On Wed, 24 May 2006 12:53:26 +0200
"Greg Wilson" <[EMAIL PROTECTED]> wrote:

> Some year ago (when transcode stable was 0.6-something), I had a
> vobs-to-xvid-script with everything tuned to suit my DVD-player (which
> plays Xvid-files on data-dvd). After a HD-crash I have reinstalled
> transcode (from cvs), and am trying to produce the same nice
> xvid-files that were produced before the crash. It works mostly well
> (isn't it way faster now?!), but there is one big obstacle left which
> I don't know how to deal with. I have tried with both xvid2 and xvid4,
> with the same results. The avi is vertically stretched.
> 
>  The commandlines are (they used to work with the old transcode stable):
> 
>  transcode  -c 0-00:01:00
>                    -J extsub=2:0:0:0:1:255:0:1:1,normalize  \
>                    --export_prof dvd \
>                   -M 3  -R1 -i vobdir/ -x vob,null \
>                    -N 0x50 -b 128,0,0  \
>                    -o /dev/null \
>                    -y xvid2,null  \
>                    -w 1400,250,100
> 
>  transcode  -c 0-00:01:00
>                    -J extsub=2:0:0:0:1:255:0:1:1,normalize  \
>                   --export_prof dvd \
>                   -M 3  -R2 -i vobdir/ -x vob,vob \
>                   -N 0x50 -b 128,0,0  \
>                   -o preview.avi \
>                   -y xvid2  \
>                   -w 1400,250,100
> 
> The produced avifile becomes vertically stretched.

Yes, this is the behaviour than I expect and I wonder how (and why!) this 
worked before!
The only explanation that I can see now is that your dvd-player honours PAR
settings even for mpeg4 bundled in AVI container (a very uncommon situation,
or maybe not, since some firmware of dvd/divx player is based on mplayer, and
it honours such setting) so it can display AVIs produced by above command line
correctly. But in general, such AVI are supposed to look strached.

Of course there is a reason for this behaviour: since the long story is
REALLY long, I'll write the short version first (if you or someone else is
interested, just let me know and I'll also post the LONG story :) ).

current (as in 1.0.x releases and before) export profile support needs
effective collaboration of some export modules to work properly. In other
words, using arbitrary export modules with an export profile will lead
to strange/out-of-spec results.
export profile support works only together with ffmpeg and mpeg2enc/mp2enc
export modules.

So, your command line it's supposed to produced strange results from the
beginning :)

> Comparing a new,
> streched file, and an old correct file, shows that there seems to be a
> difference in import frame size: "720x576 [720x576] " has become
> "720x768 [720x576] (*)". "--export_prof dvd" seems to be where the
> difference is;

Yes, this is the expected behaviour. `dvd' export profile implicitely modify
pre clipping/zooming parameters in order to produce dvd-compliant audio/video
streams. Of course, if export module isn't capable to produce such streams
(export_xvid* can't, since it can produce only mpeg4 video), strange things
will happen :)

> if I remove it, the produced avi looks better (but
> still a little stretched, maybe due to some aspect aspect):

Yep, you must explicitely set export asr/par (see --export_asr/--export_par)
or simply change aspect ratio of your video output (check -Z, -B, -j,
--pre_clip).

[...]
>  Here is the transcode output for the generation of preview.avi.
> Notable are the lines:
> ...
> XXX: zoom=no pre_clip=yes
> [transcode] V: pre clip frame   | 720x768 (-96,0,-96,0)
> ...

Yep, pre clip parameters is added by export profile support (the transcode
core part).

HTH,

Best regards,

-- 
Francesco Romani - Ikitt ['people always complain, no matther what you do']
IM contact: (email-me, I have antispam default deny!) icq://27-83-87-867
some known bugs: http://www.transcoding.org/cgi-bin/transcode?Bug_Showcase

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