Prepare the AudioSendStream to be hooked up to send-side BWE.

This CL contains three changes as a preparation for adding audio send streams
to the send-side BWE:
1. Audio packets are passed through the pacer with high priority. This
is needed to be able to set transport sequence numbers on the packets.
2. A feedback observer is passed to the audio stream's rtcp receiver so
that the BWE can get notified of any BWE feedback being received on the
audio feedback channel.
3. Support for the transport sequence number header extension is added
to audio send streams.

BUG=webrtc:5263,webrtc:5307
R=mflodman@webrtc.org, solenberg@webrtc.org

Review URL: https://codereview.webrtc.org/1479023002 .

Cr-Commit-Position: refs/heads/master@{#10909}

1 files changed, 225 insertions, 84 deletions

diff --git a/webrtc/voice_engine/channel.cc b/webrtc/voice_engine/channel.cc
index fb9835664a..37dc3b685b 100644
--- a/webrtc/voice_engine/channel.cc
+++ b/webrtc/voice_engine/channel.cc
@@ -15,12 +15,14 @@
 #include "webrtc/base/checks.h"
 #include "webrtc/base/format_macros.h"
 #include "webrtc/base/logging.h"
+#include "webrtc/base/thread_checker.h"
 #include "webrtc/base/timeutils.h"
 #include "webrtc/common.h"
 #include "webrtc/config.h"
 #include "webrtc/modules/audio_device/include/audio_device.h"
 #include "webrtc/modules/audio_processing/include/audio_processing.h"
 #include "webrtc/modules/include/module_common_types.h"
+#include "webrtc/modules/pacing/packet_router.h"
 #include "webrtc/modules/rtp_rtcp/include/receive_statistics.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_receiver.h"
@@ -44,6 +46,104 @@
 namespace webrtc {
 namespace voe {
 
