ffmpeg fails to compile

[Paul Beard]

===>  Configuring for ffmpeg-2.8.6_3,1
ERROR: libv4l2 not found using pkg-config

If you think configure made a mistake, make sure you are using the latest
version from Git.  If the latest version fails, report the problem to the
ffmpeg-user at ffmpeg.org mailing list or IRC #ffmpeg on irc.freenode.net.
Include the log file "config.log" produced by configure as this will help
solve the problem.
===>  Script "configure" failed unexpectedly.
Please report the problem to multimedia at FreeBSD.org [maintainer] and attach
the "/usr/ports/multimedia/ffmpeg/work/ffmpeg-2.8.6/config.log" including the
output of the failure of your make command. Also, it might be a good idea to
provide an overview of all packages installed on your system (e.g. a
/usr/local/sbin/pkg-static info -g -Ea).
*** Error code 1