Plz add some tutorial/reference spots for AAC-SBR

Thanks in Advance

AAC + SBR is also called HE-AAC.

It refers to a codec designed for low bitrates, usually below 80 Kbps suitable for encoding music without irritating artifacts, although it doesn't produce transparency. Rather, it is just designed not to sound annoying.

I believe SBR means "Sub-Band Replication", it is a way of synthesising high frequency data that is filtered out of the original signal in a way that isn't annoying, and avoids harsh compression artefacts.

IIRC, it is Spectral Band Replication.



First 2 links from Google:
http://en.wikipedia.org/wiki/Spectral_band_replication
http://www.codingtechnologies.com/products/sbr.htm

where i find some AAC-SBR Test Streams ?