Re: [tlug] Backing up DVDs

[Alain Hoang <hoanga@example.com>]

Hello,

On Apr 26, 2004, at 3:13 PM, Jonathan Byrne wrote:

> As I'm sure anyone with small children can attest, backing up all your
> DVDs and keeping the originals under lock and key somewhere is a must.
> I have, therefore, recently begun dabbling with dvdackup.  It pulls
> the files off the DVD readily enough and creates a mirror of the
> directory structure on disk,  The only hitch is that what I wind up
> with is nearly 8 GB of stuff, and I have not yet found the right
> magic document to tell me how to get this onto a 4.7 GB DVD blank.

	Ah, backing up DVDs.  You can thank CSS for making
life more difficult in just trying to make a backup of a DVD in case
the kids decide the DVDs make better frisbees :-).

	Unfortunately, most of the tools I assembled together
were for Windows awhile back and the process ranged from
rather straightforward to really annoying.  The 2 main problems
I found were:
1. If the DVD was encrypted you couldn't just freely copy
     the data files and remaster a new DVD disc.  You would
     have to decrypt the disc with some tool (there were piles
     for Windows).  I have seen some tools for Linux but have
     not really paid attention to what tools do what let alone
     try any of them.
2. Some DVDs are larger than  4.7 GB which means you have to start
      trimming something or re-encode the video (and/or audio)
      to be able to fit it in 4.7 GB.   Many of the newer DVD-Video
      discs I have noticed are NOT coming as 4.7GB discs (which
      I believe is referred to as DVD-5) but as 9GB or something
      discs (referred to as DVD-9).   Most of the DVD-9 burners are
      very expensive and getting the media is very difficult at this
      current point in time.

	Getting hit with 1 & 2 meant a really long time to rip
a DVD to the HD then re-encode it just right.


> I'd prefer to do this from the CLI because it's more fun that way and 
> faster
> once you know what you're doing, but I won't turn up my nose at a way 
> to
	The main trick is getting something to be able to decrypt the DVD
stream and stick it on your hard drive.  Once it's in that form there
should be plenty of tools such as ffmpeg, mplayer and others that
can re-encode the stream to an appropriate format.   However,
depending on the size of the disc the re-encoding parameters you
send will probably be different.  Note the re-encoding process is
probably the most time consuming portion of this process.    Even
with faster machines of today I'm still going to guess this is going
to take a few hours plus unless you have a Beowulf cluster
sitting around doing nothing  :-).

>
> There are a number of Windows programs that say they will back up your
> commercial DVDs to standard 4.7 GB DVD media, and k3b seems to try but
> fail, so I know there must be a way to get it done, but googling has 
> not
> so far provided me with the right clue.  Ideas, anyone?

	If you want this to be a semi-braindead task use Windows.   From
what I have seen of using Linux/BSD/etc you need to build your own
pipeline to be able to make a copy of a DVD disc.  And because of
issues 1 & 2 that I mentioned above, I believe you will have to have
different pipelines to handle different situations.  (Unless you
don't care how the re-encoded video quality comes out).

	After doing this for awhile, I took apart my whole setup and
only use it for rare occasions since the amount of CPU and human
time it took was far too long to offset spending 20 bucks on a new
DVD.  But it was educational  :-)

Alain