Macintosh Audio Compression/Expansion: Difference between revisions
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'''Macintosh Audio Compression/Expansion''' ('''MACE''') is a lossy, proprietary compression scheme developed by Apple Computer for their Macintosh line of computers. | |||
Technically, it's very similar to how [[ADPCM]] works. | Technically, it's very similar to how [[ADPCM]] works. | ||
It only works on 8bit streams. It offers two compression modes: 6:1 (1/6th of the original file size, | It only works on 8bit streams. It offers two compression modes: 6:1 (1/6th of the original file size, 117 kbps) and 3:1 (1/3rd of the original file size, 235 kbps). Quality is relatively poor. | ||
ffmpeg/libavcodec is able to decode MACE3 and MACE6 streams. | |||
Users are encouraged not to use this codec, for several reasons: | Users are encouraged not to use this codec, for several reasons: | ||
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* Won't work on bit depths other than 8bit. | * Won't work on bit depths other than 8bit. | ||
== External Links == | |||
* [http://www.quicktime.com QuickTime] plays and encodes MACE streams. | |||
* [http://cekirdek.pardus.org.tr/~ismail/ffmpeg-docs/mace_8c-source.html Reverse engineered MACE decoder sources] by Laszlo Torok, part of ffmpeg. | |||
[[Category:Codecs]] | |||
[[Category:Lossy]] | |||
Latest revision as of 13:25, 14 July 2016
Macintosh Audio Compression/Expansion (MACE) is a lossy, proprietary compression scheme developed by Apple Computer for their Macintosh line of computers.
Technically, it's very similar to how ADPCM works.
It only works on 8bit streams. It offers two compression modes: 6:1 (1/6th of the original file size, 117 kbps) and 3:1 (1/3rd of the original file size, 235 kbps). Quality is relatively poor.
ffmpeg/libavcodec is able to decode MACE3 and MACE6 streams.
Users are encouraged not to use this codec, for several reasons:
- There are better alternatives quality-wise (ADPCM, WavPack lossy, psychoacoustic codecs)
- Proprietary codec - E.G, on Windows platform, it can only be encoded and played in QuickTime
- Won't work on bit depths other than 8bit.
External Links
- QuickTime plays and encodes MACE streams.
- Reverse engineered MACE decoder sources by Laszlo Torok, part of ffmpeg.