Re: RipIt4Me==>Very large files?

(PeteCresswell) wrote:

When DVD Decrypter chokes, I'll try feeding the problem DVD to
RipIt4Me and sometimes it will work where DVD Decrypter failed.

But frequently I also wind up with directories that are 15-30
gigs in size. They will play, but....

Can anybody shed some light on what is going on there?

Sure. First thing you need to understand is how a filesystem stores it's
directory info.

In a general way, regardless of filesystem type (FAT32, NTFS, EXT2/3, UDF,
etc) somewhere on the disk there is/are header(s) and/or table entries that
hold such info for a file with regards to name, size, type, owner,
permissions (Linux/Unix etc) and for our discussion here, beginning disk
sector.

Some of what you are seeing is the results of "fake" disk directory entries.
Multiple directory entries to the same data are present on the disk which
"fakes" the copiers into copying way more data into an ISO or onto a
hard-drive.

Here's a dumbed down example:

Say we have a very simple disk structure that holds 8 sectors. Sure that's
way smaller than any real disk but the idea will still hold true.

On that disk I save a file:

file1.abc

and file1.abc is 5 sectors long. I see an entry:

file1.abc___5sectors starting sector__1

3 free sectors

I then save another file that's 1 sector: file2.abc

and yet another file that's one sector: file3.abc

and yet another file that's one sector: file4.abc

I see my disk directory entries:

file1.abc___5sectors starting sector__1
file2.abc___1sectors starting sector__6
file3.abc___1sectors starting sector__7
file4.abc___1sectors starting sector__8

0 free sectors

Suppose now that I use a disk sector editor and manually edit the disk
entries of file2, file3, file4 to start at sector 1 as follows:

file1.abc___5sectors starting sector__1
file2.abc___5sectors starting sector__1
file3.abc___5sectors starting sector__1
file4.abc___5sectors starting sector__1

0 free sectors

What? How did I possibly manage to get 20 sectors onto an 8 sector disk?
What will happen if I copy file1? I will get a copy of file1.abc that's 5
sectors long that includes sectors 1,2,3,4 and 5.

What will happen if I copy file2? I will get a copy of file2.abc that's 5
sectors long that includes sectors 1,2,3,4 and 5.

Same for the rest of the files. Hence my destination disk for the "copy to"
will crash with a "full" error.

This method of copy protection has been around for a long time. I used to
deal with it on 5 1/2" floppy disk copy protection removal.

One note that takes it a bit farther... on DVD the individual sector info
for any given piece of video/audio are hardcoded into a "navpack" as part
of the ".vob" file for various reasons such as chapters jumping and fast
forwarding. The programming info for following those navpacks are stored in
the IFOs that are coded specifically for a VTS titleset's vobs. You're
going to find that although it appears you might have backed up the movie
multiple times (as my little disk example shows), the "fake" title sets
will probably not play correctly as the IFO are purposefully glitched as
part of the protection scheme. I've seen the fakes skip scenes, play the
credits in the middle of the movie and just in general not be healthy
backups. Only one single title is the actual movie that gets played when
you navigate the DVD's menu. Oh, also... old rippers used to take the title
with the longest time and make a disk copy of it, figuring the longest
title must be the movie. One or more of these fakes is probably longer than
the real movie which of course gets you a bad rip using old rippers.

You can get rid of the other fakes by playing the ISO or hard-drive backup
and using something that shows you what title you're watching. I use Linux
so Xine does that for me. Once I have the actual title/s number, I use a
"shrink" program to copy out just the title/s I want. I get rid of
subtitles, alternate languages etc etc.

When that's done, I use PGCEdit to skip warnings and logo screens
(now-a-days these are menus, making them harder to get rid of). I make an
ISO of the DVD, burn it and hand it over to my kids and store the original
for safe keeping. :)

More bullet-proof rippers? I tried DVDFab 8 but, for reasons I
do not recall, it did not work out.

Always remember, if you can get your hands on the ripping software, so can
the protection guys. They immediately go into defeat-this-new-version mode.
Sometimes they threaten the developers with huge lawsuits.

I quit trying to use Windows to rip/copy a long time ago. The whole
operating system is built on trying to either track your use of multimedia
and/or keep you from playing/copying/backing up/rescuing your media. Open
source software developers have a completely different view. While they
certainly don't condone theft of copyright, they view restrictions
implemented for copyright protection shouldn't trump a user's ability to
view, backup or rescue legally obtained data on alternate operating
systems. In short Windows has you guilty until proven innocent whereas open
source software has you innocent until proven guilty.

To sum it up there are no "good" bullet-proof rippers for Windows. As soon
as one comes out, wham, it's ability to rip is thwarted. The copier
developers "fix" it and charge you for the new software update. Then.. wham
again. I've played this method of whack-a-mole for 25 years. When Sony came
out with ARccOS [1] and I went into high gear and learned all I could
about DVD structure. I suggest you do the same. Now with just a handful of
the same tools I used for years using Linux, some commandline, I have never
*not* been able to backup anything I wanted to backup.



[1] en.wikipedia.org/wiki/ARccOS_Protection

"Many DVD Rippers have been designed to overcome ARccOS protection, it is
also naturally overcome by using ddrescue, a linux utility designed to copy
images with errors."

note: Sony didn't invent disk error protection, Commodore 64 disks contained
this method back in 1984!! :)


disclaimer: I do not in any way condone using any information here to
infringe on any copyright. Use at your own risk. I shall remain
indemnified. I was never here. Wasn't me, you're mistaken. What you be
talking 'bout? Get outta town. Oh yea...? yer momma!!!

--
---
-= F =-
---
If linux and Windows were women, Windows would be a whore and linux would be
a lady that requires that you develop a relationship first.

.

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