Files
webtorrent-desktop/renderer/lib/capture-video-frame.js
2016-03-04 13:14:22 -08:00

24 lines
760 B
JavaScript

module.exports = captureVideoFrame
function captureVideoFrame (video, format) {
if (typeof video === 'string') video = document.querySelector(video)
if (!video || video.nodeName !== 'VIDEO') {
throw new Error('First argument must be a <video> element or selector')
}
if (format == null) format = 'png'
if (format !== 'png' && format !== 'jpg' && format !== 'webp') {
throw new Error('Second argument must be one of "png", "jpg", or "webp"')
}
var canvas = document.createElement('canvas')
canvas.width = video.videoWidth
canvas.height = video.videoHeight
canvas.getContext('2d').drawImage(video, 0, 0)
var dataUri = canvas.toDataURL('image/' + format)
var data = dataUri.split(',')[1]
return new Buffer(data, 'base64')
}