module with the settings.
  // Stop and Start the RTP module -> trigger new SSRC, if an SSRC hasn't been
  // set explicitly.
  bool restart_rtp = false;
  if (rtp_rtcp_->Sending() && new_stream) {
    restart_rtp = true;
    rtp_rtcp_->SetSendingStatus(false);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); ++it) {
      (*it)->SetSendingStatus(false);
      (*it)->SetSendingMediaStatus(false);
    }
  }

  bool fec_enabled = false;
  uint8_t payload_type_red;
  uint8_t payload_type_fec;
  rtp_rtcp_->GenericFECStatus(fec_enabled, payload_type_red, payload_type_fec);

  CriticalSectionScoped cs(rtp_rtcp_cs_.get());

  if (video_codec.numberOfSimulcastStreams > 0) {
    // Set correct bitrate to base layer.
    // Create our simulcast RTP modules.
    int num_modules_to_add = video_codec.numberOfSimulcastStreams -
        simulcast_rtp_rtcp_.size() - 1;
    if (num_modules_to_add < 0) {
      num_modules_to_add = 0;
    }

    // Add back removed rtp modules. Order is important (allocate from front of
    // removed modules) to preserve RTP settings such as SSRCs for simulcast
    // streams.
    std::list<RtpRtcp*> new_rtp_modules;
    for (; removed_rtp_rtcp_.size() > 0 && num_modules_to_add > 0;
         --num_modules_to_add) {
      new_rtp_modules.push_back(removed_rtp_rtcp_.front());
      removed_rtp_rtcp_.pop_front();
    }

    for (int i = 0; i < num_modules_to_add; ++i)
      new_rtp_modules.push_back(CreateRtpRtcpModule());

    // Initialize newly added modules.
    for (std::list<RtpRtcp*>::iterator it = new_rtp_modules.begin();
         it != new_rtp_modules.end();
         ++it) {
      RtpRtcp* rtp_rtcp = *it;

      rtp_rtcp->SetRTCPStatus(rtp_rtcp_->RTCP());

      if (rtp_rtcp_->StorePackets()) {
        rtp_rtcp->SetStorePacketsStatus(true, nack_history_size_sender_);
      } else if (paced_sender_) {
        rtp_rtcp->SetStorePacketsStatus(true, nack_history_size_sender_);
      }

      if (fec_enabled) {
        rtp_rtcp->SetGenericFECStatus(
            fec_enabled, payload_type_red, payload_type_fec);
      }
      rtp_rtcp->SetSendingStatus(rtp_rtcp_->Sending());
      rtp_rtcp->SetSendingMediaStatus(rtp_rtcp_->SendingMedia());

      int mode;
      uint32_t ssrc;
      int payload_type;
      rtp_rtcp_->RTXSendStatus(&mode, &ssrc, &payload_type);
      rtp_rtcp->SetRTXSendStatus(mode);
      simulcast_rtp_rtcp_.push_back(rtp_rtcp);

      // Silently ignore error.
      module_process_thread_.RegisterModule(rtp_rtcp);
    }

    // Remove last in list if we have too many.
    for (int j = simulcast_rtp_rtcp_.size();
         j > (video_codec.numberOfSimulcastStreams - 1);
         j--) {
      RtpRtcp* rtp_rtcp = simulcast_rtp_rtcp_.back();
      module_process_thread_.DeRegisterModule(rtp_rtcp);
      rtp_rtcp->SetSendingStatus(false);
      rtp_rtcp->SetSendingMediaStatus(false);
      rtp_rtcp->RegisterSendChannelRtcpStatisticsCallback(NULL);
      rtp_rtcp->RegisterSendChannelRtpStatisticsCallback(NULL);
      simulcast_rtp_rtcp_.pop_back();
      removed_rtp_rtcp_.push_front(rtp_rtcp);
    }
    uint8_t idx = 0;
    // Configure all simulcast modules.
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end();
         it++) {
      idx++;
      RtpRtcp* rtp_rtcp = *it;
      rtp_rtcp->DeRegisterSendPayload(video_codec.plType);
      if (rtp_rtcp->RegisterSendPayload(video_codec) != 0) {
        return -1;
      }
      if (mtu_ != 0) {
        rtp_rtcp->SetMaxTransferUnit(mtu_);
      }
      if (restart_rtp) {
        rtp_rtcp->SetSendingStatus(true);
        rtp_rtcp->SetSendingMediaStatus(true);
      }
      if (send_timestamp_extension_id_ != kInvalidRtpExtensionId) {
        // Deregister in case the extension was previously enabled.
        rtp_rtcp->DeregisterSendRtpHeaderExtension(
            kRtpExtensionTransmissionTimeOffset);
        if (rtp_rtcp->RegisterSendRtpHeaderExtension(
            kRtpExtensionTransmissionTimeOffset,
            send_timestamp_extension_id_) != 0) {
        }
      } else {
        rtp_rtcp->DeregisterSendRtpHeaderExtension(
            kRtpExtensionTransmissionTimeOffset);
      }
      if (absolute_send_time_extension_id_ != kInvalidRtpExtensionId) {
        // Deregister in case the extension was previously enabled.
        rtp_rtcp->DeregisterSendRtpHeaderExtension(
            kRtpExtensionAbsoluteSendTime);
        if (rtp_rtcp->RegisterSendRtpHeaderExtension(
            kRtpExtensionAbsoluteSendTime,
            absolute_send_time_extension_id_) != 0) {
        }
      } else {
        rtp_rtcp->DeregisterSendRtpHeaderExtension(
            kRtpExtensionAbsoluteSendTime);
      }
      rtp_rtcp->RegisterSendChannelRtcpStatisticsCallback(
          rtp_rtcp_->GetSendChannelRtcpStatisticsCallback());
      rtp_rtcp->RegisterSendChannelRtpStatisticsCallback(
          rtp_rtcp_->GetSendChannelRtpStatisticsCallback());
    }
    // |RegisterSimulcastRtpRtcpModules| resets all old weak pointers and old
    // modules can be deleted after this step.
    vie_receiver_.RegisterSimulcastRtpRtcpModules(simulcast_rtp_rtcp_);
  } else {
    while (!simulcast_rtp_rtcp_.empty()) {
      RtpRtcp* rtp_rtcp = simulcast_rtp_rtcp_.back();
      module_process_thread_.DeRegisterModule(rtp_rtcp);
      rtp_rtcp->SetSendingStatus(false);
      rtp_rtcp->SetSendingMediaStatus(false);
      rtp_rtcp->RegisterSendChannelRtcpStatisticsCallback(NULL);
      rtp_rtcp->RegisterSendChannelRtpStatisticsCallback(NULL);
      simulcast_rtp_rtcp_.pop_back();
      removed_rtp_rtcp_.push_front(rtp_rtcp);
    }
    // Clear any previous modules.
    vie_receiver_.RegisterSimulcastRtpRtcpModules(simulcast_rtp_rtcp_);
  }

