我正在尝试从视频中获取视频帧作为图像http://techslides.com/demos/sample-videos/small.mp4，我的应用程序正在 localhost:3000 上运行。下面是我从视频中获取图像的代码
<!DOCTYPE html>
<html>
<body>
<video width="400" controls>
<source src="http://techslides.com/demos/sample-videos/small.mp4" type="video/mp4">
Your browser does not support HTML5 video.
</video>
<p>These are the frames' images generated by getVideoImage():</p>
<ol id="olFrames"></ol>
<script type="text/JavaScript">
function getVideoImage(path, secs, callback) {
var me = this, video = document.createElement('video');
video.onloadedmetadata = function() {
if ('function' === typeof secs) {
secs = secs(this.duration);
}
this.currentTime = Math.min(Math.max(0, (secs < 0 ? this.duration : 0) + secs), this.duration);
};
video.onseeked = function(e) {
var canvas = document.createElement('canvas');
canvas.height = video.videoHeight;
canvas.width = video.videoWidth;
var ctx = canvas.getContext('2d');
ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
var img = new Image();
img.src = canvas.toDataURL();
callback.call(me, img, this.currentTime, e);
};
video.onerror = function(e) {
callback.call(me, undefined, undefined, e);
};
video.src = path;
}
function showImageAt(secs) {
var duration;
getVideoImage(
"http://techslides.com/demos/sample-videos/small.mp4",
function(totalTime) {
duration = totalTime;
return secs;
},
function(img, secs, event) {
if (event.type == 'seeked') {
var li = document.createElement('li');
li.innerHTML += '<b>Frame at second ' + secs + ':</b><br />';
li.appendChild(img);
document.getElementById('olFrames').appendChild(li);
if (duration >= ++secs) {
showImageAt(secs);
};
}
}
);
}
showImageAt(0);
</script>
</body>
</html>
view raw
我收到一条错误消息
Uncaught DOMException: Failed to execute 'toDataURL' on 'HTMLCanvasElement': Tainted canvases may not be exported.
这意味着我的视频源和网页不在同一个域。我怎样才能让它发挥作用？
附注您可以通过将其粘贴到 https://www.w3schools.com/html/tryit.asp?filename=tryhtml5_video
来尝试我的代码视频是问题所在。
将其粘贴到您要求的页面上（https://www.w3schools.com/html/tryit.asp?filename=tryhtml5_video），它将起作用
<!DOCTYPE html>
<html>
<body>
<video width="400" controls>
<source src="mov_bbb.mp4" type="video/mp4">
Your browser does not support HTML5 video.
</video>
<p>These are the frames' images generated by getVideoImage():</p>
<ol id="olFrames"></ol>
<script type="text/JavaScript">
function getVideoImage(path, secs, callback) {
var me = this, video = document.createElement('video');
video.onloadedmetadata = function() {
if ('function' === typeof secs) {
secs = secs(this.duration);
}
this.currentTime = Math.min(Math.max(0, (secs < 0 ? this.duration : 0) + secs), this.duration);
};
video.onseeked = function(e) {
var canvas = document.createElement('canvas');
canvas.height = video.videoHeight;
canvas.width = video.videoWidth;
var ctx = canvas.getContext('2d');
ctx.drawImage(video, 0, 0, canvas.width, canvas.height);
var img = new Image();
img.src = canvas.toDataURL();
callback.call(me, img, this.currentTime, e);
};
video.onerror = function(e) {
callback.call(me, undefined, undefined, e);
};
video.src = path;
}
function showImageAt(secs) {
var duration;
getVideoImage(
"mov_bbb.mp4",
function(totalTime) {
duration = totalTime;
return secs;
},
function(img, secs, event) {
if (event.type == 'seeked') {
var li = document.createElement('li');
li.innerHTML += '<b>Frame at second ' + secs + ':</b><br />';
li.appendChild(img);
document.getElementById('olFrames').appendChild(li);
if (duration >= ++secs) {
showImageAt(secs);
};
}
}
);
}
showImageAt(0);
</script>
</body>
</html>
view raw