Is there any code posted that performs video capture (for various codecs) from an OpenGL framebuffer using DirectShow? I’m thinking about something like Fraps or Taksi, but using DirectShow and not VFW.
Take look on Filters/Ball example in DirectShow. Anyway, this taks require some knowledge of DirectShow.
Some videocodecs accept RGB video-pixelformat so you can grab backbuffer in sys mem and send it to source filter. Most of videocodecs require YUY2 or similar video-pixelformat, so you may need to convert backbuffer to YUY2 and then copy content to source filter. If you want to send frames to overlay, then you MUST use YUY2 video-pixelformat.
Also, try to use PBO’s for async data transfer.