无法在webrtc中添加远程冰候选者

Question

我正在尝试建立一个p2p音频/视频连接b/w 2个同行.对等P1向对等P2发送提议.在获得报价时,P2确实 -

{
    pc = new RTCPeerConnection(ice);
    pc.setRemoteDescription(new RTCSessionDescription(msg.offer),
            onSetRemoteDescriptionSuccess, onSetSessionDescriptionError);                    

    function onSetRemoteDescriptionSuccess() {
        console.log('onSetRemoteDescriptionSuccess called');                                 
    }                                                                                        

    function onSetSessionDescriptionError() {
        console.log('onSetSessionDescriptionError called');                                  
    }                                                                                        

    pc.onicecandidate = function(evt) {                                                      
        if (evt.candidate) {
            console.log('got local icecandidate', evt.candidate);                            
            send_ice_candicate(evt.candidate.sdpMLineIndex,                                  
                      evt.candidate.sdpMid,
                      evt.candidate.candidate                                                
                      );                                                                     
        }                                                                                    
    }                                                                                        

    pc.onaddstream = function (evt) {
        var remote_video = document.getElementById('remote_video');                          
        remote_video.src = window.URL.createObjectURL(evt.stream);                           
    }                                                                                        

    navigator.getUserMedia({ "audio": true, "video": true },                                 
            gotStream, logError);
} 

function gotStream(stream) {                                                                     
    pc.addStream(stream);                                                                        

    var local_video = document.getElementById('local_video');                                    
    local_video.src = window.URL.createObjectURL(stream);                                        

    pc.createAnswer(function(answer) {
        pc.setLocalDescription(answer);
        console.log('creating answer', answer.sdp)                                           
        signalingChannel.send(answer.sdp);                                                 
        });
    got_ice_candidate(remote_ice_candidate);                                                     
}                                     

remote_ice_candidate是在offer之前收到的东西,因此被缓冲了,我试图在答案准备好之后添加并且其他先决条件已经完成.

但是在尝试添加远程冰候选者时我仍然遇到错误.

