轉自：https://zhuanlan.zhihu.com/p/82446482
1、Google Webrtc介紹
WebRTC（Web Real-Time Communication）實現了基於網頁的視頻會議，標准是WHATWG 協議，目的是通過瀏覽器提供簡單的javascript就可以達到實時通訊（Real-Time Communications (RTC)）能力。
提供了視頻會議的核心技術，包括音視頻的采集、編解碼、網絡傳輸、顯示等功能，並且還支持跨平台：windows，linux，mac，android，音視頻通訊技術是基於p2p實現的
2、Google Webrtc服務器配置
信令服務器(signaling)，轉發服務器(TURN)，穿透服務器(STUN)（自行百度，配置），更詳細的介紹請看書籍 WebRtc權威指南
2.1 信令服務器(signaling)
WebRTC 之間使用PeerConnection交流數據，但還需要一種機制來協調溝通和發送控制消息，這一過程稱之為信令傳輸
2.2 轉發服務器(TURN) & 穿透服務器(STUN)
WebRTC 被設計為點對點工作模式，所以用戶之間是盡可能地通過最短路線進行連接，然而在現實世界當中：客戶端應用需要穿透 NAT 網關 和防火牆，並且點對點網絡需要握手來防止直接連接失敗，在這一過程中，WebRTC使用STUN服務器和TURN服務器來獲取計算機IP地址來保證點對點連接成功
3、ICE框架
基於信令協議的多媒體傳輸是一個兩段式傳輸，首先通過信令協議（如WebSocket）建立一個連接，通過該連接，雙方交換傳輸媒體時所必須的信息。基於傳輸效率的考慮，在完成第一階段的交互之后，通信雙方會建立一條通道來實現媒體傳輸，以減少傳輸時延、降低丟包率並減少開銷。由於使用新的鏈路，當傳輸雙方有任意一方位於NAT之后，新的傳輸鏈路就需要考慮NAT穿越的問題了通常有四種形式的NAT，每一種NAT都有相應的解決方案，然而在復雜的網絡環境中，由於每一種NAT穿越方案都局限於對應的NAT方式，這些方案就給整個系統帶來了一定的復雜性。在這種背景下，交互式連通建立方式(Interactive Connectivity Establishment)即ICE解決方案應運而生，ICE能夠在不增加整個系統的復雜性和脆弱性的情況下，實現對各種形式的NAT的穿越。
官方提供的實現原理 基於下圖
4、Android Webrtc的配置
客戶端和服務端通信 采用WebSocket
攝像頭，錄音，SD卡讀取等其他權限加入，有些需要在運行時調用
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 創建websocket
private void connectionWebsocket() {
try {
webSocketClient = new WebSocketClient(URI.create(Constant.URL)) {
@Override
public void onOpen(ServerHandshake handshakedata) {
setText("已連接");
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, "連接成功");
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "注冊失敗，已經注冊");
}
break;
case Constant.CALL_RESPONSE:
if (isSucceed == Constant.RESPONSE_SUCCEED) {
Log.e(TAG, "對方在線，創建sdp offer");
createOffer();
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "對方不在線，連接失敗");
}
break;
case Constant.INCALL:
isIncall();
break;
case Constant.INCALL_RESPONSE:
if (isSucceed == Constant.RESPONSE_SUCCEED) {
createOffer();
Log.e(TAG, "對方同意接聽");
} else if (isSucceed == Constant.RESPONSE_FAILURE) {
Log.e(TAG, "對方拒絕接聽");
}
break;
case Constant.OFFER:
//收到對方offer sdp
SessionDescription sessionDescription1 = model.getSessionDescription();
peerConnection.setRemoteDescription(observer, sessionDescription1);
createAnswer();
break;
case Constant.CANDIDATE:
//服務端 發送 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("已關閉");
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 創建websocket成功后開始創建PeerConnection，穿透服務器采用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);
//創建EglBase對象
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穿透服務器 轉發服務器
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 可配參數說明：
ordered：是否保證順序傳輸；
maxRetransmitTimeMs：重傳允許的最長時間；
maxRetransmits：重傳允許的最大次數；
*/
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 初始化音頻和視頻
/**
* 創建本地視頻
*
* @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);
}
/**
* 創建本地音頻
*/
private void startLocalAudioCapture() {
//語音
MediaConstraints audioConstraints = new MediaConstraints();
//回聲消除
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googEchoCancellation", "true"));
