[MPlayer-users] arg, frustration with 3 pass divx encoding...

[Martin Pavon]

On Sun, Jan 05, 2003 at 08:21:45PM -0600, christopher j bottaro wrote:
> [Automatic answer: RTFM (read DOCS, FAQ), also read DOCS/bugreports.html]
> ok, i just did a 3 pass encoding of 'lord or the rings' to test my new 
> dvd2divx.pl script.  i'm quite disappointed.  the final divx file is not near 
> 700 mb.
> 
> here is the output of my script which should show you exactly what happened 
> (its very easy to read):
> 
> [cjb at semaphore divx]$ ../dvd2divx.pl -eq -scale 640 -autocrop 200 -vol 10
> crop detection requested
> mplayer -dvd 1 -vop cropdetect
> crop parameters detected before EOF
> crop parameters = 718:358:2:58
> mencoder -oac mp3lame -lameopts vbr=3:vol=10 -ovc frameno -o frameno.avi -dvd 
> 1
> first pass: 100% done, 0 mins remaining
> recommended vbitrate from first pass: 416
> mencoder -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vhq:vbitrate=416:vpass=1 
> -vop eq,scale,crop=718:358:2:58 -dvd 1 -zoom -xy 640 -o /dev/null
> second pass: 100% done, 0 mins remaining
> mencoder -oac copy -ovc lavc -lavcopts vcodec=mpeg4:vhq:vbitrate=416:vpass=2 
> -vop eq,scale,crop=718:358:2:58 -dvd 1  -zoom -xy 640 -o 
> lord_of_the_rings.avi
> third pass: 100% done, 0 mins remaining
> 
> the resulting file 'lord_of_the_rings.avi' is only 567 mb.  am i right in 
> thinking that the quality could have been much better if it actually used the 
> 130 mb that it could have?
> 
> i thought the whole point of the 3 pass method was to get a very good 
> approximation of the vbitrate so that the resulting file would be very close 
> to your desired size.  i could have >guessed< a better bitrate with a one 
> time pass and gotten better quality....;)  so obviously i'm doing something 
> wrong.
> 
> thanks for the help,
> christopher

Hi Christopher !!!

Is the dvd  ntsc? (for your address I  guess you are in Z1, but  ...) If it
is, then you must set -ofps 23.976.

Some times ago, I did some test and  I found that the wrong fps can produce
an avi file about 20% smaller than with the right value. This was discussed
in the thread

http://mplayerhq.hu/pipermail/mplayer-users/2002-November/023578.html

(but the samples are not there)

Regards, 

Martín
-- 
Martín Pavón
martin_199ar at yahoo.com.ar
http://mate.dm.uba.ar/~mpavon/