b7eae7c0ebe82ce235db436f818de0f06712e063
2 /* -----------------------------------------------------------------------------------------------------------
3 Software License for The Fraunhofer FDK AAC Codec Library for Android
5 © Copyright 1995 - 2013 Fraunhofer-Gesellschaft zur Förderung der angewandten Forschung e.V.
9 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software that implements
10 the MPEG Advanced Audio Coding ("AAC") encoding and decoding scheme for digital audio.
11 This FDK AAC Codec software is intended to be used on a wide variety of Android devices.
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient general perceptual
14 audio codecs. AAC-ELD is considered the best-performing full-bandwidth communications codec by
15 independent studies and is widely deployed. AAC has been standardized by ISO and IEC as part
16 of the MPEG specifications.
18 Patent licenses for necessary patent claims for the FDK AAC Codec (including those of Fraunhofer)
19 may be obtained through Via Licensing (www.vialicensing.com) or through the respective patent owners
20 individually for the purpose of encoding or decoding bit streams in products that are compliant with
21 the ISO/IEC MPEG audio standards. Please note that most manufacturers of Android devices already license
22 these patent claims through Via Licensing or directly from the patent owners, and therefore FDK AAC Codec
23 software may already be covered under those patent licenses when it is used for those licensed purposes only.
25 Commercially-licensed AAC software libraries, including floating-point versions with enhanced sound quality,
26 are also available from Fraunhofer. Users are encouraged to check the Fraunhofer website for additional
27 applications information and documentation.
31 Redistribution and use in source and binary forms, with or without modification, are permitted without
32 payment of copyright license fees provided that you satisfy the following conditions:
34 You must retain the complete text of this software license in redistributions of the FDK AAC Codec or
35 your modifications thereto in source code form.
37 You must retain the complete text of this software license in the documentation and/or other materials
38 provided with redistributions of the FDK AAC Codec or your modifications thereto in binary form.
39 You must make available free of charge copies of the complete source code of the FDK AAC Codec and your
40 modifications thereto to recipients of copies in binary form.
42 The name of Fraunhofer may not be used to endorse or promote products derived from this library without
43 prior written permission.
45 You may not charge copyright license fees for anyone to use, copy or distribute the FDK AAC Codec
46 software or your modifications thereto.
48 Your modified versions of the FDK AAC Codec must carry prominent notices stating that you changed the software
49 and the date of any change. For modified versions of the FDK AAC Codec, the term
50 "Fraunhofer FDK AAC Codec Library for Android" must be replaced by the term
51 "Third-Party Modified Version of the Fraunhofer FDK AAC Codec Library for Android."
55 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without limitation the patents of Fraunhofer,
56 ARE GRANTED BY THIS SOFTWARE LICENSE. Fraunhofer provides no warranty of patent non-infringement with
57 respect to this software.
59 You may use this FDK AAC Codec software or modifications thereto only for purposes that are authorized
60 by appropriate patent licenses.
64 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright holders and contributors
65 "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, including but not limited to the implied warranties
66 of merchantability and fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
67 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary, or consequential damages,
68 including but not limited to procurement of substitute goods or services; loss of use, data, or profits,
69 or business interruption, however caused and on any theory of liability, whether in contract, strict
70 liability, or tort (including negligence), arising in any way out of the use of this software, even if
71 advised of the possibility of such damage.
