Re: Re: avoiding jagged lines on mp2

Le 28 avr. 06 à 18:51, Robert Ramiega a écrit :

> On Fri, Apr 28, 2006 at 12:24:25PM +0200, herve.flores wrote:
> > > Date: Fri, 28 Apr 2006 00:27:23 +0200 (CEST)
> > > From: Leonardo Boselli <leo@xxxxxxxxxxxxxx>
> > > Subject: [Ffmpeg-user] avoiding jagged lines on mp2
> > >
> > > result is good if I have images without too much movements, but  
> > > is the
> > > people move too much i get a lod of annoying jagged lines due to
> > > interlacing. Other times i resorted in the dirt way, encoding as a
> > > 384x288
> > > images, so using only even fields , but losing a lot of details.
> > > since post of the movie are maps and other drawing of course i  
> > > want to
> > > keep the most detail it is possible, and the problem can be seen
> > > only when
> > > some one is gesturing.
> >
> > > There is a way to avoid it ?
> > yes, use a progressive camera to shoot, like some very expensive HD
> > camera
> >
> > seriously, you have an interlaced input and you complain about an
> > interlaced output
> > then you want to suppress half of the informations of your input but
> > without loosing quality...
>
>  Actually deinteralcing this is not needed at all. As it was  
> suggested all
> that's needed is explicitly tell ffmpeg that input is interlaced by  
> using
> -ilme and -ildct options. The jagged lines most probably come from
> some "inconsistency" between DV-AVI and MPEG-2.

a mistake with order of fields will cause you a headache (because  
you'll see fields in this order: 2-1-4-3-6-5-...)
but you can't see fields on TV (if theinput is PAL and the encoding  
is in PAL too, and whitout scaling)

did you see "jagged lines due to interlacing" on computer (=normal)?  
or in TV (=problem of size of input and output)?


> One is Top Field First and
> the other is Bottom Field First (by default) I could never remember  
> which
> one does it which way but i think DV-Avi is TFF.

DV is always bottom-field-first

> There is nothing wrong
> with TFF MPEG-2 it just needs to be specified in the MPEG-2  
> "header". AFAIK
> ffmpeg doesn't have option to set it.

to set top field first set parameter to "-top 1"
to BFF set -top 0
to write fields from the input headers "-top -1"
(see "ffmpeg -h")

> In m$ windows world this can be easily
> fixed using f.ex. ReStream  (maybe some other tools too; have a  
> look at
> www.videohelp.com)
>
> --
> Just a friendly Jedi Knight     | I find your lack of faith
> Robert Ramiega jedi@xxxxxxxxxx  | disturbing
>        http://nlj.plukwa.net/
bye

Hervé