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

[Michael Koch]

Am 25.05.2022 um 21:32 schrieb 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?

I have forwarded your question to the discord channel. I can't answer it 
myself because I'm 300 km away from the planetarium. Please feel free to 
comment in the discord channel in english, if you like.

Michael