Apple Lossless Audio Codec Project becomes open source

Posted:
in iPod + iTunes + AppleTV edited January 2014
Apple this week made its Lossless Audio Codec project for high-quality audio files open source under the Apache license, allowing anyone to make their own ALAC files.



The ALAC audio codec was developed by Apple and is supported on the iPhone, iPad, Mac, iTunes and most iPods. Apple made the announcement this week that the project is now open source via the MacOS Forge website.



ALAC compressions reduces the file size of audio files, but as represented by its "lossless" name, the compressed files do not have any loss of information. Decoded ALAC files are identical to an original uncompressed audio file.



Lossless audio formats like ALAC, FLAC (Free Lossless Audio Codec), and WavPack are popular among audiophiles, as they retain the original quality of the recording while taking up about half the space of the original file.



The ALAC project made open source by Apple contains the sources for both the ALAC encoder and decoder, as well as an example command-line utility called alaconvert. With this, users can read and write audio data to and from original Core Audio Format and WAVE files.



ALAC files are stored within an MP4 container with the file extension ".m4a" -- the same extension used by the AAC format that most iTunes purchases are stored in. However, as a lossless format, ALAC is not a variant of AAC.







Available under the free Apache license, the ALAC sources allow users to use the software for any purpose, including modification and distribution. The license requires that any original copyright, patent, trademark and attribution notices in redistributed code be preserved, and notifications be provided for every licensed file that may have been changed.



ALAC has been a part of the Mac OS X Core Audio Framework, as well as iTunes 4.5 and QuickTime 6.5.1, since April of 2004. The format is also used for Apple's AirPlay wireless streaming technology.
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Comments

  • Reply 1 of 52
    successsuccess Posts: 1,039member
    inevitable



    Btw, did I ever tell you how much I.....







    am first!?
  • Reply 2 of 52
    Quote:
    Originally Posted by success View Post


    inevitable



    Why? I'm curious.



    Quote:

    Btw, did I ever tell you how much I....am first!?



    We're not on YouTube. Please at least pretend you've passed puberty.
  • Reply 3 of 52
    dsoldsol Posts: 9member
    Good work Apple - now do the same for ProRes. We really need a standardised format for file-based digital video in the broadcast industry. You've got nothing to lose by making it an open standard.
  • Reply 4 of 52
    conradjoeconradjoe Posts: 1,887member
    Quote:
    Originally Posted by AppleInsider View Post




    The ALAC audio codec was developed by Apple and is supported on the iPhone, iPad, Mac, iTunes and most iPods. Apple made the announcement this week that the project is now open source via the MacOS Forge website.



    A



    Why is Apple even bothering with this? Does anybody really use ALAC?



    Why not simply make iOS so it supports the popular lossless formats? Is ALAC superior to the other lossless formats?
  • Reply 5 of 52
    asciiascii Posts: 5,941member
    This is the codec I used a few years ago to rip all my CDs before throwing them out (got sick of carting them from apartment to apartment).



    The resultant files are quite big (25-35MB for a single track) but I didn't want to lose any quality (well CDs aren't perfect to begin with, but any *more* quality I mean).
  • Reply 6 of 52
    conradjoeconradjoe Posts: 1,887member
    Quote:
    Originally Posted by ascii View Post


    This is the codec I used a few years ago to rip all my CDs before throwing them out (got sick of carting them from apartment to apartment).



    The resultant files are quite big (25-35MB for a single track) but I didn't want to lose any quality (well CDs aren't perfect to begin with, but any *more* quality I mean).





    I generally use .flac, because it is a popular format.



    Is ALAC better for any reason? Do popular players generally support it?
  • Reply 7 of 52
    n42n42 Posts: 34member
    For anyone who uses Apple products and cares about high quality audio, this is great news. A while back I wanted to upgrade my entire library to lossless but found that Apple products do not support FLAC, the widely adopted standard in lossless audio. Converting from FLAC to ALAC is trivial and very fast, but it sucks having to use a format that is only supported by iTunes and iProducts! This means that more software (VLC, tag editing software, etc.) will be able to natively support ALAC.



    On top of this, any open source codec is great news for the surrounding community.. keeping a file format open allows the similar formats to learn from, adapt, or provide input to each other.



    The user wins here!
  • Reply 8 of 52
    Quote:
    Originally Posted by ConradJoe View Post


    I generally use .flac, because it is a popular format.



    Is ALAC better for any reason? Do popular players generally support it?



    well, if Apple supports it for iTunes (probably more expensive :/ ) it will be better because it will become much more used.



    unless this happens, i will also stick with .flac when using my computer
  • Reply 9 of 52
    asciiascii Posts: 5,941member
    Quote:
    Originally Posted by ConradJoe View Post


    Is ALAC better for any reason? Do popular players generally support it?



    I am not a codec expert, I don't know whether it's better or worse than FLAC.