  // Don't log this error, no way to check in advance if this pl_type is
  // registered or not...
  rtp_rtcp_->DeRegisterSendPayload(video_codec.plType);
  if (rtp_rtcp_->RegisterSendPayload(video_codec) != 0) {
    return -1;
  }
  if (restart_rtp) {
    rtp_rtcp_->SetSendingStatus(true);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); ++it) {
      (*it)->SetSendingStatus(true);
      (*it)->SetSendingMediaStatus(true);
    }
  }
  return 0;
}

int32_t ViEChannel::SetReceiveCodec(const VideoCodec& video_codec) {
  if (!vie_receiver_.SetReceiveCodec(video_codec)) {
    return -1;
  }

  if (video_codec.codecType != kVideoCodecRED &&
      video_codec.codecType != kVideoCodecULPFEC) {
    // Register codec type with VCM, but do not register RED or ULPFEC.
    if (vcm_->RegisterReceiveCodec(&video_codec, number_of_cores_,
                                  wait_for_key_frame_) != VCM_OK) {
      return -1;
    }
  }
  return 0;
}

int32_t ViEChannel::GetReceiveCodec(VideoCodec* video_codec) {
  if (vcm_->ReceiveCodec(video_codec) != 0) {
    return -1;
  }
  return 0;
}

int32_t ViEChannel::RegisterCodecObserver(ViEDecoderObserver* observer) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (observer) {
    if (codec_observer_) {
      LOG_F(LS_ERROR) << "Observer already registered.";
      return -1;
    }
    codec_observer_ = observer;
  } else {
    codec_observer_ = NULL;
  }
  return 0;
}

int32_t ViEChannel::RegisterExternalDecoder(const uint8_t pl_type,
                                            VideoDecoder* decoder,
                                            bool buffered_rendering,
                                            int32_t render_delay) {
  int32_t result;
  result = vcm_->RegisterExternalDecoder(decoder, pl_type, buffered_rendering);
  if (result != VCM_OK) {
    return result;
  }
  return vcm_->SetRenderDelay(render_delay);
}

int32_t ViEChannel::DeRegisterExternalDecoder(const uint8_t pl_type) {
  VideoCodec current_receive_codec;
  int32_t result = 0;
  result = vcm_->ReceiveCodec(&current_receive_codec);
  if (vcm_->RegisterExternalDecoder(NULL, pl_type, false) != VCM_OK) {
    return -1;
  }

  if (result == 0 && current_receive_codec.plType == pl_type) {
    result = vcm_->RegisterReceiveCodec(
        &current_receive_codec, number_of_cores_, wait_for_key_frame_);
  }
  return result;
}

int32_t ViEChannel::ReceiveCodecStatistics(uint32_t* num_key_frames,
                                           uint32_t* num_delta_frames) {
  VCMFrameCount received_frames;
  if (vcm_->ReceivedFrameCount(received_frames) != VCM_OK) {
    return -1;
  }
  *num_key_frames = received_frames.numKeyFrames;
  *num_delta_frames = received_frames.numDeltaFrames;
  return 0;
}

uint32_t ViEChannel::DiscardedPackets() const {
  return vcm_->DiscardedPackets();
}

int ViEChannel::ReceiveDelay() const {
  return vcm_->Delay();
}

int32_t ViEChannel::WaitForKeyFrame(bool wait) {
  wait_for_key_frame_ = wait;
  return 0;
}

int32_t ViEChannel::SetSignalPacketLossStatus(bool enable,
                                              bool only_key_frames) {
  if (enable) {
    if (only_key_frames) {
      vcm_->SetVideoProtection(kProtectionKeyOnLoss, false);
      if (vcm_->SetVideoProtection(kProtectionKeyOnKeyLoss, true) != VCM_OK) {
        return -1;
      }
    } else {
      vcm_->SetVideoProtection(kProtectionKeyOnKeyLoss, false);
      if (vcm_->SetVideoProtection(kProtectionKeyOnLoss, true) != VCM_OK) {
        return -1;
      }
    }
  } else {
    vcm_->SetVideoProtection(kProtectionKeyOnLoss, false);
    vcm_->SetVideoProtection(kProtectionKeyOnKeyLoss, false);
  }
  return 0;
}

int32_t ViEChannel::SetRTCPMode(const RTCPMethod rtcp_mode) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->SetRTCPStatus(rtcp_mode);
  }
  return rtp_rtcp_->SetRTCPStatus(rtcp_mode);
}

int32_t ViEChannel::GetRTCPMode(RTCPMethod* rtcp_mode) {
  *rtcp_mode = rtp_rtcp_->RTCP();
  return 0;
}

int32_t ViEChannel::SetNACKStatus(const bool enable) {
  // Update the decoding VCM.
  if (vcm_->SetVideoProtection(kProtectionNack, enable) != VCM_OK) {
    return -1;
  }
  if (enable) {
    // Disable possible FEC.
    SetFECStatus(false, 0, 0);
  }
  // Update the decoding VCM.
  if (vcm_->SetVideoProtection(kProtectionNack, enable) != VCM_OK) {
    return -1;
  }
  return ProcessNACKRequest(enable);
}

int32_t ViEChannel::ProcessNACKRequest(const bool enable) {
  if (enable) {
    // Turn on NACK.
    if (rtp_rtcp_->RTCP() == kRtcpOff) {
      return -1;
    }
    vie_receiver_.SetNackStatus(true, max_nack_reordering_threshold_);
    rtp_rtcp_->SetStorePacketsStatus(true, nack_history_size_sender_);
    vcm_->RegisterPacketRequestCallback(this);

    CriticalSectionScoped cs(rtp_rtcp_cs_.get());

