[mythtv-users] cdrecord-ProDVD vs. growisofs readcd bad md5sum? Slightly OT

Cory Papenfuss papenfuss at juneau.me.vt.edu
Thu Sep 9 11:35:40 EDT 2004

 	I know this might be a bit off-topic, but I ran into it while burning 
mythtv-related discs... does that make it count?  :)

 	A bit of history.  Awhile back, I'd bothered to install the binary-only 
cdrecord-ProDVD, but after it expired a few weeks ago I decided it was time to 
use a different tool.  I used to use 'dd if=/dev/cdrom of=test.iso ; md5sum 
test.iso' to verify a CD/DVD image burned had a good checksum.  Discovering 
some padding vs. non-padding vs. block boundaries, I found 'readcd' to be a 
better CD imaging tool.

 	Now that I'm using 'growisofs -dvd-compat -Z /dev/dvd=someimage.img' to 
record dvd's, it doesn't appear to be closing them properly.  At least with 
readcd, the image comes back a different size than the original image (so of 
course fails to checksum).  I think that manually reading the data back with 
'dd if=/dev/cdrom bs=2048 count=(volume size from isoinfo)' results in the 
correct image/checksum.

 	Any thoughts on this?  With the archival prospects of nuvexport and DVD 
writing imminent, this might be a good problem to work out.  I thought I'd 
figured out reading block-copy CD images once I found readcd... perhaps not.


* Cory Papenfuss							*
* Electrical Engineering candidate Ph.D. graduate student               *
* Virginia Polytechnic Institute and State University 			*

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