转自：https://zhuanlan.zhihu.com/p/82446482
1、Google Webrtc介绍
WebRTC（Web Real-Time Communication）实现了基于网页的视频会议，标准是WHATWG 协议，目的是通过浏览器提供简单的javascript就可以达到实时通讯（Real-Time Communications (RTC)）能力。
提供了视频会议的核心技术，包括音视频的采集、编解码、网络传输、显示等功能，并且还支持跨平台：windows，linux，mac，android，音视频通讯技术是基于p2p实现的
2、Google Webrtc服务器配置
信令服务器(signaling)，转发服务器(TURN)，穿透服务器(STUN)（自行百度，配置），更详细的介绍请看书籍 WebRtc权威指南
2.1 信令服务器(signaling)
WebRTC 之间使用PeerConnection交流数据，但还需要一种机制来协调沟通和发送控制消息，这一过程称之为信令传输
2.2 转发服务器(TURN) & 穿透服务器(STUN)
WebRTC 被设计为点对点工作模式，所以用户之间是尽可能地通过最短路线进行连接，然而在现实世界当中：客户端应用需要穿透 NAT 网关 和防火墙，并且点对点网络需要握手来防止直接连接失败，在这一过程中，WebRTC使用STUN服务器和TURN服务器来获取计算机IP地址来保证点对点连接成功
3、ICE框架
基于信令协议的多媒体传输是一个两段式传输，首先通过信令协议（如WebSocket）建立一个连接，通过该连接，双方交换传输媒体时所必须的信息。基于传输效率的考虑，在完成第一阶段的交互之后，通信双方会建立一条通道来实现媒体传输，以减少传输时延、降低丢包率并减少开销。由于使用新的链路，当传输双方有任意一方位于NAT之后，新的传输链路就需要考虑NAT穿越的问题了通常有四种形式的NAT，每一种NAT都有相应的解决方案，然而在复杂的网络环境中，由于每一种NAT穿越方案都局限于对应的NAT方式，这些方案就给整个系统带来了一定的复杂性。在这种背景下，交互式连通建立方式(Interactive Connectivity Establishment)即ICE解决方案应运而生，ICE能够在不增加整个系统的复杂性和脆弱性的情况下，实现对各种形式的NAT的穿越。
官方提供的实现原理 基于下图
4、Android Webrtc的配置
客户端和服务端通信 采用WebSocket
摄像头，录音，SD卡读取等其他权限加入，有些需要在运行时调用
4.1 在build.gradle 引入websocket 和 webrtc
dependencies {
implementation 'org.webrtc:google-webrtc:1.0.28513'
implementation 'org.java-websocket:Java-WebSocket:1.4.0'
implementation 'com.google.code.gson:gson:2.8.5'
}5、Android Webrtc的使用
5.1 创建websocket
private void connectionWebsocket() {
try {
webSocketClient = new WebSocketClient(URI.create(Constant.URL)) {
@Override
public void onOpen(ServerHandshake handshakedata) {
setText("已连接");
Log.e(TAG, "onOpen == Status == " + handshakedata.getHttpStatus() + " StatusMessage == " + handshakedata.getHttpStatusMessage());
Model model = new Model(Constant.REGISTER, getFromName(), getFrom(), getToName(), getTo());
webSocketClient.send(new Gson().toJson(model));
}
@Override
public void onMessage(String message) {
Log.e(TAG, "onMessage == " + message);
if (!TextUtils.isEmpty(message)) {
Model model = new Gson().fromJson(message, Model.class);
if (model != null) {
String id = model.getId();
if (!TextUtils.isEmpty(id)) {
int isSucceed = model.getIsSucceed();
switch (id) {
case Constant.REGISTER_RESPONSE:
if (isSucceed == Constant.RESPONSE_SUCCEED) {
Message msg = new Message();
msg.obj = Constant.OPEN;
handler.sendMessage(msg);
Log.e(TAG, "连接成功");
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "注册失败，已经注册");
}
break;
case Constant.CALL_RESPONSE:
if (isSucceed == Constant.RESPONSE_SUCCEED) {
Log.e(TAG, "对方在线，创建sdp offer");
createOffer();
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "对方不在线，连接失败");
}
break;
case Constant.INCALL:
isIncall();
break;
case Constant.INCALL_RESPONSE:
if (isSucceed == Constant.RESPONSE_SUCCEED) {
createOffer();
Log.e(TAG, "对方同意接听");
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "对方拒绝接听");
}
break;
case Constant.OFFER:
//收到对方offer sdp
SessionDescription sessionDescription1 = model.getSessionDescription();
peerConnection.setRemoteDescription(observer, sessionDescription1);
createAnswer();
break;
case Constant.CANDIDATE:
//服务端 发送 接收方sdpAnswer
IceCandidate iceCandidate = model.getIceCandidate();
if (iceCandidate != null) {
peerConnection.addIceCandidate(iceCandidate);
}
break;
}
}
}
}
}
@Override
public void onClose(int code, String reason, boolean remote) {
setText("已关闭");
Log.e(TAG, "onClose == code " + code + " reason == " + reason + " remote == " + remote);
}
@Override
public void onError(Exception ex) {
