I’m facing a rather odd issue with the emulators snes8x-next and fceumm (NES). A few pixel rows on top are missing in both emulators. If i switch to other emulators like pocketsnes the screen size is just right. I also messed around with all the screen options in the menu before the actual emulator starts.
At the beginning, the ES screen was too big as well, so I adjusted the config.txt. That fixed the ES screen size and also lead to an improvement at the above-mentioned emulators. Instead of about 40 lines missing on top, it was down to 20 I would say. But regardless how much I increase/change the overscan values from that point (24), it only enlarges the black frames on the sides.
I tested this fix and it indeed shrank the ES screen. But actually it had the same effect like increasing the overscan values to about 35 or so and didn’t fix the emulator issue.
# uncomment if you get no picture on HDMI for a default "safe" mode hdmi_safe=1
# uncomment this if your display has a black border of unused pixels visible
# and your display can output without overscan
# uncomment the following to adjust overscan. Use positive numbers if console
# goes off screen, and negative if there is too much border
# uncomment to force a console size. By default it will be display's size minus
# uncomment if hdmi display is not detected and composite is being output
# uncomment to force a specific HDMI mode (this will force VGA)
# uncomment to force a HDMI mode rather than DVI. This can make audio work in
# DMT (computer monitor) modes
# uncomment to increase signal to HDMI, if you have interference, blanking, or
# no display
# uncomment for composite PAL
# for more options see http://elinux.org/RPi_config.txt