AmpliFIND is an
acoustic fingerprint
An acoustic fingerprint is a condensed digital summary, a fingerprint, deterministically generated from an audio signal, that can be used to identify an audio sample or quickly locate similar items in an audio database.
Practical uses of aco ...
ing service and a
software development kit
A software development kit (SDK) is a collection of software development tools in one installable package. They facilitate the creation of applications by having a compiler, debugger and sometimes a software framework. They are normally specific ...
developed by the US company MusicIP.
MusicIP first marketed their fingerprinting algorithm and service as MusicDNS. In 2006, MusicIP reported that the MusicDNS database had more than 22 million fingerprints of
digital audio recordings.
One of their customers was
MetaBrainz Foundation
The MetaBrainz Foundation is a 501(c)(3) tax-exempt non-profit based in San Luis Obispo, California that operates the MusicBrainz
MusicBrainz is a MetaBrainz project that aims to create a collaborative music database that is similar to the f ...
, a non-profit company that used MusicDNS in their
MusicBrainz
MusicBrainz is a MetaBrainz project that aims to create a collaborative music database that is similar to the freedb project. MusicBrainz was founded in response to the restrictions placed on the Compact Disc Database (CDDB), a database for so ...
and
MusicBrainz Picard
MusicBrainz Picard is a free and open-source software application for identifying, tagging, and organising digital audio recordings. It was developed by the MetaBrainz Foundation, a non-profit company that also operates the MusicBrainz databa ...
software products.
Even so, MusicIP dissolved in 2008. The company's CEO, Andrew Stess, bought the rights to MusicDNS, renamed the software to ''AmpliFIND'', and started a new company called AmpliFIND Music Services.
In 2011, Stess sold AmpliFIND to
Sony
, commonly stylized as SONY, is a Japanese multinational conglomerate corporation headquartered in Minato, Tokyo, Japan. As a major technology company, it operates as one of the world's largest manufacturers of consumer and professiona ...
, who incorporated it into the digital music service offerings of their
Gracenote
Gracenote, Inc. is a company owned by Nielsen Holdings that provides music, video and sports metadata and automatic content recognition (ACR) technologies to entertainment services and companies, worldwide. Formerly CDDB ("Compact Disc Data Ba ...
division.
Tribune Media
Tribune Media Company, also known as Tribune Company, was an American multimedia conglomerate headquartered in Chicago, Illinois.
Through Tribune Broadcasting, Tribune Media was one of the largest television broadcasting companies, owning 39 ...
subsequently purchased Gracenote, including the MusicDNS software.
How MusicDNS identifies a recording
To use the MusicDNS service,
software developers write a computer program that incorporates an
open-source software library
In computer science, a library is a collection of non-volatile resources used by computer programs, often for software development. These may include configuration data, documentation, help data, message templates, pre-written code and sub ...
called LibOFA.
This library implements the Open Fingerprint Architecture,
a specification developed during 2000–05 by MusicIP's previous incarnation, Predixis Corporation.
Through LibOFA, a program can fingerprint a recording, and submit the fingerprint to MusicDNS via the Internet. MusicDNS attempts to match the submission to fingerprints in its database. If the MusicDNS service finds an approximate match, it returns a code called a ''PUID'' (Portable Unique Identifier). This code does not contain any acoustic information; rather, it enables a computer program to retrieve identifying information (such as the song title and recording artist) from the MusicDNS database. The PUID code is a short, alphanumeric string based on the
universally unique identifier
A universally unique identifier (UUID) is a 128-bit label used for information in computer systems. The term globally unique identifier (GUID) is also used.
When generated according to the standard methods, UUIDs are, for practical purposes, u ...
standard.
The
source code
In computing, source code, or simply code, is any collection of code, with or without comments, written using a human-readable programming language, usually as plain text. The source code of a program is specially designed to facilitate the w ...
for LibOFA is distributed under a
dual license
Multi-licensing is the practice of distributing software under two or more different sets of terms and conditions. This may mean multiple different software licenses or sets of licenses. Prefixes may be used to indicate the number of licenses ...
: the
GNU General Public License
The GNU General Public License (GNU GPL or simply GPL) is a series of widely used free software licenses that guarantee end users the four freedoms to run, study, share, and modify the software. The license was the first copyleft for general ...
and the
Adaptive Public License
The Adaptive Public License (APL) is an open-source license from the University of Victoria. It is a weak copyleft, adaptable template license that has been approved by the Open Source Initiative.
The Initial Contributor for a project sets up the ...
. The MusicDNS software that makes the fingerprints is