Fraunhofer AAC codec.

License boilerplate update to follow.

Change-Id: I2810460c11a58b6d148d84673cc031f3685e79b5

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+/****************************************************************************
+
+                     (C) Copyright Fraunhofer IIS (2005)
+                               All Rights Reserved
+
+    Please be advised that this software and/or program delivery is
+    Confidential Information of Fraunhofer and subject to and covered by the
+
+    Fraunhofer IIS Software Evaluation Agreement
+    between Google Inc. and  Fraunhofer
+    effective and in full force since March 1, 2012.
+
+    You may use this software and/or program only under the terms and
+    conditions described in the above mentioned Fraunhofer IIS Software
+    Evaluation Agreement. Any other and/or further use requires a separate agreement.
+
+
+   This software and/or program is protected by copyright law and international
+   treaties. Any reproduction or distribution of this software and/or program,
+   or any portion of it, may result in severe civil and criminal penalties, and
+   will be prosecuted to the maximum extent possible under law.
+
+ $Id$
+
+*******************************************************************************/
+/*!
+\file
+\brief Sbr scaling factors, $Revision: 36841 $
+To deal with the dynamic range in the different processing stages, a
+fixed point specific code has to rely on scaling factors. A floating
+point code carries a scaling factor -- the exponent -- for each value,
+so scaling is not necessary there.
+
+The output of the core decoder (low band) is scaled up to cover as much
+as possible bits for each value. As high band and low band are processed
+in different algorithm sections, they require their own scaling
+factors. In addition, any static buffers, e.g. filter states, require a
+separate scaling factor as well. The code takes care to do the proper
+adjustment, if scaling factors of a filter state and the time signal differ.
+
+\sa #QMF_SCALE_FACTOR, \ref documentationOverview
+*/
+
+#ifndef __SBR_SCALE_H
+#define __SBR_SCALE_H
+
+/*!
+\verbatim
+  scale:
+    0             left aligned e.g. |max| >=0.5
+    FRACT_BITS-1  zero e.g |max| = 0
+\endverbatim
+
+  Dynamic scaling is used to achieve sufficient accuracy even when the signal
+  energy is low.  The dynamic framing of SBR produces a variable overlap area
+  where samples from the previous QMF-Analysis are stored. Depending on the
+  start position and stop position of the current SBR envelopes, the processing
+  buffer consists of differently scaled regions like illustrated in the below
+  figure.
+
+  \image html scales.png Scale
+*/
+
+
+#endif