+class TransportFeedbackProxy : public TransportFeedbackObserver {
+ public:
+  TransportFeedbackProxy() : feedback_observer_(nullptr) {
+    pacer_thread_.DetachFromThread();
+    network_thread_.DetachFromThread();
+  }
+
+  void SetTransportFeedbackObserver(
+      TransportFeedbackObserver* feedback_observer) {
+    RTC_DCHECK(thread_checker_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    feedback_observer_ = feedback_observer;
+  }
+
+  // Implements TransportFeedbackObserver.
+  void AddPacket(uint16_t sequence_number,
+                 size_t length,
+                 bool was_paced) override {
+    RTC_DCHECK(pacer_thread_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    if (feedback_observer_)
+      feedback_observer_->AddPacket(sequence_number, length, was_paced);
+  }
+  void OnTransportFeedback(const rtcp::TransportFeedback& feedback) override {
+    RTC_DCHECK(network_thread_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    if (feedback_observer_)
+      feedback_observer_->OnTransportFeedback(feedback);
+  }
+
+ private:
+  rtc::CriticalSection crit_;
+  rtc::ThreadChecker thread_checker_;
+  rtc::ThreadChecker pacer_thread_;
+  rtc::ThreadChecker network_thread_;
+  TransportFeedbackObserver* feedback_observer_ GUARDED_BY(&crit_);
+};
+
+class TransportSequenceNumberProxy : public TransportSequenceNumberAllocator {
+ public:
+  TransportSequenceNumberProxy() : seq_num_allocator_(nullptr) {
+    pacer_thread_.DetachFromThread();
+  }
+
+  void SetSequenceNumberAllocator(
+      TransportSequenceNumberAllocator* seq_num_allocator) {
+    RTC_DCHECK(thread_checker_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    seq_num_allocator_ = seq_num_allocator;
+  }
+
+  // Implements TransportSequenceNumberAllocator.
+  uint16_t AllocateSequenceNumber() override {
+    RTC_DCHECK(pacer_thread_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    if (!seq_num_allocator_)
+      return 0;
+    return seq_num_allocator_->AllocateSequenceNumber();
+  }
+
+ private:
+  rtc::CriticalSection crit_;
+  rtc::ThreadChecker thread_checker_;
+  rtc::ThreadChecker pacer_thread_;
+  TransportSequenceNumberAllocator* seq_num_allocator_ GUARDED_BY(&crit_);
+};
+
+class RtpPacketSenderProxy : public RtpPacketSender {
+ public:
+  RtpPacketSenderProxy() : rtp_packet_sender_(nullptr) {
+  }
+
+  void SetPacketSender(RtpPacketSender* rtp_packet_sender) {
+    RTC_DCHECK(thread_checker_.CalledOnValidThread());
+    rtc::CritScope lock(&crit_);
+    rtp_packet_sender_ = rtp_packet_sender;
+  }
+
+  // Implements RtpPacketSender.
+  void InsertPacket(Priority priority,
+                    uint32_t ssrc,
+                    uint16_t sequence_number,
+                    int64_t capture_time_ms,
+                    size_t bytes,
+                    bool retransmission) override {
+    rtc::CritScope lock(&crit_);
+    if (rtp_packet_sender_) {
+      rtp_packet_sender_->InsertPacket(priority, ssrc, sequence_number,
+                                       capture_time_ms, bytes, retransmission);
+    }
+  }
+
+ private:
+  rtc::ThreadChecker thread_checker_;
+  rtc::CriticalSection crit_;
+  RtpPacketSender* rtp_packet_sender_ GUARDED_BY(&crit_);
+};
+
 // Extend the default RTCP statistics struct with max_jitter, defined as the
 // maximum jitter value seen in an RTCP report block.
 struct ChannelStatistics : public RtcpStatistics {
@@ -690,89 +790,97 @@ Channel::Channel(int32_t channelId,
                  uint32_t instanceId,
                  RtcEventLog* const event_log,
                  const Config& config)
-  : _fileCritSect(*CriticalSectionWrapper::CreateCriticalSection()),
-    _callbackCritSect(*CriticalSectionWrapper::CreateCriticalSection()),
-    volume_settings_critsect_(*CriticalSectionWrapper::CreateCriticalSection()),
-    _instanceId(instanceId),
-    _channelId(channelId),
-    event_log_(event_log),
-    rtp_header_parser_(RtpHeaderParser::Create()),
-    rtp_payload_registry_(
-        new RTPPayloadRegistry(RTPPayloadStrategy::CreateStrategy(true))),
-    rtp_receive_statistics_(
-        ReceiveStatistics::Create(Clock::GetRealTimeClock())),
-    rtp_receiver_(
-        RtpReceiver::CreateAudioReceiver(Clock::GetRealTimeClock(),
-                                         this,
-                                         this,
-                                         this,
-                                         rtp_payload_registry_.get())),
-    telephone_event_handler_(rtp_receiver_->GetTelephoneEventHandler()),
-    _outputAudioLevel(),
-    _externalTransport(false),
-    _inputFilePlayerPtr(NULL),
-    _outputFilePlayerPtr(NULL),
-    _outputFileRecorderPtr(NULL),
-    // Avoid conflict with other channels by adding 1024 - 1026,
-    // won't use as much as 1024 channels.
-    _inputFilePlayerId(VoEModuleId(instanceId, channelId) + 1024),
-    _outputFilePlayerId(VoEModuleId(instanceId, channelId) + 1025),
-    _outputFileRecorderId(VoEModuleId(instanceId, channelId) + 1026),
-    _outputFileRecording(false),
-    _inbandDtmfQueue(VoEModuleId(instanceId, channelId)),
-    _inbandDtmfGenerator(VoEModuleId(instanceId, channelId)),
-    _outputExternalMedia(false),
-    _inputExternalMediaCallbackPtr(NULL),
-    _outputExternalMediaCallbackPtr(NULL),
-    _timeStamp(0),  // This is just an offset, RTP module will add it's own
-                    // random offset
-    _sendTelephoneEventPayloadType(106),
-    ntp_estimator_(Clock::GetRealTimeClock()),
-    jitter_buffer_playout_timestamp_(0),
-    playout_timestamp_rtp_(0),
-    playout_timestamp_rtcp_(0),
-    playout_delay_ms_(0),
-    _numberOfDiscardedPackets(0),
-    send_sequence_number_(0),
-    ts_stats_lock_(CriticalSectionWrapper::CreateCriticalSection()),
-    rtp_ts_wraparound_handler_(new rtc::TimestampWrapAroundHandler()),
-    capture_start_rtp_time_stamp_(-1),
-    capture_start_ntp_time_ms_(-1),
-    _engineStatisticsPtr(NULL),
-    _outputMixerPtr(NULL),
-    _transmitMixerPtr(NULL),