P2上的对等连接对象看起来像 -

RTCPeerConnection {ondatachannel: null, oniceconnectionstatechange: null, onremovestream: null, onaddstream: function, onsignalingstatechange: null…}
iceConnectionState: "new"
iceGatheringState: "gathering"
localDescription: RTCSessionDescription
sdp: "v=0
?o=- 5043546633484176483 2 IN IP4 127.0.0.1
?s=-
?t=0 0
?a=group:BUNDLE audio video
?a=msid-semantic: WMS irIWtGZ87WFi8P6XH94I85sUsKYcu775glZk
?m=audio 10990 RTP/SAVPF 111 103 104 0 8 106 105 13 126
?c=IN IP4 122.171.69.180
?a=rtcp:1 IN IP4 0.0.0.0
?a=candidate:3022624816 1 udp 2122260223 192.168.1.4 50063 typ host generation 0
?a=candidate:4205470912 1 tcp 1518280447 192.168.1.4 0 typ host generation 0
?a=candidate:494278629 1 udp 1686052607 122.171.69.180 10990 typ srflx raddr 192.168.1.4 rport 50063 generation 0
?a=ice-ufrag:1ZCyumc5I0T8mbFJ
?a=ice-pwd:+JUisFsiKa8ezPXDIuzu99tv
?a=fingerprint:sha-256 BE:16:E6:7B:C8:18:E6:B9:50:D9:31:F3:24:85:3B:63:26:BA:EA:6B:5D:F4:4E:0E:29:47:16:C0:1D:9D:B7:F3
?a=setup:active
?a=mid:audio
?a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
?a=sendrecv
?a=rtcp-mux
?a=rtpmap:111 opus/48000/2
?a=fmtp:111 minptime=10
?a=rtpmap:103 ISAC/16000
?a=rtpmap:104 ISAC/32000
?a=rtpmap:0 PCMU/8000
?a=rtpmap:8 PCMA/8000
?a=rtpmap:106 CN/32000
?a=rtpmap:105 CN/16000
?a=rtpmap:13 CN/8000
?a=rtpmap:126 telephone-event/8000
?a=maxptime:60
?a=ssrc:2173896727 cname:PZV2reyyZuw6KufJ
?a=ssrc:2173896727 msid:irIWtGZ87WFi8P6XH94I85sUsKYcu775glZk fb1b496d-ffa9-43cd-940a-7c68df86d3b3
?a=ssrc:2173896727 mslabel:irIWtGZ87WFi8P6XH94I85sUsKYcu775glZk
?a=ssrc:2173896727 label:fb1b496d-ffa9-43cd-940a-7c68df86d3b3
?m=video 10990 RTP/SAVPF 100 116 117
?c=IN IP4 122.171.69.180
?a=rtcp:1 IN IP4 0.0.0.0
?a=candidate:3022624816 1 udp 2122260223 192.168.1.4 50063 typ host generation 0
?a=candidate:4205470912 1 tcp 1518280447 192.168.1.4 0 typ host generation 0
?a=candidate:494278629 1 udp 1686052607 122.171.69.180 10990 typ srflx raddr 192.168.1.4 rport 50063 generation 0
?a=ice-ufrag:1ZCyumc5I0T8mbFJ
?a=ice-pwd:+JUisFsiKa8ezPXDIuzu99tv
?a=fingerprint:sha-256 BE:16:E6:7B:C8:18:E6:B9:50:D9:31:F3:24:85:3B:63:26:BA:EA:6B:5D:F4:4E:0E:29:47:16:C0:1D:9D:B7:F3
?a=setup:active
?a=mid:video
?a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
?a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
?a=sendrecv
?a=rtcp-mux
?a=rtpmap:100 VP8/90000
?a=rtcp-fb:100 ccm fir
?a=rtcp-fb:100 nack
?a=rtcp-fb:100 nack pli
?a=rtcp-fb:100 goog-remb
?a=rtpmap:116 red/90000
?a=rtpmap:117 ulpfec/90000
?a=ssrc:2118221653 cname:PZV2reyyZuw6KufJ
?a=ssrc:2118221653 msid:irIWtGZ87WFi8P6XH94I85sUsKYcu775glZk a735b317-1752-40fa-96df-511c0febb55e
?a=ssrc:2118221653 mslabel:irIWtGZ87WFi8P6XH94I85sUsKYcu775glZk
?a=ssrc:2118221653 label:a735b317-1752-40fa-96df-511c0febb55e
?"
type: "answer"
__proto__: RTCSessionDescription
onaddstream: function (evt) {
arguments: null
caller: null
length: 1
name: ""
prototype: Object
__proto__: function Empty() {}
<function scope>
ondatachannel: null
onicecandidate: function (evt) {
oniceconnectionstatechange: null
