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ALAC codec now open source

Apple has released its ALAC codec under the Apache license. Like FLAC, ALAC is lossless; the uncompressed stream is identical to the original. Apple does not seem to have said anything about the patent status of its algorithm, though. (Edit: the Apache license contains a patent grant that should cover users nicely).
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ALAC codec now open source

Posted Oct 28, 2011 5:02 UTC (Fri) by grpaul (guest, #81061) [Link]

They licensed it under the Apache license, however, which says:

"3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed."

Because of that, I think that the patent situation should be pretty clear, unless I'm misunderstanding something.


Posted Oct 28, 2011 5:09 UTC (Fri) by corbet (editor, #1) [Link]

Good point, I wasn't thinking it through that far. First post of the morning is always hazardous...

ALAC codec now open source

Posted Oct 28, 2011 5:34 UTC (Fri) by Jonno (subscriber, #49613) [Link]

That only covers patents Apple own themselves, not patents they license from somewhone else...

ALAC codec now open source

Posted Oct 28, 2011 13:53 UTC (Fri) by pebolle (subscriber, #35204) [Link]

Why doesn't it cover patents Apple licensed?

Apple almost certainly can't

Posted Oct 28, 2011 14:09 UTC (Fri) by david.a.wheeler (subscriber, #72896) [Link]

Two answers. One, the Apache license doesn't require it. Two, Apple almost certainly doesn't have the rights to grant patent rights to patents held by anyone else (this is the usual case, which is why the Apache license is written that way).

That means that it's possible that ALAC is covered by other patents that the courts will consider valid. (I think all codec patents should be rejected forever, but that's not my decision to make.) However, if Apple is releasing it, there are fairly good odds that ALAC is now patent-free. I suspect that several people are researching that right now, and I hope that ALAC will turn out to be clean.

Subversion URL

Posted Oct 28, 2011 5:45 UTC (Fri) by conrad (guest, #3849) [Link]

The trac page doesn't yet mention the repository URL, and the git mirror suggested on the front page of macosforge doesn't work. The code is in subversion at:

(thanks bob2 for finding it!)

ALAC codec now open source

Posted Oct 28, 2011 7:13 UTC (Fri) by danieldk (subscriber, #27876) [Link]

Although ALAC does not seem to provide any advantages over FLAC, it's still nice to have a reference implementation, since ALAC is supported by all modern 'i-devices' (iPod, iPad, iPhone) and is also the codec used for (device to device) AirPlay streaming.

Now, if they would release specs for AirPlay :).

ALAC codec now open source

Posted Oct 29, 2011 5:26 UTC (Sat) by JoeBuck (guest, #2330) [Link]

There's been a working reverse-engineered implementation since 2005 in libavcodec.

ALAC codec now open source

Posted Oct 29, 2011 9:29 UTC (Sat) by danieldk (subscriber, #27876) [Link]

Yes, but the Apache License on the Apple version grants patent rights to distribute, modify, and use the software.

And we want to adopt this why?

Posted Oct 28, 2011 15:46 UTC (Fri) by jmorris42 (guest, #2203) [Link]

Ok, it is a good day any time a code drop happens, especially when it includes a previously encumbered file format becoming open. But then the question becomes what is the use case for ALAC compared to FLAC? Other than interoperating with iProducts I don't see it. Which probably explains why they did it. They ain't #1 anymore so they are going to start caring about interoperating with other tech. And of course wanting other brands to support their 'standards' so people will keep using them.

And we want to adopt this why?

Posted Oct 28, 2011 18:59 UTC (Fri) by danieldk (subscriber, #27876) [Link]

There are currently non-Apple 'AirPlay speakers' on the market. AirPlay uses an ALAC stream for audio, so it may be useful for compatibility with those devices. Unfortunately, AirPlay is not an open standard (yet?).

If you don't have such a device or and iDevice, it's not an improvement over FLAC.

And we want to adopt this why?

Posted Oct 29, 2011 0:51 UTC (Sat) by AndreE (guest, #60148) [Link]

Yes, other than for use with Apple products, it is pointless. FLAC has much higher adoption in the hardware and digital market space. In fact I don't think you can even buy ALAC songs from iTunes.

The really nice thing would be for Apple to adopt FLAC.

And we want to adopt this why?

Posted Oct 29, 2011 7:33 UTC (Sat) by salimma (subscriber, #34460) [Link]

You can buy ALAC songs -- Apple does sell lossless songs for a slightly higher price than their normal AAC-encoded offerings.

Part of the reason ALAC was developed is that Apple needs it to support optional DRM.

And we want to adopt this why?

Posted Oct 29, 2011 8:30 UTC (Sat) by AndreE (guest, #60148) [Link]

Firstly, I'm not sure you are correct about DRM. ALAC is an encoding scheme, so it has no inherent DRM. DRM is wrapped around the container. You can have DRM around mp3, aac, FLAC, WMA, whatever. As far as I know the spec doesn't mention anything about DRM. The HydrogenAudio wiki confirms as much --

As for buying ALAC, I have never been able to find a single lossless album on iTunes, ever. Even finding one wouldn't be that relevant, since the format is obviously not prefered or promoted.

Compare this to say, bandcamp, hdtracks, lynns, eClassical, and many others that have been selling FLAC tunes for a few years.

And we want to adopt this why?

Posted Oct 29, 2011 22:45 UTC (Sat) by salimma (subscriber, #34460) [Link]

I stand corrected. I was likely thinking of iTunes Plus -- -- which is DRM-free 256 kbps AAC.

There are talks about future "high-fidelity" music purchases being in the pipeline, but no technical detail yet; they might be using 24-bit sampling but the journalist covering the story for CNN didn't say anything about lossless encoding, though references are made to musicians selling uncompressed music.

And we want to adopt this why?

Posted Nov 1, 2011 10:16 UTC (Tue) by tialaramex (subscriber, #21167) [Link]

24-bit is the enemy of lossless encoding. That's because the bottom few bits absolutely will be noise (thermal noise in the recording device, processing noise from EQ and other algorithms, or even just deliberate noise added for anti-aliasing during mastering), which you can't hear but the lossless encoder has to encode anyway.

If your "album" is a collection of unprocessed high quality samples (maybe you record duck mating calls) then 24-bit might make some sense. For anything intended as a finished product to be listened to by humans, ie music - it's massive overkill.

But the numbers are bigger, and consumers have learned to prefer the product with bigger numbers, so everyone has a "24-bit" soundcard that actually is lucky if it reaches 100dB SNR in ideal conditions and no doubt they'd prefer to buy a 24-bit recording too.

Because their algorithms are doing arithmetic with real numbers, you can get 24-bit samples out of MP3, Vorbis or other lossy encoders very easily. You don't even need to have really put 24-bit samples in at the other end. So selling a "24-bit" AAC file is a cheap way to satisfy this consumer demand with no cost to the supplier or benefit to the consumer. 24-bit FLAC or ALAC files would necessarily be larger than their 16-bit equivalent, so that's an immediate loss for everyone.

And we want to adopt this why?

Posted Nov 2, 2011 0:03 UTC (Wed) by njs (guest, #40338) [Link]

There are a bunch of audiophiles out there who do in fact rip SACD and DVD-A to 24-bit/192 kHz flac files. (And often they do this via the analog hole!)

It's ridiculous and pointless, but there you go.

Though... audiophiles aren't just making up the quality difference between ordinary CDs and "high fidelity" recordings. The SACD/DVD-A releases are mastered better, without the loudness war nonsense. And it's in the record companies's interest that the buyers misattribute this quality difference to the difference in technology -- it's a lot easier to say "you should pay us extra for this release because it has 24 bits!" than to say "you should pay us extra for this release because we didn't screw it up like we screwed up the old one!". So the reason audiophiles think that high-resolution makes a difference is because they're non-technical users getting scammed by the record companies.

OTOH, this scam makes it commercially viable to produce some releases that sound good even when you aren't in your car. And that's a good thing. So I have mixed feelings about the whole thing.

And we want to adopt this why?

Posted Nov 2, 2011 8:30 UTC (Wed) by ekj (guest, #1524) [Link]

I ain't so sure that consumers want "bigger numbers" - infact the opposite seems to be the case. Ask consumers what they want in a new audio-format to replace/upgrade that of the CD, and "higher quality" is not likely to rate highly.

Infact people do the opposite: they downgrade CD to 128Kbps constant-bitrate mp3s, and still consider that a win, because the other advantages (no plastic, easy transfer and storage, built-in metadata etc) matter whereas the loss of quality don't matter since it's "good enough" in either case.

Back when plastic wasn't obsolete, the Norwegian equivalent to the RIAA made a poll as to most wanted feature in the next format to replace CDs. "More songs on one disc", "Names of songs displayed" and "Better mechanical reliability" took the top 3 places, "Higher quality sound" was way down the list.

DVDs also still outsell bluerays -- EVEN for those households who own a blueray-player. (yeah, part of that is price, but atleast it shows people aren't willing to pay a large premium for a *real* increase in quality)

And we want to adopt this why?

Posted Nov 2, 2011 12:46 UTC (Wed) by tialaramex (subscriber, #21167) [Link]

I wasn't thinking about format replacement, but rather within a format. ie where the consumer is choosing for an individual download or purchase whether to have option A or option B, where option B has bigger numbers and perhaps a slightly higher price.

I've caught my mother seriously trying to decide if she needs a larger (ie bigger numbers) hard disk for her new PC, even though its predecessor never filled the order-of-magnitude smaller hard disk. You see the same with people considering buying a 12MP camera to replace their 5MP camera, but not paying much attention to far more important considerations like the camera optics or user interface, which aren't neatly characterised by a single number.

