[FFmpeg-user] ffmpeg screencapture from a virtual xserver larger than the physical screen

Zenny garbytrash at gmail.com
Fri Nov 20 08:57:37 CET 2015

On 11/19/15, Nicolas George <george at nsup.org> wrote:
> Le nonidi 29 brumaire, an CCXXIV, Zenny a écrit :
>> Did exactly as you described, but there is no mouse or keyboard
>> interaction with the ffmpeg-piped window. Tried with -south option and
>> brought the mouse to the bottom of the screen, no luck.
>> If anyone has glued x2x with the ffmpeg-piped displays of the Xvbf
>> virtual server, appreciate if you share.
> I just tried:
> Xvfb :1 -screen 0 1024x768x24
> x2x -east -to :1
> ffmpeg -f x11grab -i :1 -f opengl -

Thanks, Nicholos.

It worked, but compared to xpra,
1. the output is interaction lagged and,
2.  piped output only covers only 1/4th of the screen until in Slideshow mode.

I used the following commands with some modifications I needed:

$ Xvfb :99 -screen 0 3840x2160x24+32 -fbdir /var/tmp
$ x2x -east -to :99
$ ffmpeg -f x11grab -s 3840x2160 -i :99 -r 24 -pix_fmt yuv420p -f opengl -
$ export DISPLAY=:99 libreoffice

You might have noted that the virtual screen is at 4K (3840x2160)
whereas the physical screen for interaction is =<FullHD (1920x1080)

Thanks you again for valuable inputs,



> and it works. Using any other output system would not change anything. I do
> not know why it does not work for you.
> Regards,
> --
>   Nicolas George

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