error compiling mplayer

[David Banning]

getting this error on compile of mplayer;

/usr/local/lib/libgdk-x11-2.0.so: undefined reference to `XRRGetScreenResourcesCurrent'
/usr/local/lib/libgdk-x11-2.0.so: undefined reference to `XRRGetOutputPrimary'
collect2: ld returned 1 exit status
gmake: *** [mplayer] Error 1
*** Error code 1

Stop in /usr/ports/multimedia/mplayer.
*** Error code 1

I wonder if anyone could direct me as to how I could collect more information
to resolve this.

FreeBSD version is 8.2