It's an old thread, but I encountered the same problem and I'm just putting here the solution I found in case someone else gets here.
I have a 1080x1920 screen and I use 'display_rotate=1' in /boot/config.txt to put it in landscape mode. omxplayer doesn't like it and don't render the video on the entire screen.
Further, using --orientation=90 just makes it worse.
Code: Select all
--win="0 0 1920 1080" to render full-screen.
This will define the render window coordinates of omxplayer.