Data position measurement on optical discs.

[TechLord]

Hello.


I would like to know, which software/disc drive is able to extract DPM (data position measurement) information from optical disc sectors. (the rotation angle)

Is there also a software, which can burn the disc with a DPM preset/offset? (degrees/whatever).
This is more likely with DVD plus media due to the more accurate DPM, made possible by the high 817,4 kHz wobble frequency (higher than 175.6 kHz for CD-R and DVD minus.)
However, on a WORM disc (write once, read multiple), it would be hard to determine, at what angle the zero degree offset of the disc is. On a re-writable disc, the disc drive could sacrifice just one out of 1000 writing cycles for a few sectors to mark a small, optically visible track of where exactly the rotation angle offset is. A small and straight line, that goes from the inner edge perpendiculary to the outer edge. Very similar to LabelFlash.

On a damaged CD-RW, the DPM could be used for forensic data recovery.
The position of each sector should be identifyable from the DPM information extraction, and dead sectors/SCSI error sense codes should be marked in that extraction. AFFLiB should include that feature anyway.
Unreadable sectors may be visible as scratches or dust traces on the CD.

Helpful answers appreciated.
[Signature]

[TechLord]

Hello.
Just let me complete: I would prefer an open-source multi-platform software to be capable of extracting this data.
Maybe, some software can write it into the AFFLIB metadata information.

The MDF/MDS format of Alcohol120% is proprietary. Not suitable.

[aedipuss]

you might try over at the cd freaks(myce) forum. they used to have more disc centered people. https://club.myce.com/

[Cornucopia]

You are going to have some difficulty:

While the CD format is well known and even the raw sector data is exposed (thus the preponderance of sector-manipulative copy protection schemes), the DVD (of various flavors) and BD formats do not normally expose ANYTHING to standard apps except the User Data sectors (IOW, no "raw" mode).

To access raw sectors, you would need to bypass system drivers and create your own custom drivers which would expose the various sector categories, and to know how to accurately access the different levels you will need direct knowledge of the full specs (read $$ to become a corporate member and $$$ for each of the many spec documents), and then do the programming (more time & $$).

You still might not get anywhere unless you can get the optical drives to respond to calls beyond traditional mscdex-type calls. This might even entail production of custom drives. Note: many "forensic" drives ARE custom-built, hence their much higher cost.

Sounds like you are trying to reinvent the wheel.

Scott