[jmelrose]

Hi. In the info window of an AAC-encoded track in itunes there is a category called "profile" and in the files I make with itunes it is set to "low complexity." Below it is the Stereo/mono setting info, and the encoder information. Anyone know what the complexity is, what it impacts, etc?

Thanks,
J.Melrose

[jmelrose]

No one knows?

[JohnM15141]

Originally posted by jmelrose:
No one knows?

This blurb can be found in the iTunes Help:

From iTunes Help:
Variable Bit Rate Encoding (VBR): This setting varies the number of bits used to store the music depending on the complexity of the music. This can help keep file size to a minimum.

I guess Complexity is the quality of the sound, i.e if it's Mono-Voice it is not very complex, but if it is a high fidelity stereo surround sound Music Track it's very complex and needs a higher sample rate to catch it all.

[HalBou]

In an article called "AAC : life beyond MP3" from Hi-Fi News October 2000 (I found it on the web but don't remember where), they explained that :

"The AAC codec provides for two processing
settings—Low-Complexity Profile (LCP) and Main Profile (MP)—both of which were tested. Main Profile produces superior results but as the instructions accompanying the AAC codec warn: ‘Please note that all known commercially available (or upcoming) IC implementations of AAC decoding support AAC Low-Complexity Profile only.’"

I hope it helps