ECC + TOC in CD/DVD issue

vbimport

#1

Hi,
From what i traced over the net, the user can read the TOC via MMC command and not directly. What i fail to understand who is the first module which “encodes it”, prior to the write process or in other words:
Who is the first module is in the burning “chain” that got the knowledge regarding how the TOC “looks” .

Does the firmware of the burner device encodes and then write it in the PMA section (Q subcode) part of the "finalizing the disc”? Or does application that communicates with the burning device (e.g Nero etc )?

Same issue with the ECC/EDC ,who is the first module that calculates them ( firmware or application like Nero)?

I hope I explained myself clear as I am not native English speaker.

Thanks
:bow:


#2

The MMC defines 4 recording methods:

[ul]
[li]Packet/incrememental
[/li][li]TAO (Track-At-Once)
[/li][li]SAO (Session-At-Once)
[/li][li]Raw
[/li][/ul]

Also affecting the TOC are definitions:

[ul]
[li]Multi-session Field Definition
[/li][li]Data Block Type Codes
[/li][/ul]

For more info do a search in MMC on “write parameters mode page”.

[U]This is just a rough answer for CD recording:[/U]

TAO records only a track at a time, so it is clear what the toc entry would be and is generated by the drive.

SAO needs a cuesheet to be sent before recording, and that is effectively the TOC, so the drive simply decodes that to generate raw Q.

Raw with data block type codes 1, 2, 3, nothing is generated, the burning software needs to send data for whole of TOC leadin, leadout, and EDC/ECC.

For EDC/ECC being generated, that depends on the “Data Block Type Codes”. Values 0, 1, 2, 3 are codes that the drive won’t generate EDC/ECC, but it seems only raw recording mode is compatible with those. For all other values the EDC/ECC is generated by the drive.

PMA (Program Memory Area) is always managed by the drive.

I’m not 100% on PMA, but isn’t that only used for multi-session or packet/incremental recordings?

If so, then it would only be used when “Multi-session Field Definition” is set to multisession or recording mode is packet/incremental. Also in raw recording mode PMA would never be used because that field is ignored and it is DAO (Disc-At-Once) recording.

[U]For DVD recording:[/U]

Burning is only allowed 2048 bytes per sector, so ECC is always generated by the drive. The leadin stuff is also managed by the drive.


#3

Hi Truman,
Once again thanks! For the ultra-fast reply. I will review again MMC-5 draft i got.
It looks like using your reply; I will be able to finish the puzzle :wink:


#4

Hi Truman ,
Some question regarding the ECC issue. Assuming that each small frame got ECC ( C2 ECC & C1 ECC each 4 bytes size), in this case and please correct me if I am wrong , only the CD writer adds the ECC at the small frames level ?

Thanks.


#5

[QUOTE=OSTA_DUDE;2470561]Hi Truman ,
Assuming that each small frame got ECC ( C2 ECC & C1 ECC each 4 bytes size), in this case and please correct me if I am wrong , only the CD writer adds the ECC at the small frames level ?[/QUOTE]Hmm, the ECC in previous post is not C1/C2, ECC is the P & Q error correction at the higher level; inside the sector of CD-ROM sectors, and the writer will generate these depending on the settings. The C1 and C2 error correction at the lower level is always generated by the writer internally, the burning software has no control over it.

ECC is part at the end of the 2352 bytes of a CD-ROM sector:
P = 172 bytes
Q = 104 bytes

I guess you could call this level 3 error correction. For more info search for “Error correction encoding by RSPC” in:
http://www.ecma-international.org/publications/standards/Ecma-130.htm


#6

[QUOTE=Truman;2470564]Hmm, the ECC in previous post is not C1/C2, ECC is the P & Q error correction at the higher level; inside the sector of CD-ROM sectors, and the writer will generate these depending on the settings. The C1 and C2 error correction at the lower level is always generated by the writer internally, the burning software has no control over it.

ECC is part at the end of the 2352 bytes of a CD-ROM sector:
P = 172 bytes
Q = 104 bytes

I guess you could call this level 3 error correction. For more info search for “Error correction encoding by RSPC” in:
http://www.ecma-international.org/publications/standards/Ecma-130.htm[/QUOTE]
Hi,
What amazes me is why each standard “speaks” its own language.
MMC-5 refers to F3-Frames as Small Frames you need to have Diploma at forensics to make all the connections.

Anyway Truman your help is priceless:bow::flower: