Monkey's Audio

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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,^[1] with data transfer rates and bandwidth requirements being reduced accordingly.

Monkey’s Audio's drawbacks are that it is proprietary software, and has limited support on software platforms other than Windows. There are alternatives such as FLAC and WavPack that may offer more options for some users.

Monkey’s Audio files use the filename extension .ape for audio, and .apl for track metadata.

Comparisons

Monkey’s Audio generally achieves compression rates which are slightly better than FLAC and significantly better than Shorten (an older format no longer in development).^[2] Both encoding and decoding are generally somewhat slower than with FLAC or Shorten, and the decoder is problematic to implement on portable digital audio players. It suffers from relatively slow seeking, depending on the compression level chosen.^{[citation needed]}

Monkey’s Audio is freeware. It has a peculiarly ambiguous non-free software license, thus most Linux distributions and other operating systems that rely on free software alone do not include it^[3] and the software environment around Monkey’s Audio is less varied than that of other, more freely-licensed lossless compressors such as FLAC. FLAC comes pre-installed with most Linux distributions and is typically preferred by Linux users. The Shorten format is still in common use on sites such as etree, having been the de facto standard of live taping enthusiasts for years, but the advantage of FLAC as a broad-based, mature format being continuously refined by active development is prompting some to make the switch.

Since Monkey’s Audio is a lossless compression method, it is not readily comparable with lossy compression schemes such as AAC, MP3 and Vorbis. The two types of formats have different aims: lossless compression seeks to exactly preserve the original file in as small a space as possible, and lossy codecs are designed to retain sufficient audio quality to satisfy less demanding reproduction standards, through discarding varying amounts of sound data in order to shrink the file to fit the allotted file space. This is done by adjusting the sampling/bit rate, and in turn, the compression ratio. Therefore, audio files compressed using lossless audio formats are significantly larger than ones encoded in lossy formats. A typical Monkey’s Audio file will be approximately 3-5 times larger than a 192kb/second bitrate MP3.

Supported platforms

Officially, Monkey’s Audio is available only for the Microsoft Windows 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.

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.^[3][4]

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 (January 19, 2009) a directshow filter is distributed with the installer, allowing for compatibility with most mp3 players.

See also

• Comparison of audio codecs
• APE tag

References

External links

• Monkey's Audio – official website