73 5. CONTACT INFORMATION
75 Fraunhofer Institute for Integrated Circuits IIS
76 Attention: Audio and Multimedia Departments - FDK AAC LL
78 91058 Erlangen, Germany
80 www.iis.fraunhofer.de/amm
81 amm-info@iis.fraunhofer.de
82 ----------------------------------------------------------------------------------------------------------- */
84 /*************************** Fraunhofer IIS FDK Tools ***********************
86 Author(s): M. Lohwasser
87 Description: auto-correlation functions
89 ******************************************************************************/
91 #include "autocorr2nd.h"
95 /* If the accumulator does not provide enough overflow bits,
96 products have to be shifted down in the autocorrelation below. */
97 #define SHIFT_FACTOR (5)
98 #define SHIFT >> (SHIFT_FACTOR)
101 #if defined(__CC_ARM) || defined(__arm__)
102 #include "arm/autocorr2nd.cpp"
108 * \brief Calculate second order autocorrelation using 2 accumulators
111 #if !defined(FUNCTION_autoCorr2nd_real)
113 autoCorr2nd_real (ACORR_COEFS
*ac
, /*!< Pointer to autocorrelation coeffs */
114 const FIXP_DBL
*reBuffer
, /*!< Pointer to to real part of input samples */
115 const int len
/*!< Number input samples */
118 int j
, autoCorrScaling
, mScale
;
120 FIXP_DBL accu1
, accu2
, accu3
, accu4
, accu5
;
122 const FIXP_DBL
*pReBuf
;
124 const FIXP_DBL
*realBuf
= reBuffer
;
132 accu5
= ( (fMultDiv2(pReBuf
[0], pReBuf
[2]) +
133 fMultDiv2(pReBuf
[1], pReBuf
[3])) SHIFT
);
137 accu1
= fPow2Div2(pReBuf
[0]) SHIFT
;
138 accu3
= fMultDiv2(pReBuf
[0], pReBuf
[1]) SHIFT
;
141 for ( j
= (len
- 2)>>1; j
!= 0; j
--,pReBuf
+=2 ) {
143 accu1
+= ( (fPow2Div2(pReBuf
[0]) +
144 fPow2Div2(pReBuf
[1])) SHIFT
);
146 accu3
+= ( (fMultDiv2(pReBuf
[0], pReBuf
[1]) +
147 fMultDiv2(pReBuf
[1], pReBuf
[2])) SHIFT
);
149 accu5
+= ( (fMultDiv2(pReBuf
[0], pReBuf
[2]) +
150 fMultDiv2(pReBuf
[1], pReBuf
[3])) SHIFT
);
154 accu2
= (fPow2Div2(realBuf
[-2]) SHIFT
);
157 accu1
+= (fPow2Div2(realBuf
[len
- 2]) SHIFT
);
159 accu4
= (fMultDiv2(realBuf
[-1],realBuf
[-2]) SHIFT
);
162 accu3
+= (fMultDiv2(realBuf
[len
- 1],realBuf
[len
- 2]) SHIFT
);
164 mScale
= CntLeadingZeros( (accu1
| accu2
| fAbs(accu3
) | fAbs(accu4
) | fAbs(accu5
)) ) - 1;
165 autoCorrScaling
= mScale
- 1 - SHIFT_FACTOR
; /* -1 because of fMultDiv2*/
167 /* Scale to common scale factor */
168 ac
->r11r
= accu1
<< mScale
;
169 ac
->r22r
= accu2
<< mScale
;
170 ac
->r01r
= accu3
<< mScale
;
171 ac
->r12r
= accu4
<< mScale
;
172 ac
->r02r
= accu5
<< mScale
;
174 ac
->det
= (fMultDiv2(ac
->r11r
,ac
->r22r
) - fMultDiv2(ac
->r12r
,ac
->r12r
)) ;
175 mScale
= CountLeadingBits(fAbs(ac
->det
));
178 ac
->det_scale
= mScale
- 1;
180 return autoCorrScaling
;
184 #ifndef LOW_POWER_SBR_ONLY
