If your distribution of BSD comes with iso mounting software (it does) and a media player (likely) it will work too.

and to quote me

AVCHD is natively supported by all major operating systems and set top hardware

Sure there is a chance your variant of BSD is stripped of fundamental software such as a media player or ffmpeg, but at that point you should probably install a media player or an mkv would be worthless anyway.

To quote http://www.kucher.org/projects/avchd/

After compiling the latest version of FFmpeg, I found that AVCHD just works on Linux.

and this was written in 2008 or 2009.