MCN read/write not on CD-Rs?

Hi!

I wrote a program that gives me the “media catalog number” MCN of a CD. With a “commercial music CD” verything works fine on all the drives I have, they all read it correctly with my program and eg isobuster.

Nevertheless, when I burn my own CD with cdrecord and set the -mcn option, it’s different (on the same drives):
Some drives cannot read the MCN at all
Some drives report “MCN present” but give me crappy data
Some drives read everything just fine!
Of course I justed the same CD-R for all the tests.

For the tests , I burned CD-Rs and CD-RWs, on 2 different burners, all with the same outcome…

I double checked with programs like isobuster, the only difference is that it reports “not present” on drives where I get the crappy data and the “mcn present bit”

How is that? Are some drives sensitive towards “home-brew” subcode data? And if yes, is there a way to detect that so I know if a MCN is really missing or the drive has just problems writing it??

Thanks for any ideas
Maik

If your burner correctly supports arbitrary Q
subchannel writing, it should not give any
difference with a cd-da, as the constraints on
cd-r are the same (>= 1/100 subcode block).

As for reading, all programs use about the same
command (except Plextools, which use yet
another Plextor secret command). The standard
CDB you should use is therefore : 42 00 40 02 00 00 00 00 18 00 00 00.

Hi!

Well, the read command is right, no problem there.

I tryed the burning with both a Toshiba DR1312BK and a Mitsumi CR4804TE. How likely is it that both burners have the same firmware problem? With both drives, I get exactly(!) the same test results…

Has the disc been written properly? To ensure that it is not a broken disc, use cdrecord’s -raw96r option!
Exactly this is what RAW writing even of plain audio CDs is good for…

> How likely is it that both burners have the same firmware problem?

Dunno. Open your drives and check the chipsets maybe.

Originally posted by alexnoe
Has the disc been written properly? To ensure that it is not a broken disc, use cdrecord’s -raw96r option!
Exactly this is what RAW writing even of plain audio CDs is good for…

Hmmm, I did that one from the very beginning on. I don’t think cdrecord would write it at all without that option? The funny thing is that SOME readers can read it and some can not - and all the readers can read the commercial ones

It is also possible that your cdrecord does not create correct MCN data from your input.
It really should not matter whether or not you read from a pressed CD. MCN is just some Q-subchannel data, nothing more.

Do you use the latest version of cdrecord?

Version 2.0

Could you read such a not-really-working disc in clonecd, zip the sub file and upload it somewhere?

You could check the subchannel file of CloneCD manually with this tool:

Subchannel Analyzer

Unfortunately the official site isn’t up anymore. You can also download the tool here.


That one is from a pressed CD containing a MCN. The red marked number indicates that the following data is the MCN.

I don’t find any Q-mode 2 data in the file you sent me…I actually have no idea how any drive could find a MCN there :rolleyes: