问题
Response from server:
{
"rtcid": "wKAm8eeyI-mQ5dsslkhu",
"msgType": "offer",
"senderrtcid": "53wp_LP5CYDie3eIlkhw",
"msgData": {
"type": "offer",
"sdp": "v=0\r\no=- 951920257545056255 2 IN IP4 127.0.0.1\r\ns=-\r\nt=0 0\r\na=group:BUNDLE audio video\r\na=msid-semantic: WMS OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM\r\nm=audio 1 RTP/SAVPF 111 103 104 0 8 106 105 13 126\r\nc=IN IP4 0.0.0.0\r\na=rtcp:1 IN IP4 0.0.0.0\r\na=ice-ufrag:CF4q+RW54gQVPaz0\r\na=ice-pwd:hEIbgX4MME6cPkZKGih7bjQM\r\na=ice-options:google-ice\r\na=fingerprint:sha-256 1E:7F:B8:BA:1A:8D:76:BE:A9:A5:A3:9D:59:3E:CC:BD:1B:90:7B:89:EF:F0:03:B3:9A:CA:9C:07:02:97:53:6F\r\na=setup:actpass\r\na=mid:audio\r\na=extmap:1 urn:ietf:params:rtp-hdrext:ssrc-audio-level\r\na=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=sendrecv\r\na=rtcp-mux\r\na=rtpmap:111 opus/48000/2\r\na=fmtp:111 minptime=10\r\na=rtpmap:103 ISAC/16000\r\na=rtpmap:104 ISAC/32000\r\na=rtpmap:0 PCMU/8000\r\na=rtpmap:8 PCMA/8000\r\na=rtpmap:106 CN/32000\r\na=rtpmap:105 CN/16000\r\na=rtpmap:13 CN/8000\r\na=rtpmap:126 telephone-event/8000\r\na=maxptime:60\r\na=ssrc:777379316 cname:Dl+cb/nGYCzEcTvH\r\na=ssrc:777379316 msid:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM 0937b040-5691-4ae3-b533-dd9ce82c4393\r\na=ssrc:777379316 mslabel:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM\r\na=ssrc:777379316 label:0937b040-5691-4ae3-b533-dd9ce82c4393\r\nm=video 1 RTP/SAVPF 100 116 117 96\r\nc=IN IP4 0.0.0.0\r\na=rtcp:1 IN IP4 0.0.0.0\r\na=ice-ufrag:CF4q+RW54gQVPaz0\r\na=ice-pwd:hEIbgX4MME6cPkZKGih7bjQM\r\na=ice-options:google-ice\r\na=fingerprint:sha-256 1E:7F:B8:BA:1A:8D:76:BE:A9:A5:A3:9D:59:3E:CC:BD:1B:90:7B:89:EF:F0:03:B3:9A:CA:9C:07:02:97:53:6F\r\na=setup:actpass\r\na=mid:video\r\na=extmap:2 urn:ietf:params:rtp-hdrext:toffset\r\na=extmap:3 http://www.webrtc.org/experiments/rtp-hdrext/abs-send-time\r\na=sendrecv\r\na=rtcp-mux\r\na=rtpmap:100 VP8/90000\r\na=rtcp-fb:100 ccm fir\r\na=rtcp-fb:100 nack\r\na=rtcp-fb:100 nack pli\r\na=rtcp-fb:100 goog-remb\r\na=rtpmap:116 red/90000\r\na=rtpmap:117 ulpfec/90000\r\na=rtpmap:96 rtx/90000\r\na=fmtp:96 apt=100\r\na=ssrc-group:FID 187598656 415229902\r\na=ssrc:187598656 cname:Dl+cb/nGYCzEcTvH\r\na=ssrc:187598656 msid:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM 02ab4641-6cd5-43be-b0fe-9952585642bf\r\na=ssrc:187598656 mslabel:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM\r\na=ssrc:187598656 label:02ab4641-6cd5-43be-b0fe-9952585642bf\r\na=ssrc:415229902 cname:Dl+cb/nGYCzEcTvH\r\na=ssrc:415229902 msid:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM 02ab4641-6cd5-43be-b0fe-9952585642bf\r\na=ssrc:415229902 mslabel:OfkjcHABgxUkHlk8mfJ8ayYZdCHqdpQGFSTM\r\na=ssrc:415229902 label:02ab4641-6cd5-43be-b0fe-9952585642bf\r\n"
},
"serverTime": 1431342100822
}
Log
libjingle: Ignored line: c=IN IP4 0.0.0.0
libjingle: Error(transport.cc:97): Answerer must use either active or passive value for setup attribute.
libjingle:Error(webrtcsession.cc:272): Failed to set remote answer sdp: Failed to push down transport description: Answerer must use either active or passive value for setup attribute.
