An example of Unity native plugin of webrtc for Windows OS

webrtc/examples/unityplugin/simple_peer_connection.h

+/*
+ *  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.
+ */
+
+#ifndef WEBRTC_EXAMPLES_UNITYPLUGIN_SIMPLE_PEER_CONNECTION_H_
+#define WEBRTC_EXAMPLES_UNITYPLUGIN_SIMPLE_PEER_CONNECTION_H_
+
+#include <map>
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "webrtc/api/datachannelinterface.h"
+#include "webrtc/api/mediastreaminterface.h"
+#include "webrtc/api/peerconnectioninterface.h"
+#include "webrtc/examples/unityplugin/unity_plugin_apis.h"
+
+class Conductor : public webrtc::PeerConnectionObserver,
+                  public webrtc::CreateSessionDescriptionObserver,
+                  public webrtc::DataChannelObserver,
+                  public webrtc::AudioTrackSinkInterface {
+ public:
+  Conductor() {}
+  ~Conductor() {}
+
+  bool InitializePeerConnection(bool is_receiver);
+  void DeletePeerConnection();
+  void AddStreams(bool audio_only);
+  bool CreateDataChannel();
+  bool CreateOffer();
+  bool CreateAnswer();
+  bool SendDataViaDataChannel(const std::string& data);
+  void SetAudioControl(bool is_mute, bool is_record);
+
+  // Register callback functions.
+  void RegisterOnVideoFramReady(VIDEOFRAMEREADY_CALLBACK callback);
+  void RegisterOnLocalDataChannelReady(LOCALDATACHANNELREADY_CALLBACK callback);
+  void RegisterOnDataFromDataChannelReady(
+      DATAFROMEDATECHANNELREADY_CALLBACK callback);
+  void RegisterOnFailure(FAILURE_CALLBACK callback);
+  void RegisterOnAudioBusReady(AUDIOBUSREADY_CALLBACK callback);
+  void RegisterOnLocalSdpReadytoSend(LOCALSDPREADYTOSEND_CALLBACK callback);
+  void RegisterOnIceCandiateReadytoSend(
+      ICECANDIDATEREADYTOSEND_CALLBACK callback);
+  bool ReceivedSdp(const char* sdp);
+  bool ReceivedIceCandidate(const char* ice_candidate);
+
+  bool SetHeadPosition(float x, float y, float z);
+  bool SetHeadRotation(float rx, float ry, float rz, float rw);
+  bool SetRemoteAudioPosition(float x, float y, float z);
+  bool SetRemoteAudioRotation(float rx, float ry, float rz, float rw);
+
+ protected:
+  bool CreatePeerConnection(bool receiver);
+  void CloseDataChannel();
+  std::unique_ptr<cricket::VideoCapturer> OpenVideoCaptureDevice();
+  void SetAudioControl();
+
+  // PeerConnectionObserver implementation.
+  void OnSignalingChange(
+      webrtc::PeerConnectionInterface::SignalingState new_state) override{};
+  void OnAddStream(
+      rtc::scoped_refptr<webrtc::MediaStreamInterface> stream) override;
+  void OnRemoveStream(
+      rtc::scoped_refptr<webrtc::MediaStreamInterface> stream) override{};
+  void OnDataChannel(
+      rtc::scoped_refptr<webrtc::DataChannelInterface> channel) override;
+  void OnRenegotiationNeeded() override {}
+  void OnIceConnectionChange(
+      webrtc::PeerConnectionInterface::IceConnectionState new_state) override{};
+  void OnIceGatheringChange(
+      webrtc::PeerConnectionInterface::IceGatheringState new_state) override{};
+  void OnIceCandidate(const webrtc::IceCandidateInterface* candidate) override;
+  void OnIceConnectionReceivingChange(bool receiving) override{};
+
+  // CreateSessionDescriptionObserver implementation.
+  void OnSuccess(webrtc::SessionDescriptionInterface* desc) override;
+  void OnFailure(const std::string& error) override;
+
+  // DataChannelObserver implementation.
+  void OnStateChange() override;
+  void OnMessage(const webrtc::DataBuffer& buffer) override;
+
+  // AudioTrackSinkInterface implementation.
+  void OnData(const void* audio_data,
+              int bits_per_sample,
+              int sample_rate,
+              size_t number_of_channels,
+              size_t number_of_frames) override;
+
+  // Get remote audio tracks ssrcs.
+  std::vector<uint32_t> GetRemoteAudioTrackSsrcs();
+
+ private:
+  static int peer_count_;

[tommi, 2017/04/21 09:47:51]

should these static vars perhaps be in an anonymous namespace in the cc file?
Any chance we can avoid having globals at all?

[GeorgeZ, 2017/04/21 22:00:04]

I moved those static variables to the cc file.

Class Conductor represents a peerconnection. An application may have multiple
peerconnections. All those peerconnections should share one peerconnection
factory. Therefore peer_connection_factory_ and its associated threads should be
static.

One way to avoid this is to add one more layer/class to managed all instances of
class conductor. Then peerconnection factory can be the managed class's none
static member variable. However this will lead quite a bit of code change.

 

+  static std::unique_ptr<rtc::Thread> worker_thread_;
+  static std::unique_ptr<rtc::Thread> signaling_thread_;
+  static rtc::scoped_refptr<webrtc::PeerConnectionFactoryInterface>
+      peer_connection_factory_;
+
+  rtc::scoped_refptr<webrtc::PeerConnectionInterface> peer_connection_ =

[tommi, 2017/04/21 09:47:51]

initializing scoped_refptr like this, isn't necessary since the default ctor
does this anyway.

[GeorgeZ, 2017/04/21 22:00:04]

Done.

+      nullptr;
+  rtc::scoped_refptr<webrtc::DataChannelInterface> data_channel_ = nullptr;
+  std::map<std::string, rtc::scoped_refptr<webrtc::MediaStreamInterface> >
+      active_streams_;
+
+  webrtc::MediaStreamInterface* remote_stream_ = nullptr;
+
+  VIDEOFRAMEREADY_CALLBACK OnVideoFrameReady = nullptr;
+  LOCALDATACHANNELREADY_CALLBACK OnLocalDataChannelReady = nullptr;
+  DATAFROMEDATECHANNELREADY_CALLBACK OnDataFromDataChannelReady = nullptr;
+  FAILURE_CALLBACK OnFailureMessage = nullptr;
+  AUDIOBUSREADY_CALLBACK OnAudioReady = nullptr;
+
+  LOCALSDPREADYTOSEND_CALLBACK OnLocalSdpReady = nullptr;
+  ICECANDIDATEREADYTOSEND_CALLBACK OnIceCandiateReady = nullptr;
+
+  bool is_mute_audio_ = false;
+  bool is_record_audio_ = false;
+
+  // disallow copy-and-assign
+  Conductor(const Conductor&) = delete;
+  Conductor& operator=(const Conductor&) = delete;
+};
+
+#endif  // WEBRTC_EXAMPLES_UNITYPLUGIN_SIMPLE_PEER_CONNECTION_H_