[MPlayer-users] Subject: Making a DVD backup - Need advice

[Pieter Hulshoff]

On Wed, Oct 27, 2004 at 12:05:38PM +0200, nick.rienties at home.nl wrote:
> > I recently start using Mencoder to make backups of my DVD's. The command I use to encode a DVD:
> > mencoder -dvd-device /mnt/dvd/ dvd://1 -oac copy -vf crop=xxx:xxx:xx:xx -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=9999:vhq:vpass=1 -o ~/movie.avi
> > mencoder -dvd-device /mnt/dvd/ dvd://1 -oac copy -vf crop=xxx:xxx:xx:xx -ovc lavc -lavcopts vcodec=mpeg4:vbitrate=9999:vhq:vpass=2 -o ~/movie.avi
> > Question is:
> > Why is there so much difference in the used bitrate?
> > Is the bitrate setting over kill? I do care about filesize, 4485 MB is the max since the avi should fit on a dvd5.
> > Are there any other settings that I could use in the encoding command?

I think DVD quality is about 8 Mb/s, so 9999 would be overkill anyway. Just calculate the quality based on
the duration of the movie in seconds, e.g.:
1.5 hours = 5400 seconds -> 4485*8/5400 = 6.64 Mb/s, so vbitrate = 6.64*1024 = 6804

I'd set it a tad lower to make sure you don't accidently cross the 4485 MB line, but that's the general idea AFAIK, and if I'm wrong I'm sure someone 
will be ready to correct me. :)

Regards,

Pieter Hulshoff