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Re: [DONE] Database Dump Request
Posted: Wed May 01, 2019 2:18 am
by A Murder of Crows
am i able to get any forward momentum on at least the calculation for using the dats as a source?
Re: [DONE] Database Dump Request
Posted: Wed May 01, 2019 1:11 pm
by iR0b0t
A Murder of Crows wrote:am i able to get any forward momentum on at least the calculation for using the dats as a source?
Sure!
Re: [DONE] Database Dump Request
Posted: Tue May 28, 2019 2:56 pm
by Madroms
iR0b0t wrote:Yeah. This function should be similar across different scripts and is very fast in execution, this is why i chose on-the-fly calculation vs. storage. Of course it has the disadvantage that one cannot quick search for total crc32 values.
Even though it could be usable in some situations to have an extra table of "total crc32" values, like the quick search function, I am still not sure if we need that, just because one won't be able to compare the "total crc32" values of foreign images due to offset from uncorrected audio tracks.
I am also interested to see total crc32 to be stored in the db as it is an easy way to quick search this data when you make new dumps.
It is really useful to check already dumped discs with this crc32 as sometimes the serial of the disc is not already added to the db and the title is not correct (or you don't know how to write it if it is from a foreign language), and the crc is the most relevant data to search for, to know if a dump already exist.
Then you could compare crc32 of all the tracks to know if you need to submit a new dump or just a verification.
So I think it could be a good feature, and useful.
Re: [DONE] Database Dump Request
Posted: Tue May 28, 2019 3:09 pm
by A Murder of Crows
While we're here, @iRobot, i didn't see anything back from you about the calculation. I'm stuck in limbo for at least one project until we make progress with Total CRC32.
If we skip that one value and find a way to add it in later, i'd still like the rest of the data dump.
Re: [DONE] Database Dump Request
Posted: Tue May 28, 2019 3:21 pm
by iR0b0t
What do you want me to do? I thought you were going to use the dats as stated here
A Murder of Crows wrote:am i able to get any forward momentum on at least the calculation for using the dats as a source?
Re: [DONE] Database Dump Request
Posted: Tue Jun 11, 2019 9:07 am
by A Murder of Crows
I apologize, i thought my question was fairly straightforward.
I don't know how you're calculating the total CRC-32. my attempts at using various calculators to take 2 or more CRC values out of the dat/webpage result and sum them up doesn't result in the value you have as total CRC.
I'm not interested in reinventing the wheel here. i need a solution that allows me to check the site pretty much any time and see if there are changes or updates to any disc (not just saturn mind you) and if there is a change against what was last checked/calculated, obtain the total CRC again and verify it against the dumps i currently have for that title.
I'd MUCH prefer some semi static listing of Total CRC, either in the database or in the dat, but upon opening the dat, i saw the value wasn't listed there either. I don't want to factor in your on the fly calculation into my programs/scripts as doing that will add an extra potential point of failure. If you won't incorporate Total CRC as a static stat into either the dat or the webpages, i've got not choice but to do that on my own, but i still would rather be handed the code/algorithm than try to "figure it out".
And yes, the data base dump would also be super awesome since a lot of the requested data isn't in the dat file anyway.
Thank you!
Re: [DONE] Database Dump Request
Posted: Mon Jun 17, 2019 5:29 pm
by iR0b0t
A Murder of Crows wrote:I'm hoping to get a csv with the following info:
1. Title
2. Disc Number/Total Discs for title
3. System
4. Region
5. Serial
6. Build Date
7. Version
8. Edition
9. Bar Code
Dump attached.
Re: [DONE] Database Dump Request
Posted: Mon Jun 17, 2019 5:47 pm
by iR0b0t
Code: Select all
function crc32_combine($crc1, $crc2, $len2) {
$odd[0]=0xedb88320;
$row=1;
for($n=1;$n<32;$n++) {
$odd[$n]=$row;
$row<<=1;
}
gf2_matrix_square($even,$odd);
gf2_matrix_square($odd,$even);
do {
/* apply zeros operator for this bit of len2 */
gf2_matrix_square($even, $odd);
if ($len2 & 1)
$crc1=gf2_matrix_times($even, $crc1);
$len2>>=1;
/* if no more bits set, then done */
if ($len2==0)
break;
/* another iteration of the loop with odd and even swapped */
gf2_matrix_square($odd, $even);
if ($len2 & 1)
$crc1=gf2_matrix_times($odd, $crc1);
$len2>>= 1;
} while ($len2 != 0);
$crc1 ^= $crc2;
return $crc1;
}
$crc1 => pool
$crc2 => to be added to the pool
$len2 => length of the track with $crc2