**First I create offer and add localdescription then send it to server using emit and the server return callback contains remote sdp **
public void onCreateSuccess(SessionDescription arg0) {
// TODO Auto-generated method stub
try {
if(arg0.type.canonicalForm().equalsIgnoreCase("answer")){
peer.setRemoteDescription(this, sdp);
// mListener.onAddRemoteStream(localMS, 0);
}
else{
payload = new JSONObject();
payload.put("type", arg0.type.canonicalForm());
Log.d("offer", arg0.type.canonicalForm().toString());
payload.put("sdp", arg0.description);
sendMessage("rtcsid", arg0.type.canonicalForm(), payload);
peer.setLocalDescription(this, arg0);
}
} catch (JSONException e) {
e.printStackTrace();
}
IceCandidate:
public void onIceCandidate(IceCandidate arg0) {
// TODO Auto-generated method stub
Log.d("IceCandidate", arg0.toString());
JSONObject payload = new JSONObject();
try {
payload.put("type", arg0.sdpMLineIndex);
Log.d("sdpMLineIndex", Integer.toString(arg0.sdpMLineIndex));
payload.put("id", arg0.sdpMid);
Log.d("sdpMid", arg0.sdpMid.toString());
payload.put("type", arg0.sdp);
Log.d("candidate", arg0.sdp.toString());
sendMessage("easyrtcsid", "candidate", payload);
if(peer.getRemoteDescription()!=null){
IceCandidate candidate = new IceCandidate(
arg0.sdpMid,
arg0.sdpMLineIndex,
arg0.sdp.toString()
);
peer.addIceCandidate(candidate);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
Log of Candidate
{
05-11 14:59:28.495: I/libjingle(14672): Local and Remote descriptions must be applied to get SSL Role of the session.
05-11 14:59:28.495: I/libjingle(14672): Transport: audio, allocating candidates
05-11 14:59:28.495: D/IceGatheringChange(14672): GATHERING
05-11 14:59:28.495: I/libjingle(14672): Transport: audio, allocating candidates
05-11 14:59:28.495: D/IceGatheringChange(14672): GATHERING
05-11 14:59:28.495: I/libjingle(14672): Transport: video, allocating candidates
05-11 14:59:28.495: D/IceGatheringChange(14672): GATHERING
05-11 14:59:28.495: I/libjingle(14672): Transport: video, allocating candidates
05-11 14:59:28.495: D/IceGatheringChange(14672): GATHERING
05-11 14:59:28.495: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Udp
05-11 14:59:28.505: I/libjingle(14672): Jingle:Port[:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.505: I/libjingle(14672): AllocationSequence: UDPPort will be handling the STUN candidate generation.
05-11 14:59:28.505: I/libjingle(14672): Adding allocated port for audio
05-11 14:59:28.505: I/libjingle(14672): Jingle:Port[audio:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.525: D/IceCandidate(14672): audio:0:candidate:1281544012 1 udp 2122260223 10.0.0.112 49865 typ host generation 0
05-11 14:59:28.525: D/sdpMLineIndex(14672): 0
05-11 14:59:28.525: D/sdpMid(14672): audio
05-11 14:59:28.525: D/candidate(14672): candidate:1281544012 1 udp 2122260223 10.0.0.112 49865 typ host generation 0
05-11 14:59:28.525: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Udp
05-11 14:59:28.525: I/libjingle(14672): Jingle:Port[:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.525: I/libjingle(14672): AllocationSequence: UDPPort will be handling the STUN candidate generation.
05-11 14:59:28.525: I/libjingle(14672): Adding allocated port for audio
05-11 14:59:28.525: I/libjingle(14672): Jingle:Port[audio:2:0::Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.555: D/IceCandidate(14672): audio:0:candidate:1281544012 2 udp 2122260222 10.0.0.112 36221 typ host generation 0
05-11 14:59:28.555: D/sdpMLineIndex(14672): 0
05-11 14:59:28.555: D/sdpMid(14672): audio
05-11 14:59:28.555: D/candidate(14672): candidate:1281544012 2 udp 2122260222 10.0.0.112 36221 typ host generation 0
05-11 14:59:28.555: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Udp
05-11 14:59:28.555: I/libjingle(14672): Jingle:Port[:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.555: I/libjingle(14672): AllocationSequence: UDPPort will be handling the STUN candidate generation.