    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end();
         it++) {
      RtpRtcp* rtp_rtcp = *it;
      rtp_rtcp->SetStorePacketsStatus(true, nack_history_size_sender_);
    }
    // Don't introduce errors when NACK is enabled.
    vcm_->SetDecodeErrorMode(kNoErrors);
  } else {
    CriticalSectionScoped cs(rtp_rtcp_cs_.get());
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end();
         it++) {
      RtpRtcp* rtp_rtcp = *it;
      if (paced_sender_ == NULL) {
        rtp_rtcp->SetStorePacketsStatus(false, 0);
      }
    }
    vcm_->RegisterPacketRequestCallback(NULL);
    if (paced_sender_ == NULL) {
      rtp_rtcp_->SetStorePacketsStatus(false, 0);
    }
    vie_receiver_.SetNackStatus(false, max_nack_reordering_threshold_);
    // When NACK is off, allow decoding with errors. Otherwise, the video
    // will freeze, and will only recover with a complete key frame.
    vcm_->SetDecodeErrorMode(kWithErrors);
  }
  return 0;
}

int32_t ViEChannel::SetFECStatus(const bool enable,
                                       const unsigned char payload_typeRED,
                                       const unsigned char payload_typeFEC) {
  // Disable possible NACK.
  if (enable) {
    SetNACKStatus(false);
  }

  return ProcessFECRequest(enable, payload_typeRED, payload_typeFEC);
}

int32_t ViEChannel::ProcessFECRequest(
    const bool enable,
    const unsigned char payload_typeRED,
    const unsigned char payload_typeFEC) {
  if (rtp_rtcp_->SetGenericFECStatus(enable, payload_typeRED,
                                    payload_typeFEC) != 0) {
    return -1;
  }
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->SetGenericFECStatus(enable, payload_typeRED, payload_typeFEC);
  }
  return 0;
}

int32_t ViEChannel::SetHybridNACKFECStatus(
    const bool enable,
    const unsigned char payload_typeRED,
    const unsigned char payload_typeFEC) {
  if (vcm_->SetVideoProtection(kProtectionNackFEC, enable) != VCM_OK) {
    return -1;
  }

  int32_t ret_val = 0;
  ret_val = ProcessNACKRequest(enable);
  if (ret_val < 0) {
    return ret_val;
  }
  return ProcessFECRequest(enable, payload_typeRED, payload_typeFEC);
}

int ViEChannel::SetSenderBufferingMode(int target_delay_ms) {
  if ((target_delay_ms < 0) || (target_delay_ms > kMaxTargetDelayMs)) {
    LOG(LS_ERROR) << "Invalid send buffer value.";
    return -1;
  }
  if (target_delay_ms == 0) {
    // Real-time mode.
    nack_history_size_sender_ = kSendSidePacketHistorySize;
  } else {
    nack_history_size_sender_ = GetRequiredNackListSize(target_delay_ms);
    // Don't allow a number lower than the default value.
    if (nack_history_size_sender_ < kSendSidePacketHistorySize) {
      nack_history_size_sender_ = kSendSidePacketHistorySize;
    }
  }
  if (rtp_rtcp_->SetStorePacketsStatus(true, nack_history_size_sender_) != 0) {
    return -1;
  }
  return 0;
}

int ViEChannel::SetReceiverBufferingMode(int target_delay_ms) {
  if ((target_delay_ms < 0) || (target_delay_ms > kMaxTargetDelayMs)) {
    LOG(LS_ERROR) << "Invalid receive buffer delay value.";
    return -1;
  }
  int max_nack_list_size;
  int max_incomplete_time_ms;
  if (target_delay_ms == 0) {
    // Real-time mode - restore default settings.
    max_nack_reordering_threshold_ = kMaxPacketAgeToNack;
    max_nack_list_size = kMaxNackListSize;
    max_incomplete_time_ms = 0;
  } else {
    max_nack_list_size =  3 * GetRequiredNackListSize(target_delay_ms) / 4;
    max_nack_reordering_threshold_ = max_nack_list_size;
    // Calculate the max incomplete time and round to int.
    max_incomplete_time_ms = static_cast<int>(kMaxIncompleteTimeMultiplier *
        target_delay_ms + 0.5f);
  }
  vcm_->SetNackSettings(max_nack_list_size, max_nack_reordering_threshold_,
                       max_incomplete_time_ms);
  vcm_->SetMinReceiverDelay(target_delay_ms);
  if (vie_sync_.SetTargetBufferingDelay(target_delay_ms) < 0)
    return -1;
  return 0;
}

int ViEChannel::GetRequiredNackListSize(int target_delay_ms) {
  // The max size of the nack list should be large enough to accommodate the
  // the number of packets (frames) resulting from the increased delay.
  // Roughly estimating for ~40 packets per frame @ 30fps.
  return target_delay_ms * 40 * 30 / 1000;
}

int32_t ViEChannel::SetKeyFrameRequestMethod(
    const KeyFrameRequestMethod method) {
  return rtp_rtcp_->SetKeyFrameRequestMethod(method);
}

bool ViEChannel::EnableRemb(bool enable) {
  if (rtp_rtcp_->SetREMBStatus(enable) != 0)
    return false;
  return true;
}

int ViEChannel::SetSendTimestampOffsetStatus(bool enable, int id) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  int error = 0;
  if (enable) {
    // Enable the extension, but disable possible old id to avoid errors.
    send_timestamp_extension_id_ = id;
    rtp_rtcp_->DeregisterSendRtpHeaderExtension(
        kRtpExtensionTransmissionTimeOffset);
    error = rtp_rtcp_->RegisterSendRtpHeaderExtension(
        kRtpExtensionTransmissionTimeOffset, id);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); it++) {
      (*it)->DeregisterSendRtpHeaderExtension(
          kRtpExtensionTransmissionTimeOffset);
      error |= (*it)->RegisterSendRtpHeaderExtension(
          kRtpExtensionTransmissionTimeOffset, id);
    }
  } else {
    // Disable the extension.
    send_timestamp_extension_id_ = kInvalidRtpExtensionId;
    rtp_rtcp_->DeregisterSendRtpHeaderExtension(
        kRtpExtensionTransmissionTimeOffset);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); it++) {
      (*it)->DeregisterSendRtpHeaderExtension(
          kRtpExtensionTransmissionTimeOffset);
    }
  }
  return error;
}

int ViEChannel::SetReceiveTimestampOffsetStatus(bool enable, int id) {
  return vie_receiver_.SetReceiveTimestampOffsetStatus(enable, id) ? 0 : -1;
}

int ViEChannel::SetSendAbsoluteSendTimeStatus(bool enable, int id) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  int error = 0;
  if (enable) {
    // Enable the extension, but disable possible old id to avoid errors.
    absolute_send_time_extension_id_ = id;
    rtp_rtcp_->DeregisterSendRtpHeaderExtension(
        kRtpExtensionAbsoluteSendTime);
    error = rtp_rtcp_->RegisterSendRtpHeaderExtension(
        kRtpExtensionAbsoluteSendTime, id);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); it++) {
      (*it)->DeregisterSendRtpHeaderExtension(
          kRtpExtensionAbsoluteSendTime);
      error |= (*it)->RegisterSendRtpHeaderExtension(
          kRtpExtensionAbsoluteSendTime, id);
    }
  } else {
    // Disable the extension.
    absolute_send_time_extension_id_ = kInvalidRtpExtensionId;
    rtp_rtcp_->DeregisterSendRtpHeaderExtension(
        kRtpExtensionAbsoluteSendTime);
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end(); it++) {
      (*it)->DeregisterSendRtpHeaderExtension(
          kRtpExtensionAbsoluteSendTime);
    }
  }
  return error;
}

