You need to remember that Recuva is exactly that, a 'Recovery Program', not a 'Backup Program'. If you've deleted a video, then continue to work on other videos, the chances that the new video overwrites the old one on the drive are great. Thus the old video will not recover.
Recovery programs work best when you run them immediately after deleting the file, so that another file does not have a chance to overwrite the original.
In the case of Video work, I'd recommend you 'Backup' each version of your video as you go so that you can restore it at a later time if needed. An easy way would be to 'save as' incremental file names. ie: Video 1, Video 2, Video 3, etc... Then delete the ones not needed when you have a finished product.
