Multimon not working in Raspbian Buster

[chase-cobb]

Is there any chance of getting this to work in Raspbian? I make/sell kits for dynamic LCD marquees and have had folks asking me if this works for a while. I just compiled AM and it seems to run fine, but the multimon plugin doesn't seem to do anything. I've set logging mode to "debug" but don't see any errors in terminal. Tested with legacy and experimental drivers.

[chase-cobb]

After digging into this it seems there is just a silent failure, and with the right flags the feature will work. I started parsing the codepath for multimon and it looks like the only reliable path is when USE_XINERAMA is enabled.

I had to add more flags to my make command to get all of the features I currently need to verify the funtionality (multimon and scraping marquees) and came up with these additional steps on top of the build steps I outlined originally in the wiki.

sudo apt-get install libxinerama-dev libcurl4-openssl-dev
make USE_GLES=1 USE_XINERAMA=1 USE_LIBCURL=1
sudo make install USE_GLES=1 USE_XINERAMA=1 USE_LIBCURL=1

There is still an issue where I initially have to

• unplug my second monitor
• reboot
• disable multi monitor support and Multimon in AM
• shutdown
• plug second monitor in
• power up
• enable multi monitor support and Multimon in AM

Then it seems to work every time after that.