Difference between revisions of "Advanced Audio Coding"

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== Extensions ==
== Extensions ==


=== AAC+ ===
=== HE-AAC ===


[http://www.codingtechnologies.com/products/aacPlus.htm AACPlus] (a.k.a. AAC+) is LC-AAC + [http://www.codingtechnologies.com/products/sbr.htm SBR (Spectral Band Replication)] and aacPlus v2 means LC-AAC + [http://www.codingtechnologies.com/products/sbr.htm SBR (Spectral Band Replication)] + [http://www.codingtechnologies.com/products/paraSter.htm PS (Parametric Stereo)]. Standard LC-AAC decoders can decode aacPlus encoded files/streams but without [http://www.codingtechnologies.com/products/sbr.htm SBR] and [http://www.codingtechnologies.com/products/paraSter.htm PS] you do not get the full quality.
HE-AAC (also known as by the [[Dolby Technologies|Dolby]] trade name [http://www.codingtechnologies.com/products/aacPlus.htm aacPlus]) is AAC-LC + [[Spectral Band Replication|SBR (Spectral Band Replication)]] and HE-AAC v2 (aacPlus v2) is LC-AAC + SBR + [http://www.codingtechnologies.com/products/paraSter.htm PS (Parametric Stereo)]. Standard AAC-LC decoders can decode HE-AAC encoded files/streams but without SBR and PS you do not get the full quality.


* See also
* See also

Revision as of 19:12, 15 February 2009

Specification and reference source links.

Google has opensourced Android, which includes an Apache 2.0 licensed aac decoder:

Intel has source for its IPP based AAC decoder:

Real Networks has source for its Helix AAC fixedpoint decoder here:

Usually stored in an MP4 container.

See also Understanding AAC.

Extensions

HE-AAC

HE-AAC (also known as by the Dolby trade name aacPlus) is AAC-LC + SBR (Spectral Band Replication) and HE-AAC v2 (aacPlus v2) is LC-AAC + SBR + PS (Parametric Stereo). Standard AAC-LC decoders can decode HE-AAC encoded files/streams but without SBR and PS you do not get the full quality.

GAIN headers

See http://mp3gain.sourceforge.net and MP3 GAIN header.