I need to work on the framebuffer to record what is being rendered.

Now, I figure out how to convert the framebuffer in an image, I'm currently unable to obtain a constant stream of data from the fb to create a video.

/dev/fb > fb

When I do something like this my redirection just drops me and I honestly don't know how to work in another way with the framebuffer.

How I can obtain a stream?

  • 1
    /dev/fb is not a command! Use cat /dev/fb > fb
    – Guido
    May 29, 2014 at 13:43

1 Answer 1


In order to capture data from the framebuffer, you can copy from the framebuffer device file:

cp /dev/fb0 fb

If you changed the file you're copying to every time, you should be able to save every frame. Don't expect a lot of Frames per Second though, since the framebuffer is typically pretty slow.

As suggest in this forum post, ffmpeg might be a better option:

ffmpeg -f fbdev -i /dev/fb0 -r 24 -c:v libx264 -b:v 500k output.avi
  • Why should ffmpeg be faster at reading /dev/fb0 than cat? Something about that doesn’t make sense (however, I know nothing about ffmpeg).
    – Wildcard
    Sep 24, 2019 at 2:11

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