[GLLUG] DVD Copying/Decoding software

[Jeremy Bowers]

Eduardo Cesconetto wrote:
> I tried dvdbackup (command line) yesterday, but it took 2 hours to  
> create a backup in the hard disk. Since the same machine booting XP  or 
> Mac OS can do that in less than 20 minutes, I believe the software  I'm 
> using is NOT the best to do the job.
> Any suggestions?

By "backup" do you mean literally to rip a perfect image of the DVD onto 
the hard drive?  In that case, yes, that is definitely slow and 
something is wrong.

Or are you using the euphemistic meaning of the word "backup" used 
mostly by copyright violators*, when what you really mean is to 
re-encode the DVD to a smaller size, usually one that fits onto one 
burnable CD?

In that case, the likely answer is the two operations are not 
comparable. In video encoding there is a very wide range of choices 
available trading off encoding quality and space vs. processor time. 
It's most likely that your windows process is using a codec or codec 
settings that result in much smaller compression times, but much smaller 
quality as well. In that case, the solution is to figure out how to 
convince your Linux re-encoding software to either use less aggressive 
settings, or to use a different encoder.

There are a number of ways to identify the codec used for a file; one 
way is to open it in VLC and look at View->Stream and Media Info. You 
can also compare the output of mplayer for both the files, though I find 
that hard to read simply because it tends to have a lot of other junk in 
it, although the info is all there. If they are very different, 
especially if your Windows box is using MPEG2 and not MPEG4/DIVX, that's 
the source of the difference.


*: Regardless of whether you think that's a real problem or not. I'm 
pointing out that's how they (ab)use the word "backup" (mostly with 
console video game images), which personally I think should keep it's 
meaning of something you can recover a 100% copy from, and not try to 
pretend that calling it a "backup" has any meaning ethical *or* legal.