如何将此函数中的canvas
返回为webp
图像?
function capture(video) {
if(scaleFactor == null){
scaleFactor = 1;
}
//var w = video.videoWidth * scaleFactor;
//var h = video.videoHeight * scaleFactor;
var w = 700;
var h = 400;
var canvas = document.createElement('canvas');
canvas.width = w;
canvas.height = h;
var ctx = canvas.getContext('2d');
ctx.drawImage(video, 0, 0, w, h);
var uniq = 'img_' + (new Date()).getTime();
canvas.setAttribute('id', uniq);
return canvas ;
}