setText("onError == " + ex.getMessage());
Log.e(TAG, "onError== " + ex.getMessage());
}
};
webSocketClient.connect();
} catch (Exception e) {
Log.d(TAG, "socket Exception : " + e.getMessage());
}
}5.2 创建websocket成功后开始创建PeerConnection，穿透服务器采用Google提供的("stun:http://stun.l.google.com:19302")
private void createPeerConnection() {
//Initialising PeerConnectionFactory
InitializationOptions initializationOptions = InitializationOptions.builder(this)
.setEnableInternalTracer(true)
.setFieldTrials("WebRTC-H264HighProfile/Enabled/")
.createInitializationOptions();
PeerConnectionFactory.initialize(initializationOptions);
//创建EglBase对象
eglBase = EglBase.create();
PeerConnectionFactory.Options options = new PeerConnectionFactory.Options();
options.disableEncryption = true;
options.disableNetworkMonitor = true;
peerConnectionFactory = PeerConnectionFactory.builder()
.setVideoDecoderFactory(new DefaultVideoDecoderFactory(eglBase.getEglBaseContext()))
.setVideoEncoderFactory(new DefaultVideoEncoderFactory(eglBase.getEglBaseContext(), true, true))
.setOptions(options)
.createPeerConnectionFactory();
// 配置STUN穿透服务器 转发服务器
iceServers = new ArrayList<>();
PeerConnection.IceServer iceServer = PeerConnection.IceServer.builder(Constant.STUN).createIceServer();
iceServers.add(iceServer);
streamList = new ArrayList<>();
PeerConnection.RTCConfiguration configuration = new PeerConnection.RTCConfiguration(iceServers);
PeerConnectionObserver connectionObserver = getObserver();
peerConnection = peerConnectionFactory.createPeerConnection(configuration, connectionObserver);
/*
DataChannel.Init 可配参数说明：
ordered：是否保证顺序传输；
maxRetransmitTimeMs：重传允许的最长时间；
maxRetransmits：重传允许的最大次数；
*/
DataChannel.Init init = new DataChannel.Init();
if (peerConnection != null) {
channel = peerConnection.createDataChannel(Constant.CHANNEL, init);
}
DateChannelObserver channelObserver = new DateChannelObserver();
connectionObserver.setObserver(channelObserver);
initView();
initObserver();
}
- 5.2.1 初始化view
private void initSurfaceview(SurfaceViewRenderer localSurfaceView) {
localSurfaceView.init(eglBase.getEglBaseContext(), null);
localSurfaceView.setMirror(true);
localSurfaceView.setScalingType(RendererCommon.ScalingType.SCALE_ASPECT_FILL);
localSurfaceView.setKeepScreenOn(true);
localSurfaceView.setZOrderMediaOverlay(true);
localSurfaceView.setEnableHardwareScaler(false);
}- 5.2.2 初始化音频和视频
/**
* 创建本地视频
*
* @param localSurfaceView
*/
private void startLocalVideoCapture(SurfaceViewRenderer localSurfaceView) {
VideoSource videoSource = peerConnectionFactory.createVideoSource(true);
SurfaceTextureHelper surfaceTextureHelper = SurfaceTextureHelper.create(Thread.currentThread().getName(), eglBase.getEglBaseContext());
VideoCapturer videoCapturer = createVideoCapturer();
videoCapturer.initialize(surfaceTextureHelper, this, videoSource.getCapturerObserver());
videoCapturer.startCapture(Constant.VIDEO_RESOLUTION_WIDTH, Constant.VIDEO_RESOLUTION_HEIGHT, Constant.VIDEO_FPS); // width, height, frame per second
videoTrack = peerConnectionFactory.createVideoTrack(Constant.VIDEO_TRACK_ID, videoSource);
videoTrack.addSink(localSurfaceView);
MediaStream localMediaStream = peerConnectionFactory.createLocalMediaStream(Constant.LOCAL_VIDEO_STREAM);
localMediaStream.addTrack(videoTrack);
peerConnection.addTrack(videoTrack, streamList);
peerConnection.addStream(localMediaStream);
}
/**
* 创建本地音频
*/
private void startLocalAudioCapture() {
//语音
