Apple's Lossless Audio Codec (ALAC) Now Open Source 526
Revotron writes "Apple has released the full source to their Apple Lossless Audio Codec under the Apache license. ALAC was developed by Apple and deployed on all of its platforms and devices over the last 10 years. Could the release of the ALAC source code mark a possible first step in opening up more of the iOS platform?"
Great, but how about patents? (Score:4, Interesting)
Re:Why? (Score:2, Interesting)
Re:Why not... (Score:5, Interesting)
And going with a locked-down, Microsoft-created format is better how, exactly? And iPod/iTunes was compatible with MP3 from day one. I don't know any non-nerd who uses Vorbis or FLAC.
And at least Apple had the insight of going with AAC, developed by Dolby, instead of trying to re-create the wheel like Microsoft always does.
Take a screenshot with Windows: Microsoft BMP. Like there wasn't enough graphic formats at the time.
Take a screenshot on Mac OS X: 24-bit PNG (Open format which already existed).
Default audio format with Windows: Microsoft WMA. MP3 and VQF were available at the time.
Default audio format with Apple: AAC (developed by Dolby)
Try this (Score:3, Interesting)
If you're a non-audiphile trying to learn how to detect the difference with your ears, I suggest this:
Rip a CD into ALAC. Then re-rip one of the tracks into 256k mp3. Open each track side-by-side in music player apps and set the volume the same. Play each version 10 seconds at a time, paying attention to the perceived location of each instrument in the room.
You may find that it is easier to perceive that location while listening to the ALAC track.
I won't bore you with the scientific details. GIYF.
Re:Why not... (Score:4, Interesting)
I said probably because I obviously don't have any numbers to back my statements up, and I doubt they exist. I do think people--in general--run into iDevice dock connector devices far more often than devices that suport, well, anything else.
There have been over 300 million iPods alone sold. 110 million plus iphones. 40 million iphones. Every single one uses the same dock connector. It may not be a standard, but it's pretty ubiquitous. Many cars have iPod dock options. As I said in my other post, almost every single hotel I've stayed at in the 2-3 years has had an iDock alarm clock (Marriotts mostly, FWIW). In terms of 3rd party device for support non-iDevices, does such a thing even exist?
What are ALAC's technical merits? (Score:4, Interesting)
Lossless audio compression is pretty brain-dead simple. If you think of how sticking a wav file in a .zip or .gz only saves about 10% of space, (give or take,) the most basic lossless codecs work by essentially zipping the mathematical difference between each sample. Because storing the difference between each sample, instead of the sample itself, is more likely to have repetition in audio; algorithms like .zip and .gz can then be applied.
What I'd like to know is, considering how brain-dead-simple lossless audio compression is, are there technical merits for using ALAC, especially on embedded devices? Does FLAC rely on floating point when ALAC is purely integer, thus making ALAC easier to implement? Is it easier to seek within an ALAC? Or, is Apple's insistance on ALAC purely a "not invented here" mentality?
Re:Great, but how about patents? (Score:0, Interesting)
Even though it would mean other implementations cannot be used due to the patents?
Hooray.
Re:What are ALAC's technical merits? (Score:4, Interesting)
I actually don't know the details about ALAC but I know it's not what you're speculating -- FLAC Is built on integer calculations and is a very lightweight lossless codec (especially compared to something like Monkey's Audio or TAC which are very intensive and not so pleasant to use as active media files rather than archiving, although their compression is better) and is good for playback with limited CPU. I'd guess that ALAC is also integer, and that practical differences from FLAC are minor.
I think it comes down partly to a not-invented-here thing, and also that FLAC typically sits in its own container or in an OGG container, while ALAC sits in an MP4 container - not that Apple couldn't have embedded FLAC into MP4 if they really wanted to.
Re:Why not... (Score:4, Interesting)
Vorbis is also the audio codec for Google's legally-free "webm" video format, which is vp8 video and vorbis audio in a specific form of Matroska container (instead of Ogg, which seems to invoke hatred among some programmers where Matroska apparently doesn't). Hypothetically, you can make a standards-complaint audio-only webm file to use in place of Ogg Vorbis for anything that supports webm and get the superior-to-mp3 Vorbis quality sound in anything that supports webm - mostly web browsers and at least some Android devices.
(ALL android-based devices support Ogg Vorbis audio, including the ones that don't mention it in the marketing materials, as do a lot of other handheld music players that aren't iGadgets or Zunes. I can't decide if audio-only-webm is likely to displace Ogg Vorbis at some point or not. The good news is that you can take Ogg Vorbis audio and move it to a webm format without losing any quality.)
tl;dr: Vorbis audio and support for it seems to be a lot more widespread than people usually realize.