An example of Unity native plugin of webrtc for Windows OS

webrtc/examples/unityplugin/simple_peer_connection.cc

+/*
+ *  Copyright (c) 2017 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/examples/unityplugin/simple_peer_connection.h"
+
+#include <utility>
+
+#include "webrtc/api/test/fakeconstraints.h"
+#include "webrtc/base/json.h"
+#include "webrtc/media/engine/webrtcvideocapturerfactory.h"
+#include "webrtc/modules/video_capture/video_capture_factory.h"
+
+// Names used for a IceCandidate JSON object.
+const char kCandidateSdpMidName[] = "sdpMid";
+const char kCandidateSdpMlineIndexName[] = "sdpMLineIndex";
+const char kCandidateSdpName[] = "candidate";
+
+// Names used for a SessionDescription JSON object.
+const char kSessionDescriptionTypeName[] = "type";
+const char kSessionDescriptionSdpName[] = "sdp";
+
+// Names used for media stream labels.
+const char kAudioLabel[] = "audio_label";
+const char kVideoLabel[] = "video_label";
+const char kStreamLabel[] = "stream_label";
+
+std::string GetEnvVarOrDefault(const char* env_var_name,
+                               const char* default_value) {
+  std::string value;
+  const char* env_var = getenv(env_var_name);
+  if (env_var)
+    value = env_var;
+
+  if (value.empty())
+    value = default_value;
+
+  return value;
+}
+
+std::string GetPeerConnectionString() {
+  return GetEnvVarOrDefault("WEBRTC_CONNECT", "stun:stun.l.google.com:19302");
+}
+
+class DummySetSessionDescriptionObserver
+    : public webrtc::SetSessionDescriptionObserver {
+ public:
+  static DummySetSessionDescriptionObserver* Create() {
+    return new rtc::RefCountedObject<DummySetSessionDescriptionObserver>();
+  }
+  virtual void OnSuccess() { LOG(INFO) << __FUNCTION__; }
+  virtual void OnFailure(const std::string& error) {
+    LOG(INFO) << __FUNCTION__ << " " << error;
+  }
+
+ protected:
+  DummySetSessionDescriptionObserver() {}
+  ~DummySetSessionDescriptionObserver() {}
+};
+
+int Conductor::peer_count_ = 0;
+std::unique_ptr<rtc::Thread> Conductor::worker_thread_ = nullptr;
+std::unique_ptr<rtc::Thread> Conductor::signaling_thread_ = nullptr;
+rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface>
+    Conductor::peer_connection_factory_ = nullptr;
+
+bool Conductor::InitializePeerConnection(bool is_receiver) {
+  RTC_DCHECK(peer_connection_.get() == nullptr);
+
+  if (peer_connection_factory_ == nullptr) {
+    worker_thread_.reset(new rtc::Thread());
+    worker_thread_->Start();
+    signaling_thread_.reset(new rtc::Thread());
+    signaling_thread_->Start();
+
+    peer_connection_factory_ = webrtc::CreatePeerConnectionFactory(
+        worker_thread_.get(), worker_thread_.get(), signaling_thread_.get(),
+        nullptr, nullptr, nullptr);
+  }
+  if (!peer_connection_factory_.get()) {
+    DeletePeerConnection();
+    return false;
+  }
+
+  peer_count_++;
+  if (!CreatePeerConnection(is_receiver)) {
+    DeletePeerConnection();
+    return false;
+  }
+  return peer_connection_.get() != nullptr;
+}
+
+bool Conductor::CreatePeerConnection(bool is_receiver) {
+  RTC_DCHECK(peer_connection_factory_.get() != nullptr);
+  RTC_DCHECK(peer_connection_.get() == nullptr);
+
+  webrtc::PeerConnectionInterface::RTCConfiguration config;
+  webrtc::PeerConnectionInterface::IceServer server;
+  server.uri = GetPeerConnectionString();
+  config.servers.push_back(server);
+
+  webrtc::FakeConstraints constraints;
+  constraints.SetAllowDtlsSctpDataChannels();
+
+  if (is_receiver) {
+    constraints.SetMandatoryReceiveAudio(true);
+    constraints.SetMandatoryReceiveVideo(true);
+  }
+
+  peer_connection_ = peer_connection_factory_->CreatePeerConnection(
+      config, &constraints, nullptr, nullptr, this);
+
