There has been an error when using mplayer. You got the error, that a symbol named "SendingInterfaceAddr" is not found.
Ther reason has been, that the a call from the liveMedia.so library could not be resolved to the library groupsock.so of the same liveMedia package. The fix could have been put into consuming programs, in this case mplayer, or the way I've done it here:
The library file liveMedia.so now has the RPATH enhanced to search for and link to libgroupsock.so where functions SendingInferfaceAddr and ReceivingInterfaceAddr live.

How to update:
#dryrun:
shell> pfexec pkg update -nv livemedia
Packages to update: 1
Estimated space available: 8.31 GB
Estimated space to be consumed: 113.39 MB
Create boot environment: No
Create backup boot environment: Yes
Rebuild boot archive: No

Changed packages:
localhostoi151a8
library/video/livemedia
2014.12.17,5.11-0.0.151.1.8:20141221T021604Z -> 2014.12.17,5.11-0.0.151.1.8:20150517T104722Z

#really install:
shell> pfexec pkg update -v livemedia

You'll get a liveMedia.so library which now knows where the lib groupsock.so lives. This solves the following error with mplayer:

This ist how the error looks like, of the symbol SendingInterfaceAddr cannot be resolved (=libgroupsock.so is not linked)
mplayer
ld.so.1: mplayer: fatal: relocation error: file /usr/lib/live/liveMedia/libliveMedia.so: symbol SendingInterfaceAddr: referenced symbol not found
Killed

If you have questions, drop us a note here in the comments or on the mailing lists or IRC channel #pkgbuild on irc.freenode.org

Thank you for using SFE and please, spread the word!

PS: you'll need a little bit of patience until the autobuild system is finished and the packages are uploaded to the publicly accessible repositories. Check here to find a new livemedia package with datestamp *later* then 20150517-T000000Z