Help making video snaps (need a lot of help :( )

[Mezameta]

Hey guys bare with me, I don't know if this is the right kind of question or place to post this but here goes.

I want to make (I don't THINK they exist on here or elsewhere but please correct me if i'm wrong) a crapload of video snaps for MUGEN, OpenBor and hacked games (various systems, nes, genesis, snes, game gear, game boy and Gameboy advance, I've got like 800 or so games just in hacks).

I am having NO luck doing this. For the hacked games I've tried recording through Retroarch (I'm using launchbox but that shouldn't matter) and all I can get out of it is an MPK file (I want mp4 files) and these MPK files are visually blank, ONLY audio, which obviously won't work even if I found a way to convert them to mp4s.

I tried a few free programs but i'mma be frank with you guys...i'm an idiot when it comes to computer related stuff so i'm positive I did something wrong, and I honestly don't even know where to begin.

Outside of making a massive request for these things, which I know is impractical, I can only think of doing them myself, but I honestly don't even know where to begin at this point.

Would someone be willing to talk me through step by step with getting a free program that could work for me, and how to set it up and guide me through doing a few of them and then I could take over myself? I know it's a lot to ask, but let me know if so, I could add you on facebook and we could talk through the process.

Thanks for any help!!