First of all: thanks for the hard work on this tool!

But I have a question...

I'm using cdrdao 1.1.7 on Mac OS X 10.4.7 (PPC). I let fink download and install the package.

I wanted to dump a bin/toc image from a multitrack CD (data+audio in the same session). It's a pressed CD from the fabric, but from 1995 and a bit too scratched (that's why I want to make a copy but dumped it to disk first in case of a read error).

Since I wanted to make sure it did not failed to notify me about read errors, or somehow wrongly corrected them I dumped the disc twice and compared the .bin files (.toc files were identical of course).

First of all, the MD5 didn't match. Then I used cmp to print out all different bits, which were thousands of them. Then I dumped a 3rd and 4th file, from my other CD drive as well, same story. The differences appear not in the data track, but in the audio tracks, judging from the address cmd gives for the first mismatch.

So now I've searched the forums, and saw something about 'sub channel data' errors that didn't matter for the audio data (???)... but that doesn't make me feel comfortable with this.
If I burn that image, is it identical to the original, and if so, why does the .bin files differ with sequental dumps from the same CD? If not, what can I do about it, and how can I make cdrdao stop or retry at an error, or at least notice me of an error?

I used this command:
cdrdao read-cd --device IODVDServices/2 --driver generic-mmc --read-raw --paranoia-mode 3 --datafile /Volumes/Extra/CD.bin /Volumes/Extra/CD.toc

Here's the output from cdrdao:

----------------------
Cdrdao version 1.1.7 - (C) Andreas Mueller <andreas@daneb.de>
  SCSI interface library - (C) Joerg Schilling
  Paranoia DAE library - (C) Monty

Check http://cdrdao.sourceforge.net/drives.html#dt for current driver tables.

Using libscg version 'andreas-0.5-UNIXWARE_Patch'

IODVDServices/2: _NEC DVD_RW ND-4571A   Rev: 1-02
Using driver: Generic SCSI-3/MMC - Version 2.0 (options 0x0000)

Reading toc and track data...

Track   Mode    Flags  Start                Length
------------------------------------------------------------
1      DATA    4      00:00:00(     0)     21:50:16( 98266)
2      AUDIO   0      21:50:16( 98266)     00:45:42(  3417)
3      AUDIO   0      22:35:58(101683)     04:09:58( 18733)
4      AUDIO   0      26:45:41(120416)     03:44:65( 16865)
5      AUDIO   0      30:30:31(137281)     03:40:11( 16511)
6      AUDIO   0      34:10:42(153792)     03:47:24( 17049)
7      AUDIO   0      37:57:66(170841)     03:36:00( 16200)
8      AUDIO   0      41:33:66(187041)     03:59:02( 17927)
Leadout AUDIO   0      45:32:68(204968)

PQ sub-channel reading (data track) is supported, data format is BCD.
Raw P-W sub-channel reading (data track) is supported.
PQ sub-channel reading (audio track) is supported, data format is BCD.
Raw P-W sub-channel reading (audio track) is supported.
Copying data track 1 (MODE1_RAW): start 00:00:00, length 21:48:16 to "/Volumes/Extra/CD.bin"...
Copying audio tracks 2-8: start 21:50:16, length 23:42:52 to "/Volumes/Extra/CD.bin"...
Track 2...
Track 3...
Track 4...
Track 5...
Track 6...
Track 7...
Track 8...
Found 3166 Q sub-channels with CRC errors.
Found disk catalogue number.
Reading of toc and track data finished successfully.

Thanks for reading. Any light on this phenomena would be greatly appreciated!