I'll tell you how we do it at int13.
We have a built-in video capture utility in our framework lib (uEngine), this one can dump a serie of .tga or a raw (uncompressed) avi file at 30FPS.
The main advantage is that, even if the game slowdown during the capture the video is always perfectly smooth, because it's sync with the game frame rate.
The captures are done with the win32 build of course
![Smile :)](./images/smilies/icon_smile.gif)
Stephane Cocquereaumont / Game Developer at <a href=http://int13.net>int13 production</a> (code monkey)