[FFmpeg-user] FFplay, wrong output size on extended desktop

[Gyan Doshi]

On 2022-05-25 08:31 pm, Michael Koch wrote:
> Hello,
>
> we want to use FFplay in a planetarium. It's a Windows computer with 
> an extended desktop. The left monitor contains the user interface 
> (1920x1080) and at the right side is a 4Kx4K extended desktop, which 
> is shown on two 4096x2048 monitors, upper half and lower half. The 
> extended 4Kx4K desktop is mirrored to the dome with 11 projectors.
>
> We are using this 4Kx4K test image:
> http://www.paulbourke.net/dome/testpattern/4096.png
>
> This is the FFplay command line:
> ffplay -noborder -left 1920 -top 0 4096.png
>
> The problem is that the image is shown twice as large as it should be, 
> so that we see only the top left quadrant.
> You can see a screenshot in this discord channel (in german language):
> https://discord.com/channels/968113228230045706/968113812769210398
>
> If we set the size to 2048x2048, then the output is 4096x4096:
> ffplay -noborder -x 2048 -y 2048 -left 1920 -top 0 4096.png
> But then we don't have the full 4K resolution.
>
> Who has an idea what's wrong here?
> The console output is below.

What's the size value in Settings -> Display under Scale and Layout?

Regards,
Gyan