video替换webRtc视频流

经过测试，本地mp4可播放的视频可替换成功；在线的视频会报错跨域；https安全要求;

核心api

video.captureStream()

html

<video id="yyhTestVideo" src="./tmp.mp4" width="1280" height="720" autoplay loop></video>

video

const myVideo = document.getElementById('yyhTestVideo');
// 30帧也可以不指定
const myVideoStream = myVideo.captureStream(30);
/* 
    webRTc的peerConnection对象; 
    this.session.connection是我封装后的，你使用自己的new RTCPeerConnection();对象；
*/
const peerConnection = this.session.connection;
const sender = peerConnection.getSenders().find((s) => s.track.kind === "video");
sender.replaceTrack(myVideoStream.getVideoTracks()[0]);