Is it possible to adjust aspect ratio on an Android device? I have an Android device that has a 4:3 aspect ratio.

When I watch videos in full screen mode, sometimes the aspect ratio causes the video to be distorted.

Is there a way to temporarily adjust the aspect ratio?

I can see a couple different solutions:  


Adjust the actual aspect ratio.
Add a black bar on the top / bottom of the display that effectively changes the aspect ratio.
vlc is the best if they support the aspect ratio you need. MX player has custom aspect ratio setting; and pan, but needs a codec pack to play a couple audio formats due to licensing issues.