This looks as if it was from the game itself, at least the ODST and SPARTAN. Do you do character animation at all? I've been working on a Halo Machinima project for past nearly 3 years and I find myself in need of someone that can do said character animation - and these models look amazing! If you do, would you be interested? I can tell you a lot more about the project.
It says so in the description; Source Filmmaker. I ported the models over to it with 3ds Max, several hours of work went into that, as did it go into putting their respective materials together. It sure is a hell of alot easier to do than Halo CE, That's for sure.