AmpliFIND (formerly MusicDNS) is an acoustic fingerprinting service and a software development kit provided by MusicIP. MusicDNS is used by MusicIP Mixer and Jaikoz. According to MusicIP, the fingerprint database contains over 22 million fingerprints as of August, 2006. MusicDNS has nothing to do with domain name system (DNS). In 2008 MusicIP folded but the assets were purchased by former MusicIP CEO Andrew Stess and a new company formed called AmpliFIND Music Services who issued a press release announcing the new company in 2009. Additionally, MusicDNS has been rebranded as AmpliFIND.
MusicDNS was extensively used by the MusicBrainz-poweredPicard tagger for audio file identification to facilitate tagging of audio files.
The fingerprinting clientlibrary that looks up and identifies audio files based on existing fingerprints is called Libofa. While the client library is open source and dual-licensed under the GPL as well as APL, the code for performing initial music analysis and submitting new fingerprints to the MusicDNS database is proprietary as the database also contains data for style similarity analysis for use in MusicIP Mixer.
The MusicDNS client library works by first generating an acoustic fingerprint of the analyzed audio file. This acoustic fingerprint is then looked up from the MusicDNS web service. If a close enough match is found to an existing fingerprint, the service returns an identifier called a PUID (short for Portable Unique IDentifier) that unambiguously identifies the matching fingerprint. These identifiers can be used by third parties (such as MusicBrainz) to relate information to the identified audio file. PUIDs are fully qualified UUIDs and do not include any acoustic information.
The MusicDNS client library implements the Open Fingerprint Architecture specifications developed by Predixis Corporation (later known as MusicIP) during 2000–2005.