int ViEChannel::SetReceiveAbsoluteSendTimeStatus(bool enable, int id) {
  return vie_receiver_.SetReceiveAbsoluteSendTimeStatus(enable, id) ? 0 : -1;
}

void ViEChannel::SetRtcpXrRrtrStatus(bool enable) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  rtp_rtcp_->SetRtcpXrRrtrStatus(enable);
}

void ViEChannel::SetTransmissionSmoothingStatus(bool enable) {
  assert(paced_sender_ && "No paced sender registered.");
  paced_sender_->SetStatus(enable);
}

int32_t ViEChannel::EnableTMMBR(const bool enable) {
  return rtp_rtcp_->SetTMMBRStatus(enable);
}

int32_t ViEChannel::EnableKeyFrameRequestCallback(const bool enable) {

  CriticalSectionScoped cs(callback_cs_.get());
  if (enable && !codec_observer_) {
    LOG(LS_ERROR) << "No ViECodecObserver set.";
    return -1;
  }
  do_key_frame_callbackRequest_ = enable;
  return 0;
}

int32_t ViEChannel::SetSSRC(const uint32_t SSRC,
                            const StreamType usage,
                            const uint8_t simulcast_idx) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  ReserveRtpRtcpModules(simulcast_idx + 1);
  RtpRtcp* rtp_rtcp = GetRtpRtcpModule(simulcast_idx);
  if (rtp_rtcp == NULL)
    return -1;
  if (usage == kViEStreamTypeRtx) {
    rtp_rtcp->SetRtxSsrc(SSRC);
  } else {
    rtp_rtcp->SetSSRC(SSRC);
  }
  return 0;
}

int32_t ViEChannel::SetRemoteSSRCType(const StreamType usage,
                                      const uint32_t SSRC) {
  vie_receiver_.SetRtxSsrc(SSRC);
  return 0;
}

int32_t ViEChannel::GetLocalSSRC(uint8_t idx, unsigned int* ssrc) {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  RtpRtcp* rtp_rtcp = GetRtpRtcpModule(idx);
  if (rtp_rtcp == NULL)
    return -1;
  *ssrc = rtp_rtcp->SSRC();
  return 0;
}

int32_t ViEChannel::GetRemoteSSRC(uint32_t* ssrc) {
  *ssrc = vie_receiver_.GetRemoteSsrc();
  return 0;
}

int32_t ViEChannel::GetRemoteCSRC(uint32_t CSRCs[kRtpCsrcSize]) {
  uint32_t arrayCSRC[kRtpCsrcSize];
  memset(arrayCSRC, 0, sizeof(arrayCSRC));

  int num_csrcs = vie_receiver_.GetCsrcs(arrayCSRC);
  if (num_csrcs > 0) {
    memcpy(CSRCs, arrayCSRC, num_csrcs * sizeof(uint32_t));
  }
  return 0;
}

void ViEChannel::SetPadWithRedundantPayloads(bool enable) {
  {
    CriticalSectionScoped cs(callback_cs_.get());
    pad_with_redundant_payloads_ = enable;
  }
  int mode;
  uint32_t ssrc;
  int payload_type;
  rtp_rtcp_->RTXSendStatus(&mode, &ssrc, &payload_type);
  if (mode != kRtxOff) {
    // Since RTX was already enabled we have to reset it with payload-based
    // padding on.
    SetRtxSendStatus(true);
  }
}

int ViEChannel::SetRtxSendPayloadType(int payload_type) {
  rtp_rtcp_->SetRtxSendPayloadType(payload_type);
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end(); it++) {
    (*it)->SetRtxSendPayloadType(payload_type);
  }
  SetRtxSendStatus(true);
  return 0;
}

void ViEChannel::SetRtxSendStatus(bool enable) {
  int rtx_settings = kRtxOff;
  if (enable) {
    CriticalSectionScoped cs(callback_cs_.get());
    rtx_settings = kRtxRetransmitted;
    if (pad_with_redundant_payloads_)
      rtx_settings |= kRtxRedundantPayloads;
  }
  rtp_rtcp_->SetRTXSendStatus(rtx_settings);
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end(); it++) {
    (*it)->SetRTXSendStatus(rtx_settings);
  }
}

void ViEChannel::SetRtxReceivePayloadType(int payload_type) {
  vie_receiver_.SetRtxPayloadType(payload_type);
}

int32_t ViEChannel::SetStartSequenceNumber(uint16_t sequence_number) {
  if (rtp_rtcp_->Sending()) {
    return -1;
  }
  return rtp_rtcp_->SetSequenceNumber(sequence_number);
}

void ViEChannel::SetRtpStateForSsrc(uint32_t ssrc, const RtpState& rtp_state) {
  assert(!rtp_rtcp_->Sending());
  default_rtp_rtcp_->SetRtpStateForSsrc(ssrc, rtp_state);
}

RtpState ViEChannel::GetRtpStateForSsrc(uint32_t ssrc) {
  assert(!rtp_rtcp_->Sending());

  RtpState rtp_state;
  if (!default_rtp_rtcp_->GetRtpStateForSsrc(ssrc, &rtp_state)) {
    LOG(LS_ERROR) << "Couldn't get RTP state for ssrc: " << ssrc;
  }
  return rtp_state;
}

int32_t ViEChannel::SetRTCPCName(const char rtcp_cname[]) {
  if (rtp_rtcp_->Sending()) {
    return -1;
  }
  return rtp_rtcp_->SetCNAME(rtcp_cname);
}

int32_t ViEChannel::GetRemoteRTCPCName(char rtcp_cname[]) {
  uint32_t remoteSSRC = vie_receiver_.GetRemoteSsrc();
  return rtp_rtcp_->RemoteCNAME(remoteSSRC, rtcp_cname);
}

int32_t ViEChannel::RegisterRtpObserver(ViERTPObserver* observer) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (observer) {
    if (rtp_observer_) {
      LOG_F(LS_ERROR) << "Observer already registered.";
      return -1;
    }
    rtp_observer_ = observer;
  } else {
    rtp_observer_ = NULL;
  }
  return 0;
}

int32_t ViEChannel::RegisterRtcpObserver(ViERTCPObserver* observer) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (observer) {
    if (rtcp_observer_) {
      LOG_F(LS_ERROR) << "Observer already registered.";
      return -1;
    }
    rtcp_observer_ = observer;
  } else {
    rtcp_observer_ = NULL;
  }
  return 0;
}