+  return peer_connection_.get() != nullptr;
+}
+
+void Conductor::DeletePeerConnection() {
+  peer_count_--;
+
+  CloseDataChannel();
+  peer_connection_ = nullptr;
+  active_streams_.clear();
+
+  if (peer_count_ == 0) {
+    peer_connection_factory_ = nullptr;
+    signaling_thread_.reset();
+    worker_thread_.reset();
+  }
+}
+
+bool Conductor::CreateOffer() {
+  if (!peer_connection_.get())
+    return false;
+
+  peer_connection_->CreateOffer(this, nullptr);
+  return true;
+}
+
+bool Conductor::CreateAnswer() {
+  if (!peer_connection_.get())
+    return false;
+
+  peer_connection_->CreateAnswer(this, nullptr);
+  return true;
+}
+
+void Conductor::OnSuccess(webrtc::SessionDescriptionInterface* desc) {
+  peer_connection_->SetLocalDescription(
+      DummySetSessionDescriptionObserver::Create(), desc);
+
+  std::string sdp;
+  desc->ToString(&sdp);
+
+  Json::StyledWriter writer;
+  Json::Value jmessage;
+  jmessage[kSessionDescriptionTypeName] = desc->type();
+  jmessage[kSessionDescriptionSdpName] = sdp;
+
+  if (OnLocalSdpReady)
+    OnLocalSdpReady(writer.write(jmessage).c_str());
+}
+
+void Conductor::OnFailure(const std::string& error) {
+  LOG(LERROR) << error;
+
+  if (OnFailureMessage)
+    OnFailureMessage(error.c_str());
+}
+
+void Conductor::OnIceCandidate(const webrtc::IceCandidateInterface* candidate) {
+  LOG(INFO) << __FUNCTION__ << " " << candidate->sdp_mline_index();
+
+  Json::StyledWriter writer;
+  Json::Value jmessage;
+
+  jmessage[kCandidateSdpMidName] = candidate->sdp_mid();
+  jmessage[kCandidateSdpMlineIndexName] = candidate->sdp_mline_index();
+  std::string sdp;
+  if (!candidate->ToString(&sdp)) {
+    LOG(LS_ERROR) << "Failed to serialize candidate";
+    return;
+  }
+  jmessage[kCandidateSdpName] = sdp;
+
+  if (OnIceCandiateReady)
+    OnIceCandiateReady(writer.write(jmessage).c_str());
+}
+
+void Conductor::RegisterOnVideoFramReady(VIDEOFRAMEREADY_CALLBACK callback) {
+  OnVideoFrameReady = callback;
+}
+
+void Conductor::RegisterOnLocalDataChannelReady(
+    LOCALDATACHANNELREADY_CALLBACK callback) {
+  OnLocalDataChannelReady = callback;
+}
+
+void Conductor::RegisterOnDataFromDataChannelReady(
+    DATAFROMEDATECHANNELREADY_CALLBACK callback) {
+  OnDataFromDataChannelReady = callback;
+}
+
+void Conductor::RegisterOnFailure(FAILURE_CALLBACK callback) {
+  OnFailureMessage = callback;
+}
+
+void Conductor::RegisterOnAudioBusReady(AUDIOBUSREADY_CALLBACK callback) {
+  OnAudioReady = callback;
+}
+
+void Conductor::RegisterOnLocalSdpReadytoSend(
+    LOCALSDPREADYTOSEND_CALLBACK callback) {
+  OnLocalSdpReady = callback;
+}
+
+void Conductor::RegisterOnIceCandiateReadytoSend(
+    ICECANDIDATEREADYTOSEND_CALLBACK callback) {
+  OnIceCandiateReady = callback;
+}
+
+bool Conductor::ReceivedSdp(const char* msg) {
+  if (!peer_connection_)
+    return false;
+
+  std::string message(msg);
+
+  Json::Reader reader;
+  Json::Value jmessage;
+  if (!reader.parse(message, jmessage)) {
+    LOG(WARNING) << "Received unknown message. " << message;
+    return false;
+  }
+  std::string type;
+  std::string json_object;
+
+  rtc::GetStringFromJsonObject(jmessage, kSessionDescriptionTypeName, &type);
+  if (type.empty())
+    return false;
+
+  std::string sdp;
+  if (!rtc::GetStringFromJsonObject(jmessage, kSessionDescriptionSdpName,
+                                    &sdp)) {
+    LOG(WARNING) << "Can't parse received session description message.";
+    return false;
+  }
+  webrtc::SdpParseError error;
+  webrtc::SessionDescriptionInterface* session_description(
+      webrtc::CreateSessionDescription(type, sdp, &error));
+  if (!session_description) {
+    LOG(WARNING) << "Can't parse received session description message. "
