If you are playing video using MPlayer and your screen is wide, you might notice that all videos are slightly longer than expected. This problem can't be fixed using the usual aspect ratio. It is not a bug but a great feature of MPlayer that you will never see something like this in other player.

MPlayer has an ability to resize the video to fit the pixel size of your monitor. For example, in some cases, a pixel may not be a square. In other words, the width of a pixel may be less than its height. As a result, the aspect ratio of the video displayed on the monitor might be incorrect. MPlayer automatically detects this aspect ratio and corrects it silently. Unfortunately, it is all wrong on my widescreen laptop. To correct this problem, you have to specified the aspect ratio that fit your monitor using option -monitorpixelaspect as follow.

mplayer -monitorpixelaspect 1 example.avi

If you want to disable this feature, set it to 0.

mplayer -monitorpixelaspect 0 example.avi

Otherwise, you may set this option as default in $HOME/.mplayer/config.

monitorpixelaspect=1

or

monitorpixelaspect=0

Tags: linux, mplayer, monitor pixel aspect ratio