Video settings not displaying properly monitor to monitor

jrsprad

I recently set up a RetroPie on a Pi3, and after setting up onscreen overlays and RetroArch video setting for each system everything looked good. I have since noticed an issue that I assume is related to monitor/TV resolution. When I attach the RetroPie to some TVs everything is fine. However, when I attached it to my main PC monitor (not the smaller monitor it was set up on) and some TVs the video does not display properly. The overlay looks okay in most instances, but the emulator screen is no longer displaying in the correct position or size in relation to the overlay. It is smaller and too far to the upper left of the screen. The video setting values are the unchanged so it likely is a difference in the displays. I am assuming that this might be because the RetroArch video settings are pixel specific and the monitors may be 1080p/i vs 720p. So my two questions are...

Is a difference in monitor/TV resolution likely what is causing this?

Is there an easy way to fix this without changing the RetroArch video settings for each system from display to display?

Thanks in advance.
J

jonnykesh

@jrsprad

Yes, almost certainly.
If you are going to be moving the Pi about you should get used to editing the /boot/config.txt file. This file sets the video output of the Pi when you boot it.

If you leave things as stock and turn the monitor / TV on before the PI it should use EDID to communicate what resolution it uses. This doesn't always work. In that case you will probably need to edit the file I mentioned above and reboot. Read this. https://www.raspberrypi.org/documentation/configuration/config-txt/video.md

Just to add, this is nothing to do with RetroArch, as far as I can tell, based on the info provided.

Edited to add: I'm unsure what will happen if you try to use a 1080p overlay on a 720p screen but I doubt it will place properly or even look good if it scales it down.

jrsprad

@jonnykesh

So if I were to add like...

hdmi_mode=4

...to my config.txt would this in theory force my TV/monitor to display the signal in 720p format/resolution when the TV without this line would assume highest resolution (1080)?

I guess what I'm really asking is this. Does that setting inform the Pie what resolution to expect from the monitor, or does it tell the monitor what resolution to display the Pie signal in?

jrsprad

Nevermind. I was able to test even though I'm away from it and I have an idea of how it works.

Thanks for the help.