The best way to do this would probably be a multi-part rar.
If your torrented video was corrupted, it's because the original file was corrupted. Your torrent client would have thrown away anything that's different from the original.
> The best way to do this would probably be a multi-part rar.
They already offer multiple-file downloads. The compression algorithm isn't going to change the fact that multiple concurrent downloads fail.
As for the file being corrupt, I suspect something else may have been going on, such as bugs with torrent clients. I don't know why the original source file would have been corrupted, as it was supplied by the maker of the film.