[MEncoder-users] Encoding to DVD: to deinterlace or not?

[Rich Felker]

On Mon, Oct 08, 2007 at 05:53:38PM -0500, James Hastings-Trew wrote:
> Moritz Barsnick wrote:
> > If my assumptions and not your search results are correct ;-), leaving
> > interlaced to be interlaced is best, because that's what your TV's
> > display is doing anyway. (Okay, nowaday, CRTs are getting rare, and your
> > LCD/TFT/Plasma may be all progressive after all.) I don't see the point
> > of deinterlacing, just to have the player revert the signal to
> > interlaced.
> You can't buy CRT tvs anymore, at least not around here. The LCD/Plasma 
> sets you can buy all have to deinterlace any analog signal you feed them 
> because they are scaling the image up to fit a finite resolution panel. 
> This gives analog video a very unpleasant (in my opinion) over-processed 
> look on such sets. Yet, large amounts of TV programming, and commercials 
> are still produced as interlaced video (I know, I work in advertising, 
> and I routinely have to "deinterlace" the  advertising samples for use 
> in other formats like for the web or in presentations), even though it 
> is the extremely rare new TV set that even displays an interlaced image 
> at all.
> 
> I'm of the opinion that interlaced video should go the way of the dodo 
> bird - it has outlived its welcome.

While this is all true, it's not an argument for deinterlacing.
Deinterlacing will just destroy half of the content, so that you have
30fps (or 25fps if pal) video instead of 60fps (or 50fps if pal)
video. It's possible to use mencoder to get 60/50 fps progressive
output from interlaced video, but DVD does not support this.

Your best bet is thus to leave the interlacing intact. Converting DV
to mpeg for DVD may require chroma resampling, in which case you need
to make sure the scale filter is loaded in the special
interlaced-video mode. The best way to do this is manually loading it
with the interlaced scaling option.

Rich