After a little pause, I thought I add another entry to my ongoing tips series. Today we'll get rid of the black bars you can most likely observe on a widescreen display, when playing a video DVD with MPlayer.

This little post assumes that you've already inserted the DVD you'd like to watch, your MPlayer setup works with dvd:// style addresses, you know which title from the DVD you want to watch (the examples will use the first title) and you know your monitor's aspect ratio (the examples uses 16:9).

Now all that is needed are the following two steps:

1. Detect the cropping parameters:

   mplayer -vf cropdetect -monitoraspect 16:9 dvd://1

   The previous line is followed by the usual MPlayer header and output. The film should start playing and after a few seconds you can press q (just wait until the detected values stop changing). Now there should be a few lines looking like:

   [CROP] Crop area: X: 0..719  Y: 76..499  (-vf crop=720:416:0:80).
   A:   1.5 V:   1.5 A-V: -0.000 ct: -0.018  38/ 38  5%  7%  1.0% 0 0
   [CROP] Crop area: X: 0..719  Y: 75..500  (-vf crop=720:416:0:80).
   A:   1.6 V:   1.6 A-V: -0.000 ct: -0.018  39/ 39  5%  7%  1.1% 0 0
   [CROP] Crop area: X: 0..719  Y: 75..500  (-vf crop=720:416:0:80).
   A:   1.6 V:   1.6 A-V: -0.000 ct: -0.018  40/ 40  5%  7%  1.1% 0 0

2. Play the film with the detected crop values and the correct aspect for the video material (4:3 for PAL and 3:2 for NTSC):

   mplayer -vf crop=720:416:0:80 -monitoraspect 16:9 -aspect 4:3 dvd://1

Of course you can add any other options to the invocation as usual, though you only need to add those to the second invocation (e.g. select the correct audio stream or start in fullscreen mode). Also, you might want to set the monitor aspect permantly in your MPlayer configuration (just add monitoraspect = "16:9"), as the monitor rarely changes for the average machine /etc/mplayer/mplayer.conf.local is probably the best place (make sure your /etc/mplayer/mplayer.conf includes that file at the end).

Now you should be able to enjoy all video DVDs on your widescreen display without black bars at the top and bottom!