[mythtv] Removing dependencies via ffmpeg

[Robert Lippmann]

hi all,

i noticed a recent resync of ffmpeg into mythtv cvs.  i was wondering, since
native ogg/vorbis/theora muxing and demuxing was added recently, and ffmpeg
can probably nowadays handle mp3 encoding/decoding natively, if perhaps the
configs should be modified to use those (i believe that's the default now).
less dependencies is better, right?

also, you can enable/disable individual codecs now, so it might be worth
looking into that to make the executables smaller.  don't think some of the
more esoteric codecs are needed (ie segafilm, etc), and anything codec wise
that's done in mythtv internally can either be replaced with ffmpeg's
implementation, or just disabled within the ffmpeg configure/build.

just my $.02

-- rob