In some dailymotion videos (like http://www.dailymotion.com/video/x3k0dtv from #8156) the segments URLs don't have the 'Content-Length' header and HttpFD sets the 'totat_bytes' field to None, so we also use '0' in that case (since we do different math operations with it).
Add an IE to support bigflix.com. It uses some sort of silverlight
plugin whose video url is being populated using base64 encoded
flashvars. So it is quite straightforward to extract.
"This check should take place earlier and should be more general if not video_url:. Same should be done for video_play_path. Also these fields better extracted with xpath_text."
Suggestions by @dstftw