05-11 14:59:28.555: I/libjingle(14672): Adding allocated port for video
05-11 14:59:28.555: I/libjingle(14672): Jingle:Port[video:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.565: D/IceCandidate(14672): video:1:candidate:1281544012 1 udp 2122260223 10.0.0.112 57380 typ host generation 0
05-11 14:59:28.565: D/sdpMLineIndex(14672): 1
05-11 14:59:28.565: D/sdpMid(14672): video
05-11 14:59:28.565: D/candidate(14672): candidate:1281544012 1 udp 2122260223 10.0.0.112 57380 typ host generation 0
05-11 14:59:28.575: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Udp
05-11 14:59:28.575: I/libjingle(14672): Jingle:Port[:1:0::Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.575: I/libjingle(14672): AllocationSequence: UDPPort will be handling the STUN candidate generation.
05-11 14:59:28.575: I/libjingle(14672): Adding allocated port for video
05-11 14:59:28.575: I/libjingle(14672): Jingle:Port[video:2:0::Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.605: D/IceCandidate(14672): video:1:candidate:1281544012 2 udp 2122260222 10.0.0.112 48445 typ host generation 0
05-11 14:59:28.605: D/sdpMLineIndex(14672): 1
05-11 14:59:28.605: D/sdpMid(14672): video
05-11 14:59:28.605: D/candidate(14672): candidate:1281544012 2 udp 2122260222 10.0.0.112 48445 typ host generation 0
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.625: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Relay
05-11 14:59:28.625: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Relay
05-11 14:59:28.635: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.635: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Relay
05-11 14:59:28.635: W/libjingle(14672): Warning(thread.cc:320): Waiting for the thread to join, but blocking calls have been disallowed
05-11 14:59:28.635: D/IceCandidate(14672): audio:0:candidate:2940422560 1 udp 1686052607 197.44.239.36 49865 typ srflx raddr 10.0.0.112 rport 49865 generation 0
05-11 14:59:28.635: D/sdpMLineIndex(14672): 0
05-11 14:59:28.635: D/sdpMid(14672): audio
05-11 14:59:28.635: D/candidate(14672): candidate:2940422560 1 udp 1686052607 197.44.239.36 49865 typ srflx raddr 10.0.0.112 rport 49865 generation 0
05-11 14:59:28.645: D/IceCandidate(14672): audio:0:candidate:2940422560 2 udp 1686052606 197.44.239.36 36221 typ srflx raddr 10.0.0.112 rport 36221 generation 0
05-11 14:59:28.645: D/sdpMLineIndex(14672): 0
05-11 14:59:28.645: D/sdpMid(14672): audio
05-11 14:59:28.645: D/candidate(14672): candidate:2940422560 2 udp 1686052606 197.44.239.36 36221 typ srflx raddr 10.0.0.112 rport 36221 generation 0
05-11 14:59:28.665: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Relay
05-11 14:59:28.675: D/IceCandidate(14672): video:1:candidate:2940422560 1 udp 1686052607 197.44.239.36 57380 typ srflx raddr 10.0.0.112 rport 57380 generation 0
05-11 14:59:28.675: D/sdpMLineIndex(14672): 1
05-11 14:59:28.675: D/sdpMid(14672): video
05-11 14:59:28.675: D/candidate(14672): candidate:2940422560 1 udp 1686052607 197.44.239.36 57380 typ srflx raddr 10.0.0.112 rport 57380 generation 0
05-11 14:59:28.685: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Tcp
05-11 14:59:28.685: I/libjingle(14672): Jingle:Port[:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.685: I/libjingle(14672): Adding allocated port for audio
05-11 14:59:28.685: I/libjingle(14672): Jingle:Port[audio:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.685: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Tcp
05-11 14:59:28.685: D/IceCandidate(14672): audio:0:candidate:48313276 1 tcp 1518280447 10.0.0.112 40627 typ host tcptype passive generation 0
05-11 14:59:28.685: D/sdpMLineIndex(14672): 0
05-11 14:59:28.685: D/sdpMid(14672): audio
05-11 14:59:28.685: D/candidate(14672): candidate:48313276 1 tcp 1518280447 10.0.0.112 40627 typ host tcptype passive generation 0
