I've been using "Mencoder" (MPlayer)
Here's an example of one with high bitrate/high quality:
Code:
mencoder -oac lavc -lavcopts acodec=mp3 -ovc lavc -lavcopts vbitrate=2400 -tv driver=v4l:norm=ntsc:channel=03:chanlist=us-cable:width=640:height=480:adevice=/dev/dsp -o myshow.avi tv://
This gives about 1GB per hour.
This is just an example, you may be using v4l2, and you can always reduce
the bitrate and resolution.
I normally edit afterwards with "AviDemux".