The "More songs on one disc" result is amusing because music albums almost never come anywhere close to filling a CD. The artist may write, record and re-record 2-3 hours worth of tracks over a period of several months, but most will be cut for one reason or another so that a typical CD album lasts around 45 minutes to one hour, nowhere close to the standard specification of 74 minutes let alone the practical limit. If consumers want longer albums, they need to talk to the artists and producers about that, not the technology companies.

And we want to adopt this why?

Posted Nov 3, 2011 7:46 UTC (Thu) by ekj (guest, #1524) [Link]

Offcourse !

At this point, nearly all the wishes of the public for new features from music/movies/ebooks are about politics or law, not about technology.

I'd like to be able to buy music from abroad digitally - the selection is better and prices are often lower, yet all the major retailers refuse to sell to me.

I'd like to be able to subscribe to services that offer movies for streaming - yet again the powers that be, has decided to not sell to me. This is infact a case where *less* technology would be required to offer something globally, relative to restricting it by geography.

I'd like to be able to buy DRM-free ebooks at a reasonable price. (I'm willing to consider any price that is equal or lower than the paperback-price as reasonable) Yet the offerings are meagre. Again the largest shops all either use DRM or refuse to sell to me - frequently both - and the tiny local shops that exist use DRM *and* think that double-paperback-price is a reasonable ebook-price.

I'd like to be able to send DVDs that I like, to friends of mine, as christmas-presents, for example. Yet the powers that be, has used considerable resources in order to PREVENT me from doing this if I dare have friends on different continents.

Technology, isn't the problem. Even plain old mp3s are good enough to offer "good-enough" quality music to the entire world-population at damn-near-zero reproduction and distribution-cost. The technological progress possible over this, are modest.

And we want to adopt this why?

Posted Oct 29, 2011 9:32 UTC (Sat) by danieldk (subscriber, #27876) [Link]

I regularly use the iTunes Store, and I have never found an option to purchase lossless music. You must be confused by the former distinction that existed between 128kbps DRMed music and 256kbps non-DRMed music (iTunes Plus). Some time ago they switched to iTunes Plus completely.

And we want to adopt this why?

Posted Oct 29, 2011 19:58 UTC (Sat) by JanC_ (guest, #34940) [Link]

There are some tracks in ALAC format on iTunes, I've heard, but probably not many...

It's similar to how most competitors of iTunes support FLAC next to MP3, but at the same time most of their tracks aren't available as FLAC; the format(s) used depends on what the rights holders want to sell/provide. Most "artist representants" see no point in selling lossless tracks, it seems.

The same issue is true about Vorbis BTW: I understand Canonical would love to sell Ogg Vorbis tracks in addition or instead of MP3 tracks in their music store, and as I understand it 7Digital (their service provider) is open to such alternative track formats, but they are only allowed to sell what the rights holders (or the companies appointed by the rights holders) want to provide.

And we want to adopt this why?

Posted Oct 30, 2011 14:49 UTC (Sun) by tialaramex (subscriber, #21167) [Link]

On the occasions when I have purchased music in the last year or so, it was always available as FLAC or zipped up PCM WAV.

My criteria are generally something like: I must have this specific track / album, I must have lossless audio, I would like to buy from the artist's web site or wherever the artist recommends if possible, I would like to use a credit card.

But I may just have been very lucky. My tastes do run to individuals and bands who maybe care a bit more about this stuff than some.

And we want to adopt this why?

Posted Oct 30, 2011 23:16 UTC (Sun) by AndreE (guest, #60148) [Link]

HDtracks, eClassical, and Lyns all sell FLAC tracks for their entire catalogue. Similarly Bandcamp allows FLAC (and a variety of other formats)

Suffice to say, FLAC adoption in hardware and in digital markets far surpasses that of ALAC

ALAC codec now open source

Posted Oct 29, 2011 9:31 UTC (Sat) by Hanno (guest, #41730) [Link]

How do FLAC and ALAC compare? (e.g. file size, CPU usage for encoding and decoding, which is easier to implement in embedded hardware, etc.) Does anybody know?


Posted Oct 29, 2011 11:37 UTC (Sat) by hmh (subscriber, #3838) [Link]

ALAC is useful when FLAC is not available on a device, or when the particular implementation of FLAC in that specific device is worse than the ALAC implementation.


Posted Oct 30, 2011 20:54 UTC (Sun) by Hanno (guest, #41730) [Link]

Thank you, but that page is outdated and does not answer any of the questions I mentioned previously.


Posted Oct 31, 2011 15:39 UTC (Mon) by patrick_g (subscriber, #44470) [Link]


Posted Nov 4, 2011 10:30 UTC (Fri) by grmd (subscriber, #4391) [Link]

Hanno, perhaps I misread the page in the first link but it includes a table that compares encode time, decode time and compression, which seems to answer some of your questions.

ALAC codec now open source

Posted Oct 30, 2011 23:18 UTC (Sun) by AndreE (guest, #60148) [Link]

For whatever reason FLAC is found in a large range of audio hardware. I have no hard facts, but I would suggest that it isn't a hugely problematic format. Yamaha, Denon, Onkyo, etc etc all receivers that can natively play back FLAC

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