onnegotiationneeded: null
onremovestream: null
onsignalingstatechange: null
remoteDescription: RTCSessionDescription
sdp: "v=0
?o=- 8847796014807563532 2 IN IP4 127.0.0.1
?s=-
?t=0 0
?a=group:BUNDLE audio video
?a=msid-semantic: WMS na7tuNpnYZpmg56IJULDdF8oMUG8V5ndTjkK
?m=audio 1 RTP/SAVPF 111 103 104 0 8 106 105 13 126
?c=IN IP4 0.0.0.0
?a=rtcp:1 IN IP4 0.0.0.0
?a=ice-ufrag:mfL29tarMKRBN9F/
?a=ice-pwd:/my1DZo1Yjne4BrcQGKN1o3I
?a=ice-options:google-ice
?a=fingerprint:sha-256 BE:16:E6:7B:C8:18:E6:B9:50:D9:31:F3:24:85:3B:63:26:BA:EA:6B:5D:F4:4E:0E:29:47:16:C0:1D:9D:B7:F3
?a=setup:actpass
?a=mid:audio
?a=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level
?a=sendrecv
?a=rtcp-mux
?a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:ggGTdSmkygu0aVidv2M6kO25w5DX/OknOXFnRBYK
?a=rtpmap:111 opus/48000/2
?a=fmtp:111 minptime=10
?a=rtpmap:103 ISAC/16000
?a=rtpmap:104 ISAC/32000
?a=rtpmap:0 PCMU/8000
?a=rtpmap:8 PCMA/8000
?a=rtpmap:106 CN/32000
?a=rtpmap:105 CN/16000
?a=rtpmap:13 CN/8000
?a=rtpmap:126 telephone-event/8000
?a=maxptime:60
?a=ssrc:702054304 cname:++QJWJ3eyXhSOSgH
?a=ssrc:702054304 msid:na7tuNpnYZpmg56IJULDdF8oMUG8V5ndTjkK 054d6450-034f-48ca-85dc-3a843c7f7554
?a=ssrc:702054304 mslabel:na7tuNpnYZpmg56IJULDdF8oMUG8V5ndTjkK
?a=ssrc:702054304 label:054d6450-034f-48ca-85dc-3a843c7f7554
?m=video 1 RTP/SAVPF 100 116 117
?c=IN IP4 0.0.0.0
?a=rtcp:1 IN IP4 0.0.0.0
?a=ice-ufrag:mfL29tarMKRBN9F/
?a=ice-pwd:/my1DZo1Yjne4BrcQGKN1o3I
?a=ice-options:google-ice
?a=fingerprint:sha-256 BE:16:E6:7B:C8:18:E6:B9:50:D9:31:F3:24:85:3B:63:26:BA:EA:6B:5D:F4:4E:0E:29:47:16:C0:1D:9D:B7:F3
?a=setup:actpass
?a=mid:video
?a=extmap:2 urn:ietf:params:rtp-hdrext:toffset
?a=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time
?a=sendrecv
?a=rtcp-mux
?a=crypto:1 AES_CM_128_HMAC_SHA1_80 inline:ggGTdSmkygu0aVidv2M6kO25w5DX/OknOXFnRBYK
?a=rtpmap:100 VP8/90000
?a=rtcp-fb:100 ccm fir
?a=rtcp-fb:100 nack
?a=rtcp-fb:100 nack pli
?a=rtcp-fb:100 goog-remb
?a=rtpmap:116 red/90000
?a=rtpmap:117 ulpfec/90000
?a=ssrc:846853801 cname:++QJWJ3eyXhSOSgH
?a=ssrc:846853801 msid:na7tuNpnYZpmg56IJULDdF8oMUG8V5ndTjkK c0dde33c-f422-4774-9f7b-65cec136e107
?a=ssrc:846853801 mslabel:na7tuNpnYZpmg56IJULDdF8oMUG8V5ndTjkK
?a=ssrc:846853801 label:c0dde33c-f422-4774-9f7b-65cec136e107
?"
type: "offer"
__proto__: RTCSessionDescription
signalingState: "stable"
__proto__: RTCPeerConnection    

我得到的错误是

Failed to add Ice Candidate: Error processing ICE candidate      

Answer 1

我不知道你从哪里得到remote_ice_candidate对象。但要正确处理冰消息，你应该有这样的东西：

第一：在冰候选活动中，您应该将其发送给其他同行。例如：

pc.onicecandidate = function (event) {
    if (!event || !event.candidate) return;
    socket.emit("iceCandidate", event.candidate); //send ice candidate through your signaling server to other peer
};

然后：我们还应该监听来自信令服务器的“iceCandidate”消息并将ice Candidate添加到RTCPeerConnection，例如：

socket.on("iceCandidate", function(iceCandidate){
  pc.addIceCandidate(new RTCIceCandidate(iceCandidate));
});

就这样。根据我的观察，交换ice消息是在offer/answer通信之后开始的，所以在那之前你不应该准备好ice候选对象。当然这段代码只适用于chrome。