AmpliFIND is an
acoustic fingerprint
An acoustic fingerprint is a condensed digital summary, a digital fingerprint, deterministically generated from an audio signal, that can be used to identify an audio sample or quickly locate similar items in a music database.
Practical u ...
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 t ...
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
Digital audio is a representation of sound recorded in, or converted into, digital signal (signal processing), digital form. In digital audio, the sound wave of the audio signal is typically encoded as numerical sampling (signal processing), ...
recordings.
One of their customers was
MetaBrainz Foundation
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 soft ...
, 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 CDDB, Compact Disc Database (CDDB), a database for ...
and
MusicBrainz Picard
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 soft ...
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
is a Japanese multinational conglomerate (company), conglomerate headquartered at Sony City in Minato, Tokyo, Japan. The Sony Group encompasses various businesses, including Sony Corporation (electronics), Sony Semiconductor Solutions (i ...
, who incorporated it into the digital music service offerings of their
Gracenote
Gracenote, Inc. is a company and service that provides music, video, and sports metadata and automatic content recognition (ACR) technologies to entertainment services and companies worldwide. Formerly CDDB ("Compact Disc Data Base"), Gracenote ...
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 developer
Software development is the process of designing and Implementation, implementing a software solution to Computer user satisfaction, satisfy a User (computing), user. The process is more encompassing than Computer programming, programming, wri ...
s write a computer program that incorporates an
open-source
Open source is source code that is made freely available for possible modification and redistribution. Products include permission to use and view the source code, design documents, or content of the product. The open source model is a decentrali ...
software library
In computing, a library is a collection of resources that can be leveraged during software development to implement a computer program. Commonly, a library consists of executable code such as compiled functions and classes, or a library can ...
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 to uniquely identify objects in computer systems. The term Globally Unique Identifier (GUID) is also used, mostly in Microsoft systems.
When generated according to the standard methods ...
standard.
The
source code
In computing, source code, or simply code or source, is a plain text computer program written in a programming language. A programmer writes the human readable source code to control the behavior of a computer.
Since a computer, at base, only ...
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 Licenses (GNU GPL or simply GPL) are a series of widely used free software licenses, or ''copyleft'' licenses, that guarantee end users the freedom to run, study, share, or modify the software. The GPL was the first ...
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 th ...
. The MusicDNS software that makes the fingerprints is