HTML 5 Canvas 参考手册
浏览器支持
Internet Explorer 9、Firefox、Opera、Chrome 以及 Safari 支持 <canvas> 及其属性和方法。
reference:
http://www.w3school.com.cn/tags/html_ref_canvas.asp
主要有4种绘法
chapter4:cxt.drawImage(img,0,0);
function getElementById(id){ return document.getElementById(id); } var canvas = getElementById("canvas"); var cxt = canvas.getContext("2d"); var img = new Image(); img.src = "../img/test3/cutegirl.png"; img.onload = function(e){ cxt.drawImage(img,0,0); }//用这种比较保险 cxt.drawImage(img,0,0);//sometime光用这种有不行
<p>要使用的视频:</p>
<video id="video1" controls width="270" autoplay>
<source src="/example/html5/mov_bbb.mp4" type='video/mp4'>
<source src="/example/html5/mov_bbb.ogg" type='video/ogg'>
<source src="/example/html5/mov_bbb.webm" type='video/webm'>
</video>
<p>画布(每 20 毫秒,代码就会绘制视频的当前帧):</p>
<canvas id="myCanvas" width="270" height="135" style="border:1px solid #d3d3d3;">
Your browser does not support the HTML5 canvas tag.
</canvas>
var v=document.getElementById("video1");var c=document.getElementById("myCanvas");
ctx=c.getContext('2d');
var v=document.getElementById("video1"); var c=document.getElementById("myCanvas"); ctx=c.getContext('2d'); v.addEventListener('play', function () { var i = window.setInterval(function () { ctx.drawImage(v, 0, 0, 270, 135) }, 20); }, false); v.addEventListener('pause', function () { window.clearInterval(i); }, false); v.addEventListener('ended', function () { clearInterval(i); }, false);