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Problem finding out combined read+write offset

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Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 9:04 am
by hydr0x
I'm having problems with one particular PC game: Battlezone

Please note I have dumped a couple of discs with audio before so it's not the process itself I'm having problems with:

My problem is this: When I open track 2 in ISOBuster Sector View it goes to sector 128166. The determined pregap with EAC was 2s. Which means I should go to sector 128017 and then one back to 128016, right?

Well, when I try to switch to sector 128017 this error pops up.

---------------------------
The data may be unreliable !
---------------------------
It seems the CD-ROM drive is returning unexpected data.
Please verify the data after extraction.

If I select ignore I get a sector full of scrambled data. It's the same with sector 128016. Sector 128018 does not produce the error and is filled like this:

Code: Select all

LBA :128018

0000 : 41 D7 70 5E A4 38 7B 52  A3 7D B9 E1 B2 C8 75 96   A.p^.8{R.}....u.
0010 : A7 2E FA 9C 43 29 F1 DE  C4 58 53 7A BD E3 31 89   ....C)...XSz..1.
0020 : D4 66 DF 6A D8 2F 1A 9C  0B 29 C7 5E D2 B8 5D B2   .f.j./...).^..].
0030 : B9 B5 B2 F7 35 86 97 22  EE 99 8C 6A E5 EF 0B 0C   ....5.."...j....
0040 : 07 45 C2 B3 11 B5 CC 77  15 E6 8F 0A E4 07 0B 42   .E.....w.......B
0050 : 87 71 A2 A4 79 BB 62 F3  69 85 EE E3 0C 49 C5 F6   .q..y.b.i....I..
0060 : D3 06 DD C2 D9 91 9A EC  6B 0D EF 45 8C 33 25 D5   ........k..E.3%.
0070 : DB 1F 1B 48 0B 76 87 66  E2 AA C9 BF 16 F0 0E C4   ...H.v.f........
0080 : 04 53 43 7D F1 E1 84 48  63 76 A9 E6 FE CA C0 57   .SC}...Hcv.....W
0090 : 10 3E 8C 10 65 CC 2B 15  DF 4F 18 34 0A 97 47 2E   .>..e.+..O.4..G.
00A0 : B2 9C 75 A9 E7 3E CA 90  57 2C 3E 9D D0 69 9C 2E   ..u..>..W,>..i..
00B0 : E9 DC 4E D9 F4 5A C7 7B  12 A3 4D B9 F5 B2 C7 35   ..N..Z.{..M....5
00C0 : 92 97 2D AE 9D BC 69 B1  EE F4 4C 47 75 F2 A7 05   ..-...i...LGu...
00D0 : BA 83 33 21 D5 D8 5F 1A  B8 0B 32 87 55 A2 BF 39   ..3!.._...2.U..9
00E0 : B0 12 F4 0D 87 45 A2 B3  39 B5 D2 F7 1D 86 89 A2   .....E..9.......
00F0 : E6 F9 8A C2 E7 11 8A 8C  67 25 EA 9B 0F 2B 44 1F   ........g%...+D.
0100 : 73 48 25 F6 9B 06 EB 42  CF 71 94 24 6F 5B 6C 3B   sH%....B.q.$o[l;
0110 : 6D D3 6D 9D ED A9 8D BE  E5 B0 4B 34 37 57 56 BE   m.m.......K47WV.
0120 : BE F0 70 44 24 33 5B 55  FB 7F 03 60 01 E8 00 4E   ..pD$3[U...`...N
0130 : 80 34 60 17 68 0E AE 84  7C 63 61 E9 E8 4E CE B4   .4`.h...|ca..N..
0140 : 54 77 7F 66 A0 2A F8 1F  02 88 01 A6 80 7A E0 23   Tw.f.*.......z.#
0150 : 08 19 C6 8A D2 E7 1D 8A  89 A7 26 FA 9A C3 2B 11   ..........&...+.
0160 : DF 4C 58 35 FA 97 03 2E  81 DC 60 59 E8 3A CE 93   .LX5......`Y.:..
0170 : 14 6D CF 6D 94 2D AF 5D  BC 39 B1 D2 F4 5D 87 79   .m.m.-.].9...].y
0180 : A2 A2 F9 B9 82 F2 E1 85  88 63 26 A9 DA FE DB 00   .........c&.....
0190 : 5B 40 3B 70 13 64 0D EB  45 8F 73 24 25 DB 5B 1B   [@;p.d..E.s$%.[.
01A0 : 7B 4B 63 77 69 E6 AE CA  FC 57 01 FE 80 40 60 30   {Kcwi....W...@`0
01B0 : 06 87 DA 45 48 64 36 AB  56 FF 7E C0 10 60 5E C9   ...EHd6.V.~..`^.
01C0 : 0A 91 C7 2C 52 9D FD A9  81 BE E0 70 48 24 36 9B   ...,R......pH$6.
01D0 : 56 EB 7E CF 60 54 28 3F  5E 90 38 6C 12 AD CD BD   V.~.`T(?^.8l....
01E0 : 95 B1 AF 34 7C 17 61 CE  A8 54 7E BF 60 70 28 24   ...4|.a..T~.`p($
01F0 : 1E 9B 48 6B 76 AF 66 FC  2A C1 DF 10 58 0C 3A 85   ..Hkv.f.*...X.:.
0200 : D3 23 1D D9 C9 9A A4 43  4F 8C 48 54 36 BF 56 F0   .#.....CO.HT6.V.
0210 : 3E C4 08 4B 6F C9 F5 D1  87 1C 62 89 E9 A6 CE FA   >..Ko.....b.....
0220 : D4 43 1F 71 C8 24 56 9B  7E EB 60 4F 68 34 2E 97   .C.q.$V.~.`Oh4..
0230 : 5C 6E B9 EC 72 CD E5 95  8B 2F 27 5C 1A B9 CB 32   \n..r..../'\...2
0240 : D7 55 9E BF 28 70 1E A4  08 7B 46 A3 72 F9 E5 82   .U..(p...{F.r...
0250 : CB 21 97 58 6E BA AC 73  3D E5 D1 8B 40 5C DC 63   .!.Xn..s=...@\.c
0260 : B6 CF 36 D4 16 DF 4E D8  49 27 97 7B 2E A3 5C 79   ..6...N.I'.{..\y
0270 : F9 E2 C2 C9 91 96 EC 6E  CD EC 55 8D FF 25 F1 0D   .......n..U..%..
0280 : 28 62 0A DE 51 24 A3 21  B9 D8 72 DA A5 9B 3B 2B   (b..Q$.!..r...;+
0290 : 53 5F 7D F8 21 82 30 04  A8 42 A8 CC F5 45 78 0C   S_}.!.0..B...Ex.
02A0 : 22 85 D9 A3 1A F9 CB 02  D7 41 9E B0 68 74 2E A7   "........A..ht..
02B0 : 5C 7A 0C 3F 45 70 60 6E  A8 B3 D8 1C 5A 89 FB 26   \z.?Ep`n....Z..&
02C0 : C3 5A D1 FB 1C 43 49 F1  F6 C4 A8 43 63 F3 4F 72   .Z...CI....Cc.Or
02D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
02E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
02F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0300 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0310 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0320 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0330 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0340 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0350 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0360 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0370 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0380 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0390 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
03F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0400 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0410 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0420 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0430 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0440 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0450 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0460 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0470 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0480 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0490 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
04F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0500 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0510 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0520 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0530 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0540 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0550 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0560 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0570 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0580 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0590 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
05F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0600 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0610 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0620 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0630 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0640 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0650 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0660 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0670 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0680 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0690 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
06F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0700 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0710 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0720 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0730 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0740 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0750 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0760 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0770 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0780 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0790 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
07F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0800 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0810 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0820 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0830 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0840 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0850 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0860 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0870 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0880 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0890 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08A0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08B0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08C0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08D0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08E0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
08F0 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0900 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0910 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
0920 : 00 00 00 00 00 00 00 00  00 00 00 00 00 00 00 00   ................
Any idea what's up here and how I should handle this? Did EAC miscalulate the pregap? Track 02 shows a gap of 2s, all following tracks a gap of 1.98s.