MediaConstraints audioConstraints = new MediaConstraints();
//回声消除
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googEchoCancellation", "true"));
//自动增益
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googAutoGainControl", "true"));
//高音过滤
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googHighpassFilter", "true"));
//噪音处理
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googNoiseSuppression", "true"));
AudioSource audioSource = peerConnectionFactory.createAudioSource(audioConstraints);
audioTrack = peerConnectionFactory.createAudioTrack(Constant.AUDIO_TRACK_ID, audioSource);
MediaStream localMediaStream = peerConnectionFactory.createLocalMediaStream(Constant.LOCAL_AUDIO_STREAM);
localMediaStream.addTrack(audioTrack);
audioTrack.setVolume(Constant.VOLUME);
peerConnection.addTrack(audioTrack, streamList);
peerConnection.addStream(localMediaStream);
}5.3 创建PeerConnection成功后通过信令传输交换各自信息，实现视频通话，调整后的流程如下图
信令
public static final String REGISTER = "register";//注册
public static final String REGISTER_RESPONSE = "register_response";//注册回复
public static final int RESPONSE_SUCCEED = 1;//1成功
public static final int RESPONSE_FAILURE = 2;//2失败
public static final String CALL = "call";//拨打
public static final String CALL_RESPONSE = "call_response";//拨打回复
public static final String INCALL = "incall";//接听
public static final String INCALL_RESPONSE = "incall_response";//接听回复
public static final String OFFER = "offer";//发送sdp信息
public static final String CANDIDATE = "candidate";//ice互传流程内容： 客户端A，客户端B
- 5.3.1 -->> A 和 B 都注册成功后，A 发起 call，服务端收到A的指令后转发给B， B接受后发给服务器，服务器转发给A
- 5.3.2 -->> A createOffer 将自己的SessionDescription 发给服务器，服务器转发给B
- 5.3.3 -->> B 收到后将A的SessionDescription 设置到自己的setRemoteDescription，同时createAnswer 发给服务器，服务器在转发A
- 5.3.4 -->> A 收到后将B的SessionDescription 设置到自己的setRemoteDescription
- 5.3.5 -->> A 在PeerConnectionObserver 的 onIceCandidate方法中，将收到的IceCandidate 发给服务端，服务器转发给B
- 5.3.6 -->> B 收到后在将IceCandidate 设置到自己的addIceCandidate
- 5.3.7 -->> B 在PeerConnectionObserver 的 onIceCandidate方法中，将收到的IceCandidate 发给服务端，服务器转发给A
- 5.3.8 -->> A 收到后在将IceCandidate 设置到自己的addIceCandidate
- 5.3.9 -->> A 和 B 在PeerConnectionObserver 的 onAddStream方法中，将远端的流媒体加入到本地的View
- 5.3.10 -->> 交互已经结束，可以正常视频通话
详细的流程，json 格式
isSucceed 1成功 2失败
"from": "11", "fromName": "王安", "to": "12", "toName": "往事"
1.注册
from 发送服务端：register
{
"from": "11",
"fromName": "王安",
"id": "register",
"isSucceed": 0
}
from接收：register_response
{
"id": "register_response",
"isSucceed": 1
}
2.呼叫
from 发送服务端：call
{
"from": "11",
"fromName": "王安",
"id": "call",
"isSucceed": 0,
"to": "12",
"toName": "往事"
}
2.1服务端做判断
如果不在线 直接返回 "isSucceed": 1
{
"id": "call_response",
"isSucceed": 1
}
在线 返回给to做判断
to 接收：incall
改变本地状态
{
"id": "incall",
"isSucceed": 0
}
to 发送服务端 拒绝："isSucceed": 2
{
"from": "12",
"fromName": "往事",
"id": "incall",
"isSucceed": 2,
"to": "11",
"toName": "王安"
}
from接收：incall_response
做拒绝的操作
{
"id": "incall_response",
"from": "12",
"fromName": "往事",
"to": "11",
"toName": "王安",
"isSucceed": 2
}
-------------------------------------------------
to 发送服务端 同意："isSucceed": 1
{
"from": "12",
"fromName": "往事",
"id": "incall",
"isSucceed": 1,
"to": "11",
"toName": "王安"
}
from接收 同意：incall_response
{
"id": "incall_response",
"from": "12",
"fromName": "往事",
"to": "11",
"toName": "王安",
"isSucceed": 1
}
3.to同意后 from发送流
from 发送服务端：offer
{
"from": "11",
"fromName": "王安",
"id": "offer",
"isSucceed": 0,
"sessionDescription": {
