[Clubkill]

Are there any implications for the new MPEG-4 format as it relates to audio compression?

From Apple:

"MPEG-4 is designed to deliver DVD (MPEG-2) quality video at lower data rates and smaller file sizes. And the same folks who created the popular .mp3 file format — a.k.a. MPEG-1 layer III — developed the new Advanced Audio Coding (AAC) codec, providing much more efficient compression than MP3 with a quality rivaling that of uncompressed CD audio."

Anybody know about the new audio codec?

 

[Ricky]

Sure, AAC is not so new. I'm no expert at it, but I can tell you that it has better performance than mp3 at both high bitrates and low bitrates, has multichannel capabilities, and strong patent issues that make not possible to use it as freely as mp3 format.

 

[Oliver :)]

I just tested AAC with the Quicktime6 preview, and it rocks!
I might be even more impressed with smaller bitrates, the differences might also be more evident there, but at 256kbps it sounded quite a bit better than the 320kbps VBR7 MP3 I made of the same song. Better high-end detail, bass seemed a pinch more detailed, better stage, I even have the impression of better timing (need more testing), very very close to the CDDA file it came from.
Trouble is that my iBook interferes with my TAH (which I wrapped in aluminium foil, did help a bit, but I still had to connect it...brrrzzzz..) so the setup is far from perfect, but I cannot wait until Apple updates both iTunes and the iPod with AAC. If my math was right it would give my iPod additional 2 hours in capacity, and that not by loosing, but by gaining quality.

 

[Clubkill]

That is wicked. Good to hear.

What is the deal with the copyright issues? Could an individual encode his own music with the codec and keep it? Does it just relate to distribution etc.?

 

[Oliver :)]

I did not see anything DRM related concerning AAC, but I did not look for it either... all I can say is that it is no problem to take a CDDA-File and use Quicktime 6 preview to export it to MPEG4 Video (there is of course no video), and then get a neat .mp4 file afterwards, which does not even pretend to have video.