At a press conference in London yesterday, Apple and music label EMI announced that starting in May the iTunes Store will offer tracks from select EMI artists in unencrypted AAC format, encoded at 256Kbps instead of the 128Kbps of standard iTunes Store fare. The unlocked, higher-bitrate songs will also be priced 30 percent higher than their restricted-format brethren.
On one hand, this is clearly welcome news for Linux users, since up until now the restricted M4P format of iTunes Store purchases made listening to them anywhere other than on a Windows or Mac machine an ordeal, to say the least. Unless there is some yet-to-be-disclosed wrinkle to the deal, most Linux audio players should be able to play the new AAC files through a free library like FAAD.
Projects like JHymn and QTFairUse periodically found a way to decrypt M4P files into vanilla AAC, but rarely was it a convenient solution. Often the decryption could only be done at real-time playback speeds or only on a platform with an official iTunes client. On top of that was the "arms race" factor -- Apple's periodic updates to the iTunes application or the store would break the decryption solution du jour.
The EMI-Apple deal also covers music videos, which will be made available for purchase in unencrypted format -- presumably standard MPEG4, since the currently offered video format is encrypted MPEG4. There should be no barrier to playing these files under Linux either.
On the other hand, accessing the iTunes Store to purchase such Linux-friendly material will not get any easier: only the iTunes application itself can access the store and process purchases. You can try running the Windows version of iTunes via WINE, but that is a gamble at best. I have done it successfully in the past, but between Apple's compatibility-breaking updates and WINE's complexity, it is not a solution that you can count on.
There used to be a working standalone iTunes Store client called SharpeMusique and a plug-in for Banshee based upon it, but both have fallen out of active maintenance. SharpMusique was released by Jon Lech Johansen, who has subsequently launched a commercial venture to try and license his reverse-engineered crack of iTunes' track encryption.
When the iTunes Store was exclusively selling encrypted content, permitting only the officially sanctioned client to interface with the store was imperative -- the client was responsible for encrypting the track with a unique user key after the raw, unencrypted version was downloaded. For unencrypted content, that is no longer necessary. Were Apple to let non-iTunes clients interface to the store it would still collect the revenue, and arguably more of it courtesy of more customers. Apple's bean-counters are certainly wise to that business opportunity, but cannot move on it so long as part of the store's inventory still requires encryption.
Hopefully, the EMI-Apple deal is a harbinger of things to come, not just on the unrestricted format front, but the unrestricted access front as well.