Alternative FRAPS: Where to Look and Why?

Later this year I will have a lot of time on my hands and I thought I would start a "small" project for myself and release it as open source.

I would like to code my own Fraps alternative. (or continue with Taksi http://taksi.sourceforge.net ).

Fraps is a video and audio recording software that captures the screen while you play. This one has more features than I need and their commercials.

All I want is the ability to record the screen / game I'm currently playing, including audio without other additional features.

Now this is a new area for me, but not programming languages. I thought I would be using C ++ (and others if needed).

I need clues on where to look and what to look for, where to read the things that create it. Etc. etc.

I hope you can help me!