UPDATE - inject user details into a mpeg movie on the fly
OK, so I was pushed to get my head around injecting user data (or any unique idenitifer) into a downloadable movie without having to re-encode the movie....
Well, I figured it out and with zero server load and very very minimal delay (time taken to inject into a 905KB test movie: 0.155 microseconds)
Test it out for yourselves:
http://borkedcoder.com/movie_injector/?user=borkedcoder
(user=borkedcoder is just an example of how to display username in the injection, of course it would be done in a live script from cookie/session vars)
skip through the movie 1 frame at a time - the identifier is injected every 100KB of movie (modifiable) and so the first one is within the first second.
For the moment, this isn't production ready as the injection comes from a transparent PNG that doesn't work well (grey background). When I get more time, I'll modify the script to use the last frame of each chunk to overlay the text onto which will create a seemless movie where the end user has no idea it's been overlayed with his identifiable details....