capture-frame

Capture video screenshot from a <video> tag (at the current time)

Works in the browser with browserify! This module is used by WebTorrent Desktop.

install

npm install capture-frame

usage

simple example

const captureFrame = require('capture-frame')
const frame = captureFrame('.video') // Buffer that contains .png file data
// show the captured video frame in the DOM
const image = document.createElement('img')
image.width = frame.width
image.height = frame.height
image.src = window.URL.createObjectURL(new window.Blob([frame.image]))
document.body.appendChild(image)

complete example

const captureFrame = require('capture-frame')
const video = document.createElement('video')
video.addEventListener('canplay', onCanPlay)
video.volume = 0
video.autoplay = true
video.muted = true // most browsers block autoplay unless muted
video.setAttribute('crossOrigin', 'anonymous') // optional, when cross-domain
video.src = 'http://example.com/test.mp4'
function onCanPlay () {
  video.removeEventListener('canplay', onCanPlay)
  video.addEventListener('seeked', onSeeked)
  video.currentTime = 2 // seek 2 seconds into the video
}
function onSeeked () {
  video.removeEventListener('seeked', onSeeked)
  const frame = captureFrame(video)
  // unload video element, to prevent memory leaks
  video.pause()
  video.src = ''
  video.load()
  // show the captured image in the DOM
  const image = document.createElement('img')
  image.width = frame.width
  image.height = frame.height
  image.src = window.URL.createObjectURL(new window.Blob([frame.image]))
  document.body.appendChild(image)
}

api

frame = captureFrame(video, [format])

Capture a video frame the the video tag specified by video. This can be a
reference to a video element in the page, or a string CSS selector. This must
refer to a video element.

Optionally, specify a format for the image to be captured in. Must be one of
“png”, “jpeg”, or “webp”.

The returned object, frame, has three properties:

frame.image

The captured image, as a Buffer.

frame.width

The captured image’s width, as a number.

frame.height

The captured image’s height, as a number.

license

MIT. Copyright (c) Feross Aboukhadijeh.