Monkey's Audio is an algorithm and

file format A file format is a Computer standard, standard way that information is encoded for storage in a computer file. It specifies how bits are used to encode information in a digital storage medium. File formats may be either proprietary format, pr ...

for

lossless Lossless compression is a class of data compression that allows the original data to be perfectly reconstructed from the compressed data with no loss of information. Lossless compression is possible because most real-world data exhibits statisti ...

audio data compression In information theory, data compression, source coding, or bit-rate reduction is the process of encoding information using fewer bits than the original representation. Any particular compression is either lossy or lossless. Lossless compression ...

. Lossless data compression does not discard data during the process of encoding, unlike

lossy compression In information technology, lossy compression or irreversible compression is the class of data compression methods that uses inexact approximations and partial data discarding to represent the content. These techniques are used to reduce data size ...

methods such as

Advanced Audio Coding Advanced Audio Coding (AAC) is an audio coding standard for lossy digital audio compression. It was developed by Dolby, AT&T, Fraunhofer and Sony, originally as part of the MPEG-2 specification but later improved under MPEG-4.ISO (2006ISO/ ...

MP3 MP3 (formally MPEG-1 Audio Layer III or MPEG-2 Audio Layer III) is a coding format for digital audio developed largely by the Fraunhofer Society in Germany under the lead of Karlheinz Brandenburg. It was designed to greatly reduce the amount ...

Vorbis Vorbis is a free and open-source software project headed by the Xiph.Org Foundation. The project produces an audio coding format and software reference encoder/decoder ( codec) for lossy audio compression, libvorbis. Vorbis is most comm ...

, and

Opus Opus (: opera Opera is a form of History of theatre#European theatre, Western theatre in which music is a fundamental component and dramatic roles are taken by Singing, singers. Such a "work" (the literal translation of the Italian word "opera ...

. Similar to other lossless audio codecs, files encoded to Monkey's Audio are typically reduced to about half of the original size, with data transfer time and storage requirements being reduced accordingly.

Comparisons

Like any lossless compression scheme, Monkey's Audio format takes up several times as much space as lossy compression formats - typically, about twice as much as a 320

kbit/s In telecommunications, data transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are mu ...

bitrate In telecommunications and computing, bit rate (bitrate or as a variable ''R'') is the number of bits that are conveyed or processed per unit of time. The bit rate is expressed in the unit bit per second (symbol: bit/s), often in conjunction ...

MP3 file. The upside is that no data is lost compared to the input file, making lossless codecs suitable for transcoding, or simply taking up approximately half as much space as raw PCM data. Relative to

FLAC FLAC (; Free Lossless Audio Codec) is an audio coding format for lossless compression of digital audio, developed by the Xiph.Org Foundation, and is also the name of the free software project producing the FLAC tools, the reference software ...

Apple Lossless Audio Codec The Apple Lossless Audio Codec (ALAC, ), also known as Apple Lossless, or Apple Lossless Encoder (ALE), is an audio coding format, and its reference audio codec implementation, developed by Apple for lossless data compression of digital music. ...

, or

WavPack WavPack is a free and open-source lossless audio compression format and application implementing the format. It is unique in the way that it supports hybrid audio compression alongside normal compression which is similar to how FLAC works. ...

, Monkey's Audio is slow to encode or decode files. While Monkey's Audio can achieve high compression ratios, the cost is a dramatic increase in requirements on the decoding end. Many older portable media players, and even older smartphones, have difficulty handling this. In comparison, most lossless codecs are asymmetric, meaning that the work done to achieve higher compression ratios, if selected by the user, slows down the encoding process, but has essentially no effect on the decoding requirements.

Licensing

On 10 August 2023, with the release of version 10.18, Monkey's Audio switched to the

Open Source Initiative The Open Source Initiative (OSI) is a California public benefit corporation "actively involved in Open Source community-building, education, and public advocacy to promote awareness and the importance of non-proprietary software". Governance The ...

