Monkey's Audio
Encyclopedia
Monkey's Audio is a file format
for audio data compression. Being a lossless
format, Monkey's Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC
, MP3
, Vorbis
and Musepack
.
Data file compression is employed in order to reduce bandwidth, file transfer time, and/or storage requirements. A digital recording (such as a CD) encoded to the Monkey's Audio format can be decompressed into an identical copy of the original audio data. As with the FLAC
and Apple Lossless
format, files encoded to Monkey's Audio are typically reduced to about half of the original size, with data transfer rates and bandwidth requirements being reduced accordingly.
Monkey's Audio's advantages are slightly better compression rates compared to FLAC
and WavPack
, as well as multithreading
/multicore support. Monkey's Audio main drawbacks are the fact that it employs a symmetric algorithm, meaning the decoding takes comparable resources to encoding, which makes it unsuitable for all but the fastest portable players (via Rockbox
firmware), and that it has limited support on software platforms other than Windows; on other platforms only decoding is officially supported by third-party programs. Although the original source code
is freely available, the license is not considered to be an open source
one. A GPL version of the decoder has been independently written for rockbox and then included in ffmpeg
.
Monkey's Audio files use the filename extension
.ape for audio, and .apl for track metadata.
, MP3
and Vorbis
. A Monkey's Audio file is 3–5 times as large as a 192 kbit/s bitrate MP3.
The latest version of Monkey's Audio, Version 4.10, was released on 2011-04-16. The Shorten
format, popular with live taping enthusiasts for years, is no longer in development, but is still in use on some sites such as etree
. FLAC has an active development community that continues to refine the format. Because Monkey's Audio is relatively slow when encoding or decoding files (what FLAC accomplishes in several seconds can take a minute or more with Monkey's Audio) FLAC has largely eclipsed it as the preferred format for commercial distribution of lossless audio.
Although Monkey's Audio is distributed as freeware
, the source code includes license terms that prevent most Linux distribution
s and other free software
projects from including it. In contrast, FLAC has only open source licenses, so it comes pre-installed with most Linux distributions, is preferred by Linux users, and enjoys broad support in applications.
platform, though discussion on the Monkey's Audio website has hinted at future support for Linux
and Mac OS
. A developer using the moniker SuperMMX released an unofficial port in early 2005, which also includes plugins to allow playback using Beep Media Player
and the XMMS
audio player. This port was originally developed for Linux but, since version 3.99 update 4 build 4, it has included support for Mac OS X
as well as Linux on the PowerPC
and SPARC
architectures. The port has not been updated since late 2006, but there are updates maintained by the community.
The multi-platform ffmpeg
supports decoding Monkey's Audio files since version 0.5. A GStreamer
plug-in is also available, but only for the older 0.8.x version. A number of OS X players and rippers support the format as well.
While the license text claims to permit using the official Monkey's Audio codec in GPL projects, several Linux distribution
maintainers have found the license to be contradictory. It does not permit redistribution or modification, and thus is not considered open source
or free software
.
Monkey's Audio files can be encoded and decoded on any platform which has a J2SE
implementation, by the means of the unofficial JMAC library, which is Free software
licensed under the GNU LGPL
.
On hardware platforms, the open source jukebox firmware project Rockbox
supports playback of Monkey's Audio-encoded files on most of its supported targets, but many lack sufficient processing power to play the files back in real time on any but the lowest compression settings. In addition, there are a few MP3 players that natively support Monkey's Audio, including the Cowon D2 and the Iriver Spinn. As of version 4.02 (19 January 2009) a directshow filter is distributed with the installer, allowing for compatibility with most mp3 players.
File format
A file format is a particular way that information is encoded for storage in a computer file.Since a disk drive, or indeed any computer storage, can store only bits, the computer must have some way of converting information to 0s and 1s and vice-versa. There are different kinds of formats for...
for audio data compression. Being a lossless
Lossless data compression
Lossless data compression is a class of data compression algorithms that allows the exact original data to be reconstructed from the compressed data. The term lossless is in contrast to lossy data compression, which only allows an approximation of the original data to be reconstructed, in exchange...
format, Monkey's Audio does not discard data during the process of encoding, unlike lossy compression methods such as AAC
Advanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
, MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
, Vorbis
Vorbis
Vorbis is a free software / open source project headed by the Xiph.Org Foundation . The project produces an audio format specification and software implementation for lossy audio compression...
and Musepack
Musepack
Musepack or MPC is an open source lossy audio codec, specifically optimized for transparent compression of stereo audio at bitrates of 160–180 kbit/s...
.
