I wrote video recorder which uses ffmpeg (ffmpeg.sourceforge.net) a
while ago, and it works fine for me.  Although I don't have time to
tidy up things, I decided to provide my sources as is, because some of
you might find this item useful.

Some random notes:
0. You must be prepared to read the source if you have question or
trouble. :)
1. The only supported video capture device is bktr(4), of course.
 I guess bktr have trouble if the source isn't NTSC, but I haven't confirmed.
2. You will need recent ffmpeg from ffmpeg.sourceforge's cvs
repository.
3. Fast CPU is necessary. I use Athlon XP 1700+.
 But tuning quality parameters (bitrate, qmax, ...) should reduce CPU
 load somewhat. 
4. You'll probably need to look at main.c and adjust device file
names.
5. I copyed fastmemcpy stuff from mplayer and linked into libavcodec,
iirc.  Just commenting out USE_FASTMEMCPY in the Makefile might work.

That said, this program works fine for me and I've been successfully
recording a bunch of animes for months.
You can watch TV while recording if you have a XVideo capable video card.

The code is available at
 http://www.sat.t.u-tokyo.ac.jp/~iwamoto/comp/mrec/
You need to apply syssrc.bktr.diff.gz to the kernel source.
The diff is against -current tree.

--
IWAMOTO Toshihiro