Why would you want to upload a file through websockets anyway?
The strategy I used was to parse the MOV/MP4 locally, consider between 2-60 frames of data, hash it, then stream up the hashes to the server. Any hash the server didn't have got a reply to push those bytes.
The two-way nature of this dialog made WebSockets a good fit, although it certainly could have been emulated using other methods, it would have been much more code.
That means that slowness is a bug; inefficiency is a bug.
For what reason would you put bugs in your code on purpose?
We also probably have different ideas about how much "much" is.