Data CD error checking question

[Guest]

Hi

I am doing some software to read ISO9660 data CD files on an
an embedded system.

The raw CD sector has 2358 bytes composed of 2048 bytes user
data, EDC and parity data, sync header and etc. My question
is does my software need to check the EDC and parity for
data corruption, every time a CD sector is read back? My
concern is, if it is a dusty CD and I do not check, then
the CD reading may be a disaster as the directory/file
information may be corrupted. If you think I should, can
you tell me where I can find any source code to check the
EDC and parity in a CD sector.

Alvin

[Andy McFadden]

In comp.publish.cdrom.hardware dairy1234id@yahoo.com wrote: I am doing some software to read ISO9660 data CD files on an an embedded system. The raw CD sector has 2358 bytes composed of 2048 bytes user data, EDC and parity data, sync header and etc. My question is does my software need to check the EDC and parity for data corruption, every time a CD sector is read back? My concern is, if it is a dusty CD and I do not check, then the CD reading may be a disaster as the directory/file information may be corrupted. If you think I should, can you tell me where I can find any source code to check the EDC and parity in a CD sector.

The raw sector should have 2352 bytes.

From section (2-43-6) in the FAQ:

If you want source code for the CIRC, RSPC, EDC, and scramble functions,
look for Heiko Eissfeldt's edc_ecc.c (and related files). The code is
part of Mode2CDMaker, CDRDAO, and possibly others.

I would recommend you find an API for doing "cooked" reads unless you
really need to do them in the raw.

--
Send mail to fadden@fadden.com (Andy McFadden) - http://www.fadden.com/
CD-Recordable FAQ - http://www.cdrfaq.org/
CiderPress Apple II archive utility for Windows - http://www.faddensoft.com/
Fight Internet Spam - http://spam.abuse.net/spam/ & http://spamcop.net/

[Guest]

Andy McFadden <fadden@fadden.com> wrote in message news:<RBCbc.3606$Fo4.38851@typhoon.sonic.net>... In comp.publish.cdrom.hardware dairy1234id@yahoo.com wrote: I am doing some software to read ISO9660 data CD files on an an embedded system. The raw CD sector has 2358 bytes composed of 2048 bytes user data, EDC and parity data, sync header and etc. My question is does my software need to check the EDC and parity for data corruption, every time a CD sector is read back? My concern is, if it is a dusty CD and I do not check, then the CD reading may be a disaster as the directory/file information may be corrupted. If you think I should, can you tell me where I can find any source code to check the EDC and parity in a CD sector. The raw sector should have 2352 bytes. From section (2-43-6) in the FAQ: If you want source code for the CIRC, RSPC, EDC, and scramble functions, look for Heiko Eissfeldt's edc_ecc.c (and related files). The code is part of Mode2CDMaker, CDRDAO, and possibly others. I would recommend you find an API for doing "cooked" reads unless you really need to do them in the raw.

Thanks.