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AAC has several patents and needs to be licensed. Both MP3 and AAC are open formats (in that the format is documented), but they're not free. One of the major roles of MPEG (the organization) is to act as a patent pool for licensing their codecs.

Besides, I will not tolerate ANY DRM in my music files.

By "weird itunes format", I assume you're referring to the AAC MPEG4 format, which is an industry standard.

Also, there's only DRM in files that you buy from iTunes Music store. Please stop spreading the FUD that "AAC == DRM", because it's simply not true. Just like "EXE file" does not translate to "software which needs a registration key" and "VHS tape" does not translate to "protected by Macrovision". AAC is an open MPEG4 format to which DRM _CAN_ be applied. By default, it is not applied.

Also, what do you mean by "A2D" converter? Why would an MP3 player, which decodes digital signals into analog signals which your ear can hear need an "analog to digital to converter"?

Here is the AAC Licensing FAQ. Lots of answers there.

AAC is an open standard you insensitive clod!

Dolby licensing for MPEG-4 AAC:
- MPEG-4 AAC licensing
Reading the FAQ, you realise that you still have to pay something, due to Dolby's patents.

AAC implementations:
- FAAC
- XMMS AAC plugin

OK, here we go:

If you mean that the iTunes software only supports AAC, then you're wrong. It supports wav, MP3, AAC, and probably a few others.

If you mean iTunes music store only supports AAC, then you're right.
On the flip side, the Dell store only supplies files in the proprietary WMA format.

Checking on the licensing FAQ for MPEG4-AAC, it would appear that fees are charged for sales of encoders/decoders. No word in there on what happens with freely available ones.

As for the DRM being proprietary, well, what did you expect? Do you really think the RIAA is going to allow someone to distrubte digital copies of their product without making sure there's strict controls on who can use them and how they can do so?

The WMA files you get from the Dell DJ music store are going to have DRM in them too, and you better believe that it's going to be proprietary.

Which is curious, considering the fact that the AAC format is an industry standard, while the WMA format is purely a Microsoft format.

AAC is a proprietary format designed by Dolby Laboratories (Sony and Fraunhofer signed on after the fact) which requires a license to use. The licensing terms can be found here.

WMA is a proprietary format developed by Microsoft. It is a proven industry standard, already in use by thousands of consumer-level electronic devices. The licensing terms can be found here.

Note that AAC is considerably more expensive to use, and therefore isn't any more "open" than WMA. And given that WMA is used by thousands more devices than AAC, wouldn't it be considered the "industry standard" and not the other way around?

• AudioCoding
• AAC input plugin for XMMS

Actually, Apple won't start making a profit on this until they sell several songs to each downloader of the iTunes software. Remember that because it includes mp3 and AAC encoders, they've got to pay Fraunhofer $2.50 for each download (that's assuming that they're not getting a volume discount), and Dolby about 12 cents.

Files *created* by iTunes when you rip your CDs are standard AAC files. However, files downloaded from the music store are NOT standard AAC files, and the DRM is most definitely NOT "volutarily enforced" by itunes. They are encrypted and keyed to the computer which you license with Apple.

Files *created* by iTunes when you rip your CDs are standard AAC files. However, files downloaded from the music store are NOT standard AAC files, and the DRM is most definitely NOT "volutarily enforced" by itunes. They are encrypted and keyed to the computer which you license with Apple.

DRM issues aside, AAC has the advantage of being an open audio format. Anyone can implement AAC and not need a license from M$ or Apple, or trying to reverse engineer the software.

That's odd. I thought that AAC was licensed by Dolby. I don't see any exemption there for Free/Open Source software, though there may be one I haven't seen. It look to me that it requires a pay license to distribute both decoders and encoders.

AAC Licensing
In other words, it's not free as in ogg.

From Apple's AAC page

Because of its exceptional performance and quality, Advanced Audio Coding (AAC) is at the core of the MPEG-4 and 3GPP specifications and is the new audio codec of choice for Internet, wireless, and digital broadcast arenas. AAC provides audio encoding that compresses much more efficiently than older formats such as MP3, yet delivers quality rivaling that of uncompressed CD audio.

AAC was developed by the MPEG group that includes Dolby, Fraunhofer (FhG), AT&T, Sony, and Nokia--companies that have also been involved in the development of audio codecs such as MP3 and AC3 (also known as Dolby Digital). The AAC codec in QuickTime 6 builds upon new, state-of-the art signal processing technology from Dolby Laboratories and brings true variable bit rate (VBR) audio encoding to QuickTime.

