Use capture-frame package

See: https://github.com/feross/capture-frame
Capture video screenshot from a `<video>` tag (at the current time)

Changes from our version:

- Added tests in Chrome/Firefox browsers.
- Use built-in TypeError (which is meant for bad arguments) instead of
custom IllegalArgumentError.

src/renderer/lib/capture-video-frame.js

@@ -1,32 +0,0 @@
-module.exports = captureVideoFrame
-
-const {IllegalArgumentError} = require('./errors')
-
-function captureVideoFrame (video, format) {
-  if (typeof video === 'string') {
-    video = document.querySelector(video)
-  }
-
-  if (video == null || video.nodeName !== 'VIDEO') {
-    throw new IllegalArgumentError('First argument must be a <video> element or selector')
-  }
-
-  if (format == null) {
-    format = 'png'
-  }
-
-  if (format !== 'png' && format !== 'jpg' && format !== 'webp') {
-    throw new IllegalArgumentError('Second argument must be one of "png", "jpg", or "webp"')
-  }
-
-  const canvas = document.createElement('canvas')
-  canvas.width = video.videoWidth
-  canvas.height = video.videoHeight
-
-  canvas.getContext('2d').drawImage(video, 0, 0)
-
-  const dataUri = canvas.toDataURL('image/' + format)
-  const data = dataUri.split(',')[1]
-
-  return new Buffer(data, 'base64')
-}

src/renderer/lib/errors.js

@@ -35,10 +35,6 @@ class TorrentKeyNotFoundError extends TorrentError {
 
 class InvalidTorrentError extends TorrentError {}
 
-/* Miscellaneous */
-
-class IllegalArgumentError extends ExtendableError {}
-
 module.exports = {
   CastingError,
   PlaybackError,
@@ -49,6 +45,5 @@ module.exports = {
   PlaybackTimedOutError,
   InvalidSoundNameError,
   TorrentKeyNotFoundError,
-  InvalidTorrentError,
-  IllegalArgumentError
+  InvalidTorrentError
 }

src/renderer/lib/torrent-poster.js

@@ -1,6 +1,6 @@
 module.exports = torrentPoster
 
-const captureVideoFrame = require('./capture-video-frame')
+const captureFrame = require('capture-frame')
 const path = require('path')
 
 function torrentPoster (torrent, cb) {
@@ -61,7 +61,7 @@ function torrentPosterFromVideo (file, torrent, cb) {
     function onSeeked () {
       video.removeEventListener('seeked', onSeeked)
 
-      const buf = captureVideoFrame(video)
+      const buf = captureFrame(video)
 
       // unload video element
       video.pause()