Difference between revisions of "FreeDB"

From MusicBrainz Wiki
Jump to navigationJump to search
(→‎MusicBrainz and FreeDB: the FreeDB 2:30 bug / 2:32 bug and last track length approximation)
(→‎MusicBrainz and FreeDB: the FreeDB 2:30 bug / 2:32 bug and last track length approximation)
 
(No difference)

Latest revision as of 13:44, 12 November 2021

FreeDB.org

FreeDB.org is another database of music metadata; it is the open version of CDDB. It was formed in response to the actions of Escient, which through its subsidiary, Gracenote, bought the rights to CDDB and restricted access to the data.

FreeDB took the last available snapshot of data, and created their own server and database. Technologically, it has remained fairly static since then, but it has amassed a very large number of releases. The quality of the data is not always the best, and there is a lot of duplication in the FreeDB database.

There is a web interface to FreeDB but most access (lookups, submissions) takes place via the FreeDB protocol (which may be embedded in HTTP, but is not really accessible via a browser). One of the advantages of this protocol is that it is practically the same as the original CDDB protocol, and could thus be used as a drop-in replacement for CDDB when Gracenote took it over.

As a result, FreeDB has taken over as the de-facto standard CD recognition database for open source music software.

GnuDB.org

In 2020, FreeDB went down. GnuDB, created in 2006 to make sure CDDB remains alive and free, has been the natural successor.

Status: The following details a deprecated feature and is being retained only for historic value.

MusicBrainz and FreeDB

MusicBrainz has many features included to import data from FreeDB. Eventually, it is hoped that MusicBrainz will take over from FreeDB as the preferred open-source free-database way to look up CDs, especially since Gracenote has since developed (and is forcing customers to switch to) CDDB2, a proprietary replacement for the original CDDB protocol.

Alert.png You must carefully examine the FreeDB data since it needs to be corrected in most cases to conform with the MusicBrainz style guidelines. Also, it is good practice to provide proof of your release in the edit notes – FreeDB is not considered as a proof, as their submissions process is not monitored.

Known issues

Disc ID computed last track length is only an approximation

This affects only the releases imported from FreeDB, with a computed disc ID.

FreeDB entries don't contain the leadout frame. They only contain the total length of the CD in seconds. When MusicBrainz used to create disc ID out of FreeDB entries, last track length had only 1 chance out of 75 to be correct (there are 75 frames per second).

last audio track before data track is 2:32 too long

Sometimes mistakenly referred to as the FreeDB 2:30 bug.

This affects only the releases imported from FreeDB Enhanced CD entries.

If the last track of a CD is a data track, the 11400 sector (152 seconds, 2:32) gap between the last audio track and this data track is included in the last audio track length.

These Enhanced CD that were added by the FreeDB automoderator, have their last audio track with an exceeding 2:32 length.

Read more in this awesome article (archived)

FreeDB MusicBrainz user

Prior to the 2004-10-10 server update, releases that met certain criteria were automatically imported from FreeDB by the MusicBrainz FreeDB bot as a method of growing the database when the MusicBrainz project was just starting out. This feature was eventually disabled after some mailing list discussion because the poor quality of raw freeDB data and the frequency of duplicated entries were felt to outweigh the benefits of additional data for MusicBrainz.

Nonetheless, even though the automatic addition of releases was disabled, certain elements of the implementation still remain in MusicBrainz. For example, the concept of adding disc IDs to existing releases was kept, although since the addition of disc IDs to a release happens automatically, without voting, the FreeDB editor is not used for these additions. Additionally, the MusicBrainz search page still retains special support for running queries that include or exclude the FreeDB editor.

Import criteria

These were the then-current import criteria before the automatic imports were disabled.

The following rules are applied in order. Processing stops at the first rule to "match":

  1. If there are fewer than 5 tracks, the release will NOT be auto-inserted.
  2. If the release's artist is either "Various" or "Various Artists", the release will NOT be auto-inserted (but the determination of the release's artist is itself an inexact science).
  3. If at least 70% of tracks contain " - ", or at least 70% of tracks contain " / ", or at least 85% of tracks contain "-", or at least 85% of tracks contain "/", then the release will NOT be auto-inserted.
  4. If the release's name or artist fail the "Style Check", the release will NOT be auto-inserted.
  5. Otherwise the release WILL be auto-inserted.

Import process

This was the then-current import process before the automatic imports were disabled.

This is in two parts:

  1. If the FreeDB release matches an existing release in MB, then the disc ID will be added to that release.
    • To "match", we look for an artist where the name matches (by name or sortname),
    • and where the release name matches exactly (case-insensitive),
    • and where the number of tracks matches.
    • If we find such an release, we attempt to add the disc ID to that release. Any errors encountered while doing so are silently ignored.
  2. Otherwise, a new release will be created, as the "FreeDB" moderator
    • All these auto-insertions are done as the "FreeDB" moderator. This is because, since the original web service request which started all this is not authenticated, we have no idea to whom we might otherwise attribute this change.
    • All releases inserted as a result of FreeDB moderations should have exactly one discid (but due to a bug some may not).

This page is referenced from the FreeDB editor profile page; if you are moving, renaming, or redirecting this page, please ask a MusicBrainz administrator to update that as well.