use http server for poster generation

main/lib/torrent-poster.js

@@ -3,23 +3,43 @@ module.exports = torrentPoster
 var captureVideoFrame = require('./capture-video-frame')
 
 function torrentPoster (torrent, cb) {
-  if (torrent.ready) onReady()
-  else torrent.once('ready', onReady)
+  // use largest file
+  var index = torrent.files.indexOf(torrent.files.reduce(function (a, b) {
+    return a.length > b.length ? a : b
+  }))
 
-  function onReady () {
-    // use largest file
-    var file = torrent.files.reduce(function (a, b) {
-      return a.length > b.length ? a : b
-    })
+  var server = torrent.createServer(0)
+  server.listen(0, onListening)
+
+  function onListening () {
+    var port = server.address().port
+    var url = 'http://localhost:' + port + '/' + index
     var video = document.createElement('video')
-    file.renderTo(video)
+    video.addEventListener('canplay', onCanPlay)
 
-    video.currentTime = 10
-    video.addEventListener('seeked', onSeeked)
+    video.volume = 0
+    video.src = url
+    video.play()
 
-    function onSeeked (e) {
+    function onCanPlay () {
+      video.removeEventListener('canplay', onCanPlay)
+      video.addEventListener('seeked', onSeeked)
+
+      video.currentTime = Math.min((video.duration || 600) * 0.03, 60)
+    }
+
+    function onSeeked () {
       video.removeEventListener('seeked', onSeeked)
+
       var buf = captureVideoFrame(video)
+
+      // unload video element
+      video.pause()
+      video.src = ''
+      video.load()
+
+      server.destroy()
+
       cb(null, buf)
     }
   }