    I imagine until today no-one supported ALAC except Quicktime and iTunes, but now that it's open source we should see it appear in libavcodec, which is the library most of the other players use.
  • Reply 10 of 52
    rob55rob55 Posts: 1,255member
    Quote:
    Originally Posted by AppleInsider View Post


    Lossless audio formats like ALAC, FLAC (Free Lossless Audio Codec), and WavPack are popular among audiophiles, as they retain the original quality of the recording while taking up about half the space of the original file.



    In my experience, the resulting Apple Lossless file ends up being about 60-65% of the original AIFF or WAV file. I've been encoding in ALAC for a while now and it eats up space fast. For me, I grew tired of re-ripping my collection every time I got a new computer that provided a substantial increase in drive space. Now, everything goes to ALAC and from there I can scale down to anything I would need. Before ALAC, I couldn't really get rid of my CDs in case I wanted to re-rip in the future, but since converting to it, I really don't need those CDs any more (they just sit collecting dust in my storage room).
  • Reply 11 of 52
    The true benefit of compressing audio in like manner as any other data is compressed, i.e., without using perceptual encoding that produces a bit stream from which the original bit stream cannot be recovered, is with archiving. For any large-scale archiving endeavor, the required amount of storage is reduced significantly relative to non-compressed audio encoding. But for playback purposes on portable devices, or even for at-home playback, it is silly. Of course there are always people who claim that they can hear things that they cannot actually hear, just as there are people who claim that they see flying saucers and bigfoot that they did not actually see. You do not have to experiment with audio encoding very long at all to realize that with perceptual encoding such as AAC, that the bit rate at which the sound is perceptually identical to the original is but a small fraction of the original bit rate. When you encode and listen carefully as you increase the bit rate one step at a time, you reach a point where there is almost not perceptual difference between the two bit rates. Then go a step or two higher, to where you cannot hear any difference whatsoever. Then for good measure, go one step higher. At that point you are using a higher bit rate than what is needed in order for the sound you hear to be perceptually identical to the original, and that bit rate is still a small fraction of the bit rate using any non-perceptual encoding scheme. It is also a well-established fact that when encoding AAC at a bit rate way below the bit rate that you get with non-perceptual encoding, the measurable distortion that results is quite small in comparison to the distortion present in any loudspeaker or headphone. The situation here is much the same as it is with people who claim that they can hear differences in amplifiers, when the fact is that for any decent high fidelity amplifier, the degradation of the signal is orders of magnitude less than it is with even the very finest loudspeakers and headphones. Since the beginning of audio transmission people have claimed that they can hear things that they cannot actually hear. Non-perceptual encoding techniques for audio have a place in professional archiving of music, but for anyone not in that business, and who only has the need to encode audio for personal and home use, non-perceptual encoding of audio has no relevance. It makes about as much sense as it would make to use a high-end supercomputer to browse the web.
  • Reply 12 of 52
    asciiascii Posts: 5,941member
    Quote:
    Originally Posted by Rob55 View Post


    In my experience, the resulting Apple Lossless file ends up being about 60-65% of the original AIFF or WAV file. I've been encoding in ALAC for a while now and it eats up space fast. For me, I grew tired of re-ripping my collection every time I got a new computer that provided a substantial increase in drive space. Now, everything goes to ALAC and from there I can scale down to anything I would need. Before ALAC, I couldn't really get rid of my CDs in case I wanted to re-rip in the future, but since converting to it, I really don't need those CDs any more (they just sit collecting dust in my storage room).



    I'm pretty sure Apple's computers are going to start coming without optical drives soon, so ripping CDs once and for all is a good strategy now (they will continue to sell the external optical drive for a while probably though).
  • Reply 13 of 52
    solipsismsolipsism Posts: 25,726member
    Quote:
    Originally Posted by ConradJoe View Post


    I generally use .flac, because it is a popular format.



    Is ALAC better for any reason? Do popular players generally support it?



    Yes, the most popular players all support ALAC, and none of them support FLAC. The iPod Shuffle, iPod Nano, iPod Classic, iPod Touch, iPhone, iPad, and any machine with iTunes installed.



    Yes, an iPod Shuffle can playback ALAC files, but it's best for those who have iDevices and many CDs to rip their content in ALAC for storage, then backup those files, and then use iTunes to create 256-320Kbit/s AAC versions of tracks for their devices. You save space, which is more costly and limited on your iDevices than on your Mac/PC drive.



    I suppose you can use FLAC, but if you need to convert to AAC then you have to go through more steps than needed while iTunes simply makes it easy.





    PS: Pro Tip: For those wanting to convert all your content into ALAC, 1) remember that it won't make the quality any better than it already is so taking a 64Kbit/s Mp3 you grabbed from KaZaA back in the day will still be the same shitty quality but will now take up 1Mbit/s on your drive., 2) don't convert a 12 hour audiobook to lossless as you're have 1Mbit x 43,200 seconds or about 40GB just for some spoken word. For poor quality audio you can either use iTunes Match to get updated music files to DRM-free 256Kbit/s AAC, or purchase/replace another way. For audiobooks there is a setting in iTunes specifically for spoken word.
  • Reply 14 of 52
    MacProMacPro Posts: 18,260member
    The PC users who also have iDevices will be moaning about .FLAC as they are in the middle of being able to use both while most Apple only users are happy with ALAC. Given both FLAC and ALAC are lossless discussions about superiority are pointless. It comes down to use and convenience.