Data file compression is employed in order to reduce bandwidth, file transfer time, and/or storage requirements. A digital recording (such as a CD) encoded to the Monkey's Audio format can be decompressed into an identical copy of the original audio data. As with the FLAC
FLAC
FLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
and Apple Lossless
Apple Lossless
Apple Lossless Apple Lossless Apple Lossless (also known as ALAC (Apple Lossless Audio Codec), or ALE (Apple Lossless Encoder) is an audio codec developed by Apple Inc. for lossless data compression of digital music. After initially being proprietary for many years, in late 2011 Apple open sourced...
format, files encoded to Monkey's Audio are typically reduced to about half of the original size, with data transfer rates and bandwidth requirements being reduced accordingly.
Monkey's Audio's advantages are slightly better compression rates compared to FLAC
FLAC
FLAC is a codec which allows digital audio to be losslessly compressed such that file size is reduced without any information being lost...
and WavPack
WavPack
WavPack is a free, open source lossless audio compression format developed by David Bryant.-Features:WavPack compression can compress 8-, 16-, 24-, and 32-bit fixed-point, and 32-bit floating point audio files in the .WAV file format. It also supports surround sound streams and high frequency...
, as well as multithreading
Thread (computer science)
In computer science, a thread of execution is the smallest unit of processing that can be scheduled by an operating system. The implementation of threads and processes differs from one operating system to another, but in most cases, a thread is contained inside a process...
/multicore support. Monkey's Audio main drawbacks are the fact that it employs a symmetric algorithm, meaning the decoding takes comparable resources to encoding, which makes it unsuitable for all but the fastest portable players (via Rockbox
Rockbox
Rockbox is a replacement for the standard firmware in various forms of digital audio players . It offers an alternative to the player's operating system, in many cases without removing the original firmware, which provides a plug-in architecture for adding various enhancements and functions...
firmware), and that it has limited support on software platforms other than Windows; on other platforms only decoding is officially supported by third-party programs. Although the original source code
Source code
In computer science, source code is text written using the format and syntax of the programming language that it is being written in. Such a language is specially designed to facilitate the work of computer programmers, who specify the actions to be performed by a computer mostly by writing source...
is freely available, the license is not considered to be an open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
one. A GPL version of the decoder has been independently written for rockbox and then included in ffmpeg
FFmpeg
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
.
Monkey's Audio files use the filename extension
Filename extension
A filename extension is a suffix to the name of a computer file applied to indicate the encoding of its contents or usage....
.ape for audio, and .apl for track metadata.
Comparisons
Like any lossless compression scheme, Monkey's Audio format takes up several times as much space as lossy compression formats like AACAdvanced Audio Coding
Advanced Audio Coding is a standardized, lossy compression and encoding scheme for digital audio. Designed to be the successor of the MP3 format, AAC generally achieves better sound quality than MP3 at similar bit rates....
, MP3
MP3
MPEG-1 or MPEG-2 Audio Layer III, more commonly referred to as MP3, is a patented digital audio encoding format using a form of lossy data compression...
and Vorbis
Vorbis
Vorbis is a free software / open source project headed by the Xiph.Org Foundation . The project produces an audio format specification and software implementation for lossy audio compression...
. A Monkey's Audio file is 3–5 times as large as a 192 kbit/s bitrate MP3.
The latest version of Monkey's Audio, Version 4.10, was released on 2011-04-16. The Shorten
Shorten
Shorten is a file format used for compressing audio data. It is a form of data compression of files and is used to losslessly compress CD-quality audio files . Shorten is no longer developed and more recent lossless audio codecs such as FLAC, Monkey's Audio , TTA, and WavPack have become more...
format, popular with live taping enthusiasts for years, is no longer in development, but is still in use on some sites such as etree
Etree
etree, or electronic tree, is a music community created in the summer of 1998 for the online trading of live concerts. etree pioneered the standards for distributing lossless audio on the net and only permits its users to distribute the music of artists that allow the free taping and trading of...
. FLAC has an active development community that continues to refine the format. Because Monkey's Audio is relatively slow when encoding or decoding files (what FLAC accomplishes in several seconds can take a minute or more with Monkey's Audio) FLAC has largely eclipsed it as the preferred format for commercial distribution of lossless audio.
Although Monkey's Audio is distributed as freeware
Freeware
Freeware is computer software that is available for use at no cost or for an optional fee, but usually with one or more restricted usage rights. Freeware is in contrast to commercial software, which is typically sold for profit, but might be distributed for a business or commercial purpose in the...
, the source code includes license terms that prevent most Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...
s and other free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
projects from including it. In contrast, FLAC has only open source licenses, so it comes pre-installed with most Linux distributions, is preferred by Linux users, and enjoys broad support in applications.
