View Full Version : Mode2XA ISO files

19.10.2003, 21:55
Operating System: Win2K
Burning Software: Sony CD Extreme
Anti-virus Software: eTrust EZAntivirus
DAEMON Tools Version: 3.41

I occasionally get given data cd's that are burned as Mode2 rather than Mode1 disks, and ripping the data off with CdExtreme and mounting the ISO with DT works fine with Mode1 disks, but fails everytime with mode2 disks. Filedisk also can't mount Mode2 images (though they do burn fine back to cdrw media and are readable)

Will (or does) DT ever support Mode 2 ISO images?


19.10.2003, 23:03
Afaik, .iso supports 2048 a single mode1 data track.

20.10.2003, 11:50
Well, SonyCdExtreme, (and from memory Nero and EasyCdCreator) can all dump and successfully burn mode2 ISO files and IsoBuster has no trouble reading them.... So I don't think it's a limit in the ISO format, also, according to the cdrfaq, Mode 2 has 2336 byte 'sectors' so I assume it doesn't have some of the error correction mode 1 has

But I take it from your response DT doesn't (and won't?) support mode2 ISO's? I've been browsing around and can't find a spec for the .ISO format (yet)
but I'll keep looking, I hoped for some links off the ISOBuster page, or the CdrFaq, but so far haven't found anything.

From the CDRFaq

The mode byte determines what the remaining 2336 bytes in the sector looks like:

Mode 0: null data; serves no practical purpose for CD recording
Mode 1: the typical CD-ROM layout 2048 bytes of user data
4 bytes of EDC (Error Detection Code, a 32-bit CRC)
8 bytes of reserved space, set to zeros
172 bytes of "P" parity
104 bytes of "Q" parity

Mode 2: 2336 bytes of user data, usually used for CD-ROM/XA (see below)

The Mode 1 CD-ROM ECC is independent of and in addition to the CIRC encoding. It uses a Reed-Solomon Product Code (RSPC) to achieve a combined error rate of 1 error per 1e15 (quadrillion) bits. CD-ROM/XA (eXtended Architecture) Mode 2 extends the definition of a Mode 2 CD-ROM. Form 1 looks like a slight rearrangement of a Mode 1 sector, with the 8 bytes of space moved ahead of the user data and filled with a sub-header. Form 2, intended for compressed audio/video data, has the 8-byte sub-header, 2324 bytes of data, and an optional 4-byte EDC code. The sub-header contains some channel and data type flags.
A CD session must be written in a single mode, but the XA spec allows the form to change. Using CD-ROM/XA Mode 2 allows you to choose between extended error correction and increased data capacity, and also change your mind several times in a single track.

20.10.2003, 14:40
Can you email me (andareed@daemon-tools.cc) the first 10 sectors (23520 bytes) of such an image? I think your best option is to create a wrapper cue file, and specify mode2 here.