Extracting from SVCD?

[Dennis R. Cohen]

On 3/30/03 at 9:36 PM, Charles Martin <chasm at mac.com> transmitted the
following electronic message:

>Hi all:
>
>I was wondering if anyone has a method for "ripping" an SVCD. I have 
>just burned some music videos onto SVCD and now I'm wondering if I can 
>ever get them back off of there if I were to want to make a new 
>compilation at some point in the future.
>
VCD Copy X (free download from Version Tracker).

>The files on the SVCD disc are still MPEG-2, but they are substantially 
>different (and unplayable through Quicktime) to the MPEG-2 files I 
>mastered with, which play fine with QT Pro + MPEG-2 component.
>
The MPEGs are not "substantially different" -- they're written Mode 2
Form 2 on the CD (2352 bytes/sector, no error checking) and the IO
routines used by the Finder and QuickTime in OS X don't deal well with
non-"data" formatted (Mode 1 Form 1, 2048 bytes/sector with
error-checking). VCD Copy X will copy the data back to your hard disk as
a DAT file. You can use VCD GearX (also free) to strip the DAT header
information (use the dat2mpg option).

>I'd like to be able to delete the "source" MPEG-2 files after they are 
>burned to SVCD, but at present I'm stumped on how to extract them back 
>to "regular" MPEG-2.
>
See above.

>Advice or URL pointers (bearing in mind that OS X solutions are 
>preferred) are appreciated.
>

The one caveat has to do with the fact that when data discs are written,
some of the bytes in a sector are used for error detection/recovery. No
such correction is done when writing audio/VCD/SVCD.

--Dennis Cohen
  iLife Bible (May/June 2003)
  iTunes, iPhoto, iMovie, and iDVD Bible
  Mac OS X Bible