Very specific media player needed

I’m looking for a free .avi player with some specific features:

- I need it to be able to play in a resizable window, preferably that will stay at that size once I put it there, even after closing and re-opening the program.
- I would like to be able to control the playback speed.
- I NEED to be able to advance one frame at a time.

Here’s why: I’m comparing two .avi files at the same time, frame by frame. WMP 10 does exactly what I need, but I have to be able to run two instances at the same time, which WMP doesn’t allow. UltraPlayer does almost everything I need, but I can’t advance frame by frame, so getting the frames the same between it and WMP takes some fiddling. It works, but it’d save time if I could just advance by a frame.

I’ve tried a few different players, and I’m tired of downloading and installing software just to find out it doesn’t do what I need it to, so I thought I’d see if anyone already knows what could work.

Thanks so much for any help!!

— Amanda