capture-frame___video_tag's Introduction

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 buf = captureFrame('.video') // Buffer that contains .png file data

// show the captured video frame in the DOM
const image = document.createElement('img')
image.src = window.URL.createObjectURL(new window.Blob([buf]))
document.body.appendChild(image)

complete example

const captureFrame = require('capture-frame')

const video = document.createElement('video')
video.addEventListener('canplay', onCanPlay)

video.volume = 0
video.setAttribute('crossOrigin', 'anonymous') // optional, when cross-domain
video.src = `http://example.com/test.webm`
video.play()

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 buf = 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.src = window.URL.createObjectURL(new window.Blob([buf]))
  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", "jpg", or "webp".