generate QR thumbnails for .webm

src/Posting/QR.post.coffee

@@ -162,27 +162,32 @@ QR.post = class
     @nodes.label.hidden = false if QR.spoiler
     URL.revokeObjectURL @URL
     @showFileData() if @ is QR.selected
-    unless /^image/.test file.type
+    unless /^(image|video)\//.test file.type
       @nodes.el.style.backgroundImage = null
       return
     @setThumbnail()
 
   setThumbnail: ->
     # Create a redimensioned thumbnail.
-    img = $.el 'img'
+    isVideo = /^video\//.test @file.type
+    img = $.el (if isVideo then 'video' else 'img')
 
-    img.onload = =>
+    $.on img, (if isVideo then 'loadeddata' else 'load'), =>
       # Generate thumbnails only if they're really big.
       # Resized pictures through canvases look like ass,
       # so we generate thumbnails `s` times bigger then expected
       # to avoid crappy resized quality.
       s = 90 * 2 * window.devicePixelRatio
       s *= 3 if @file.type is 'image/gif' # let them animate
-      {height, width} = img
-      if height < s or width < s
-        @URL = fileURL
-        @nodes.el.style.backgroundImage = "url(#{@URL})"
-        return
+      if isVideo
+        height = img.videoHeight
+        width = img.videoWidth
+      else
+        {height, width} = img
+        if height < s or width < s
+          @URL = fileURL
+          @nodes.el.style.backgroundImage = "url(#{@URL})"
+          return
       if height <= width
         width  = s / height * width
         height = s