05-11 14:59:28.685: I/libjingle(14672): Jingle:Port[:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.685: I/libjingle(14672): Adding allocated port for audio
05-11 14:59:28.685: I/libjingle(14672): Jingle:Port[audio:2:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.685: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Tcp
05-11 14:59:28.685: D/IceCandidate(14672): audio:0:candidate:48313276 2 tcp 1518280446 10.0.0.112 48390 typ host tcptype passive generation 0
05-11 14:59:28.685: D/sdpMLineIndex(14672): 0
05-11 14:59:28.685: D/sdpMid(14672): audio
05-11 14:59:28.685: D/candidate(14672): candidate:48313276 2 tcp 1518280446 10.0.0.112 48390 typ host tcptype passive generation 0
05-11 14:59:28.695: I/libjingle(14672): Jingle:Port[:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.695: I/libjingle(14672): Adding allocated port for video
05-11 14:59:28.695: I/libjingle(14672): Jingle:Port[video:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.695: D/IceCandidate(14672): video:1:candidate:48313276 1 tcp 1518280447 10.0.0.112 60960 typ host tcptype passive generation 0
05-11 14:59:28.695: D/sdpMLineIndex(14672): 1
05-11 14:59:28.695: D/sdpMid(14672): video
05-11 14:59:28.695: D/candidate(14672): candidate:48313276 1 tcp 1518280447 10.0.0.112 60960 typ host tcptype passive generation 0
05-11 14:59:28.705: D/IceCandidate(14672): video:1:candidate:2940422560 2 udp 1686052606 197.44.239.36 48445 typ srflx raddr 10.0.0.112 rport 48445 generation 0
05-11 14:59:28.705: D/sdpMLineIndex(14672): 1
05-11 14:59:28.715: D/sdpMid(14672): video
05-11 14:59:28.715: D/candidate(14672): candidate:2940422560 2 udp 1686052606 197.44.239.36 48445 typ srflx raddr 10.0.0.112 rport 48445 generation 0
05-11 14:59:28.725: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=Tcp
05-11 14:59:28.725: I/libjingle(14672): Jingle:Port[:1:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Port created
05-11 14:59:28.725: I/libjingle(14672): Adding allocated port for video
05-11 14:59:28.725: I/libjingle(14672): Jingle:Port[video:2:0:local:Net[wlan0:10.0.0.0/8:Unknown]]: Added port to allocator
05-11 14:59:28.725: D/IceCandidate(14672): video:1:candidate:48313276 2 tcp 1518280446 10.0.0.112 59723 typ host tcptype passive generation 0
05-11 14:59:28.725: D/sdpMLineIndex(14672): 1
05-11 14:59:28.725: D/sdpMid(14672): video
05-11 14:59:28.725: D/candidate(14672): candidate:48313276 2 tcp 1518280446 10.0.0.112 59723 typ host tcptype passive generation 0
05-11 14:59:28.735: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=SslTcp
05-11 14:59:28.735: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=SslTcp
05-11 14:59:28.735: I/libjingle(14672): All candidates gathered for audio:2:0
05-11 14:59:28.735: I/libjingle(14672): Transport: audio, component 2 allocation complete
05-11 14:59:28.745: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=SslTcp
05-11 14:59:28.745: I/libjingle(14672): All candidates gathered for video:1:0
05-11 14:59:28.745: I/libjingle(14672): Transport: video, component 1 allocation complete
05-11 14:59:28.775: I/libjingle(14672): Jingle:Net[wlan0:10.0.0.0/8:Unknown]: Allocation Phase=SslTcp
05-11 14:59:28.775: I/libjingle(14672): All candidates gathered for video:2:0
05-11 14:59:28.775: I/libjingle(14672): Transport: video, component 2 allocation complete
05-11 14:59:28.775: I/libjingle(14672): Transport: video allocation complete
05-11 14:59:28.775: I/libjingle(14672): Candidate allocation not done for audio
05-11 14:59:28.795: I/libjingle(14672): All candidates gathered for audio:1:0
05-11 14:59:28.795: I/libjingle(14672): Transport: audio, component 1 allocation complete
05-11 14:59:28.795: I/libjingle(14672): Transport: audio allocation complete
05-11 14:59:28.795: I/libjingle(14672): Candidate gathering is complete.