"description": "v=0
o=- 3285195603599485281 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE video
a=msid-semantic: WMS localstream
m=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:9Jqg
a=ice-pwd:lM34EvVxjaPGBislEH9VccVu
a=ice-options:trickle renomination
a=mid:video
a=extmap:14 urn:ietf:params:rtp-hdrext:toffset
a=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:3 urn:3gpp:video-orientation
a=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
a=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
a=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing
a=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07
a=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space
a=sendrecv
a=rtcp-mux
a=rtcp-rsize
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 goog-remb
a=rtcp-fb:96 transport-cc
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
a=rtpmap:98 VP9/90000
a=rtcp-fb:98 goog-remb
a=rtcp-fb:98 transport-cc
a=rtcp-fb:98 ccm fir
a=rtcp-fb:98 nack
a=rtcp-fb:98 nack pli
a=rtpmap:99 rtx/90000
a=fmtp:99 apt=98
a=rtpmap:100 H264/90000
a=rtcp-fb:100 goog-remb
a=rtcp-fb:100 transport-cc
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=rtpmap:101 rtx/90000
a=fmtp:101 apt=100
a=rtpmap:127 red/90000
a=rtpmap:124 rtx/90000
a=fmtp:124 apt=127
a=rtpmap:125 ulpfec/90000
a=ssrc-group:FID 1791802911 305163890
a=ssrc:1791802911 cname:8uTWIc2YbUNSY02u
a=ssrc:1791802911 msid:localstream videtrack
a=ssrc:1791802911 mslabel:localstream
a=ssrc:1791802911 label:videtrack
a=ssrc:305163890 cname:8uTWIc2YbUNSY02u
a=ssrc:305163890 msid:localstream videtrack
a=ssrc:305163890 mslabel:localstream
a=ssrc:305163890 label:videtrack
",
"type": "OFFER"
},
"to": "12",
"toName": "往事"
}
to接收：offer
{
"id": "offer",
"from": "11",
"fromName": "王安",
"to": "12",
"toName": "往事",
"sessionDescription": {
"type": "OFFER",
"description": "v=0
o=- 3285195603599485281 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE video
a=msid-semantic: WMS localstream
m=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:9Jqg
a=ice-pwd:lM34EvVxjaPGBislEH9VccVu
a=ice-options:trickle renomination
a=mid:video
a=extmap:14 urn:ietf:params:rtp-hdrext:toffset
a=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:3 urn:3gpp:video-orientation
a=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
a=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
a=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing
a=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07
a=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space
a=sendrecv
a=rtcp-mux
a=rtcp-rsize
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 goog-remb
a=rtcp-fb:96 transport-cc
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
a=rtpmap:98 VP9/90000
a=rtcp-fb:98 goog-remb
a=rtcp-fb:98 transport-cc
a=rtcp-fb:98 ccm fir
a=rtcp-fb:98 nack
a=rtcp-fb:98 nack pli
a=rtpmap:99 rtx/90000
a=fmtp:99 apt=98
a=rtpmap:100 H264/90000
a=rtcp-fb:100 goog-remb
a=rtcp-fb:100 transport-cc
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=rtpmap:101 rtx/90000
a=fmtp:101 apt=100
a=rtpmap:127 red/90000
a=rtpmap:124 rtx/90000
a=fmtp:124 apt=127
a=rtpmap:125 ulpfec/90000
a=ssrc-group:FID 1791802911 305163890
a=ssrc:1791802911 cname:8uTWIc2YbUNSY02u
a=ssrc:1791802911 msid:localstream videtrack
a=ssrc:1791802911 mslabel:localstream
a=ssrc:1791802911 label:videtrack
a=ssrc:305163890 cname:8uTWIc2YbUNSY02u
a=ssrc:305163890 msid:localstream videtrack
