MusicBrainz has used several audio fingerprinting systems over its lifetime.
All of them (so far) work in essentially the same way. It is generally a two-step process of submission and lookup. First, the raw audio is used to create a fingerprint, which is then submitted to a third-party server. This server analyzes the fingerprint, compares it to other fingerprints, and decides whether it is sufficiently different from known fingerprints as to issue a new ID.
Once this step is done, a fingerprint can be calculated for any file and this can be used to look up the corresponding ID.
This ID is associated with a given track (pre-NGS) or recording (post-NGS), and metadata can be gathered from there.MusicBrainz has used several audio fingerprinting systems over its lifetime.
All of them (so far) work in essentially the same way. It is generally a two-step process of submission and lookup. First, the raw audio is used to create a fingerprint, which is then submitted to a third-party server. This server analyzes the fingerprint, compares it to other fingerprints, and decides whether it is sufficiently different from known fingerprints as to issue a new ID.
Once this step is done, a fingerprint can be calculated for any file and this can be used to look up the corresponding ID.
This ID is associated with a given track (pre-NGS) or recording (post-NGS), and metadata can be gathered from there.