How to capture OpenGL video output?

Hello everybody.

I have the following situation:

Application “A” - a closed-source game, use OpenGL as rendering API.
I was wondering - is there a way to capture the output (framebuffer?) of this particular app in program created by me? If so, how complicated would that be? Where to start looking for the necessary OpenGL functions?

I already tried using “desktop capture” applications - and, although they work - the video is not “smooth” even when using 60 FPS capture mode - probably because timing differences between frame rendering and capture (some frames are captured twice for example - while others are missing - and according to the video codec, frame dropping is not occurring)

Thanks in advance.

You may want to try this .kkapture :

GLIntercept is supposed to be able to output a movie with some very configurable params (including codec, resolution and framerate) but I have never used it in this mode and can’t vouch for it. It is however free (and Free). Look for the FrameMovie options in it’s config file.