iTunes Store and EMI: A good deal for the AAC file format

Posted by Pierre Igot in: iTunes, Music, Technology
April 5th, 2007 • 9:43 am

One of the more intriguing side-effects of the recently announced deal between EMI and Apple is that the new higher quality music files that will be sold by the iTunes Store will be sold, not in DRM-free MP3 format, but in DRM-free AAC format.

The DRM-free (i.e. unprotected) AAC format has been available to iTunes and QuickTime users for a while. At the same bit rate, it’s supposed to be a better quality compression format than MP3. With the higher bit rate (256 kbps vs. 128 kbps), the music can be expected to sound even better—although it still won’t be the same as uncompressed CD quality.

What is interesting here is that, for many years now, Apple has been trying to push its own file formats against the competition coming from Microsoft and other companies. The most obvious example is the file format for video files. Apple was a pioneer in digital video with QuickTime, but never quite managed to impose the QuickTime file format (“.mov” files). Competing file formats from Microsoft, Real, and others represent the majority of video files and streams available on the Internet today.

When it comes to uncompressed audio files, Apple has AIFF, whereas most PC users use WAV. Granted, since the sound is uncompressed, it is pretty easy to convert one format to the other with no loss in quality. (There can be various sampling rates, but even then the switch between file formats is pretty painless.) But the fact remains that, when people talk about uncompressed sound files, most of the time they mean WAV rather than AIFF.

The situation with compressed audio files is obviously somewhat different, with the huge popularity of the MP3 file format. It’s an “open” file format, and that has played a huge part in the popularity of the format. When most people talk of “DRM-free” music files, they usually mean MP3 files, like the ones sold by the emusic store.

But this new deal between the iTunes Store and EMI to sell DRM-free music files does not involve the MP3 file format. The DRM-free files will be sold in AAC. At first, I was a bit surprised by this, because I thought that many non-iPod portable music players didn’t support this file format. But a quick search online showed me that most other music players, including Microsoft’s Zune, do indeed support the unprotected AAC file format, in addition to MP3 and DRM-protected Windows media files.

This makes sense, since unprotected AAC is actually also an “open” standard that is part of the larger MPEG-4 family of file formats. But since, from the beginning, Apple has been the main purveyor of files in AAC, I have always felt that the file format risked not being taken seriously by non-Apple hardware and software companies.

The new deal between Apple and EMI (hopefully with other major record labels joining in soon) might signal a significant shift in that respect. I am not saying that the MP3 file format will decrease in popularity any time soon. As far as I know, if you want to be able to play an AAC file on a PC running Windows XP, you still need to manually install Apple’s QuickTime or iTunes on your machine. (Maybe Windows Vista comes with built-in support for AAC.)

And I am also not saying that DRM-free AAC files sold by the iTunes Store will lead to widespread piracy and become suddenly ubiquitous because of that.

But the move to DRM-free AAC for music files sold through the iTunes Store has to be good news for the AAC file format—as opposed to, say, the adoption by online music stores of a DRM-free Windows Media file format (gasp!).

The only major remaining problem that I see with the AAC file format is pretty basic. It is that the very name of the file format does not correspond to the file extension attached to files in that format. Music files in the DRM-free AAC file format actually use the “.m4a” file extension (as in “MPEG-4 Audio”), rather than the expected “.aac” file extension. I cannot help but feel that this can be confusing for the average computer user, who is inevitably exposed to file extensions, in spite of Microsoft’s and Apple’s best efforts (ahem) to hide such file extensions in their user interfaces.

But I don’t suspect that anything can be done about this now. The AAC file format with its “.m4a” file extension is here to stay and, on the whole, this can only be good news for people attached to “open” file formats.

8 Responses to “iTunes Store and EMI: A good deal for the AAC file format”

  1. ebernet1 says:

    “What is interesting here is that, for many years now, Apple has been trying to push its own file formats against the competition coming from Microsoft and other companies.”
    Well, if Microsoft had offered protected WMA on the Mac, things may be different. Apple offered protected AAC on both Mac AND Windows.

    Apple’s .mov is the basis for the container for all MPEG4 files, and the .mov container has won HANDS DOWN, as Final Cut has taken over, and the new Adobe Premiere is once again a QuickTIme authoring App. Even Microsoft has thrown in the towel, and now has the Mac use WM QuickTime components rather than a WM Player. The biggest winner these days with Internet streaming is Flash, not Real nor Windows Media.

    AAC is an open standard with less restriction by the licenses than MP3, as the current court cases show. They learned their lessons after MP3 and it has very simple legal terms (read unambiguous)

    AIFF is an open standard based on an Electronics Arts format, modified by Apple and Silicon Graphics. It is supported by ANY audio EDITING application.

    Anyone implementing MP3 can easily add support for AAC with a firmware upgrade.

    The expected extension for MPEG 4 Audio would be M4A, NOT AAC.

    EMI said that vendors are not beholden to any format and are free to choose to sell in MP3, AAC (MP4), WMA, or what have you.

    Your lack of knowledge is upsetting. Your article is riddled with errors. I recommend doing a little more research in the future.