int32_t ViEChannel::SendApplicationDefinedRTCPPacket(
    const uint8_t sub_type,
    uint32_t name,
    const uint8_t* data,
    uint16_t data_length_in_bytes) {
  if (!rtp_rtcp_->Sending()) {
    return -1;
  }
  if (!data) {
    LOG_F(LS_ERROR) << "Invalid input.";
    return -1;
  }
  if (data_length_in_bytes % 4 != 0) {
    LOG(LS_ERROR) << "Invalid input length.";
    return -1;
  }
  RTCPMethod rtcp_method = rtp_rtcp_->RTCP();
  if (rtcp_method == kRtcpOff) {
    LOG_F(LS_ERROR) << "RTCP not enable.";
    return -1;
  }
  // Create and send packet.
  if (rtp_rtcp_->SetRTCPApplicationSpecificData(sub_type, name, data,
                                               data_length_in_bytes) != 0) {
    return -1;
  }
  return 0;
}

int32_t ViEChannel::GetSendRtcpStatistics(uint16_t* fraction_lost,
                                          uint32_t* cumulative_lost,
                                          uint32_t* extended_max,
                                          uint32_t* jitter_samples,
                                          int32_t* rtt_ms) {
  // Aggregate the report blocks associated with streams sent on this channel.
  std::vector<RTCPReportBlock> report_blocks;
  rtp_rtcp_->RemoteRTCPStat(&report_blocks);
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       ++it) {
    (*it)->RemoteRTCPStat(&report_blocks);
  }

  if (report_blocks.empty())
    return -1;

  RTCPReportBlock report;
  if (report_blocks.size() > 1)
    report = AggregateReportBlocks(report_blocks, &prev_report_blocks_);
  else
    report = report_blocks[0];

  *fraction_lost = report.fractionLost;
  *cumulative_lost = report.cumulativeLost;
  *extended_max = report.extendedHighSeqNum;
  *jitter_samples = report.jitter;

  uint16_t dummy;
  uint16_t rtt = 0;
  if (rtp_rtcp_->RTT(
          vie_receiver_.GetRemoteSsrc(), &rtt, &dummy, &dummy, &dummy) != 0) {
    return -1;
  }
  *rtt_ms = rtt;
  return 0;
}

void ViEChannel::RegisterSendChannelRtcpStatisticsCallback(
    RtcpStatisticsCallback* callback) {
  rtp_rtcp_->RegisterSendChannelRtcpStatisticsCallback(callback);
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       ++it) {
    (*it)->RegisterSendChannelRtcpStatisticsCallback(callback);
  }
}

// TODO(holmer): This is a bad function name as it implies that it returns the
// received RTCP, while it actually returns the statistics which will be sent
// in the RTCP.
int32_t ViEChannel::GetReceivedRtcpStatistics(uint16_t* fraction_lost,
                                              uint32_t* cumulative_lost,
                                              uint32_t* extended_max,
                                              uint32_t* jitter_samples,
                                              int32_t* rtt_ms) {
  uint32_t remote_ssrc = vie_receiver_.GetRemoteSsrc();
  StreamStatistician* statistician =
      vie_receiver_.GetReceiveStatistics()->GetStatistician(remote_ssrc);
  RtcpStatistics receive_stats;
  if (!statistician || !statistician->GetStatistics(
      &receive_stats, rtp_rtcp_->RTCP() == kRtcpOff)) {
    return -1;
  }
  *fraction_lost = receive_stats.fraction_lost;
  *cumulative_lost = receive_stats.cumulative_lost;
  *extended_max = receive_stats.extended_max_sequence_number;
  *jitter_samples = receive_stats.jitter;

  uint16_t dummy = 0;
  uint16_t rtt = 0;
  rtp_rtcp_->RTT(remote_ssrc, &rtt, &dummy, &dummy, &dummy);
  *rtt_ms = rtt;
  return 0;
}

void ViEChannel::RegisterReceiveChannelRtcpStatisticsCallback(
    RtcpStatisticsCallback* callback) {
  vie_receiver_.GetReceiveStatistics()->RegisterRtcpStatisticsCallback(
      callback);
}

int32_t ViEChannel::GetRtpStatistics(uint32_t* bytes_sent,
                                     uint32_t* packets_sent,
                                     uint32_t* bytes_received,
                                     uint32_t* packets_received) const {
  StreamStatistician* statistician = vie_receiver_.GetReceiveStatistics()->
      GetStatistician(vie_receiver_.GetRemoteSsrc());
  *bytes_received = 0;
  *packets_received = 0;
  if (statistician)
    statistician->GetDataCounters(bytes_received, packets_received);
  if (rtp_rtcp_->DataCountersRTP(bytes_sent, packets_sent) != 0) {
    return -1;
  }
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    uint32_t bytes_sent_temp = 0;
    uint32_t packets_sent_temp = 0;
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->DataCountersRTP(&bytes_sent_temp, &packets_sent_temp);
    *bytes_sent += bytes_sent_temp;
    *packets_sent += packets_sent_temp;
  }
  for (std::list<RtpRtcp*>::const_iterator it = removed_rtp_rtcp_.begin();
       it != removed_rtp_rtcp_.end(); ++it) {
    uint32_t bytes_sent_temp = 0;
    uint32_t packets_sent_temp = 0;
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->DataCountersRTP(&bytes_sent_temp, &packets_sent_temp);
    *bytes_sent += bytes_sent_temp;
    *packets_sent += packets_sent_temp;
  }
  return 0;
}

void ViEChannel::RegisterSendChannelRtpStatisticsCallback(
      StreamDataCountersCallback* callback) {
  rtp_rtcp_->RegisterSendChannelRtpStatisticsCallback(callback);
  {
    CriticalSectionScoped cs(rtp_rtcp_cs_.get());
    for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
         it != simulcast_rtp_rtcp_.end();
         it++) {
      (*it)->RegisterSendChannelRtpStatisticsCallback(callback);
    }
  }
}

void ViEChannel::RegisterReceiveChannelRtpStatisticsCallback(
    StreamDataCountersCallback* callback) {
  vie_receiver_.GetReceiveStatistics()->RegisterRtpStatisticsCallback(callback);
}

void ViEChannel::GetRtcpPacketTypeCounters(
    RtcpPacketTypeCounter* packets_sent,
    RtcpPacketTypeCounter* packets_received) const {
  rtp_rtcp_->GetRtcpPacketTypeCounters(packets_sent, packets_received);

