Other than MP3, What Compressed Audio Formats Exist?

cd asks: "While the MP3 format has become the dominant form for compressed music on the Internet, is it the most technically superior? What other forms of music compression are available for those who don't wish to download new music or upload their music, but for those who simply want to archive their music CDs? In this article Ken Thompson mentions PAC format. Is this the way to go? Is their encoding and playback software available for Linux?"

Re:Shorten & others

[BirksNCap]

While I take issue with the word "bootlegged" regarding CD's, Shorten does compress at a ballpark 2:1 ratio. Most people with whom I'm involved use it to save cd's we ship to each other in trading fair-use recordings, such as live performances from artists who allow taping [eklektix.com]. The kind folks over at etree.org [etree.org] maintain a thorough FAQ. The developers of Shorten have versions for Win9x, WinNT, Linux/BSD/*nix, BeOS i think, and there's even been a push to develop a WinAMP plug-in for it.

One key issue that's vital to us in the live recording trading community is the lossless compression. MP3 is just not good enough for the DAT-head and other audiophiles among us, since it's by very nature a lossy compression algorithm, chopping off key bands of audio information. Shorten avoids that by not cutting any audio information. True, it does not compress as much, thus making download times longer, but that's no excuse for sloppy sounding audio.

Re:Codecs

[kcarnold]

PAC [lucent.com] by Lucent [lucent.com] appears to be a proprietary, closed, for-cost product. I'm going with Vorbis (and in fact have done some Vorbis developemnt).

Shorten

[pyite]

Shorten is the best WAV compression around if you want lossless. We use it at etree.org [etree.org] for trading of music (bands that allow taping, legally) exclusively. There's even source available so you can use it on linux.

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Other compresion formats, plus detailed MP3 info

[xeos]

There are the 4 ACs, PAC, and ATRAC (more info:
http://www.cs.tut.fi/~ypsilon/80545/CoderExample s.html)

Also, you don't have to through away data to compress bitstreams. There are many different technologies that employ clever representations that decode to the exact same PCM which was used as source. Generally, the compression ranges from 40% to 80% of the original PCM, with the average tending towards 50%. Certainly, an improvement over nothing, but not nearly as compressed as MP3s. But when quality absolutely must be maintained, this is the only way to do it. So this seems like the best way to archive your CDs if you have lots of space. This page includes benchmarks of different systems, quick descriptions of the different technologies, and lots of good links:
http://www.firstpr.com.au/audiocomp/lossless/

Finally, a general overview on mp3s, how they work, some other standards not listed above, and
more: http://hamp.hampshire.edu/~aer98/mp3links.html

Other formats

[CaptainSuperBoy]

• Some people say that Yamaha's VQF has better quality than MP3 given the same bitrate: http://www.yamaha-xg.com/english/xg/So undVQ/ [yamaha-xg.com], http://www.vqf.com/ [vqf.com]
• AAC had some popularity for a while but I haven't heard much about it lately: http://www.mpeg.org/MPEG/aac.html [mpeg.org]
• Many people use shorten for lossless compression: http://www.softsound.com/Shorten.html [softsound.com]
• Some proprietary formats:
• Windows media: http://www.mi crosoft.com/windows/windowsmedia/en/download/defau lt.asp [microsoft.com]
• Liquid audio: http://www.liquidaudio.com/ [liquidaudio.com]
• Realplayer G2: http://www.real.com [real.com]

Shorten & others

[Chris Pimlott]

If you are concerned primarily with archiving your sound, there's a program I've seen being used by people trading bootlegged CD's called Shorten. It's a non-lossy compression that displays around a 2:1 ratio (there's also a lossy version but I don't know much about it, the ratio is less than MP3 though). There's a company called SoftSound [softsound.com] that markets a commerical version for Windows/DOS but I believe there's other version.

I also came across the comp.speech FAQ [faqs.org] which has a specific section regarding audio compression standards.

Codecs

[brank]

You can always use Ogg Vorbis [xiph.org] a free (as in speech) MP3-like audio codec. Vorbis is part of the Ogg [xiph.org] family of codecs.

Here is a link [tu-berlin.de] to download a Lossless Predictive Audio Compression encoder for Linux (and the page [tu-berlin.de] I found it on).

PAC is very likely to be avalible for some other Unix, so it would (with a little work) probably work on Linux.