On Sun, 28 May 2006 22:59:48 +0200
Marschall Kurt <[EMAIL PROTECTED]> wrote:
[...]
> The DVB-T Stream looks good, and after transcoding it it is distorted
> (streched or whatever).
>
> I retrieve the aspect ratio and the resolution with tcprobe.
> Then I use the following appropriate resizing options (found out by mere
> trying what looks best):
>
> _ASPECTRATIO=$(tcprobe -i "$1.vob" | grep aspect\ ratio: | awk -F: 'BEGIN
> {FS=" "} {print $3}' | sed 's/^ *\(.*\) *$/\1/')
> _FRAMESIZE=$(tcprobe -i "$1.vob" | grep frame\ size: | awk -F: 'BEGIN
> {FS=""} {print $5}' | sed 's/^ *\(.*\) *$/\1/')
>
> 720:576 aspect ratio 16:9:
> transcode -B 0,0,8 -X 0,38,8 x vob -y xvid4 -w $bitrate -I 3
>
> 704x576 [720x576] (*) aspect ratio 16:9:
> transcode -B 0,0,8 -X 0,40,8 -x vob -y xvid4 -I 3
>
> 4:3 720:576
> transcode -B 2,0,8 -X 0,3,8 -x vob -y xvid4 -I 3
>
> 4:3 704:576:
> transcode -B 4,0,8 -X 0,3,8 -x vob -y xvid4 -I 3
If you use -B and -X you could be also interested in using -Z WWWxHHH,fast
(note the ",fast" part) which automatically computes those parameters.
[...]
> With the deinterlacing, the resizing and -a bitrate of 1200 I get a fps of
> 13 on an Amd64 3200+.
Looks a bit slower. Are you using xvid 1.1.0?
> Does someone know better resizing options? I am not asking about other
> comandline options. Just better values?
Regarding -B/-X, AFAIK no. Using, to say, -B X,Y,8 and -B X/2,Y/2,16 should
lead to identical results both in speed and in output quality.
> For instance does -B 0,0,8 -X 0,38,8 the same job as -B 4,0 -Y 24,0 on a
> 720:576 aspect ratio 16:9, just that -B 4,0 -Y 24,0 works more than twice
> as fast.
Well, -Y it's a clipping option, -X it's a resizing one, so the latter it's
supposed to be slower than the former.
It's definitively possible to achieve (roughly) the same results using
different command line options combinations, but the choice should be left to
the user.
> I would be very thankful, if someone could tell me some better values then
> the ones I found out.
Generally speaking, AFAIK if you have black bars in your source materials
(i.e., they aren't added by transcode using -X or similar) the fastest thing
it's to cut they first with -j, then adapt the aspect ratio using -B alone.
> By the way it would be very nice if one could put
> these values on the transcoding wiki.
That's a nice idea.
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