  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end(); ++it) {
    RtcpPacketTypeCounter sent;
    RtcpPacketTypeCounter received;
    (*it)->GetRtcpPacketTypeCounters(&sent, &received);
    packets_sent->Add(sent);
    packets_received->Add(received);
  }
  for (std::list<RtpRtcp*>::const_iterator it = removed_rtp_rtcp_.begin();
       it != removed_rtp_rtcp_.end(); ++it) {
    RtcpPacketTypeCounter sent;
    RtcpPacketTypeCounter received;
    (*it)->GetRtcpPacketTypeCounters(&sent, &received);
    packets_sent->Add(sent);
    packets_received->Add(received);
  }
}

void ViEChannel::GetBandwidthUsage(uint32_t* total_bitrate_sent,
                                   uint32_t* video_bitrate_sent,
                                   uint32_t* fec_bitrate_sent,
                                   uint32_t* nackBitrateSent) const {
  rtp_rtcp_->BitrateSent(total_bitrate_sent, video_bitrate_sent,
                         fec_bitrate_sent, nackBitrateSent);
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end(); it++) {
    uint32_t stream_rate = 0;
    uint32_t video_rate = 0;
    uint32_t fec_rate = 0;
    uint32_t nackRate = 0;
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->BitrateSent(&stream_rate, &video_rate, &fec_rate, &nackRate);
    *total_bitrate_sent += stream_rate;
    *video_bitrate_sent += video_rate;
    *fec_bitrate_sent += fec_rate;
    *nackBitrateSent += nackRate;
  }
}

bool ViEChannel::GetSendSideDelay(int* avg_send_delay,
                                  int* max_send_delay) const {
  *avg_send_delay = 0;
  *max_send_delay = 0;
  bool valid_estimate = false;
  int num_send_delays = 0;
  if (rtp_rtcp_->GetSendSideDelay(avg_send_delay, max_send_delay)) {
    ++num_send_delays;
    valid_estimate = true;
  }
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end(); it++) {
    RtpRtcp* rtp_rtcp = *it;
    int sub_stream_avg_delay = 0;
    int sub_stream_max_delay = 0;
    if (rtp_rtcp->GetSendSideDelay(&sub_stream_avg_delay,
                                   &sub_stream_max_delay)) {
      *avg_send_delay += sub_stream_avg_delay;
      *max_send_delay = std::max(*max_send_delay, sub_stream_max_delay);
      ++num_send_delays;
    }
  }
  if (num_send_delays > 0) {
    valid_estimate = true;
    *avg_send_delay = *avg_send_delay / num_send_delays;
    *avg_send_delay = (*avg_send_delay + num_send_delays / 2) / num_send_delays;
  }
  return valid_estimate;
}

void ViEChannel::RegisterSendSideDelayObserver(
    SendSideDelayObserver* observer) {
  send_side_delay_observer_.Set(observer);
}

void ViEChannel::RegisterSendBitrateObserver(
    BitrateStatisticsObserver* observer) {
  send_bitrate_observer_.Set(observer);
}

void ViEChannel::GetReceiveBandwidthEstimatorStats(
    ReceiveBandwidthEstimatorStats* output) const {
  vie_receiver_.GetReceiveBandwidthEstimatorStats(output);
}

int32_t ViEChannel::StartRTPDump(const char file_nameUTF8[1024],
                                 RTPDirections direction) {
  if (direction == kRtpIncoming) {
    return vie_receiver_.StartRTPDump(file_nameUTF8);
  } else {
    return vie_sender_.StartRTPDump(file_nameUTF8);
  }
}

int32_t ViEChannel::StopRTPDump(RTPDirections direction) {
  if (direction == kRtpIncoming) {
    return vie_receiver_.StopRTPDump();
  } else {
    return vie_sender_.StopRTPDump();
  }
}

int32_t ViEChannel::StartSend() {
  CriticalSectionScoped cs(callback_cs_.get());
  if (!external_transport_) {
    LOG(LS_ERROR) << "No transport set.";
    return -1;
  }
  rtp_rtcp_->SetSendingMediaStatus(true);

  if (rtp_rtcp_->Sending()) {
    return kViEBaseAlreadySending;
  }
  if (rtp_rtcp_->SetSendingStatus(true) != 0) {
    return -1;
  }
  CriticalSectionScoped cs_rtp(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->SetSendingMediaStatus(true);
    rtp_rtcp->SetSendingStatus(true);
  }
  return 0;
}

int32_t ViEChannel::StopSend() {
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  rtp_rtcp_->SetSendingMediaStatus(false);
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->SetSendingMediaStatus(false);
  }
  if (!rtp_rtcp_->Sending()) {
    return kViEBaseNotSending;
  }

  // Reset.
  rtp_rtcp_->ResetSendDataCountersRTP();
  if (rtp_rtcp_->SetSendingStatus(false) != 0) {
    return -1;
  }
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->ResetSendDataCountersRTP();
    rtp_rtcp->SetSendingStatus(false);
  }
  return 0;
}

bool ViEChannel::Sending() {
  return rtp_rtcp_->Sending();
}

int32_t ViEChannel::StartReceive() {
  CriticalSectionScoped cs(callback_cs_.get());
  if (StartDecodeThread() != 0) {
    vie_receiver_.StopReceive();
    return -1;
  }
  vie_receiver_.StartReceive();
  return 0;
}

int32_t ViEChannel::StopReceive() {
  vie_receiver_.StopReceive();
  StopDecodeThread();
  vcm_->ResetDecoder();
  return 0;
}

int32_t ViEChannel::RegisterSendTransport(Transport* transport) {
  if (rtp_rtcp_->Sending()) {
    return -1;
  }

  CriticalSectionScoped cs(callback_cs_.get());
  if (external_transport_) {
    LOG_F(LS_ERROR) << "Transport already registered.";
    return -1;
  }
  external_transport_ = transport;
  vie_sender_.RegisterSendTransport(transport);
  return 0;
}

int32_t ViEChannel::DeregisterSendTransport() {
  CriticalSectionScoped cs(callback_cs_.get());
  if (!external_transport_) {
    return 0;
  }
  if (rtp_rtcp_->Sending()) {
    LOG_F(LS_ERROR) << "Can't deregister transport when sending.";
    return -1;
  }
  external_transport_ = NULL;
  vie_sender_.DeregisterSendTransport();
  return 0;
}

int32_t ViEChannel::ReceivedRTPPacket(
    const void* rtp_packet, const int32_t rtp_packet_length,
    const PacketTime& packet_time) {
  {
    CriticalSectionScoped cs(callback_cs_.get());
    if (!external_transport_) {
      return -1;
    }
  }
  return vie_receiver_.ReceivedRTPPacket(
      rtp_packet, rtp_packet_length, packet_time);
}