Any help is appreciated Image

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 9:19 am
by Rocknroms
hydr0x wrote:Any idea what's up here and how I should handle this? Did EAC miscalulate the pregap? Track 02 shows a gap of 2s, all following tracks a gap of 1.98s.
It's very possible that EAC finds wrong pregap, it's better you submit a sub here taken with CloneCD to determine the right gaps. If gap is confirmed to be 1.74 instead of 2.00, error reported by Isobuster is because of a mastering error.

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 10:13 am
by themabus
it's just the way IsoBuster reacts to this scrambled data exceeding sector
i do get this warning on 1858 offset drive almost every time
so combined offset for this CD would be (2352+2352+$02d0)/4=1356
to confirm gap, you could check whether 128015 is last sector for data track

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 10:32 am
by F1ReB4LL
This method is unreliable for finding the offset for PC games, btw. There's a number of games with 0 disc offset, but some garbage in the 2nd track pregap, so the offset will be found wrong in this case (Jackal has dumped some of such games).

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 10:41 am
by hydr0x
@rocknroms

I don't have CloneCD Image

@themabus

Sorry, I don't get what you're saying there.
F1ReB4LL wrote:This method is unreliable for finding the offset for PC games, btw. There's a number of games with 0 disc offset, but some garbage in the 2nd track pregap, so the offset will be found wrong in this case (Jackal has dumped some of such games).
Which method? And if you mean my method (which is 1:1 what the guide says), what's the alternative?

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 10:54 am
by themabus
i mean your offset is 2 full sectors + offset from 3rd
it's described in guide
guide wrote:Note 2: It is also possible that the sector is full of data. A full sector contains 2352 bytes of data. If the first sector is full of data, browse on to the next sector(s) and make sure all data is counted until you reach the end of the data (start of zeroes).
yeah, it could be F1ReB4LL, but if persond doesn't have Plextor and is not going to open drive up
it's the only thing left

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 11:28 am
by hydr0x
themabus wrote:i mean your offset is 2 full sectors + offset from 3rd
Yeah, that's a possibility, although I'd still wonder why IsoBuster gives me that error message.

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 12:38 pm
by F1ReB4LL
hydr0x wrote:Which method? And if you mean my method (which is 1:1 what the guide says), what's the alternative?
D8 (Plextors only) or swapping with AudioCD (not supported by all the drives).

Re: Problem finding out combined read+write offset

Posted: Thu Sep 10, 2009 12:54 pm
by hydr0x
F1ReB4LL wrote:
hydr0x wrote:Which method? And if you mean my method (which is 1:1 what the guide says), what's the alternative?
D8 (Plextors only) or swapping with AudioCD (not supported by all the drives).
I see. My LG 4167B is supposed to support D8, at least some versions but I had no success with it. I don't think swapping is possible either.

So, this leaves me with which solution? Just assuming that the offset is indeed +1356?

Re: Problem finding out combined read+write offset

Posted: Fri Sep 11, 2009 1:08 am
by themabus
IsoBuster is just wired this way, to give this warning
you wouldn't get it with other programs

additionally, to be certain, you could try to descramble this garbage data
and would it match to last few data track sectors, it's pretty sure to be just usual offset manifestation then
(though from fragment you provided in 1st post it's already apperant it comes from empty Mode1 sector with LBA:128015
which is expected last data track sector)

chances of running into one of those CDs F1ReB4LL is referring to,
with this garbage actually being mastered in, are very slim
probably there aren't more than 10 of those in whole DB
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