I’m fairly new so I will probably get yelled at for posting it in wrong section so… sorry.
But I have Plex player app on my windows, I have ultra wide screen but the movie does not fill the screen, I mean, I have 10cm border on left/right and 4 cm border on top/bottom. How can I “zoom” in retaining ratio to fill as much of the screen as I can ? MPC produces correct result but plex makes “small” image.
Your video probably has the black bars embedded in the video at the top and bottom. The Plex for Windows app doesn’t have a feature to zoom so it will display the black bars at the top and bottom. The bars on the sides are due to the aspect ratio of the entire video (including the bars). The only way to fix this is to re-rip your videos without the black bars.