//自動增益
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googAutoGainControl", "true"));
//高音過濾
audioConstraints.mandatory.add(new MediaConstraints.KeyValuePair("googHighpassFilter", "true"));
//噪音處理
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 創建PeerConnection成功后通過信令傳輸交換各自信息，實現視頻通話，調整后的流程如下圖
信令
public static final String REGISTER = "register";//注冊
public static final String REGISTER_RESPONSE = "register_response";//注冊回復
public static final int RESPONSE_SUCCEED = 1;//1成功
public static final int RESPONSE_FAILURE = 2;//2失敗
public static final String CALL = "call";//撥打
public static final String CALL_RESPONSE = "call_response";//撥打回復
public static final String INCALL = "incall";//接聽
public static final String INCALL_RESPONSE = "incall_response";//接聽回復
public static final String OFFER = "offer";//發送sdp信息
public static final String CANDIDATE = "candidate";//ice互傳流程內容： 客戶端A，客戶端B
- 5.3.1 -->> A 和 B 都注冊成功后，A 發起 call，服務端收到A的指令后轉發給B， B接受后發給服務器，服務器轉發給A
- 5.3.2 -->> A createOffer 將自己的SessionDescription 發給服務器，服務器轉發給B
- 5.3.3 -->> B 收到后將A的SessionDescription 設置到自己的setRemoteDescription，同時createAnswer 發給服務器，服務器在轉發A
- 5.3.4 -->> A 收到后將B的SessionDescription 設置到自己的setRemoteDescription
- 5.3.5 -->> A 在PeerConnectionObserver 的 onIceCandidate方法中，將收到的IceCandidate 發給服務端，服務器轉發給B
- 5.3.6 -->> B 收到后在將IceCandidate 設置到自己的addIceCandidate
- 5.3.7 -->> B 在PeerConnectionObserver 的 onIceCandidate方法中，將收到的IceCandidate 發給服務端，服務器轉發給A
- 5.3.8 -->> A 收到后在將IceCandidate 設置到自己的addIceCandidate
- 5.3.9 -->> A 和 B 在PeerConnectionObserver 的 onAddStream方法中，將遠端的流媒體加入到本地的View
- 5.3.10 -->> 交互已經結束，可以正常視頻通話
詳細的流程，json 格式
isSucceed 1成功 2失敗
"from": "11", "fromName": "王安", "to": "12", "toName": "往事"
1.注冊
from 發送服務端：register
{
"from": "11",
"fromName": "王安",
"id": "register",
"isSucceed": 0
}
from接收：register_response
{
"id": "register_response",
"isSucceed": 1
}
2.呼叫
from 發送服務端：call
{
"from": "11",
"fromName": "王安",
"id": "call",
"isSucceed": 0,
"to": "12",
"toName": "往事"
}
2.1服務端做判斷
如果不在線 直接返回 "isSucceed": 1
{
"id": "call_response",
"isSucceed": 1
}
在線 返回給to做判斷
to 接收：incall
改變本地狀態
{
"id": "incall",
"isSucceed": 0
}
to 發送服務端 拒絕："isSucceed": 2
{
"from": "12",
"fromName": "往事",
"id": "incall",
"isSucceed": 2,
"to": "11",
"toName": "王安"
}
from接收：incall_response
做拒絕的操作
{
"id": "incall_response",
"from": "12",
"fromName": "往事",
"to": "11",
"toName": "王安",
"isSucceed": 2
}
-------------------------------------------------
to 發送服務端 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發送流
from 發送服務端：offer
{
"from": "11",
"fromName": "王安",
"id": "offer",
"isSucceed": 0,
"sessionDescription": {
