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Doctor Q

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Original poster
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Sep 19, 2002
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Los Angeles
I was just ripping the CD "Urban Hymns" by The Verve with iTunes v4.6 and I got this message. It's easy enough to pick the right one, but why did I get the prompt?

Does it mean that somebody goofed when registering these CDs? All three or four of them?
 

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Well, besides the fact that someone may have goofed on all four albums, there is one other, although far less likely explanation. Correct me if I'm wrong, but doesn't iTunes just check the length and number of all the tracks on the CD to determine what CD it is? If so, then perhaps all four of these CDs have the exact same number of tracks with the exact same length. I know it doesn't seem likely, but I'm pretty sure all four have 13 tracks...
 
wordmunger: No, not the same CD. Different artists, different albums, even different genres (The Verve is Alternative; Robbie Williams is Pop).

Macaddicttt: That's an interesting theory, so I checked. Sing When You're Winning has only has 12 tracks, while "Urban Hymns" has 13. Both are in the iTunes Music Store, while "My Private War" is not. Side note: In the iTunes Music Store, Urban Hymns is only a partial album, with 10 of the 13 tracks.

So we haven't yet solved my first mystery. And we can add another question to that one: Why did "My Private War" show up twice in the dialog box?
 
I found this little tid bit on how the system works.

The CDDB Disc Recogintion Service works like this:
1 - A CD is placed in the CD-ROM drive of your PC and start the Add a CD process.
2 - The software generates an ID number based on the track number and track lengths which is 99.9% unique.
3 - Using the created ID number the software searches the CDDB database for a matching number.
4 - If found the CD information is brought into the program and entered into your database.
 
Doctor Q said:
Macaddicttt: That's an interesting theory, so I checked. Sing When You're Winning has only has 12 tracks, while "Urban Hymns" has 13. Both are in the iTunes Music Store, while "My Private War" is not. Side note: In the iTunes Music Store, Urban Hymns is only a partial album, with 10 of the 13 tracks.

So we haven't yet solved my first mystery. And we can add another question to that one: Why did "My Private War" show up twice in the dialog box?

I did a search on Amazon and CDNow and found an special edition import of the Robbie Williams album with 13 tracks. And "My Private War" also has 13 tracks. So Macaddict's theory is most likely correct.
 
I once burned a CD of only 2 tracks, iTunes recognised it as a pavarotti album but only the first tracks of it. Think it's more than number of tracks, or track length in goes off.
 
It sounds like the system is essentially a hashing function that sometimes has collisions. The ID number it uses must be a compressed form of the track count and individual track lengths since these CDs don't have the same track lengths; they don't match up at all. But if collisions are that rare, I must have been really "lucky" to get not one but two false hits!
 
Welcome to the world of "WTF?, CDDB"

The problem you're encountering is due to the quality of the data (or lack thereof) in the CDDB. Notice how "My Private War" is listed twice. Why should that be?
 
dejo said:
The problem you're encountering is due to the quality of the data (or lack thereof) in the CDDB. Notice how "My Private War" is listed twice. Why should that be?

Well, "My Private War" could be listed twice because two people submitted the same album with one tiny difference. For example, one could have submitted "Alternative" for the genre, while the other submitted "Alternative Rock." If you could see the two side-by-side, I'm sure there would be some differences that just comes up by chance because two people submitted slightly different things.
 
Macaddicttt said:
Well, "My Private War" could be listed twice because two people submitted the same album with one tiny difference. For example, one could have submitted "Alternative" for the genre, while the other submitted "Alternative Rock." If you could see the two side-by-side, I'm sure there would be some differences that just comes up by chance because two people submitted slightly different things.

Do you believe that CDDB includes in their database anything that is submitted?
 
CDDB is great, but sometimes is annoying. Like, say, when you insert a burned CD and iTunes chooses to recognze it as some forgein artist that I've never heard of...but now all 20 tracks need renaming, including Name, Album, Artist...etc.

But when it is a standard CD it is generally right.
 
crazzyeddie said:
CDDB is a great thing. The amount of time that it saves you in incredible, especially when you're ripping multiple CDs.

CDDB is a great concept. The problem I have with them is that the quality control of the data in their system is not great (good, maybe) and seems to be getting worse as time goes on.
 
dejo said:
Do you believe that CDDB includes in their database anything that is submitted?

They must. I put together a CD of random songs for my wedding and uploaded the track info via iTunes. Now, anyone who has the CD can drop it into iTunes and it will pull the track info. I don't think that CDDB is paying someone to check everything that gets submitted. That being said, I'm sure you can submit a comment to them and notify them of a wrong CD.

-- Ben
 
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