webrtc对讲摄像头开发使用说明

1. 摄像头开放了 9001 端口作为https接口
2. 开放了 9000 端口作为http的接口
3. 通过以下四个http的 post 接口调用，来完成webrtc协议播放
4. 代码里的接口的基地址deviceUrl：局域网访问为https://[IP]/9001/ 或 http://[IP]/9000/
   公网地址为:https://live.xstrive.com/[序列号]/webrtc/

• connect 接口
  方法：POST
  参数：无
  返回：sessionID(在请求头的"Session-ID"里)

调用此接口会分配一个唯一的SessionID,后面的接口调用都要带上这个生成的SessionID
js调用示例:
 function send_post_connect()
{
    var xhr = new XMLHttpRequest();
    const loc = deviceUrl;
    console.log("send post connect: " + loc);
    xhr.open("POST", '' + loc + 'connect', true);
    xhr.onreadystatechange = function() {
        if (this.readyState === XMLHttpRequest.DONE &&
            this.status === 200) {
            const sessid = xhr.getResponseHeader("Session-ID");
            console.log("connect: session: %s", sessid);
            /* Save the session ID */
            session_id = sessid;
            pc.createOffer(offerOptions)
            .then(function (desc) {
                console.log("got local description: %s", desc.type);

                pc.setLocalDescription(desc).then(() => {

                    const sd = pc.localDescription;
                    const json = JSON.stringify(sd);
                    retryCount = 0;
                    send_post_sdp(json);
                },
                function (error) {
                    console.log("setLocalDescription: %s",
                            error.toString());
                });
            })
            .catch(function(error) {
                   console.warn("Failed to create session description: %s",
                       error.toString());
            });
        }
    }
    xhr.send();
}

• offersdp接口
  方法：POST
  参数：无
  返回：sessionID(在请求头的"Session-ID"里) 和 sdp(在body中)

调用此接口，可以获取offer sdp,和一个sessionID
js调用示例：
function send_post_connect()
{
    var xhr = new XMLHttpRequest();
    const loc = self.location;
    console.log("send post connect: " + loc);

    xhr.open("POST", '' + loc + 'connect/offerer', true);
    xhr.onreadystatechange = function() {
        if (this.readyState === XMLHttpRequest.DONE &&
            (this.status === 200 || this.status === 201)) {
                const sessid = xhr.getResponseHeader("Session-ID");
                console.log("connect: new session: '%s' (%d %s)",
                        sessid, this.status, this.statusText);
                /* Save the session ID */
                session_id = sessid;
                handle_offer(xhr.response);
            }
        }
    }
    xhr.send();
}

• sdp 接口
  参数： 本地的sdp(offer)
  返回： 远程的sdp(answer)

调用此接口把本地的sdp信息(offer)发送给摄像头，并接收摄像头返回的sdp值(answer)
js调用示例:
function send_post_sdp(descr)
{
    var xhr = new XMLHttpRequest();
    const loc = deviceUrl;

    console.log("send post sdp: " + loc);

    xhr.open("POST", '' + loc + 'sdp', true);
    xhr.setRequestHeader("Content-Type", "application/json");
    xhr.setRequestHeader("Session-ID", session_id);

    xhr.onreadystatechange = function() {
        console.log("onreadystatechange:" + this.status);
        if (this.readyState === XMLHttpRequest.DONE &&
            this.status === 200) {
            retryCount = maxRetryCount;
            console.log("post sdp: 200 ok");

            const descr = JSON.parse(xhr.response);

            console.log("remote description: type='%s'", descr.type);

            pc.setRemoteDescription(descr).then(() => {
                console.log('set remote description -- success');
            }, function (error) {
                console.warn("setRemoteDescription: %s",
                        error.toString());
                disconnect_call();
            });
        }
        else if (this.readyState === XMLHttpRequest.DONE && this.status === 401){
            retry_send_sdp(descr, xhr);
        }
    } 

    xhr.send(descr);
}

• candidate 接口
  参数：iceServer返回的打洞信息
  返回：无

调用此接口把iceServer返回的p2p连接信息发给摄像头，以方便ice框架建立p2p连接
js调用示例
function send_candidate(json)
{
    var xhr = new XMLHttpRequest();
    const loc = deviceUrl;

    xhr.open("POST", '' + loc + 'candidate', true);
    xhr.setRequestHeader("Content-Type", "application/json");
    xhr.setRequestHeader("Session-ID", session_id);

    xhr.onreadystatechange = function() {
        if (this.readyState === XMLHttpRequest.DONE &&
            this.status !== 200) {

            /* todo: print warning and close call */
        }
    }

    xhr.send(json);
}

• disconnect 接口
  参数：sessionId
  返回：无

断开与服务器的连接并释放资源
js调用示例
function disconnect_call()
{
    console.log("Disconnecting call");
    if(localStream){
        localStream.getTracks().forEach(track => track.stop());
    }

    if (pc) {
        pc.close();
        pc = null;
    }

    disconnectButton.disabled = true;
    connectButton.disabled = false;

    if (session_id) {
        // send a message to the server
        var xhr = new XMLHttpRequest();
        xhr.open("POST", '' + deviceUrl + 'disconnect', true);
        xhr.setRequestHeader("Session-ID", session_id);
        xhr.send();
    }

    session_id = null;
}

js接口调用的示例代码可以用chrome打开网页https://[设备IP]:9001/ 右键选择查看源代码获取。
android调用的示例代码，可以联系我们获取