Data inside pregap?

[ssjkakaroto]

Hi guys, I'm trying to dump Twinsen's Odyssey, which has the following structure

Code: Select all

FILE "Twinsen's Odyssey (Track 01).bin" BINARY
  TRACK 01 MODE1/2352
    INDEX 01 00:00:00
FILE "Twinsen's Odyssey (Track 02).bin" BINARY
  TRACK 02 AUDIO
    INDEX 00 00:00:00
    INDEX 01 00:03:00
FILE "Twinsen's Odyssey (Track 03).bin" BINARY
  TRACK 03 AUDIO
    INDEX 01 00:00:00
FILE "Twinsen's Odyssey (Track 04).bin" BINARY
  TRACK 04 AUDIO
    INDEX 01 00:00:00
FILE "Twinsen's Odyssey (Track 05).bin" BINARY
  TRACK 05 AUDIO
    INDEX 01 00:00:00
FILE "Twinsen's Odyssey (Track 06).bin" BINARY
  TRACK 06 AUDIO
    INDEX 01 00:00:00
FILE "Twinsen's Odyssey (Track 07).bin" BINARY
  TRACK 07 AUDIO
    INDEX 01 00:00:00

I used px_d8 to detect the write offset (+2) and I was able to get somewhat consistent results:
Track 1: Plextor 760A = Plextor Premium = NEC 3540A = Pioneer 115D (after using 'resize')
Track 2: Plextor 760A = Plextor Premium <> NEC 3540A = Pioneer 115D
Tracks 3-6: Plextor 760A = Plextor Premium = NEC 3540A = Pioneer 115D
Track 7: Plextor 760A = Plextor Premium <> NEC 3540A = Pioneer 115D (No overread in these two, so I'm not worried)

The problem is this:
If I try to use the Isobuster way to find the write offset, either the drives can't seek to the sector (192504 - 225) or the sector is always full of data, but if I just click on track 2 and use sector view (which leads to sector 192504) I can calculate the write offset.
So I took a look with HxD at what was at those 529200 bytes (3 second pregap) that I was removing with 'resize' and what I got was actual data, as you can see in the attachment (scroll to 2B80).

So what should I do here?

[Haldrie]

That file looks to be part of one of the files on the disc. I can see the data inside what appears to be a text or ini file (or maybe some other file that has human readable text in it). Maybe if I had a copy of more of the data I might be able to see what is going on.

[ssjkakaroto]

I'll upload the first part of track 1 and post the link tomorrow (gonna leave it uploading overnight )

[ghost]

https://redump.info/disc/9360/

Similar case. 3seconds pregap, 1 sec data, 2 secs silence.

[ssjkakaroto]

Here's the first part of the file:
http://www.megaupload.com/?d=Q8DRQC6G

[F1ReB4LL]

3.00 is correct, subs are also clear. https://redump.info/disc/3872/ and https://redump.info/disc/4032/ -- similar cases with CD32 discs, just a weird mastering, but has nothing to do with the protection. If the gap is marked as data in the subs, it should be descrambled, if as audio (common for Saturn) - should be scrambled. PerfectRip is unable to make the proper dumps of such tracks, btw, EAC also fails in most cases. You should dump the disc with d8 cdtoimg and manually extract the track from it.

PCE CD subs should be read backwards (from the last sector upto the first, then inverted) to get the proper subs and proper gaps, all the current dumps are bad. And please, don't ever give any advices, when you don't understand the case.

[ssjkakaroto]

So F1ReB4LL, can you post a little tutorial on how I extract the first track after dumping the image with cdtoimg?

[F1ReB4LL]

You need a chopfile tool or similar. bytes_to_skip = (datatrack_length + combined_offset_in_bytes); length = audiotrack_length.

For example: https://redump.info/disc/6896/ -- datatrack_lenth is 319512144, audiotrack_length is 24025680 (both should be found using the subs only), combined offset for the most plerxtors with +30 read offset would be +30+0=+30=120 bytes. So, bytes_to_skip = 120+319512144=319512264 bytes. But _only_ if the gap is marked as data in the subs. If audio - should be cut from CloneCD dump instead (and in 3 stages). Anyway, upload the subs at first.

[ssjkakaroto]

Subs (Plextor Premium): http://sharebee.com/3b7e318e
Subs (Plextor PX-760A): http://sharebee.com/fec7ea62

[F1ReB4LL]

Data track is 452240208 bytes, then 3secs of audio pregap. If there are data sectors - should be extracted in scrambled form from cdtoimg dump.