Supported platforms
Officially, Monkey's Audio is available only for the Microsoft WindowsMicrosoft Windows
Microsoft Windows is a series of operating systems produced by Microsoft.Microsoft introduced an operating environment named Windows on November 20, 1985 as an add-on to MS-DOS in response to the growing interest in graphical user interfaces . Microsoft Windows came to dominate the world's personal...
platform, though discussion on the Monkey's Audio website has hinted at future support for Linux
Linux
Linux is a Unix-like computer operating system assembled under the model of free and open source software development and distribution. The defining component of any Linux system is the Linux kernel, an operating system kernel first released October 5, 1991 by Linus Torvalds...
and Mac OS
Mac OS
Mac OS is a series of graphical user interface-based operating systems developed by Apple Inc. for their Macintosh line of computer systems. The Macintosh user experience is credited with popularizing the graphical user interface...
. A developer using the moniker SuperMMX released an unofficial port in early 2005, which also includes plugins to allow playback using Beep Media Player
Beep Media Player
The Beep Media Player was a free audio player, based on the XMMS multimedia player. The lead developer was Milosz “deadchip” Derezynski. The BMP is mainly a port of XMMS to GTK+ 2 and, as such, integrates better with the look and feel of more recent versions of GNOME, Xfce, and, if using the...
and the XMMS
XMMS
The X Multimedia System is a free audio player for Unix-like systems.-History:XMMS was originally written as X11Amp by Peter and Mikael Alm in November 1997. The player was made to resemble Winamp, which was first released in May that year. As such, XMMS has supported Winamp 2 "classic" skins...
audio player. This port was originally developed for Linux but, since version 3.99 update 4 build 4, it has included support for Mac OS X
Mac OS X
Mac OS X is a series of Unix-based operating systems and graphical user interfaces developed, marketed, and sold by Apple Inc. Since 2002, has been included with all new Macintosh computer systems...
as well as Linux on the PowerPC
PowerPC
PowerPC is a RISC architecture created by the 1991 Apple–IBM–Motorola alliance, known as AIM...
and SPARC
SPARC
SPARC is a RISC instruction set architecture developed by Sun Microsystems and introduced in mid-1987....
architectures. The port has not been updated since late 2006, but there are updates maintained by the community.
The multi-platform ffmpeg
FFmpeg
FFmpeg is a free software project that produces libraries and programs for handling multimedia data. The most notable parts of FFmpeg are libavcodec, an audio/video codec library used by several other projects, libavformat, an audio/video container mux and demux library, and the ffmpeg command line...
supports decoding Monkey's Audio files since version 0.5. A GStreamer
GStreamer
GStreamer is a pipeline-based multimedia framework written in the C programming language with the type system based on GObject.GStreamer allows a programmer to create a variety of media-handling components, including simple audio playback, audio and video playback, recording, streaming and editing...
plug-in is also available, but only for the older 0.8.x version. A number of OS X players and rippers support the format as well.
While the license text claims to permit using the official Monkey's Audio codec in GPL projects, several Linux distribution
Linux distribution
A Linux distribution is a member of the family of Unix-like operating systems built on top of the Linux kernel. Such distributions are operating systems including a large collection of software applications such as word processors, spreadsheets, media players, and database applications...
maintainers have found the license to be contradictory. It does not permit redistribution or modification, and thus is not considered open source
Open source
The term open source describes practices in production and development that promote access to the end product's source materials. Some consider open source a philosophy, others consider it a pragmatic methodology...
or free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
.
Monkey's Audio files can be encoded and decoded on any platform which has a J2SE
Java Platform, Standard Edition
Java Platform, Standard Edition or Java SE is a widely used platform for programming in the Java language. It is the Java Platform used to deploy portable applications for general use...
implementation, by the means of the unofficial JMAC library, which is Free software
Free software
Free software, software libre or libre software is software that can be used, studied, and modified without restriction, and which can be copied and redistributed in modified or unmodified form either without restriction, or with restrictions that only ensure that further recipients can also do...
licensed under the GNU LGPL
GNU Lesser General Public License
The GNU Lesser General Public License or LGPL is a free software license published by the Free Software Foundation . It was designed as a compromise between the strong-copyleft GNU General Public License or GPL and permissive licenses such as the BSD licenses and the MIT License...
.
On hardware platforms, the open source jukebox firmware project Rockbox
Rockbox
Rockbox is a replacement for the standard firmware in various forms of digital audio players . It offers an alternative to the player's operating system, in many cases without removing the original firmware, which provides a plug-in architecture for adding various enhancements and functions...
supports playback of Monkey's Audio-encoded files on most of its supported targets, but many lack sufficient processing power to play the files back in real time on any but the lowest compression settings. In addition, there are a few MP3 players that natively support Monkey's Audio, including the Cowon D2 and the Iriver Spinn. As of version 4.02 (19 January 2009) a directshow filter is distributed with the installer, allowing for compatibility with most mp3 players.
External links
- Monkey's Audio Official Website
- APE Player Play Monkey's Audio files