Sac
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Sac can refer to (at least) one out of two lesser-known audio codecs, which are not aimed at end-users.
Sac – also referred to as State-of-the-Art lossless compression – by Sebastian Lehmann[1]: a lossless (on given architecture[2]) codec, described by the author as a lossless audio compression intended as a research project to find the limits on compression ratio[3]. It comes with source code and a Windows 64-bit executable.
Being a an experimental research project, it lacks pretty much all the features of an end-user codec (including playback support, see also the HA Wiki's Lossless Codec Comparison). Rather, Sac is dedicated to achieving smaller file size than any other lossless codec, at great expenses in computing power: Decoding might fall severely short of real-time speeds. The developer uses as benchmark OptimFROG's max preset, which in the 2023 edition of Martin van Beurden's lossless test[4] was measured to decode at 10x realtime speed on current hardware; cursory testing indicates that Sac (v0.5.1) is order of magnitude ten times as CPU intensive. Independent comparison measured Sac does to smaller files size on average (but not all) material.[5]
Sac – Simple Audio Compression – by Marcus Geelnard[6]: a simple codec for 4-bit and 8-bit DDPCM. Released as a library.[7]
References:
- ↑ https://github.com/slmdev/sac Sebastian Lehmann's Sac at github
- ↑ https://github.com/slmdev/sac/issues/7 Github issue: losslessness not preserved across CPU architectures
- ↑ https://encode.su/threads/1137-Sac-(State-of-the-Art)-Lossless-Audio-Compression Lehmann's 2010 post at encode.su, updated
- ↑ http://www.audiograaf.nl/losslesstest/Lossless%20audio%20codec%20comparison%20-%20revision%206%20-%20cdda.html Martijn van Beurden's 2023 lossless comparison study
- ↑ http://www.squeezechart.com/audio.html Squeezechart's comparison of (lossless) compressors
- ↑ https://www.bitsnbites.eu/hiqh-quality-dpcm-attempts Marcus Geelnard's 2014 blog post
- ↑ https://gitlab.com/mbitsnbites/libsac Marcus Geelnard's Sac at gitlab