[MPlayer-users] parameters to record from analog capture card

[Andrew Daviel]

I have a Bt878-based capture card on Linux (bttv.ko, V4L(2))
which I'm trying to use to record some video from an NTSC VCR and/or 
camcorder.

I used
mencoder tv:// -tv input=1:norm=NTSC:driver=v4l2 -of mpeg \
  -oac mp3lame -ovc lavc -quiet -o foo.mpg
which seems to work - if I view the file in mplayer, it looks
OK.
But if I seek through the video with the cursor keys, I get repeated
warnings: first frame is no keyframe, and there are severe artefacts in 
the display until things settle down.
A second tape is not so good - things never settle down entirely, and the 
audio sounds distorted in places.
Encoding also produces errors like
ERROR: scr 1.180, dts 0.000, pts 0.946
BUFFER UNDEFLOW at stream 1, raising muxrate to 3188 kb/s, delta_scr: 138725
ERROR: scr 1.237, dts 0.000, pts 1.103

Are there some encoding parameters I should use, or driver parameters for 
bttv, that would make this more reliable ? I tried
sc_threshold=-500000000 with little effect


-- 
Andrew Daviel, TRIUMF, Canada