Capturing video out of an OpenGL window in Windows

Question

I am supposed to provide my users a really simple way of capturing video clips out of my OpenGL application\'s main window. I am thinking of adding buttons and/or keyboard s

Answer 1

The easiest option is going to be saving each rendered frame from within your app and then merging them into an AVI. When you have the AVI there are many libraries available that can convert it into a more optimal format, or possibly skip the AVI step altogether.

In terms of getting each frame, you could accomplish this either by rendering into an offscreen texture as you suggest or using the backbuffer directly as a source if your hardware supports this. Doing either of these (and saving each frame) is going to be difficult without a heavy penalty on framerate.

Providing your application is deterministic you could "record" the users actions as a series of inputs and then have an export mode that sequentially renders these to an offscreen surface to generate the AVI.