  2. Pierre Igot says:

    I was speaking from a user’s point of view, not from an authoring point of view. And Apple’s .mov format existed before MPEG-4 was even invented. It just so happens that Apple played a big part in the creation of the MPEG-4 standard and integrated it into QuickTime.

    I said Microsoft, Real, and others. That includes YouTube and Flash video, of course.

    I didn’t say that AIFF was not supported. I just said it’s not the standard known/mentioned by most PC users when talking about uncompressed audio.

    And I didn’t say that the “.m4a'” was not correct, just that it wasn’t intuitive.

    Maybe before blaming my lack of knowledge, you should read my post more carefully.

  3. ebernet1 says:

    Paul Thurrot actually has some interesting pricing, pointing out some errors in my post. See here:

  4. WaltFrench says:

    It’s time to be more careful about the use of the words “compressed,” “lossless” etc in discussing music.

    ALL recorded formats are approximations to the original sound; many audio fanatics wish for better fidelity than CDs can provide. While most of us may find that the CD gives us all we want, it, too, is compressed from the original master recording, down to about 640 kbits/sec from several times that. Often various distortions are introduced to keep it at a steady volume (“loud enough”) for typical listening situations as envisioned by the studio engineers.

    The CD format is now 25 years old, and today’s higher-power computers can easily encode all of its data into about half the space and still be able to recover it exactly. That’s “lossless” compression in that all the CD contents are still there, but the 320 kbits/second do not have the full master tape fidelity. AAC and MP3 each sacrifice additional fidelity, hopefully in ways that even a careful listening won’t make too obvious.

    My experience is that a 192 kb/s AAC recording will have times when you can tell a difference from the CD but you may not be able to say which is “better” and you might not even care which you’d rather listen to. Given that I have much more music than I can squeeze onto my 30GB iPod, I’m OK with having a third more songs at 192 than I’d be able to choose from if they were 256.

    So the situation is much more relative than most discussions admit. Let’s lose the term “uncompressed CD quality” and just say something like, “works even for critical listenng.”

  5. kurisu says:

    I agree with you about the possible confusion the .m4a, .m4p, .m4v can induce, but remember that .mp4 is a container format (i.e. you can put whatever the heck you want in it, actually, by means of the so-called “private streams”), extremely similar to .mov (it’s basically 95% the same, it has the same “atom” system, support the same tags, etc.).
    Actually, .aac files DO exist, but those are raw audio streams, without tags, or info about the data of the file. (strictly speaking, .aac files are unencapsulated data files).
    The MP4 files can contain many different types of data, whereas MP3 files can only contain mp3 streams.
    While on paper, all files containing MPEG4 data should just be ” .mp4 “, I guess Apple wanted to make it easier to spot which of your files are audio, and which are video, and thus introduced various extensions to that end.

  6. Pierre Igot says:

    WaltFrench: I use “compressed” in the usual sense, i.e. in relation to AIFF/CD quality, which is uncompressed, but of course uses a certain sampling rate (44 KHz). I think it would be confusing to say that CD quality is a “compressed” format. Yes, it’s an approximation of “real” sound, but it’s compressed.

    So-called “lossless” compression can indeed reduce CD quality file size approximately by half, but that’s still too big to be manageable with today’s hard drive capacities. So for the foreseeable future, we’re still going to be relying on compressed formats, especially for so-called pop music.

    Personally I rip my CDs using 160 kbps AAC. It’s a compromise.

    kurisu: I know that MP4 is a “container” format. I am just saying that having a file format (AAC) whose name differs from the file extension associated with it is somewhat confusing for end users. Even if Apple were using “.mp4” instead of “.m4a” for the reasons you indicated, it would still be confusing.

    Of course, “MP3” itself is misleading as a file format name, but at least it’s the same as the file extension.

    I did suspect that .aac files existed, although I didn’t take the time to research this. Thanks for the pointers.

  7. ebernet1 says:

    Ok, grant you that. I’m sorry.

    I don’t think Apple ever tried to push their standard – they tried to push their container, and they won that. From the beginning QT was open to multiple CODECs, and Apple had very few. The Sorenson CODEC Apple often championed was also in AVI and is the most commonly used one in Flash Video.

    You wrote:
    “Apple’s .mov format existed before MPEG-4 was even invented.”
    Very true, and that was the point I was making. It is the basis of MPEG4, implying that Apple WAS the winner as far as containers and transports went. Look here:

    For a thorough (albeit slightly biased view) of the adoption of QuickTime as the basis for MPEG-4, look here:


  8. kurisu says:

    By the way, a weird twist in this is that you can produce perfectly compliant mp4 files that contain mp3 streams… (without using “private streams”).

    And though people call me a bit extreme, I rip all my CDs in Apple Lossless (to my knowledge, the only lossless format that can be contained in mp4 containers). Granted it takes quite some space, and I have a NAS appliance to hold everything, but the sheer difference in quality that it makes on my studio monitors is worth it,at least to my ears.

    An added benefit to ripping everything in lossless is that when the new “codec du jour” makes its apparition, I can just convert the files without quality loss and more importantly without having to rip the CDs again and again :) Ripping 3000 discs is not something I want to do again.

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