If you record TV shows using your MythTV DVR, you may want to play them on an iPod, a PSP, or even through a Windows Media Center system. Another desire might be to burn your recordings onto a DVD. This excerpt from the ExtremeTech book, Hacking MythTV, shows you how to do all of this, and gives you pointers on using MythTV with Wi-Fi.
There are several different ways you can export MythTV recordings to a different format for consumption by devices not running MythTV. This might be a Windows Media Center computer or it might be a portable device capable of playing digital video files, such as the Video iPod or a PlayStation Portable. You might also have reason to burn recordings onto either VCD or DVD. All these uses require you to convert MythTV native formats into something else.

If you simply want to be able to browse your recordings outside MythTV and make sense of them based on filename alone, check out mythrename.pl in the contribs subdirectory of the official MythTV distribution. Copy mythrename.pl from the MythTV distribution contribs subdirectory to /usr/local/bin/ and make it executable:

# cp mythrename.pl /usr/local/bin/
# chmod +x /usr/local/bin/mythrename.pl

MythTV stores recordings with a filename that is almost purely numeric, based on the channel from which the program was recorded, along with a date and time stamp. All mythrename.pl does is rename your recordings from their default numeric format into something more human-decipherable.

By default, mythrename.pl alters the filename in your file system and changes its reference in MythTV’s database. If you prefer, you can use the –links flag with mythrename.pl to instruct it to create symbolic links instead, inside a show_names directory in your MythTV recordings directory. Either method should provide you with a directory of files you can browse easily and play from any other computer, if you share that recordings directory with your network (assuming you have video players on your other computers with the right decoding capabilities).

For example, recordings created with HDTV capture cards and hardware MPEG2-encoding cards are simply MPEG-2 files, with standard .mpg file extensions, so it should be possible to view them using any video player that supports MPEG-2 (and has enough CPU horsepower, especially relevant for HDTV content). The mythrename.pl script has a number of other options you can check out by running mythrename.pl with a –help flag.

If you find yourself running mythrename.pl frequently, you may want to schedule it to run as a cron job, perhaps on an hourly basis. Better yet, set it up as a recording post-processing job, which is addressed later.

If you have a specific format in which you want to export your recordings, you have a few options, depending on exactly what it is you are trying to accomplish. You could use a format that compresses recordings more so you can save disk space, or a format at a lower resolution that allows a less-powerful device to play it back.

http://www.extremetech.com/article2/0,1697,2062433,00.asp