How can the linux frame buffer, on Cell Linux, be captured to obtain either screen shots or movies?
Is there a tool to do this for a running program, or must the program writing to, and presumably controlling, the frame buffer also handle capture and recording? If so, how would the program do so?
Many tools for doing so, for example FBGrab and fbdump; look at the sources for those two, it would be pretty easy to extend either one or write your own which captures video instead of just snapshots.
However, I would recommend that the program writing to the framebuffer be the one recording as well, in order to synchronize capturing frames between writing them (and not partially through a write, or skipping, or ...)
you could use ffmpeg
or avconv
(eg. avconv -f fbdev -i /dev/fb0 mymovie.flv
).