+                 << "SdpParseError was: " << error.description;
+    return false;
+  }
+  LOG(INFO) << " Received session description :" << message;
+  peer_connection_->SetRemoteDescription(
+      DummySetSessionDescriptionObserver::Create(), session_description);
+
+  return true;
+}
+
+bool Conductor::ReceivedIceCandidate(const char* ice_candidate) {
+  if (!peer_connection_)
+    return false;
+
+  std::string message(ice_candidate);
+
+  Json::Reader reader;
+  Json::Value jmessage;
+  if (!reader.parse(message, jmessage)) {
+    LOG(WARNING) << "Received unknown message. " << message;
+    return false;
+  }
+  std::string type;
+  std::string json_object;
+
+  rtc::GetStringFromJsonObject(jmessage, kSessionDescriptionTypeName, &type);
+  if (!type.empty())
+    return false;
+
+  std::string sdp_mid;
+  int sdp_mlineindex = 0;
+  std::string sdp;
+  if (!rtc::GetStringFromJsonObject(jmessage, kCandidateSdpMidName, &sdp_mid) ||
+      !rtc::GetIntFromJsonObject(jmessage, kCandidateSdpMlineIndexName,
+                                 &sdp_mlineindex) ||
+      !rtc::GetStringFromJsonObject(jmessage, kCandidateSdpName, &sdp)) {
+    LOG(WARNING) << "Can't parse received message.";
+    return false;
+  }
+  webrtc::SdpParseError error;
+  std::unique_ptr<webrtc::IceCandidateInterface> candidate(
+      webrtc::CreateIceCandidate(sdp_mid, sdp_mlineindex, sdp, &error));
+  if (!candidate.get()) {
+    LOG(WARNING) << "Can't parse received candidate message. "
+                 << "SdpParseError was: " << error.description;
+    return false;
+  }
+  if (!peer_connection_->AddIceCandidate(candidate.get())) {
+    LOG(WARNING) << "Failed to apply the received candidate";
+    return false;
+  }
+  LOG(INFO) << " Received candidate :" << message;
+  return true;
+}
+
+void Conductor::SetAudioControl(bool is_mute, bool is_record) {
+  is_mute_audio_ = is_mute;
+  is_record_audio_ = is_record;
+
+  SetAudioControl();
+}
+
+void Conductor::SetAudioControl() {
+  if (!remote_stream_)
+    return;
+  webrtc::AudioTrackVector tracks = remote_stream_->GetAudioTracks();
+  if (tracks.empty())
+    return;
+
+  webrtc::AudioTrackInterface* audio_track = tracks[0];
+  std::string id = audio_track->id();
+  if (is_record_audio_)
+    audio_track->AddSink(this);
+  else
+    audio_track->RemoveSink(this);
+
+  for (auto& track : tracks) {
+    if (is_mute_audio_)
+      track->set_enabled(false);
+    else
+      track->set_enabled(true);
+  }
+}
+
+void Conductor::OnAddStream(
+    rtc::scoped_refptr<webrtc::MediaStreamInterface> stream) {
+  LOG(INFO) << __FUNCTION__ << " " << stream->label();
+  remote_stream_ = stream;
+
+  SetAudioControl();
+}
+
+std::unique_ptr<cricket::VideoCapturer> Conductor::OpenVideoCaptureDevice() {
+  std::vector<std::string> device_names;
+  {
+    std::unique_ptr<webrtc::VideoCaptureModule::DeviceInfo> info(
+        webrtc::VideoCaptureFactory::CreateDeviceInfo());
+    if (!info) {
+      return nullptr;
+    }
+    int num_devices = info->NumberOfDevices();
+    for (int i = 0; i < num_devices; ++i) {
+      const uint32_t kSize = 256;
+      char name[kSize] = {0};
+      char id[kSize] = {0};
+      if (info->GetDeviceName(i, name, kSize, id, kSize) != -1) {
+        device_names.push_back(name);
+      }
+    }
+  }
+
+  cricket::WebRtcVideoDeviceCapturerFactory factory;
+  std::unique_ptr<cricket::VideoCapturer> capturer;
+  for (const auto& name : device_names) {
+    capturer = factory.Create(cricket::Device(name, 0));
+    if (capturer) {
+      break;
+    }
+  }
+  return capturer;
+}
+
+void Conductor::AddStreams(bool audio_only) {
+  if (active_streams_.find(kStreamLabel) != active_streams_.end())
+    return;  // Already added.