05-11 14:59:28.795: D/IceGatheringChange(14672): COMPLETE
}
MediaConstraints
pcConstraints.mandatory.add(new MediaConstraints.KeyValuePair("OfferToReceiveAudio", "true"));
pcConstraints.mandatory.add(new MediaConstraints.KeyValuePair("OfferToReceiveVideo", "true"));
pcConstraints.optional.add(new MediaConstraints.KeyValuePair("DtlsSrtpKeyAgreement", "true"));
回答1:
Keep in mind that this my own humble code, it might not be perfect, and it might be hard to just copy everything to your own project. It works for me, but that doesn't mean it will for everyone else.
The process for setting up a call is as follows (note, this is not set in stone):
There are 2 devices, A and B, both are connected to some kind of signaling server to allow them to exchange SDPs and ICE candidates, as well as inviting each other to calls etc...
A starts a call, the first step will likely be to send an invite to B. I like to also init the peerconnection object at this point, using the following code:
//initialize the peerconnection factory
PeerConnectionFactory.initializeAndroidGlobals(MainActivity.context, true, true, true, parent.tex_remote);
factory = new PeerConnectionFactory();
//ice server initialization
ArrayList<PeerConnection.IceServer> iceServers = new ArrayList<>();
iceServers.add(new PeerConnection.IceServer("stun:stun.xxx.xxx:xxx"));
iceServers.add(new PeerConnection.IceServer("turn:turn.xxx.xxx:xxx", "xxx", "xxx"));
//create a new contraints object to configure the connection
MediaConstraints connectionConstraints = new MediaConstraints();
connectionConstraints.mandatory.add(new MediaConstraints.KeyValuePair("offerToReceiveAudio", "true"));
connectionConstraints.mandatory.add(new MediaConstraints.KeyValuePair("offerToReceiveVideo", "true"));
connectionConstraints.optional.add(new MediaConstraints.KeyValuePair("DtlsSrtpKeyAgreement", "true"));
//create a new peerconnection object
peerConnection = factory.createPeerConnection(iceServers, connectionConstraints, observer);
When this is done, and you have your peerconnection object, you can initialize the local media stream, using the following code:
//create a new audio and video source, this is the stream that will be sent to the remote
VideoSource videoSource = factory.createVideoSource(VideoCapturer.create("Camera 1, Facing front, Orientation 270"), new MediaConstraints());
AudioSource audioSource = factory.createAudioSource(new MediaConstraints());
//create a new audio and video track
VideoTrack videoTrack = factory.createVideoTrack("ARDAMSv0", videoSource);
AudioTrack audioTrack = factory.createAudioTrack("ARDAMSa0", audioSource);
//create a new media stream, this holds all local streams and their tracks
MediaStream lms = factory.createLocalMediaStream("ARDAMS");
//create a new video renderer and add it to the video track
VideoRenderer renderer = new VideoRenderer(parent);
videoTrack.addRenderer(renderer);
//add the video track to the stream
lms.addTrack(videoTrack);
//add the audio track to the stream
lms.addTrack(audioTrack);
//add the stream to the connection
peerConnection.addStream(lms);
Meanwhile, B will receive the call invite from the signaling server and will have to present some kind of incoming call view to the user. When the user decides to answer the call, B sends an accept signal back to A.
When A receives this accept signal, it's time to start setting up the call itself. Call createOffer() on A, and the library will call onCreateSuccess() if it succeeds:
peerConnection.createOffer(observer, new MediaConstraints());
In onCreateSuccess(), you can call setLocalDescription() with the newly created SDP. You also have to send this SDP to B, so you might as well do that here:
peerConnection.setLocalDescription(this, sessionDescription);
//send this SDP to your remote peer
B will now receive A's offer, which you will have to set by calling setRemoteDescription():
peerConnection.setRemoteDescription(observer, sdp);
The library will call onSetSuccess() if this succeeds. In onSetSuccess() you can call createAnswer():
peerConnection.createAnswer(observer, constraints);
Because you are now sure you have the initial offer SDP set. The library will call onCreateSuccess() again for you. The same thing as with A's offer now happens with B's answer. It will set the answer as a local SDP, and send it to A:
peerConnection.setLocalDescription(this, sessionDescription);
//send this SDP to your remote peer
When all of this is done, exchanging SDPs is complete. The library will also call onIceCandidate() a number of times. You only have to send this ICE candidate to the other peer and call peerConnection.addIceCandidate() when you receive an ICE candidate from the other peer.
回答2:
pcConstraints.optional.add(new KeyValuePair("DtlsSrtpKeyAgreement", "true"));
pcConstraints.optional.add(new KeyValuePair("RtpDataChannels", "true"));
来源：https://stackoverflow.com/questions/30166113/cant-add-remote-session-description-in-webrtc-android-client