int32_t ViEChannel::ReceivedRTCPPacket(
  const void* rtcp_packet, const int32_t rtcp_packet_length) {
  {
    CriticalSectionScoped cs(callback_cs_.get());
    if (!external_transport_) {
      return -1;
    }
  }
  return vie_receiver_.ReceivedRTCPPacket(rtcp_packet, rtcp_packet_length);
}

int32_t ViEChannel::SetMTU(uint16_t mtu) {
  if (rtp_rtcp_->SetMaxTransferUnit(mtu) != 0) {
    return -1;
  }
  CriticalSectionScoped cs(rtp_rtcp_cs_.get());
  for (std::list<RtpRtcp*>::iterator it = simulcast_rtp_rtcp_.begin();
       it != simulcast_rtp_rtcp_.end();
       it++) {
    RtpRtcp* rtp_rtcp = *it;
    rtp_rtcp->SetMaxTransferUnit(mtu);
  }
  mtu_ = mtu;
  return 0;
}

uint16_t ViEChannel::MaxDataPayloadLength() const {
  return rtp_rtcp_->MaxDataPayloadLength();
}

int32_t ViEChannel::EnableColorEnhancement(bool enable) {
  CriticalSectionScoped cs(callback_cs_.get());
  color_enhancement_ = enable;
  return 0;
}

RtpRtcp* ViEChannel::rtp_rtcp() {
  return rtp_rtcp_.get();
}

CallStatsObserver* ViEChannel::GetStatsObserver() {
  return stats_observer_.get();
}

// Do not acquire the lock of |vcm_| in this function. Decode callback won't
// necessarily be called from the decoding thread. The decoding thread may have
// held the lock when calling VideoDecoder::Decode, Reset, or Release. Acquiring
// the same lock in the path of decode callback can deadlock.
int32_t ViEChannel::FrameToRender(
    I420VideoFrame& video_frame) {  // NOLINT
  CriticalSectionScoped cs(callback_cs_.get());

  if (decoder_reset_) {
    // Trigger a callback to the user if the incoming codec has changed.
    if (codec_observer_) {
      // The codec set by RegisterReceiveCodec might not be the size we're
      // actually decoding.
      receive_codec_.width = static_cast<uint16_t>(video_frame.width());
      receive_codec_.height = static_cast<uint16_t>(video_frame.height());
      codec_observer_->IncomingCodecChanged(channel_id_, receive_codec_);
    }
    decoder_reset_ = false;
  }
  // Post processing is not supported if the frame is backed by a texture.
  if (video_frame.native_handle() == NULL) {
    if (pre_render_callback_ != NULL)
      pre_render_callback_->FrameCallback(&video_frame);
    if (effect_filter_) {
      unsigned int length = CalcBufferSize(kI420,
                                           video_frame.width(),
                                           video_frame.height());
      scoped_ptr<uint8_t[]> video_buffer(new uint8_t[length]);
      ExtractBuffer(video_frame, length, video_buffer.get());
      effect_filter_->Transform(length,
                                video_buffer.get(),
                                video_frame.ntp_time_ms(),
                                video_frame.timestamp(),
                                video_frame.width(),
                                video_frame.height());
    }
    if (color_enhancement_) {
      VideoProcessingModule::ColorEnhancement(&video_frame);
    }
  }

  uint32_t arr_ofCSRC[kRtpCsrcSize];
  int32_t no_of_csrcs = vie_receiver_.GetCsrcs(arr_ofCSRC);
  if (no_of_csrcs <= 0) {
    arr_ofCSRC[0] = vie_receiver_.GetRemoteSsrc();
    no_of_csrcs = 1;
  }
  DeliverFrame(&video_frame, no_of_csrcs, arr_ofCSRC);
  return 0;
}

int32_t ViEChannel::ReceivedDecodedReferenceFrame(
  const uint64_t picture_id) {
  return rtp_rtcp_->SendRTCPReferencePictureSelection(picture_id);
}

void ViEChannel::IncomingCodecChanged(const VideoCodec& codec) {
  CriticalSectionScoped cs(callback_cs_.get());
  receive_codec_ = codec;
}

int32_t ViEChannel::OnReceiveStatisticsUpdate(const uint32_t bit_rate,
                                              const uint32_t frame_rate) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (codec_observer_) {
    codec_observer_->IncomingRate(channel_id_, frame_rate, bit_rate);
  }
  return 0;
}

void ViEChannel::OnDecoderTiming(int decode_ms,
                                 int max_decode_ms,
                                 int current_delay_ms,
                                 int target_delay_ms,
                                 int jitter_buffer_ms,
                                 int min_playout_delay_ms,
                                 int render_delay_ms) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (!codec_observer_)
    return;
  codec_observer_->DecoderTiming(decode_ms,
                                 max_decode_ms,
                                 current_delay_ms,
                                 target_delay_ms,
                                 jitter_buffer_ms,
                                 min_playout_delay_ms,
                                 render_delay_ms);
}

int32_t ViEChannel::RequestKeyFrame() {
  {
    CriticalSectionScoped cs(callback_cs_.get());
    if (codec_observer_ && do_key_frame_callbackRequest_) {
      codec_observer_->RequestNewKeyFrame(channel_id_);
    }
  }
  return rtp_rtcp_->RequestKeyFrame();
}

int32_t ViEChannel::SliceLossIndicationRequest(
  const uint64_t picture_id) {
  return rtp_rtcp_->SendRTCPSliceLossIndication((uint8_t) picture_id);
}

int32_t ViEChannel::ResendPackets(const uint16_t* sequence_numbers,
                                        uint16_t length) {
  return rtp_rtcp_->SendNACK(sequence_numbers, length);
}

bool ViEChannel::ChannelDecodeThreadFunction(void* obj) {
  return static_cast<ViEChannel*>(obj)->ChannelDecodeProcess();
}

bool ViEChannel::ChannelDecodeProcess() {
  vcm_->Decode(kMaxDecodeWaitTimeMs);
  return true;
}

void ViEChannel::OnRttUpdate(uint32_t rtt) {
  vcm_->SetReceiveChannelParameters(rtt);
}

void ViEChannel::ReserveRtpRtcpModules(size_t num_modules) {
  for (size_t total_modules =
           1 + simulcast_rtp_rtcp_.size() + removed_rtp_rtcp_.size();
       total_modules < num_modules;
       ++total_modules) {
    RtpRtcp* rtp_rtcp = CreateRtpRtcpModule();
    rtp_rtcp->SetSendingStatus(false);
    rtp_rtcp->SetSendingMediaStatus(false);
    rtp_rtcp->RegisterSendChannelRtcpStatisticsCallback(NULL);
    rtp_rtcp->RegisterSendChannelRtpStatisticsCallback(NULL);
    removed_rtp_rtcp_.push_back(rtp_rtcp);
  }
}

