[MPlayer-users] Scaling and expanding when encoding tv

[Barton Bosch]

Here's a noob question that I was surprised not to find a clear 
answer to in the archives:

What is the best way to crop the bands and noise from the edges of 
the frame when capturing NTSC tv from a tuner card and encoding it 
to mpeg4?  I gather that it is best to keep the w and h dimensions 
divisible by 16 and also in a 4:3 ratio.  Which is more important if 
they are mutually exclusive?

This command removes the unwanted areas from all channels but it 
results in a file with a 1.29:1 aspect ratio, with an x dimension 
that is not a multiple of 16:

mplayer tv:// -tv 
driver=v4l2:device=/dev/video0:chanlist=us-bcast:channel=10:normid=1:width=640:height=480:fps=25 
-vf crop=618:480:12:0 -vo x11


What is the optimal way to capture and encode NTSC tv?  Change the x 
and y dimensions in the crop filters parameters?  Add a scale or 
expand command to the filter chain?  Does the order of filters in 
the chain matter?


TIA,

Barton