问如何在RecordRTC中删除空白帧

EN

var videosLength = videos.length;
if(videosLength > 2){
    videosLength = 2;
}

var fullcanvas = false;
var remaining = [];

var length = videos.length;
videos.forEach(function(video,idx) {
    if (!video.stream) {
        video.stream = {};
    }
    if (video.stream.fullcanvas) {
        fullcanvas = video;
    } else {
        if(idx==0 || idx == (length-1)){
            if(video.stream.active)
                remaining.push(video);
        }
    }
});