-    _moduleProcessThreadPtr(NULL),
-    _audioDeviceModulePtr(NULL),
-    _voiceEngineObserverPtr(NULL),
-    _callbackCritSectPtr(NULL),
-    _transportPtr(NULL),
-    _rxVadObserverPtr(NULL),
-    _oldVadDecision(-1),
-    _sendFrameType(0),
-    _externalMixing(false),
-    _mixFileWithMicrophone(false),
-    _mute(false),
-    _panLeft(1.0f),
-    _panRight(1.0f),
-    _outputGain(1.0f),
-    _playOutbandDtmfEvent(false),
-    _playInbandDtmfEvent(false),
-    _lastLocalTimeStamp(0),
-    _lastPayloadType(0),
-    _includeAudioLevelIndication(false),
-    _outputSpeechType(AudioFrame::kNormalSpeech),
-    video_sync_lock_(CriticalSectionWrapper::CreateCriticalSection()),
-    _average_jitter_buffer_delay_us(0),
-    _previousTimestamp(0),
-    _recPacketDelayMs(20),
-    _RxVadDetection(false),
-    _rxAgcIsEnabled(false),
-    _rxNsIsEnabled(false),
-    restored_packet_in_use_(false),
-    rtcp_observer_(new VoERtcpObserver(this)),
-    network_predictor_(new NetworkPredictor(Clock::GetRealTimeClock())),
-    assoc_send_channel_lock_(CriticalSectionWrapper::CreateCriticalSection()),
-    associate_send_channel_(ChannelOwner(nullptr)) {
+    : _fileCritSect(*CriticalSectionWrapper::CreateCriticalSection()),
+      _callbackCritSect(*CriticalSectionWrapper::CreateCriticalSection()),
+      volume_settings_critsect_(
+          *CriticalSectionWrapper::CreateCriticalSection()),
+      _instanceId(instanceId),
+      _channelId(channelId),
+      event_log_(event_log),
+      rtp_header_parser_(RtpHeaderParser::Create()),
+      rtp_payload_registry_(
+          new RTPPayloadRegistry(RTPPayloadStrategy::CreateStrategy(true))),
+      rtp_receive_statistics_(
+          ReceiveStatistics::Create(Clock::GetRealTimeClock())),
+      rtp_receiver_(
+          RtpReceiver::CreateAudioReceiver(Clock::GetRealTimeClock(),
+                                           this,
+                                           this,
+                                           this,
+                                           rtp_payload_registry_.get())),
+      telephone_event_handler_(rtp_receiver_->GetTelephoneEventHandler()),
+      _outputAudioLevel(),
+      _externalTransport(false),
+      _inputFilePlayerPtr(NULL),
+      _outputFilePlayerPtr(NULL),
+      _outputFileRecorderPtr(NULL),
+      // Avoid conflict with other channels by adding 1024 - 1026,
+      // won't use as much as 1024 channels.
+      _inputFilePlayerId(VoEModuleId(instanceId, channelId) + 1024),
+      _outputFilePlayerId(VoEModuleId(instanceId, channelId) + 1025),
+      _outputFileRecorderId(VoEModuleId(instanceId, channelId) + 1026),
+      _outputFileRecording(false),
+      _inbandDtmfQueue(VoEModuleId(instanceId, channelId)),
+      _inbandDtmfGenerator(VoEModuleId(instanceId, channelId)),
+      _outputExternalMedia(false),
+      _inputExternalMediaCallbackPtr(NULL),
+      _outputExternalMediaCallbackPtr(NULL),
+      _timeStamp(0),  // This is just an offset, RTP module will add it's own
+                      // random offset
+      _sendTelephoneEventPayloadType(106),
+      ntp_estimator_(Clock::GetRealTimeClock()),
+      jitter_buffer_playout_timestamp_(0),
+      playout_timestamp_rtp_(0),
+      playout_timestamp_rtcp_(0),
+      playout_delay_ms_(0),
+      _numberOfDiscardedPackets(0),
+      send_sequence_number_(0),
+      ts_stats_lock_(CriticalSectionWrapper::CreateCriticalSection()),
+      rtp_ts_wraparound_handler_(new rtc::TimestampWrapAroundHandler()),
+      capture_start_rtp_time_stamp_(-1),
+      capture_start_ntp_time_ms_(-1),
+      _engineStatisticsPtr(NULL),
+      _outputMixerPtr(NULL),
+      _transmitMixerPtr(NULL),
+      _moduleProcessThreadPtr(NULL),
+      _audioDeviceModulePtr(NULL),
+      _voiceEngineObserverPtr(NULL),
+      _callbackCritSectPtr(NULL),
+      _transportPtr(NULL),
+      _rxVadObserverPtr(NULL),
+      _oldVadDecision(-1),
+      _sendFrameType(0),
+      _externalMixing(false),
+      _mixFileWithMicrophone(false),
+      _mute(false),
+      _panLeft(1.0f),
+      _panRight(1.0f),
+      _outputGain(1.0f),
+      _playOutbandDtmfEvent(false),
+      _playInbandDtmfEvent(false),
+      _lastLocalTimeStamp(0),
+      _lastPayloadType(0),
+      _includeAudioLevelIndication(false),
+      _outputSpeechType(AudioFrame::kNormalSpeech),
+      video_sync_lock_(CriticalSectionWrapper::CreateCriticalSection()),
+      _average_jitter_buffer_delay_us(0),
+      _previousTimestamp(0),
+      _recPacketDelayMs(20),
+      _RxVadDetection(false),
+      _rxAgcIsEnabled(false),
+      _rxNsIsEnabled(false),
+      restored_packet_in_use_(false),
+      rtcp_observer_(new VoERtcpObserver(this)),
+      network_predictor_(new NetworkPredictor(Clock::GetRealTimeClock())),
+      assoc_send_channel_lock_(CriticalSectionWrapper::CreateCriticalSection()),
+      associate_send_channel_(ChannelOwner(nullptr)),
+      pacing_enabled_(config.Get<VoicePacing>().enabled),
+      feedback_observer_proxy_(pacing_enabled_ ? new TransportFeedbackProxy()
+                                               : nullptr),
+      seq_num_allocator_proxy_(
+          pacing_enabled_ ? new TransportSequenceNumberProxy() : nullptr),
+      rtp_packet_sender_proxy_(pacing_enabled_ ? new RtpPacketSenderProxy()
+                                               : nullptr) {
     WEBRTC_TRACE(kTraceMemory, kTraceVoice, VoEId(_instanceId,_channelId),
                  "Channel::Channel() - ctor");
     AudioCodingModule::Config acm_config;
@@ -797,6 +905,10 @@ Channel::Channel(int32_t channelId,
     configuration.audio_messages = this;
     configuration.receive_statistics = rtp_receive_statistics_.get();
     configuration.bandwidth_callback = rtcp_observer_.get();
+    configuration.paced_sender = rtp_packet_sender_proxy_.get();
+    configuration.transport_sequence_number_allocator =
+        seq_num_allocator_proxy_.get();
+    configuration.transport_feedback_callback = feedback_observer_proxy_.get();
 
