Compact Disc Database

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The Compact Disc Database ( CDDB abbreviation ) is a database containing information about audio CDs on the market (artists, titles, track lengths, music genre) that can be accessed over the Internet . There are currently around 7.6 million CDs with 97.2 million titles (as of December 21, 2008). The recognition takes place with the help of a so-called hash value . Conversely, it is also possible for users to enter CD data that has not yet been recorded into the database. This information can be obtained from many computer music encoding and playback programs or directly from the CDDB website.

CDDB was developed in 1995 by Ti Kan and Steve Scherf , and in 1998 they founded the company of the same name. This was taken over by Escient and renamed Gracenote . Gracenote has held the rights to the database since then. In April 2008, it was bought by Sony Corporation of America for $ 260 million . Since the Gracenote website was relaunched in September 2010, the music search in the CDDB is no longer publicly accessible via the website.

A change in the license conditions in 2001 and the introduction of a modified protocol made free database access for commercial software and shareware impossible (the Gracenote license conditions, on the other hand, allow free access for non-commercial software; as of August 18, 2007). As an alternative, the freedb database and the MusicBrainz project were then founded. Gracenote is now used in various music playback programs (e.g. iTunes ), but in some cases this is only possible after registration.

Example hash value according to CDDB1

To generate the hash value, the table of contents ( TOC , "Table of Contents") is read out from the CD. The number and order of the tracks on the CD as well as the respective track length are relevant.

Example: 

 # Track frame offsets:
 # 150
 # 15095
 # 28530
 # 40556
 # 60479
 # 81952
 # 100762
 # 112675
 # 128656
 # 145954
 #
 # Disc length: 2258

A 4-byte hash value in the format XXYYYYZZ is formed from the values ​​read. For the above example: 6808d20a

  • The last byte (ZZ, in the example: 0a) is the number of tracks on the album.
  • The two middle bytes (YYYY, in the example: 08d2) result from the sum of the title lengths in seconds.
  • The first byte is a checksum of all values ​​in the table of contents. The sum is formed from all positions of the starting positions of all titles ( tracks ) (in seconds), modulo 255.

There are several programs on the web that can compute sample IDs for CDDB1.

ID collisions

If two CDs have the same number of tracks and the same total length, there is a 1 in 255 or greater chance that they will have the same ID.

Such a collision was cited as a possible reason for incorrect title information on the SOS Children's Villages CD.

Web links

Individual evidence

  1. ^ Sony Acquires Gracenote . drmwatch.com
  2. ↑ heise.de CDDB only accepts registered users
  3. ^ Robert Sedgewick, Wayne, Kevin: CDDB.java . Princeton University Computer Science Department. March 5, 2007. Archived from the original on February 11, 2008. Retrieved October 19, 2007.
  4. ↑ quimby.gnus.org
  5. ↑ heise.de