a=ssrc:305163890 mslabel:localstream
a=ssrc:305163890 label:videtrack
"
},
"isSucceed": 0
}
to接收到 offer 创建answer 创建完 to 发送服务端：offer
{
"from": "12",
"fromName": "往事",
"id": "offer",
"isSucceed": 0,
"sessionDescription": {
"description": "v=0
o=- 8665372075017263288 2 IN IP4 127.0.0.1
s=-
t=0 0
a=group:BUNDLE video
a=msid-semantic: WMS localstream
m=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125
c=IN IP4 0.0.0.0
a=rtcp:9 IN IP4 0.0.0.0
a=ice-ufrag:zoQn
a=ice-pwd:oBePBH1X7SehiT6Tb83SZV2U
a=ice-options:trickle renomination
a=mid:video
a=extmap:14 urn:ietf:params:rtp-hdrext:toffset
a=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
a=extmap:3 urn:3gpp:video-orientation
a=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01
a=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay
a=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type
a=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing
a=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07
a=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space
a=sendrecv
a=rtcp-mux
a=rtcp-rsize
a=rtpmap:96 VP8/90000
a=rtcp-fb:96 goog-remb
a=rtcp-fb:96 transport-cc
a=rtcp-fb:96 ccm fir
a=rtcp-fb:96 nack
a=rtcp-fb:96 nack pli
a=rtpmap:97 rtx/90000
a=fmtp:97 apt=96
a=rtpmap:98 VP9/90000
a=rtcp-fb:98 goog-remb
a=rtcp-fb:98 transport-cc
a=rtcp-fb:98 ccm fir
a=rtcp-fb:98 nack
a=rtcp-fb:98 nack pli
a=rtpmap:99 rtx/90000
a=fmtp:99 apt=98
a=rtpmap:100 H264/90000
a=rtcp-fb:100 goog-remb
a=rtcp-fb:100 transport-cc
a=rtcp-fb:100 ccm fir
a=rtcp-fb:100 nack
a=rtcp-fb:100 nack pli
a=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f
a=rtpmap:101 rtx/90000
a=fmtp:101 apt=100
a=rtpmap:127 red/90000
a=rtpmap:124 rtx/90000
a=fmtp:124 apt=127
a=rtpmap:125 ulpfec/90000
a=ssrc-group:FID 330040035 1917181902
a=ssrc:330040035 cname:uxoKaX6C0J4LHdZ2
a=ssrc:330040035 msid:localstream videtrack
a=ssrc:330040035 mslabel:localstream
a=ssrc:330040035 label:videtrack
a=ssrc:1917181902 cname:uxoKaX6C0J4LHdZ2
a=ssrc:1917181902 msid:localstream videtrack
a=ssrc:1917181902 mslabel:localstream
a=ssrc:1917181902 label:videtrack
",
"type": "ANSWER"
},
"to": "11",
"toName": "王安"
}
4.ice交换
from 发送服务端：candidate
{
"from": "11",
"fromName": "王安",
"iceCandidate": {
"sdp": "candidate:3575964346 1 udp 2122260223 192.168.0.166 47369 typ host generation 0 ufrag 9Jqg network-id 3 network-cost 10",
"sdpMLineIndex": 0,
"sdpMid": "video",
"serverUrl": ""
},
"id": "candidate",
"isSucceed": 0,
"to": "12",
"toName": "往事"
}
to 接收：candidate
{
"from": "11",
"fromName": "王安",
"iceCandidate": {
"sdp": "candidate:3575964346 1 udp 2122260223 192.168.0.166 47369 typ host generation 0 ufrag 9Jqg network-id 3 network-cost 10",
"sdpMLineIndex": 0,
"sdpMid": "video",
"serverUrl": ""
},
"id": "candidate",
"isSucceed": 0,
"to": "12",
"toName": "往事"
}
to 发送服务端：candidate
{
"from": "12",
"fromName": "往事",
"iceCandidate": {
"sdp": "candidate:559267639 1 udp 2122202367 ::1 55843 typ host generation 0 ufrag zoQn network-id 2",
"sdpMLineIndex": 0,
"sdpMid": "video",
"serverUrl": ""
},
"id": "candidate",
"isSucceed": 0,
"to": "11",
"toName": "王安"
}
from接收：candidate
{
"from": "12",
"fromName": "往事",
"iceCandidate": {
"sdp": "candidate:559267639 1 udp 2122202367 ::1 55843 typ host generation 0 ufrag zoQn network-id 2",
"sdpMLineIndex": 0,
"sdpMid": "video",
"serverUrl": ""
},
"id": "candidate",
"isSucceed": 0,
"to": "11",
"toName": "王安"
}5.4 实现视频通话，部分截图