    For those wishing to convert here is an excellent utility. http://tmkk.pv.land.to/xld/index_e.html



    As to those arguing we can't hear the extra quality in lossless I'd point out I don't really need my pictures at max res to look at them most of the time but I sure as hell like to know I have the max quality stored away. I see no problem storing lossless versions with such low cost of storage these days even if I can't hear the difference. Once you go down you can never go back ... or something like that



    AsI understand it, iCloud will be making the lack storage size on iDevices and file size conflict moot soon.
  • Reply 15 of 52
    john.bjohn.b Posts: 2,720member
    Quote:
    Originally Posted by ConradJoe View Post


    Why is Apple even bothering with this? Does anybody really use ALAC?



    Why not simply make iOS so it supports the popular lossless formats? Is ALAC superior to the other lossless formats?



    Because nobody uses FLAC except audiophiles and the Linux crowd. This opens ALAC to third party applications which solves the audiophile half of the equation, and the FOSS crowd can fend for themselves (as per normal).



    I believe it enables ALAC distribution for the future, though I have nothing to base that on. I certainly don't expect to see ALAC downloads from iTunes in my lifetime, but I'd like to be wrong.



    BTW, ALAC is superior to FLAC in low-power usage scenarios (like PMPs, smartphones, etc.)



    One thing I would really like to see is an option to downres ALAC audio to 256k AAC in iTunes, instead of 128k AAC. It would make it much simpler to consolidate lossless + AAC within one library.
  • Reply 16 of 52
    solipsismsolipsism Posts: 25,726member
    Quote:
    Originally Posted by digitalclips View Post


    The PC users who also have iDevices will be moaning about .FLAC as they are in the middle of being able to use both while most Apple only users are happy with ALAC. Given both FLAC and ALAC are lossless discussions about superiority are pointless. It comes down to use and convenience..



    I wrote on another thread that those that support open source codecs don't care about ALAC being open source. They'll still use FLAC because it's not owned by a big bad corporate entity. They don't care about supporting the best option or must universally accepted option, it's about politics (or anti-politics) to them.





    Quote:
    Originally Posted by John.B View Post


    BTW, ALAC is superior to FLAC in low-power usage scenarios (like PMPs, smartphones, etc.



    The iPod Shuffle has supported ALAC for years. I pointed this out to AI when this finally changed but they didn't seem interested. I thought it was a big deal.
  • Reply 17 of 52
    MacProMacPro Posts: 18,260member
    Quote:
    Originally Posted by solipsism View Post


    I wrote on another thread that those that support open source codecs don't care about ALAC being open source. They'll still use FLAC because it's not owned by a big bad corporate entity. They don't care about supporting the best option or must universally accepted option, it's about politics (or anti-politics) to them.



    My comment was more end user oriented I don't know much about the open source fraternity so I accept your opinion there. I assume they all want us to be using Ubunto etc. ?



    p.s. love the footer. So true lol
  • Reply 18 of 52
    The question I have is will we now be able to download ALAC files in something more than 16bit 48kHz and will iTunes play them? Another person mentioned that CD quality is not all that great anymore and that is right. I download FLAC files at 24bit 96kHz which is really the start for High Rez sound now-a-days. A typical album will take up a little over a GiG of space at the rez but it is much better quality. There are more and more albums now available at an even higher 24bit 196kHz too.



    If ALAC is stuck at 16/48 then it is still only good for ripping old CD's.
  • Reply 19 of 52
    solipsismsolipsism Posts: 25,726member
    Quote:
    Originally Posted by MidwestAppleFan View Post


    The question I have is will we now be able to download ALAC files in something more than 16bit 48kHz and will iTunes play them? Another person mentioned that CD quality is not all that great anymore and that is right. I download FLAC files at 24bit 96kHz which is really the start for High Rez sound now-a-days. A typical album will take up a little over a GiG of space at the rez but it is much better quality. There are more and more albums now available at an even higher 24bit 196kHz too.



    If ALAC is stuck at 16/48 then it is still only good for ripping old CD's.



    Where are you getting these FLAC files? How do you know the source isn't just a CD that someone ripped to FLAC 24bit 196KHz?
  • Reply 20 of 52
    john.bjohn.b Posts: 2,720member
    Quote:
    Originally Posted by solipsism View Post


    The iPod Shuffle has supported ALAC for years. I pointed this out to AI when this finally changed but they didn't seem interested. I thought it was a big deal.



    The complaint I've heard from a friend with audiophile-itis is that the D/A converters in most PMPs (iPods included) aren't really good enough to benefit from lossless audio.
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