RtpRtcp* ViEChannel::GetRtpRtcpModule(size_t index) const {
  if (index == 0)
    return rtp_rtcp_.get();
  if (index <= simulcast_rtp_rtcp_.size()) {
    std::list<RtpRtcp*>::const_iterator it = simulcast_rtp_rtcp_.begin();
    for (size_t i = 1; i < index; ++i) {
      ++it;
    }
    return *it;
  }

  // If the requested module exists it must be in the removed list. Index
  // translation to this list must remove the default module as well as all
  // active simulcast modules.
  size_t removed_idx = index - simulcast_rtp_rtcp_.size() - 1;
  if (removed_idx >= removed_rtp_rtcp_.size())
    return NULL;

  std::list<RtpRtcp*>::const_iterator it = removed_rtp_rtcp_.begin();
  while (removed_idx-- > 0)
    ++it;

  return *it;
}

RtpRtcp* ViEChannel::CreateRtpRtcpModule() {
  RtpRtcp::Configuration configuration;
  configuration.id = ViEModuleId(engine_id_, channel_id_);
  configuration.audio = false;  // Video.
  configuration.default_module = default_rtp_rtcp_;
  configuration.outgoing_transport = &vie_sender_;
  configuration.intra_frame_callback = intra_frame_observer_;
  configuration.bandwidth_callback = bandwidth_observer_.get();
  configuration.rtt_stats = rtt_stats_;
  configuration.paced_sender = paced_sender_;
  configuration.send_side_delay_observer = &send_side_delay_observer_;

  return RtpRtcp::CreateRtpRtcp(configuration);
}

int32_t ViEChannel::StartDecodeThread() {
  // Start the decode thread
  if (decode_thread_) {
    // Already started.
    return 0;
  }
  decode_thread_ = ThreadWrapper::CreateThread(ChannelDecodeThreadFunction,
                                                   this, kHighestPriority,
                                                   "DecodingThread");
  if (!decode_thread_) {
    return -1;
  }

  unsigned int thread_id;
  if (decode_thread_->Start(thread_id) == false) {
    delete decode_thread_;
    decode_thread_ = NULL;
    LOG(LS_ERROR) << "Could not start decode thread.";
    return -1;
  }
  return 0;
}

int32_t ViEChannel::StopDecodeThread() {
  if (!decode_thread_) {
    return 0;
  }

  decode_thread_->SetNotAlive();
  if (decode_thread_->Stop()) {
    delete decode_thread_;
  } else {
    assert(false && "could not stop decode thread");
  }
  decode_thread_ = NULL;
  return 0;
}

int32_t ViEChannel::SetVoiceChannel(int32_t ve_channel_id,
                                          VoEVideoSync* ve_sync_interface) {
  if (ve_sync_interface) {
    // Register lip sync
    module_process_thread_.RegisterModule(&vie_sync_);
  } else {
    module_process_thread_.DeRegisterModule(&vie_sync_);
  }
  return vie_sync_.ConfigureSync(ve_channel_id,
                                 ve_sync_interface,
                                 rtp_rtcp_.get(),
                                 vie_receiver_.GetRtpReceiver());
}

int32_t ViEChannel::VoiceChannel() {
  return vie_sync_.VoiceChannel();
}

int32_t ViEChannel::RegisterEffectFilter(ViEEffectFilter* effect_filter) {
  CriticalSectionScoped cs(callback_cs_.get());
  if (effect_filter && effect_filter_) {
    LOG(LS_ERROR) << "Effect filter already registered.";
    return -1;
  }
  effect_filter_ = effect_filter;
  return 0;
}

void ViEChannel::RegisterPreRenderCallback(
    I420FrameCallback* pre_render_callback) {
  CriticalSectionScoped cs(callback_cs_.get());
  pre_render_callback_ = pre_render_callback;
}

void ViEChannel::RegisterPreDecodeImageCallback(
    EncodedImageCallback* pre_decode_callback) {
  vcm_->RegisterPreDecodeImageCallback(pre_decode_callback);
}

void ViEChannel::OnApplicationDataReceived(const int32_t id,
                                           const uint8_t sub_type,
                                           const uint32_t name,
                                           const uint16_t length,
                                           const uint8_t* data) {
  if (channel_id_ != ChannelId(id)) {
    return;
  }
  CriticalSectionScoped cs(callback_cs_.get());
  {
    if (rtcp_observer_) {
      rtcp_observer_->OnApplicationDataReceived(
          channel_id_, sub_type, name, reinterpret_cast<const char*>(data),
          length);
    }
  }
}

int32_t ViEChannel::OnInitializeDecoder(
    const int32_t id,
    const int8_t payload_type,
    const char payload_name[RTP_PAYLOAD_NAME_SIZE],
    const int frequency,
    const uint8_t channels,
    const uint32_t rate) {
  LOG(LS_INFO) << "OnInitializeDecoder " << payload_type << " "
               << payload_name;
  vcm_->ResetDecoder();

  CriticalSectionScoped cs(callback_cs_.get());
  decoder_reset_ = true;
  return 0;
}

void ViEChannel::OnIncomingSSRCChanged(const int32_t id, const uint32_t ssrc) {
  assert(channel_id_ == ChannelId(id));
  rtp_rtcp_->SetRemoteSSRC(ssrc);

  CriticalSectionScoped cs(callback_cs_.get());
  {
    if (rtp_observer_) {
      rtp_observer_->IncomingSSRCChanged(channel_id_, ssrc);
    }
  }
}

void ViEChannel::OnIncomingCSRCChanged(const int32_t id,
                                       const uint32_t CSRC,
                                       const bool added) {
  assert(channel_id_ == ChannelId(id));
  CriticalSectionScoped cs(callback_cs_.get());
  {
    if (rtp_observer_) {
      rtp_observer_->IncomingCSRCChanged(channel_id_, CSRC, added);
    }
  }
}

void ViEChannel::ResetStatistics(uint32_t ssrc) {
  StreamStatistician* statistician =
      vie_receiver_.GetReceiveStatistics()->GetStatistician(ssrc);
  if (statistician)
    statistician->ResetStatistics();
}

void ViEChannel::RegisterSendFrameCountObserver(
    FrameCountObserver* observer) {
  send_frame_count_observer_.Set(observer);
}

void ViEChannel::ReceivedBWEPacket(int64_t arrival_time_ms,
    int payload_size, const RTPHeader& header) {
  vie_receiver_.ReceivedBWEPacket(arrival_time_ms, payload_size, header);
}
}  // namespace webrtc