From Via Licensing

MPEG-4 AAC has been specified as the high-quality general audio coder for 3G wireless terminals. Apple Computer has incorporated MPEG-4 AAC into QuickTime 6 and iTunes 4, as well as the latest version of its award-winning iPod portable music player. The Digital Radio Mondiale system (the next-generation digital replacement for radio broadcasting under 30 MHZ) builds on the audio coding of MPEG-4 AAC. These exciting platforms represent the state of the art in audio coding--and Via Licensing is pleased to offer the MPEG-4 AAC Patent License Agreement.

The MPEG-4 AAC standard incorporates MPEG-2 AAC, forming the basis of the MPEG-4 audio compression technology for data rates above 32 kbps per channel. Additional tools increase the effectiveness of MPEG-2 AAC at lower bit rates, and add scalability or error resilience characteristics. These additional tools extend AAC into its MPEG-4 incarnation (ISO/IEC 14496-3, Subpart 4).

A copy of the MPEG-4 Audio standard can be purchased from the ISO online store (search for "14496-3").

I should say one very big reason to run Linux: Eric S. Raymond said it best with his arguement against OS X's core, Darwin, when it first came out.

License problems don't seem like a big deal for an operating system someone else is working on but it will always bother me that they took FreeBSD and made it not-exactly-free. I just can't see the strategy behind that, especially now with OS X's popularity.

Also, "closed-source so those that know better" just doesn't fly with me and most people here at slashdot. Open Source projects are generally quite good at removing excess code. You mentioned Quicktime? I just can't see Apple's music format of choice, AAC, as going anywhere outside of apple with IT'S moronic license. Ogg Vorbis does very well completely open source.

Actually it's not; you have to pay to distribute encoders or decoders.

And AAC [apple.com] will beat Vorbis at about the same bitrate as well.

Though AAC's licensing leaves a lot to be desired.

Considering that every trailer they release uses more and more obscure codecs making them actively hard to play on anything other than QuickTime itself (AAC anybody?)

Umm, AAC is a MPEG standard. And considering they ship music with their consumer products encoded in MP3 and their own audio application encodes only into MP3 I'd have to say your comments are pretty far off.

Also, it may be of interest to take a look here for AAC Audio licensing information:
http://www.vialicensing.com/products/mpeg4aac/lice nse.terms.html

Of all the online music providers, this should be a greater success.

My reasons for being reluctant for this technology to become commonplace mainly center around the specifications for the audio file's quality, and its ability to be backed up. All of the current online providers only offer MP3, WMA (shudder) and Real, none of which offer anywhere near acceptable listening quality for me to pay for. (any of these formats is acceptable for preview purposes)

In this respect, using AAC sounds like a great idea, and although AAC files can be DRM-enabled, Apple has required that every song have the ability to be burnt to CD (which effectively eliminates the DRM).

A dollar a song is still somewhat expensive, but again, as with everything Apple, you pay for quality. Hopefully the catalog selection is decent, otherwise it is doomed to fail under the weight of the crap pop that's out there now.. Out of print stuff would be ideal :)

Liner notes (perhaps in PDF) will hopefully be offered as well.

It's a bold move by Apple, one that will be interesting to follow.

For those who are interested, AAC is the "Advanced Audio Coding" codec, and apparantly a Dolby standard. It's the same format that BMG and Universal are using for their online downloads, and it claims to have better audio quality than MP3 while using 1/3 the space.

It does contain DRM tech to prevent copying. There appear to be a number of portable digital music players that support it, such as the Panasonic SV-SD80 and the Nokia Music Player.

For more info, see the AAC homepage and a Google cache of Dolby's announcement regarding BMG and Universal.

Personally, I'd rather see FLAC or some other lossless encoding available. But that'd give them DRM nightmares (burn it to CD as CD-A and the DRM is gone, but you can recreate the song perfectly - no transcoding issues). Oh well. They'll eventually get there.

The LA Times article says that the AAC files can be DRM locked, but that Apple has required that they can be burned onto a CD, which would unlock them.

Liquid's technology is just an envelope that can securely transfer any kind of file. There are even a few non-music files in the system for various specific purposes.

The audio compression types that I was aware of while I was there were mostly Dolby AAC with a handful of MP3s. They were working on WMA when I left the company, so I wouldn't be surprised if a lot of the current library is in that format.

Chris Owens
San Carlos, CA