-approved 3-Clause BSD Licence. Other lossless codecs such as FLAC and WavPack are also available under open source licences, and are well supported in

Linux distributions A Linux distribution, often abbreviated as distro, is an operating system that includes the Linux kernel for its kernel (operating system), kernel functionality. Although the name does not imply distribution (marketing), product distribution pe ...

and in many applications. Since all of these formats are lossless, users can transcode between formats without

generation loss Generation loss is the loss of quality between subsequent copies or transcodes of data. Anything that reduces the quality of the representation when copying, and would cause further reduction in quality on making a copy of the copy, can be con ...

Supported platforms

Officially, Monkey's Audio is available for the

Microsoft Windows Windows is a Product lining, product line of Proprietary software, proprietary graphical user interface, graphical operating systems developed and marketed by Microsoft. It is grouped into families and subfamilies that cater to particular sec ...

platform. As of version 4.02 (19 January 2009) a

DirectShow DirectShow (sometimes abbreviated as DS or DShow), codename Quartz, is a multimedia framework and API produced by Microsoft for software developers to perform various operations with media files or streams. It is the replacement for Microsoft's ea ...

filter is distributed with the installer, allowing for compatibility with most media players running on the Windows operating system. Monkey's Audio is also supported on Linux and OS X using

JRiver Media Center JRiver Media Center is a multimedia application that allows the user to play and organize various types of media on a computer running Windows, macOS, or Linux operating systems. Developed by JRiver, Inc., it is offered as shareware. JRiver Me ...

Plex Plex Inc. is an American software company that runs its namesake over-the-top ad-supported streaming television service and develops media server software that lets users stream their personal media collections to their devices. The company is ...

. A GPL-licensed version of the Monkey's Audio decoder has been independently written for Rockbox and is included in

FFmpeg FFmpeg is a free and open-source software project consisting of a suite of libraries and programs for handling video, audio, and other multimedia files and streams. At its core is the command-line ffmpeg tool itself, designed for processing vide ...

. This code also provides playback support in applications that use

GStreamer GStreamer is a Pipeline (computing), pipeline-based multimedia framework that links together a wide variety of media processing systems to complete complex workflows. For instance, GStreamer can be used to build a system that reads files in one f ...

, as well as

DeaDBeeF DeaDBeeF is an audio player software available for Windows, Linux and other Unix-like operating systems. An ad-supported Android version is available, but has not been updated since 2017. DeaDBeeF is free and open-source software, except on An ...

. A number of players and rippers support the format as well. It is also available as a port and package on

FreeBSD FreeBSD is a free-software Unix-like operating system descended from the Berkeley Software Distribution (BSD). The first version was released in 1993 developed from 386BSD, one of the first fully functional and free Unix clones on affordable ...

. Monkey's Audio files can be encoded and decoded on any platform which has a J2SE implementation, by the means of the unofficia
JMAC library
which is

free software Free software, libre software, libreware sometimes known as freedom-respecting software is computer software distributed open-source license, under terms that allow users to run the software for any purpose as well as to study, change, distribut ...

licensed under the

GNU LGPL The GNU Lesser General Public License (LGPL) is a free-software license published by the Free Software Foundation (FSF). The license allows developers and companies to use and integrate a software component released under the LGPL into their own ...

Hardware support

Monkey's Audio is supported natively on all modern

Cowon Cowon Systems, Inc. (simply known as Cowon) is a South Korean consumer electronics and software corporation. The company’s initial focus was software development and microelectronics, specializing in speech synthesis and speech recognition ...

multimedia media players, the

FiiO X Series The FiiO X Series is a line of portable music players designed and manufactured by the Chinese company FiiO Electronics Technology. Models * All models support digital audio sampled up to 192 kHz with samples of up to 24 bits. * All mode ...

and some Cayin digital audio players. On other hardware platforms, the open source firmware project

Rockbox Rockbox is a free and open-source software replacement for the OEM firmware in various forms of digital audio players (DAPs) with an original kernel. It offers an alternative to the player's operating system, in many cases without removing the o ...

supports playback of Monkey's Audio files on most of its supported targets, but many lack sufficient processing power to play them on the higher compression settings.

References

External links