+
+  rtc::scoped_refptr<webrtc::MediaStreamInterface> stream =
+      peer_connection_factory_->CreateLocalMediaStream(kStreamLabel);
+
+  rtc::scoped_refptr<webrtc::AudioTrackInterface> audio_track(
+      peer_connection_factory_->CreateAudioTrack(
+          kAudioLabel, peer_connection_factory_->CreateAudioSource(nullptr)));
+  std::string id = audio_track->id();
+  stream->AddTrack(audio_track);
+
+  if (!audio_only) {
+    std::unique_ptr<cricket::VideoCapturer> capture = OpenVideoCaptureDevice();
+    if (capture) {
+      rtc::scoped_refptr<webrtc::VideoTrackInterface> video_track(
+          peer_connection_factory_->CreateVideoTrack(
+              kVideoLabel, peer_connection_factory_->CreateVideoSource(
+                               OpenVideoCaptureDevice(), nullptr)));
+
+      stream->AddTrack(video_track);
+    }
+  }
+
+  if (!peer_connection_->AddStream(stream)) {
+    LOG(LS_ERROR) << "Adding stream to PeerConnection failed";
+  }
+
+  typedef std::pair<std::string,
+                    rtc::scoped_refptr<webrtc::MediaStreamInterface>>
+      MediaStreamPair;
+  active_streams_.insert(MediaStreamPair(stream->label(), stream));
+}
+
+bool Conductor::CreateDataChannel() {
+  struct webrtc::DataChannelInit init;
+  init.ordered = true;
+  init.reliable = true;
+  data_channel_ = peer_connection_->CreateDataChannel("Hello", &init);
+  if (data_channel_.get()) {
+    data_channel_->RegisterObserver(this);
+    LOG(LS_INFO) << "Succeeds to create data channel";
+    return true;
+  } else {
+    LOG(LS_INFO) << "Fails to create data channel";
+    return false;
+  }
+}
+
+void Conductor::CloseDataChannel() {
+  if (data_channel_.get()) {
+    data_channel_->UnregisterObserver();
+    data_channel_->Close();
+  }
+  data_channel_ = nullptr;
+}
+
+bool Conductor::SendDataViaDataChannel(const std::string& data) {
+  if (!data_channel_.get()) {
+    LOG(LS_INFO) << "Data channel is not established";
+    return false;
+  }
+  webrtc::DataBuffer buffer(data);
+  data_channel_->Send(buffer);
+  return true;
+}
+
+// Peerconnection observer
+void Conductor::OnDataChannel(
+    rtc::scoped_refptr<webrtc::DataChannelInterface> channel) {
+  channel->RegisterObserver(this);
+}
+
+void Conductor::OnStateChange() {
+  if (data_channel_) {
+    webrtc::DataChannelInterface::DataState state = data_channel_->state();
+    if (state == webrtc::DataChannelInterface::kOpen) {
+      if (OnLocalDataChannelReady)
+        OnLocalDataChannelReady();
+      LOG(LS_INFO) << "Data channel is open";
+    }
+  }
+}
+
+//  A data buffer was successfully received.
+void Conductor::OnMessage(const webrtc::DataBuffer& buffer) {
+  size_t size = buffer.data.size();
+  char* msg = new char[size + 1];
+  memcpy(msg, buffer.data.data(), size);
+  msg[size] = 0;
+  if (OnDataFromDataChannelReady)
+    OnDataFromDataChannelReady(msg);
+  delete[] msg;
+}
+
+// AudioTrackSinkInterface implementation.
+void Conductor::OnData(const void* audio_data,
+                       int bits_per_sample,
+                       int sample_rate,
+                       size_t number_of_channels,
+                       size_t number_of_frames) {
+  if (OnAudioReady)
+    OnAudioReady(audio_data, bits_per_sample, sample_rate,
+                 static_cast<int>(number_of_channels),
+                 static_cast<int>(number_of_frames));
+}
+
+std::vector<uint32_t> Conductor::GetRemoteAudioTrackSsrcs() {
+  std::vector<rtc::scoped_refptr<webrtc::RtpReceiverInterface>> receivers =
+      peer_connection_->GetReceivers();
+
+  std::vector<uint32_t> ssrcs;
+  for (const auto& receiver : receivers) {
+    if (receiver->media_type() != cricket::MEDIA_TYPE_AUDIO)
+      continue;
+
+    std::vector<webrtc::RtpEncodingParameters> params =
+        receiver->GetParameters().encodings;
+
+    for (const auto& param : params) {
+      uint32_t ssrc = param.ssrc.value_or(0);
+      if (ssrc > 0)
+        ssrcs.push_back(ssrc);
+    }
+  }
+
+  return ssrcs;
+}