[libdvdcss-devel] Unscrambling ISO file - questions

[jrvirwty]

Attached is a simple program that I wrote to unscramble DVD ISO files.  
I
hope to use this program, along with dd_rescue, to create unscrambled 
ISO
files of the latest Disney (and other) DVDs.  It appears to work in
initial "smoke testing" with a Tropic Thunder DVD that happened to be
lying around.

A have several questions:

1)  This program is *SLOW* -- 4 hours or more to unscramble the 8 GB
     Tropic Thunder ISO.  Is there any way to use the library more
     intelligently to speed it up?

     (Note that I do want to stick with a block-by-block approach,
     avoiding the file system-level shenanigans that some copy 
protection
     systems use.)

2)  The ISO file contains 4 blocks that could not be unscrambled.
     dvdcss_seek returns a "fatal error in vts css key".  I am assuming
     that this is yet another copy protection "trick", and the fact that
     the unscrambled ISO appears to work seems to bear this out.

     Have others seen this?

3)  Just to confirm, there does not appear to be any sort of error code
     or similar when a library function fails, so there's no way for my
     program to know if dvdcss_seek has encountered the "fatal error in
     vts css key" problem or some other error.  Correct?

4)  I am checking for a scrambled sectors using

       if (buffer[0x14] & 0x30)

     which I found in csstest.c.

     Is this what dvdcss_is_scrambled does?

Thanks!

-- 
Posting anonymously from the land of the DMCA, the MPAA, the RIAA, and
other A-holes
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