[MEncoder-users] mencoder output

Marco brbromo at gmail.com
Wed Mar 8 16:44:54 CET 2006

On 3/6/06, RC <rcooley at spamcop.net> wrote:
> > >>Right here mencoder is specifying that the video should be scaled to
> > >>match the original 1.33:1 aspect ratio. If you
> > >>don't want that to happen you can either:
> > No, I don't want to match the original aspect ratio, because the
> > cropped image would be stretched.
> You've completely misunderstood.  It's scaling to the correct aspect
> BEFORE cropping/scaling.
Cropping is made on the sampled image, not on the
scaled-to-correct-aspect-ratio image, right?

Encoding is made using the sampled image, too. Right?

I suppose that the -vf scale filter is applied on the sampled image,
correcting the specified scale ratio to take into account the image
aspect ratio.

So what's the reason of this prescaling? Who needs the
scaled-to-correct-aspect-ratio image?

> I think you're just making this far more difficult for yourself.  If you
> want the correct aspect ratio set in the output file, use "-lavcopts
> autoaspect".
I'm using xvid. Does it work with xvid, too?

> If you want square pixels (for players like that don't
> support an aspect in MPEG-4 video or in an AVI) then just use "-vf
> scale=-1:-10".
I don't care about such players. I don't want *square pixels* (i.e.
same display and sampled width and height in the encoded movie). I
just want squares to keep their aspect ratio.

I'm getting this result with dsize=newAR, where newAR =
(w'/h')/(w/h)*(oldAR). But this *seems* mencoder default behaviour. Is
it true?


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