     _rtpRtcpModule.reset(RtpRtcp::CreateRtpRtcp(configuration));
 
@@ -2787,6 +2899,33 @@ int Channel::SetReceiveAbsoluteSenderTimeStatus(bool enable, unsigned char id) {
   return 0;
 }
 
+void Channel::EnableSendTransportSequenceNumber(int id) {
+  int ret =
+      SetSendRtpHeaderExtension(true, kRtpExtensionTransportSequenceNumber, id);
+  RTC_DCHECK_EQ(0, ret);
+}
+
+void Channel::SetCongestionControlObjects(
+    RtpPacketSender* rtp_packet_sender,
+    TransportFeedbackObserver* transport_feedback_observer,
+    PacketRouter* packet_router) {
+  RTC_DCHECK(feedback_observer_proxy_.get());
+  RTC_DCHECK(seq_num_allocator_proxy_.get());
+  RTC_DCHECK(rtp_packet_sender_proxy_.get());
+  RTC_DCHECK(packet_router != nullptr || packet_router_ != nullptr);
+  feedback_observer_proxy_->SetTransportFeedbackObserver(
+      transport_feedback_observer);
+  seq_num_allocator_proxy_->SetSequenceNumberAllocator(packet_router);
+  rtp_packet_sender_proxy_->SetPacketSender(rtp_packet_sender);
+  _rtpRtcpModule->SetStorePacketsStatus(rtp_packet_sender != nullptr, 600);
+  if (packet_router != nullptr) {
+    packet_router->AddRtpModule(_rtpRtcpModule.get());
+  } else {
+    packet_router_->RemoveRtpModule(_rtpRtcpModule.get());
+  }
+  packet_router_ = packet_router;
+}
+
 void Channel::SetRTCPStatus(bool enable) {
   WEBRTC_TRACE(kTraceInfo, kTraceVoice, VoEId(_instanceId, _channelId),
                "Channel::SetRTCPStatus()");
@@ -3165,7 +3304,9 @@ bool Channel::GetCodecFECStatus() {
 
 void Channel::SetNACKStatus(bool enable, int maxNumberOfPackets) {
   // None of these functions can fail.
-  _rtpRtcpModule->SetStorePacketsStatus(enable, maxNumberOfPackets);
+  // If pacing is enabled we always store packets.
+  if (!pacing_enabled_)
+    _rtpRtcpModule->SetStorePacketsStatus(enable, maxNumberOfPackets);
   rtp_receive_statistics_->SetMaxReorderingThreshold(maxNumberOfPackets);
   rtp_receiver_->SetNACKStatus(enable ? kNackRtcp : kNackOff);
   if (enable)