DiscImageCreator

[sarami]

Have you done anything with regard to the above copy protection.

No.

I have several Original releases from that publisher, which always seem to use the same protection scheme.

See this. /viewtopic.php?p=24287#p24287
I want more report about this protection.

[iR0b0t]

redump.org/disc/29657/

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Aug 18 2017 00:05:27
DiscImageCreator cd x \dic\dic_PX-760A 8 /c2 /q

Main channel is shifted by 1 sector forwards

As a note:

• subs are filled with FF
• subdump times differ by 2 seconds

DIC logs and subdump file

[iR0b0t]

redump.org/disc/32765/

Code: Select all

Aug 18 2017 00:05:27
DiscImageCreator cd x \raw\raw_PX-760A 8 /c2 /q /p /raw 

Main channel is shifted by 30 samples forwards

As a note:

• subs leadin and the first 75 sectors are filled with repeating pattern

DIC logs

[idlord]

Been trying to dump the following disc Tomb Raider II - Starring Lara Croft (USA), but been running into the following error messages:

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- [ERROR] Number of sector(s) where mode is unknown: 23259
- [ERROR] Number of sector(s) where sync is invalid: 173395
- [ERROR] Number of sector(s) where sync is zero: 12260
- [F:CreateBin][L:1310] GetLastError: 8, Not enough storage is available to process this command.

Drive used was a Plextor PX-755A and tested with DIC 20170818, 20170702, and 20160805, all have been giving me the same problems. Disc looks mint with hardly any scratches at all so I can't figure out what the problem could be.

[iR0b0t]

[F:CreateBin][L:1310] GetLastError: 8, Not enough storage is available to process this command.

This most likely means you were low on hard drive space.

[idlord]

I would assume that is what it refers to but there is more than enough space available to dump the disc, the disc is most likely bad as I'm unable to dump it with other software.

[reentrant]

I checked idlord's logs and the issue is because subchannels are corrupted.

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Listing the different protection schemes for the 8 subcoding channels...
Channel P: no protection, Channel Q: 16-bit CRC, Channels R to W:

[FONT=Arial][SIZE=2][SIZE=2][FONT=Arial][SIZE=2][FONT=Arial]To protect the data in the subcoding channels R to W, a (24, 20) Reed-Solomon error correction code is used. To improve the burst error correction capability, 8 times interleaving is added to this error-correction system. The first two symbols in a PACK have additional protection with a (4, 2) Reed-Solomon error correction code.
[/FONT][/SIZE][/SIZE][/FONT][/SIZE][/FONT]

https://club.myce.com/t/subchannel-issues/195516/9

Sarami maybe you could take the CRC16 from Sub Q and attempt to detect single bit errors by bit swapping each bit in Sub Q and checking if CRC16 matches (CRC16 could also be corrupted). cdgtool is using such approach to clean the subs for random bit errors. Could you implement this simple algorithm. That could solve issue with such rotting CDs...

[sarami]

subchannels are corrupted.

This? /viewtopic.php?p=24193#p24193

Main channel is shifted by 1 sector forwards

Uploaded test version.

Main channel is shifted by 30 samples forwards

Only this disc? or all disc you have? I tried the same option with MegaRace of 3DO but Main channel was shifted correctly with offset.

[reentrant]

subchannels are corrupted.

This? /viewtopic.php?p=24193#p24193

I'm not the original dumper, I only saw the logs. In idlord's case /s 2 didn't help. In one of the logs you output a table describing TOC with pregap and this table is computed using RMSF in SubQ, yes? The problem with the CD is that RMSF in Q channel is bad but not random. For example at some point (say LBA 90000), RMSF is changed to some low value like 00:24:24 and goes up on each frame. After some sectors it restarts again and goes up.

RMSF goes 1 frame up with each sector (it's good) but the value is shifted and it screwes everything...

[iR0b0t]

Main channel is shifted by 30 samples forwards

Only this disc? or all disc you have? I tried the same option with MegaRace of 3DO but Main channel was shifted correctly with offset.

Only this particular disc.