[MPlayer-users] transcode 1080i to interlaced DVD?

[Rich Felker]

On Sun, Nov 20, 2005 at 01:57:09PM -0500, Norman Ramsey wrote:
>  > > Running a deinterlace filter (-vf pp=fd) leaves the picture somewhat
>  > > blurry.  
>  > 
>  > First off, are you sure it's purely interlaced?  If it's a movie
>  > or animation rather than a TV show, it's almost certainly telecined, and
>  > needs to be handled differently than interlacing.
> 
> It's TV broadcast of a live sports event.  As far as I can tell, I'm
> getting 29.97 fps with 2 fields in each frame.

Yes sports are real interlaced content. Dropping half the fields will
look very shitty (choppy motion).

>  > There are many deinterlacers.  kerndeint might work out for you.  But,
>  > since you already have it as 1080, why not try "-vf field" to omit half
>  > of the lines?  Then you can crop and scale to the dimentions you want
>  > normally.
> 
> Hmm, that never even occurred to me.  So the idea would be just to
> drop half the lines?

Yes but it's a bad idea.

>  > >   -vf il=d,crop=1440:1080,scale=720:480:1,il=i
>  > >   -lavcopts ildct:ilme:mbd=2
>  > > 
>  > > but I have no idea what I'm doing. Do all these make sense in
>  > > combination?
>  > 
>  > lavcopts are fine (you'll want a lot more of course), but those vf
>  > options are all wrong. il takes two parameters, and cropping height
>  > after 'il=d:d' will give you completely mismatched fields.  Leave 'il'
>  > completely out, and it'll work.  Make sure for your crop parameters that
>  > you keep the height (and height offset) multiples of 4.
> 
> Cool---that might be like Christmas come early :-)
> 
> So what *does* one use -vf il for?

You would use -vf il if you weren't using the interlaced-mode flag to
scale. :) Sorry I missed seeing that you were already using that in
your original post. It's also useful for other things like denoising
interlaced video, sharpening interlaced video, etc. Basically anything
where you'll ruin the video if you try to process two interleaved
fields as one picture.

Rich