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Opensource Apple Lossless Decoder Released

Posted by Zonk on from the alternate-options dept.

Cody Brocious writes "David Hammerton has released version 1.0 of an ALAC decoder. This allows users of operating systems not supported by iTunes/QuickTime to listen to their Apple Lossless files, a proprietary competitor to FLAC. This is a large leap forward in audio codec interoperability, and paves the way for an ALAC encoder." The site also asks for additional help on the project.

6 of 294 comments (clear)

  1. Small correction by bajo77 · · Score: 5, Informative

    This initial release is version is 0.1, not 1.0

  2. Re:Stream Ripping? by crazney · · Score: 5, Informative

    Hey,

    I'm the author of the decoder in quesiton.

    I originally started doing the decoder so I could have my own little Airport Express emulator.

    However, Apple have (for once) secured their system pretty well, and I have been unable to break their encryption so far. I know exactly what I need to do, and I'm fairly confident that I'll be able to do it... But first I actually need to get one of these devices.

    So yeah, It's certinately on the table. Shouldn't be too far off.

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    stuff
  3. Re:Pardon me for asking... by crazney · · Score: 5, Informative

    I don't really believe that. As I mention on the web page, ALAC is very similar to FLAC - however it is slightly more complicated, not less. It requires more CPU power to decode ALAC than it does to decode FLAC. That said, it should generally have a better rate of compression.

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    stuff
  4. Re:Pardon me for asking... by Anonymous Coward · · Score: 5, Informative
    I don't really believe that. As I mention on the web page, ALAC is very similar to FLAC - however it is slightly more complicated, not less. It requires more CPU power to decode ALAC than it does to decode FLAC. That said, it should generally have a better rate of compression.
    Huh? Comparison tests have found that ALAC compression is, on average, slightly worse than FLAC.

    http://members.home.nl/w.speek/comparison.htm
    http://flac.sourceforge.net/comparison.html

  5. Re:Pardon me for asking... by cbrocious · · Score: 5, Informative

    You're very, very far off.

    ALAC has absolutely nothing to do with the MPEG-4 lossless encoding. (I should know, as I worked on the decoder as well. See the authors list on the site)
    This is a common misconception that having an opensource decoder (and encoder soon... I have a prototype already) will hopefully fix.

    --
    Disconnect and self-destruct, one bullet at a time.
  6. Re:Pardon me for asking... by DavidTC · · Score: 5, Informative
    To keep people from having to read that, FLAC is not significantly smaller (1), but a hell of a lot faster if you use it right.

    The important stats:
    FLAC at 8 took 55:02 to encode, 7:07 to decode, at a ratio of 1:0.5437.

    ALAC took 19:53 to encode, and 10:01 to decode, at a ratio of 1:0.5496.

    So, yes, FLAC at the tightest takes much longer than ALAC. (Alghought it's only 3/4th the CPU to play!)

    However FLAC at 5 took 12:54 to encode and 7:08 to decode, at a ration of 1:0.5459. Much faster than ALAC, barely smaller, and decodes much easier than ALAC.

    So, yes, if you ramp FLAC all the way up it takes much longer to encode, and slightly longer to decode, and you don't gain anything. So obviously doing that is a bit silly unless you're talking about long term storage.

    If you leave it at the default, though, it beats ALAC in every single way, unless there's some differences in CPU architechure that changes the relative decoding difficulties between an iPod and a PC. Which isn't that impossible. But I have to point out that a lot of people use iTunes sans iPod, on a PC.

    1) No lossless compression is significantly smaller than anything else. All the serious contenders are between 1:0.56 and 1:0.48 or so.

    --
    If corporations are people, aren't stockholders guilty of slavery?