webrtc - DOMException : Failed to set remote offer sdp: Called in wrong state: STATE_SENTOFFER

我正在尝试使用webRTC制作视频通话Web应用程序。我正在使用angularjs和express.io

我收到此错误:
DOMException:无法设置远程商品sdp:在错误状态下调用:STATE_SENTOFFER

我的一些代码是:

// in controller (socket is already defined in controller)
var videolocal = document.getElementById('videolocal');
var videoremote = document.getElementById('videoremote');
var streamlocal = null;
var pc = null;
window.URL = window.URL || window.webkitURL;
navigator.getUserMedia = navigator.getUserMedia || navigator.webkitGetUserMedia || navigator.mozGetUserMedia || navigator.msGetUserMedia;
window.RTCPeerConnection = window.RTCPeerConnection || window.mozRTCPeerConnection || window.webkitRTCPeerConnection;

var configuration = {'iceServers': [
        // {'url': 'stun:stun.services.mozilla.com'},
        {'url': 'stun:stun.l.google.com:19302'}
    ]};

// run start(true) to initiate a call
$scope.start = function() {
    console.log('start');

    // get the local stream, show it in the local video element and send it
    navigator.getUserMedia({ "audio": true, "video": true }, function (stream) {
        videolocal.src = URL.createObjectURL(stream);
        pc = new RTCPeerConnection(configuration);
        pc.addStream(stream);

        // once remote stream arrives, show it in the remote video element
        pc.onaddstream = function (evt) {
            console.log('onaddstream');
            videoremote.src = URL.createObjectURL(evt.stream);
        };

        // send any ice candidates to the other peer
        pc.onicecandidate = function (evt) {
            console.log('onicecandidate');
            if(evt.candidate){
                socket.emit('video_call',{user:2, type: 'candidate', candidate: evt.candidate});
            }
        };

        // create an offer
        pc.createOffer(function (offer) {
            socket.emit('video_call', {user:2,  type: "offer", offer: offer});
            pc.setLocalDescription(offer);
        }, function (error) {
            alert("Error when creating an offer");
        });
    }, function () {alert('error in start')});
}
$scope.start();

socket.on('video_call', function (data) {
    console.log(data);
    //when somebody sends us an offer
    function handleOffer(offer) {
        // this line is giving error
        pc.setRemoteDescription(new RTCSessionDescription(offer), function(){alert('success')}, function(e){ console.log(e); alert(e)});

        //create an answer to an offer
        pc.createAnswer(function (answer) {
            pc.setLocalDescription(answer);
            socket.emit('video_call', {user:2, type: "answer", answer: answer});
        }, function (error) {
            console.log(error);
            alert("Error when creating an answer");
        });
    };

    //when we got an answer from a remote user
    function handleAnswer(answer) {
       pc.setRemoteDescription(new RTCSessionDescription(answer));
    };

    //when we got an ice candidate from a remote user
    function handleCandidate(candidate) {
       pc.addIceCandidate(new RTCIceCandidate(candidate));
    };

    switch(data['type']) {
        case "offer":
            handleOffer(data["offer"]);
            break;
        case "answer":
            handleAnswer(data['answer']);
            break;
        //when a remote peer sends an ice candidate to us
        case "candidate":
            handleCandidate(data['candidate']);
            break;
        default:
            break;
   }
});

在服务器上:

// this function is called on video_call event
video_call: function (data) {
    var id = data.user;

    // if user is active
    // users is dict of users (user_id as key)
    if(Object.keys(users).indexOf(id.toString()) > -1){
        // for each device of the user
        users[id].forEach(function(user_socket){
            console.log(data);
            user_socket.emit('video_call', data);
        });
    }
}

请谁能告诉我这段代码有什么问题。本地流正在正确捕获。我正在使用 Chrome 浏览器。

服务器上的数据:

最佳答案

我认为问题在于，您需要在handleOffer()函数中创建另一个PeerConnection并在该PC上调用setRemoteDescription()。

var remote_pc = new RTCPeerConnection(configuration)
remote_pc.setRemoteDescription(new RTCSessionDescription(offer), ...) {
  remote_pc.createAnswer()
}

这就是我的代码中的内容。

编辑:在official link中，您可以转到第11.7章，并检查15以后的步骤(发送要约且另一方收到要约时)。

关于webrtc - DOMException : Failed to set remote offer sdp: Called in wrong state: STATE_SENTOFFER，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/37787372/