This has been an issue for me for quite a while, but I have simply overcome it by using the menu to change the aspect ratio.
It all stems from the perplexing confusion of recording dvb tv for later playback. Watching live TV on the TV, the picture fills the screen. It’s a 16:9 42″ TV (720p). When I record dvb tv using my main pc in its raw .ts state it is 720×576 (16:9). If I play this back using the GeexBox, mplayer squeezes the picture to a display of something like Cinemascope, so a change of aspect ratio to 4:3 usually sorts this out. But it got me thinking, if the original video is 16:9 why doesn’t play as such? The Pc in use to run GeexBox has an nvidia 6200 and is connected to the TV using VGA (DVI/HDMI went “pop” a while ago on the TV!).
First off, I tried all sorts of encoding options, changing the aspect ratio and resolution using mencoder. I got some success if I encoded with aspect=4/3 as an option. but this still didn’t make sense; if I had a 16:9 aspect ratio TV, why the original video didn’t fit.
This is what I did to sort things out. I have a HDD install of GeexBox so can ftp in to edit files. If you use a live cd, then you will need to edit the files before you generate a custom iso.
Boot up the GeexBox
FTP in, and make doubly sure you get into the right place
Open up tvout in that directory and change the Aspect Ratio line to this:
By just making this change alone, it squeezed my display horizontally to make a 4:3 image, so more to do
Browse to /mnt/Geexbox-partition/GEEXBOX/etc/mplayer and open up mplayer.conf
In the [default] section, add the following two lines:
and save. It may be worth noting that I have vo=vidix,vesa in the default section of mplayer.conf
Log out of the ftp and reboot the GeexBox. The Main Menu and background.avi should be filling the screen.
Now try playing any recorded dvb tv or video that was previously letterboxed, even though it was 16:9 ratio or 720×576 resolution. You should see it playback in full screen.
Caveats: This may not work in your setup, and you may not need to make all the adjustments to get this to work, this is what worked for me.