"description": "v=0\r\no=- 3285195603599485281 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE video\r\na=msid-semantic: WMS localstream\r\nm=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:9Jqg\r\na=ice-pwd:lM34EvVxjaPGBislEH9VccVu\r\na=ice-options:trickle renomination\r\na=mid:video\r\na=extmap:14 urn:ietf:params:rtp-hdrext:toffset\r\na=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=extmap:3 urn:3gpp:video-orientation\r\na=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type\r\na=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing\r\na=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07\r\na=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space\r\na=sendrecv\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 goog-remb\r\na=rtcp-fb:96 transport-cc\r\na=rtcp-fb:96 ccm fir\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=rtpmap:98 VP9/90000\r\na=rtcp-fb:98 goog-remb\r\na=rtcp-fb:98 transport-cc\r\na=rtcp-fb:98 ccm fir\r\na=rtcp-fb:98 nack\r\na=rtcp-fb:98 nack pli\r\na=rtpmap:99 rtx/90000\r\na=fmtp:99 apt=98\r\na=rtpmap:100 H264/90000\r\na=rtcp-fb:100 goog-remb\r\na=rtcp-fb:100 transport-cc\r\na=rtcp-fb:100 ccm fir\r\na=rtcp-fb:100 nack\r\na=rtcp-fb:100 nack pli\r\na=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=rtpmap:101 rtx/90000\r\na=fmtp:101 apt=100\r\na=rtpmap:127 red/90000\r\na=rtpmap:124 rtx/90000\r\na=fmtp:124 apt=127\r\na=rtpmap:125 ulpfec/90000\r\na=ssrc-group:FID 1791802911 305163890\r\na=ssrc:1791802911 cname:8uTWIc2YbUNSY02u\r\na=ssrc:1791802911 msid:localstream videtrack\r\na=ssrc:1791802911 mslabel:localstream\r\na=ssrc:1791802911 label:videtrack\r\na=ssrc:305163890 cname:8uTWIc2YbUNSY02u\r\na=ssrc:305163890 msid:localstream videtrack\r\na=ssrc:305163890 mslabel:localstream\r\na=ssrc:305163890 label:videtrack\r\n",
"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\r\no=- 3285195603599485281 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE video\r\na=msid-semantic: WMS localstream\r\nm=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:9Jqg\r\na=ice-pwd:lM34EvVxjaPGBislEH9VccVu\r\na=ice-options:trickle renomination\r\na=mid:video\r\na=extmap:14 urn:ietf:params:rtp-hdrext:toffset\r\na=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=extmap:3 urn:3gpp:video-orientation\r\na=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type\r\na=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing\r\na=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07\r\na=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space\r\na=sendrecv\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 goog-remb\r\na=rtcp-fb:96 transport-cc\r\na=rtcp-fb:96 ccm fir\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=rtpmap:98 VP9/90000\r\na=rtcp-fb:98 goog-remb\r\na=rtcp-fb:98 transport-cc\r\na=rtcp-fb:98 ccm fir\r\na=rtcp-fb:98 nack\r\na=rtcp-fb:98 nack pli\r\na=rtpmap:99 rtx/90000\r\na=fmtp:99 apt=98\r\na=rtpmap:100 H264/90000\r\na=rtcp-fb:100 goog-remb\r\na=rtcp-fb:100 transport-cc\r\na=rtcp-fb:100 ccm fir\r\na=rtcp-fb:100 nack\r\na=rtcp-fb:100 nack pli\r\na=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=rtpmap:101 rtx/90000\r\na=fmtp:101 apt=100\r\na=rtpmap:127 red/90000\r\na=rtpmap:124 rtx/90000\r\na=fmtp:124 apt=127\r\na=rtpmap:125 ulpfec/90000\r\na=ssrc-group:FID 1791802911 305163890\r\na=ssrc:1791802911 cname:8uTWIc2YbUNSY02u\r\na=ssrc:1791802911 msid:localstream videtrack\r\na=ssrc:1791802911 mslabel:localstream\r\na=ssrc:1791802911 label:videtrack\r\na=ssrc:305163890 cname:8uTWIc2YbUNSY02u\r\na=ssrc:305163890 msid:localstream videtrack\r\na=ssrc:305163890 mslabel:localstream\r\na=ssrc:305163890 label:videtrack\r\n"
