bcd6a38a05
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.
84 lines
2.5 KiB
JavaScript
84 lines
2.5 KiB
JavaScript
module.exports = torrentPoster
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const captureFrame = require('capture-frame')
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const path = require('path')
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function torrentPoster (torrent, cb) {
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// First, try to use a poster image if available
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const posterFile = torrent.files.filter(function (file) {
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return /^poster\.(jpg|png|gif)$/.test(file.name)
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})[0]
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if (posterFile) return torrentPosterFromImage(posterFile, torrent, cb)
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// Second, try to use the largest video file
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// Filter out file formats that the <video> tag definitely can't play
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const videoFile = getLargestFileByExtension(torrent, ['.mp4', '.m4v', '.webm', '.mov', '.mkv'])
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if (videoFile) return torrentPosterFromVideo(videoFile, torrent, cb)
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// Third, try to use the largest image file
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const imgFile = getLargestFileByExtension(torrent, ['.gif', '.jpg', '.jpeg', '.png'])
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if (imgFile) return torrentPosterFromImage(imgFile, torrent, cb)
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// TODO: generate a waveform from the largest sound file
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// Finally, admit defeat
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return cb(new Error('Cannot generate a poster from any files in the torrent'))
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}
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function getLargestFileByExtension (torrent, extensions) {
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const files = torrent.files.filter(function (file) {
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const extname = path.extname(file.name).toLowerCase()
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return extensions.indexOf(extname) !== -1
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})
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if (files.length === 0) return undefined
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return files.reduce(function (a, b) {
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return a.length > b.length ? a : b
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})
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}
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function torrentPosterFromVideo (file, torrent, cb) {
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const index = torrent.files.indexOf(file)
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const server = torrent.createServer(0)
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server.listen(0, onListening)
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function onListening () {
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const port = server.address().port
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const url = 'http://localhost:' + port + '/' + index
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const video = document.createElement('video')
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video.addEventListener('canplay', onCanPlay)
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video.volume = 0
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video.src = url
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video.play()
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function onCanPlay () {
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video.removeEventListener('canplay', onCanPlay)
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video.addEventListener('seeked', onSeeked)
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video.currentTime = Math.min((video.duration || 600) * 0.03, 60)
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}
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function onSeeked () {
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video.removeEventListener('seeked', onSeeked)
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const buf = captureFrame(video)
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// unload video element
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video.pause()
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video.src = ''
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video.load()
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server.destroy()
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if (buf.length === 0) return cb(new Error('Generated poster contains no data'))
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cb(null, buf, '.jpg')
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}
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}
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}
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function torrentPosterFromImage (file, torrent, cb) {
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const extname = path.extname(file.name)
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file.getBuffer((err, buf) => cb(err, buf, extname))
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}
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