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

[Zenny]

On 11/19/15, Nicolas George <george at nsup.org> wrote:
> Le nonidi 29 brumaire, an CCXXIV, Zenny a écrit :
>> However, I have never forwarded xserver display with ffmpeg. Any hints
>> appreciated.
>
> There is nothing special:
>
> ffmpeg -f x11grab -i :0 -f opengl -
>
> The first half grabs the display, the second half displays the resulting
> video stream in a window. You can use all the options you want to scale
> down, reduce rate, etc.

I tried with:

$ ffmpeg -f x11grab -s 3840x2160 -i :99 -r 24 -s 1280x720 -f opengl
"4k_window" -

as well as simply:

$ ffmpeg -f x11grab -i :99 -f opengl -

Both of the times, I got:

"[NULL @ 0x3d89f60] Requested output format 'opengl' is not a suitable
output format
pipe:: Invalid argument"


>
> Regards,
>
> --
>   Nicolas George
>