},
"isSucceed": 0
}
to接收到 offer 創建answer 創建完 to 發送服務端：offer
{
"from": "12",
"fromName": "往事",
"id": "offer",
"isSucceed": 0,
"sessionDescription": {
"description": "v=0\r\no=- 8665372075017263288 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE video\r\na=msid-semantic: WMS localstream\r\nm=video 9 RTP/AVPF 96 97 98 99 100 101 127 124 125\r\nc=IN IP4 0.0.0.0\r\na=rtcp:9 IN IP4 0.0.0.0\r\na=ice-ufrag:zoQn\r\na=ice-pwd:oBePBH1X7SehiT6Tb83SZV2U\r\na=ice-options:trickle renomination\r\na=mid:video\r\na=extmap:14 urn:ietf:params:rtp-hdrext:toffset\r\na=extmap:13 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=extmap:3 urn:3gpp:video-orientation\r\na=extmap:2 http://www.ietf.org/id/draft-holmer-rmcat-transport-wide-cc-extensions-01\r\na=extmap:5 http://www.webrtc.org/experiments/rtp-hdrext/playout-delay\r\na=extmap:6 http://www.webrtc.org/experiments/rtp-hdrext/video-content-type\r\na=extmap:7 http://www.webrtc.org/experiments/rtp-hdrext/video-timing\r\na=extmap:8 http://tools.ietf.org/html/draft-ietf-avtext-framemarking-07\r\na=extmap:9 http://www.webrtc.org/experiments/rtp-hdrext/color-space\r\na=sendrecv\r\na=rtcp-mux\r\na=rtcp-rsize\r\na=rtpmap:96 VP8/90000\r\na=rtcp-fb:96 goog-remb\r\na=rtcp-fb:96 transport-cc\r\na=rtcp-fb:96 ccm fir\r\na=rtcp-fb:96 nack\r\na=rtcp-fb:96 nack pli\r\na=rtpmap:97 rtx/90000\r\na=fmtp:97 apt=96\r\na=rtpmap:98 VP9/90000\r\na=rtcp-fb:98 goog-remb\r\na=rtcp-fb:98 transport-cc\r\na=rtcp-fb:98 ccm fir\r\na=rtcp-fb:98 nack\r\na=rtcp-fb:98 nack pli\r\na=rtpmap:99 rtx/90000\r\na=fmtp:99 apt=98\r\na=rtpmap:100 H264/90000\r\na=rtcp-fb:100 goog-remb\r\na=rtcp-fb:100 transport-cc\r\na=rtcp-fb:100 ccm fir\r\na=rtcp-fb:100 nack\r\na=rtcp-fb:100 nack pli\r\na=fmtp:100 level-asymmetry-allowed=1;packetization-mode=1;profile-level-id=42e01f\r\na=rtpmap:101 rtx/90000\r\na=fmtp:101 apt=100\r\na=rtpmap:127 red/90000\r\na=rtpmap:124 rtx/90000\r\na=fmtp:124 apt=127\r\na=rtpmap:125 ulpfec/90000\r\na=ssrc-group:FID 330040035 1917181902\r\na=ssrc:330040035 cname:uxoKaX6C0J4LHdZ2\r\na=ssrc:330040035 msid:localstream videtrack\r\na=ssrc:330040035 mslabel:localstream\r\na=ssrc:330040035 label:videtrack\r\na=ssrc:1917181902 cname:uxoKaX6C0J4LHdZ2\r\na=ssrc:1917181902 msid:localstream videtrack\r\na=ssrc:1917181902 mslabel:localstream\r\na=ssrc:1917181902 label:videtrack\r\n",
"type": "ANSWER"
},
"to": "11",
"toName": "王安"
}
4.ice交換
from 發送服務端：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 發送服務端：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 實現視頻通話，部分截圖
