Is it possible to configure overscan settings for runcommand video mode switching?

sockscap

It's latest Retropie v4.7.1 running on Pi3B, output to CRT in PAL mode. I've edited config.txt to add overscan settings, and everything is working fine.

However, there are some games that I want to run in NTSC 4:3 mode, so I set the video mode for these games via runcommand. The problem is, the overscan settings for NTSC mode is wrong.

Is it possible to define the overscan settings when runcommand switches video mode to NTSC 4:3 mode?

BuZz

@sockscap it's not sorry.

sockscap

@buzz
Just to double check, is it technically possible to manually edit the script, to pass the overscan settings when it switch the video mode?

I'm asking this because if I edit config.txt to put it in NTSC mode with a different set of overscan settings, it also works fine. I just hope that I can use PAL by default, and only switch to NTSC for specific games. It looks a bit strange to me that this is not possible.

I fully understand the customization is for my specific needs, and if I manually edit the script, it won't be officially supported. Any hints of the script or the method for video mode switch would be appreciated. The runcommand.sh looks complex, as I'm not an expert of linux script.

BuZz

@sockscap You could maybe script it if this still works (or something like it).

https://github.com/ukscone/set_overscan

sockscap

@buzz
Thanks! I will take a look and do some research.

sockscap

@buzz
I have a quick look of the link. I'm afraid it's not what I'm looking for. The tool writes the overscan_left/right/top/buttom values to /boot/config.txt, which should not be changed in my scenario.

To my understanding, on system startup there's a mechanism to read the overscan_left/right/top/buttom values from /boot/config.txt and set video output (PAL mode in my case).

When I use runcommand to set NTSC for a specifc game, a similar mechanism changes the video mode to NTSC, the difference is, it reads the target video mode from videomodes.cfg instead of config.txt. Because videomodes.cfg doesn't contain overscan settings, of course the video output would be incorrect.

I just don't know exactly how this mechnism is implemented. Is this something that can be achieved via command line? Is it easier to simply put it in runcommand-onlaunch.sh?

mitu

@sockscap said in Is it possible to configure overscan settings for runcommand video mode switching?:

I have a quick look of the link. I'm afraid it's not what I'm looking for. The tool writes the overscan_left/right/top/buttom values to /boot/config.txt, which should not be changed in my scenario.

The shell script does write the values to config.txt, but the overscan.c file can change the overscan values at runtime.

I just don't know exactly how this mechnism is implemented. Is this something that can be achieved via command line?

The resolution change is done via tvservice , which doesn't set any overscan values, as @BuZz mentioned. You can however change the overscan with the utility mentioned by @BuZz in the runcommand-onlauch.sh, since at that point the video mode has been changed and you only need to apply the overscan values.

sockscap

@mitu
Ok. All clear now. Thanks for the clarification.
I'm not a dev guy, so it's beyond my knowledge to modify the source code. I guess I have to prepare two set of config.txt, and reboot into the proper video mode when needed.