AAC: Apple’s Preferred Audio Codec
It seems that almost every day I read something about people not wanting to rip their music in AAC (the default format for iTunes and the iPod) because, “it is a proprietary format”, or, “because it is owned by Apple.” I see this in iPod mailing lists and newsgroups, from people who seem to have a fair understanding of technical issues, and among the classical music community. Yet this is another case of confusion, lack of information, and, perhaps, a tricky abbreviation.
Could it be that people think AAC stands for Apple Audio Codec, rather than its real name, Advanced Audio Coding? It’s true that Apple was the first major hardware or software manufacturer to champion AAC over MP3, but this format is simply a part of the MPEG-4 standard, and is owned by a consortium of companies. Like MP3, this format is available to all for licensing, and there are even open-source encoders and decoders for AAC. Apple’s page about the AAC format explains much of this, and this page on Wikipedia goes into more detail and has links to many pages about AAC.
So why are people “afraid” of using AAC? The proprietary claim is simply one of ignorance. It is true that many portable devices don’t support AAC yet (though Microsoft’s Zune does, as do Palm PDAs and Sony’s PlayStation Portable) and on the software side, Real Player and the popular WinAmp both support it. AAC has many advantages: better quality at equivalent bit rates, meaning you can rip your music in smaller files, multi-channel capabilities (which, while not yet used, should see the light soon), and higher resolution audio, with sampling rates up to 96 kHz.
It’s worth noting that AAC is here to stay; it’s not Apple’s audio format, and more and more devices and software are supporting it. So if you haven’t understood this whole point, and still think that AAC is “owned by Apple”, think again.
Posted: 3/3/2009 by kirk | Filed under: iPod & iTunes | 4 Comments »
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Ironically, the player-independant version of Mpeg4 video (.mp4) seems to
suffer from a similar problem.
It’s ironic because Mp4 (.mp4) is the most open movie file format, as it has
been designed to be playable with any application, much like AAC. (In
contrast to QuickTime Mpeg4 movies (.mov), or Windows Media Mpeg4
movies (.wmv), etc.) In the same way AAC is like Mp3, Mp4 is like Mpeg.
The designers of the format seem to have taken pity on users who otherwise
have to manage an array of video players – one for each format of video. Now
we don’t! Now video is like Mp3 or AAC.
I suspect Windows users think .mp4 is a QuickTime format, as QuickTime
seems to be one of the first major players to support this new-found
openness – and Windows Media Player apparently won’t play .mp4! I’ll refrain
from speculating on why that might be. In any case, Mac and Linux users
seem pretty keen on .mp4.
And like AAC, .mp4 isn’t going away any time soon. Apple likes it, Sony likes
it, Linux likes it, Google likes it, etc.
Here’s a tip: if there’s a download link available for a Google Video, flip the
switch from "Windows/Mac" to
"Video iPod/Sony PSP" and click the download link. An .mp4 file will
download. (If you leave it set to "Windows/Mac," a Google Video Player will
begin downloading. Not sure what it does – I just know I don’t want yet
another video player.
I rip all my music in Apple Lossless. I’m guessing that is an Apple codec, since it
has Apple in the name.
Actually, I kind of wish Apple supported APE or FLAC with iTunes, so I don’t have
to use XLD all the time. From what I’ve seen, APE has good compression,
though FLAC and Apple Lossless are fast decoders. I only use lossless, so any
discussion about AAC is useless to me.
It was once suggested to me that Apple does not support FLAC because of a
worry about the actual open-ness of the codec; that there may be elements of
its implementation that could be open to a lawsuit at some time. I see no other
reason for them _not_ using FLAC, since it is so ubiquitous.