Howdy,
I am not sure if what I made is new, but searching around didn't turn up anything.
In any case, after not finding anything useful, I made a new crc tool to find (in a fast way) a matching crc in a dump with some offset.
This is whipped up in a few hours, so it is still kind of rough and not idiotproof (no software of mine is idiotproof actually )
Usecase:
Finding an offset in a dump of specific audiotracks to match against the redump database.
If all tracks match with an offset to redump, it is further confirmation that the dump was successful.
This is NOT meant to actually find a drive offset or to be used in a way to matchup a dump to validate an entry!
Use the proper redump guides to dump discs! Different pressings of audio disks have factory offsets which this tool mainly detects.
README:
What:
This is a not yet idiotproof version of findcrcs.
It is to be used for finding a block of data which matches a specific crc.
How:
findcrcs <file> <size of window> <crc> [more crcs...]
File is a big file which should or may contain the searched for data.
Size of window is the size of the block of data to find.
Crc is the crc to find in the file (may be more then 1, but all will be matched on the window size).
If a match is found it will print out an md5sum of the matched block for further inspection.
For best results, add some (1MB or so) zero bytes padding around the file first.
In a future version, this might be a selectable option of this program.
Why:
Useful for finding audio offsets in disk images together with the redump.org database.
Warning:
This software is not yet idiotproof!
- It does not check arguments for validity yet (especially size of window and crc's.)
- No paddiong option yet.
if matching audiodata, you should pad the combined audiotracks with zero bytes at the start and end.
Compiling:
Use "make" on any linux/unix/bsd console nearby, or if you must, an msys or cygwin environment.
You need to use a relatively recent gcc (4.5.0+ ish I guess).
This software uses crcutil-1.0 for providing fast crc calculations.
crcutil is made by Andrew Kadatch and Bob Jenkins and can be found on http://code.google.com/p/crcutil/
Do not contact them for support on findcrcs.
The Makefile will try to pull in version 1.0 through wget if it is not supplied yet.
Also, this program makes use of the MD5 implementation of Alexander Peslyak.
This is found at http://openwall.info/wiki/people/solar/software/public-domain-source-code/md5
A small casting patch was made to support g++, this small patch is released under the same license as the original md5.c file.
Contact:
At the moment, see the redump.org forum thread where you got this.
-V.
Disclaimer:
I write my tools mainly for myself to use in a specific way.
If however someone has some issues using this, or has some suggestions, i MIGHT be able to change, fix or add things, but only if time and effort are permitting (which is not usually the case).
Source: http://winaoe.org/findcrcs-0.2.tar.gz
Win32 binary: http://winaoe.org/findcrcs-0.2-bin-win32.zip