Topic: FBA source mods for video creation

[megadriver]

Hi Guys,

As this is my first post here, please allow me to introduce myself. I'm the guitarist and founder of MegaDriver, a Brazilian video game band. We've been playing heavy metal remixes of classic videogames for almost ten years now, playing gigs all over our country (Brazil).

The reason for my post here is because I often do some mods/hacks to open source emulators to help us create videos to use with our band. In our gigs we play in sync with videos and I also often record some for YouTube.

For example, I modified the DGEN Sega Genesis emulator, expanding the VDP to 3x wider. The first part with full scroller/sprites layers showing, and the other two showing only what I need. This way I can record a gameplay, do some cropping and afterwards insert elements in the middle of the game. Furthermore, I did some hacking on the RAM to disable the stage music, keeping only the sound FX.

Here's a picture o my modified DGEN:


And here's a sample video made using this technique, in this case, with me inserted in the middle of the stage:
http://www.youtube.com/watch?v=PPmgzIKTKbQ

I'm now messing with the FBA source code so I can also use it to create videos and achieve similar results. I've already done a small modification to disable the music of Sunset Riders, which may also work with any other game that uses Z80 for controlling audio. This way I was able to use footage from the game and keep only the sound fx.

Here's the result with Sunset Riders:
http://www.youtube.com/watch?v=HgXdxM8R-i4

This was a very simple modification. I've just added a "ctl-z" shortcut, so I could reset the Z80 CPU when the music started.

I recently found the "RR" version of FBA, which let us record the gameplay. So, I don't actually need to clone or expand screens (like I did with DGEN) if I want to record a foreground and a background video of the very same gameplay. I can record a "FBM" and then play it back how many times I need, with the desired layers/sprites enabled. To enable/disable layers and sprites I found the nSpriteEnable and the nBurnLayer variables.

What I'm not figuring how to do is how to change the fill color of the screen. I'd like, for example, to disable some layers and keep some color in the background (green, pink, blue) so I could use it for chroma keying. I'm not familiar with DirectX and I haven't found a simplistic way to do it. I'd like to ask you guys for some directions. Is is possible to fill the screen with a constant color (other than "black") at some point or will I have to hack each driver?

Thanks guys and sorry for my big text, I couldn't think of an easier way to explain what I need and why I need it, lol!

[]'s
Nino

[megadriver]

Well, changing the first color from the palette works for some games, but is there any other more simple way to change the background color?

I know that this mods are more likely hacks than something related to development and improvement, but I guess it doesn't hurt to ask
Please don't get angry on me guys...

[]'s