update info of scaling issue in FAQ.md

[NewUserHa]

• I have checked that a similar feature request does not already exist.

https://github.com/Genymobile/scrcpy/blob/master/FAQ.md#the-quality-is-low seems to be outdated now.

actually, I found when the screen resolution or the window is way smaller than the desktop resolution(like 4k), the upscaling result is not as clear as the scrcpy 1.22 with DPIawareness on.

So the FAQ.md should encourage the users to update to the least version as first solution, than Override high DPI scaling behavior, then than try opengl

[rom1v]

Please review #3032.

[NewUserHa]

👍

[NewUserHa]

Is it possible without opengl to use better filters like lanczos3, bicubic, etc. for up/downscaling?
because if the window is not the same size as the native resolution of the device screen, the image is still be resized/up/downscaled.

[rom1v]

@NewUserHa Basically, no: #40 (comment)

[NewUserHa]

I saw scrcpy use ffmpeg library, what process(like filters, renders) does scrcpy use to the image received from the device?

For my 1440x3120 device, bicubic swscaling takes between 20ms and 60ms (...

I saw the madvr render report that the render time it costs is about only 10ms.