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+
+/* -----------------------------------------------------------------------------------------------------------
+Software License for The Fraunhofer FDK AAC Codec Library for Android
+
+© Copyright  1995 - 2012 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
+  All rights reserved.
+
+ 1.    INTRODUCTION
+The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
+the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
+This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
+
+AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
+audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
+independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
+of the MPEG specifications.
+
+Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
+may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
+individually for the purpose of encoding or decoding bit streams in products that are compliant with
+the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
+these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
+software may already be covered under those patent licenses when it is used for those licensed purposes only.
+
+Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
+are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
+applications information and documentation.
+
+2.    COPYRIGHT LICENSE
+
+Redistribution and use in source and binary forms, with or without modification, are permitted without
+payment of copyright license fees provided that you satisfy the following conditions:
+
+You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
+your modifications thereto in source code form.
+
+You must retain the complete text of this software license in the documentation and/or other materials
+provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
+You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
+modifications thereto to recipients of copies in binary form.
+
+The name of Fraunhofer may not be used to endorse or promote products derived from this library without
+prior written permission.
+
+You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
+software or your modifications thereto.
+
+Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
+and the date of any change. For modified versions of the FDK AAC Codec, the term
+"Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
+"Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
+
+3.    NO PATENT LICENSE
+
+NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
+ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
+respect to this software.
+
+You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
+by appropriate patent licenses.
+
+4.    DISCLAIMER
+
+This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
+"AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
+of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
+CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
+including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
+or business interruption, however caused and on any theory of liability, whether in contract, strict
+liability, or tort (including negligence), arising in any way out of the use of this software, even if
+advised of the possibility of such damage.
+
+5.    CONTACT INFORMATION
+
+Fraunhofer Institute for Integrated Circuits IIS
+Attention: Audio and Multimedia Departments - FDK AAC LL
+Am Wolfsmantel 33
+91058 Erlangen, Germany
+
+www.iis.fraunhofer.de/amm
+amm-info@iis.fraunhofer.de
+----------------------------------------------------------------------------------------------------------- */
+
+/******************************** MPEG Audio Encoder **************************
+
+   Initial author:       M. Werner
+   contents/description: Chaos measure calculation
+
+******************************************************************************/
+
+#include "chaosmeasure.h"
+
+/*****************************************************************************
+    functionname: FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast
+    description:  Eberlein method of chaos measure calculation by high-pass
+                  filtering amplitude spectrum
+                  A special case of FDKaacEnc_CalculateChaosMeasureTonalGeneric --
+                  highly optimized
+*****************************************************************************/
+static void
+FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast( FIXP_DBL  *RESTRICT paMDCTDataNM0,
+                               INT        numberOfLines,
+                               FIXP_DBL  *RESTRICT chaosMeasure )
+{
+  INT i, j;
+
+  /* calculate chaos measure by "peak filter" */
+  for (i=0; i<2; i++) {
+    /* make even and odd pass through data */
+    FIXP_DBL left,center; /* left, center tap of filter */
+
+    left   = (FIXP_DBL)((LONG)paMDCTDataNM0[i]^((LONG)paMDCTDataNM0[i]>>(DFRACT_BITS-1)));
+    center = (FIXP_DBL)((LONG)paMDCTDataNM0[i+2]^((LONG)paMDCTDataNM0[i+2]>>(DFRACT_BITS-1)));
+
+    for (j = i+2; j < numberOfLines - 2; j+=2) {
+      FIXP_DBL right = (FIXP_DBL)((LONG)paMDCTDataNM0[j+2]^((LONG)paMDCTDataNM0[j+2]>>(DFRACT_BITS-1)));
+      FIXP_DBL tmp = (left>>1)+(right>>1);
+
+      if (tmp < center ) {
+         INT leadingBits = CntLeadingZeros(center)-1;
+         tmp = schur_div(tmp<<leadingBits, center<<leadingBits, 8);
+         chaosMeasure[j] = fMult(tmp,tmp);
+      }
+      else {
+         chaosMeasure[j] = (FIXP_DBL)MAXVAL_DBL;
+      }
+
+      left   = center;
+      center = right;
+    }
+  }
+
+  /* provide chaos measure for first few lines */
+  chaosMeasure[0] = chaosMeasure[2];
+  chaosMeasure[1] = chaosMeasure[2];
+
+  /* provide chaos measure for last few lines */
+  for (i = (numberOfLines-3); i < numberOfLines; i++)
+    chaosMeasure[i] = FL2FXCONST_DBL(0.5);
+}
+
+
+/*****************************************************************************
+    functionname: FDKaacEnc_CalculateChaosMeasure
+    description:  calculates a chaosmeasure for every line, different methods
+                  are available. 0 means tonal, 1 means noiselike
+    returns:
+    input:        MDCT data, number of lines
+    output:       chaosMeasure
+*****************************************************************************/
+void
+FDKaacEnc_CalculateChaosMeasure( FIXP_DBL    *paMDCTDataNM0,
+                       INT          numberOfLines,
+                       FIXP_DBL    *chaosMeasure )
+
+{
+    FDKaacEnc_FDKaacEnc_CalculateChaosMeasurePeakFast( paMDCTDataNM0,
+                                   numberOfLines,
+                                   chaosMeasure );
+}
+