If you can’t FTP it up, you won’t be able to do it via WP, sadly (there’s a PHP limit on how large uploaded files can be).
314Megs is a pretty huge video, though, and video hosting is one of the more complicated things to do with self-hosting. In part, this is because playing videos is really server intensive, but also the playback is annoying based on what you uploaded as. Like iOS won’t play FLVs, which are the smallest, or OOG, and only use MP4s. The larger the video, the more CPU and memory you use, every time it plays, because it doesn’t cache the same way.
So that was a long way around to say this: You can increase your PHP upload file size : http://wiki.dreamhost.com/index.php/PHP.ini#Increase_Filesize_Upload_Limit
But that may not solve all the problems of large video uploads DreamObjects may help, but also if you plan on doing a lot of video, you may want to invest in video hosting (like VideoPress or Vimeo)