[MPlayer-users] gmplayer can not play video but mplayer does

[dcw]

I have tested mplayer with three files (test.mov, test.avi, test.mpg). 
It works as it should. When I tried with gmplayer it failed. It could 
not display the video (on mplayer it did). The error message displayed 
in the konsole window was:

Xv: could not grab port 61
Could not find free Xvideo port - maybe another process is already using 
it.
Close all video applications, and try again. If that does not help,

I looked in KDE configuration -> information -> X-Server -> supported 
Extensions and it shows that Xvideo is supported.

I do not know where to look next.

Any help will be greatly appreciated,

David