185 #if !defined(FUNCTION_autoCorr2nd_cplx)
187 autoCorr2nd_cplx (ACORR_COEFS
*ac
, /*!< Pointer to autocorrelation coeffs */
188 const FIXP_DBL
*reBuffer
, /*!< Pointer to real part of input samples */
189 const FIXP_DBL
*imBuffer
, /*!< Pointer to imag part of input samples */
190 const int len
/*!< Number of input samples */
194 int j
, autoCorrScaling
, mScale
, len_scale
;
196 FIXP_DBL accu0
, accu1
,accu2
, accu3
, accu4
, accu5
, accu6
, accu7
, accu8
;
198 const FIXP_DBL
*pReBuf
, *pImBuf
;
200 const FIXP_DBL
*realBuf
= reBuffer
;
201 const FIXP_DBL
*imagBuf
= imBuffer
;
203 (len
>64) ? (len_scale
= 6) : (len_scale
= 5);
211 accu1
= accu3
= accu5
= accu7
= accu8
= FL2FXCONST_DBL(0.0f
);
213 pReBuf
= realBuf
-2, pImBuf
= imagBuf
-2;
214 accu7
+= ( (fMultDiv2(pReBuf
[2], pReBuf
[0]) + fMultDiv2(pImBuf
[2], pImBuf
[0])) >> len_scale
);
215 accu8
+= ( (fMultDiv2(pImBuf
[2], pReBuf
[0]) - fMultDiv2(pReBuf
[2], pImBuf
[0])) >> len_scale
);
217 pReBuf
= realBuf
-1, pImBuf
= imagBuf
-1;
218 for ( j
= (len
- 1); j
!= 0; j
--,pReBuf
++,pImBuf
++ ){
219 accu1
+= ( (fPow2Div2(pReBuf
[0] ) + fPow2Div2(pImBuf
[0] )) >> len_scale
);
220 accu3
+= ( (fMultDiv2(pReBuf
[0], pReBuf
[1]) + fMultDiv2(pImBuf
[0], pImBuf
[1])) >> len_scale
);
221 accu5
+= ( (fMultDiv2(pImBuf
[1], pReBuf
[0]) - fMultDiv2(pReBuf
[1], pImBuf
[0])) >> len_scale
);
222 accu7
+= ( (fMultDiv2(pReBuf
[2], pReBuf
[0]) + fMultDiv2(pImBuf
[2], pImBuf
[0])) >> len_scale
);
223 accu8
+= ( (fMultDiv2(pImBuf
[2], pReBuf
[0]) - fMultDiv2(pReBuf
[2], pImBuf
[0])) >> len_scale
);
226 accu2
= ( (fPow2Div2(realBuf
[-2]) + fPow2Div2(imagBuf
[-2])) >> len_scale
);
229 accu1
+= ( (fPow2Div2(realBuf
[len
-2]) +
230 fPow2Div2(imagBuf
[len
-2])) >> len_scale
);
231 accu0
= ( (fPow2Div2(realBuf
[len
-1]) +
232 fPow2Div2(imagBuf
[len
-1])) >> len_scale
) -
233 ( (fPow2Div2(realBuf
[-1]) +
234 fPow2Div2(imagBuf
[-1])) >> len_scale
);
237 accu4
= ( (fMultDiv2(realBuf
[-1], realBuf
[-2]) +
238 fMultDiv2(imagBuf
[-1], imagBuf
[-2])) >> len_scale
);
241 accu3
+= ( (fMultDiv2(realBuf
[len
-1], realBuf
[len
-2]) +
242 fMultDiv2(imagBuf
[len
-1], imagBuf
[len
-2])) >> len_scale
);
244 accu6
= ( (fMultDiv2(imagBuf
[-1], realBuf
[-2]) -
245 fMultDiv2(realBuf
[-1], imagBuf
[-2])) >> len_scale
);
248 accu5
+= ( (fMultDiv2(imagBuf
[len
- 1], realBuf
[len
- 2]) -
249 fMultDiv2(realBuf
[len
- 1], imagBuf
[len
- 2])) >> len_scale
);
251 mScale
= CntLeadingZeros( (accu0
| accu1
| accu2
| fAbs(accu3
) | fAbs(accu4
) | fAbs(accu5
) |
252 fAbs(accu6
) | fAbs(accu7
) | fAbs(accu8
)) ) - 1;
253 autoCorrScaling
= mScale
- 1 - len_scale
; /* -1 because of fMultDiv2*/
255 /* Scale to common scale factor */
256 ac
->r00r
= (FIXP_DBL
)accu0
<< mScale
;
257 ac
->r11r
= (FIXP_DBL
)accu1
<< mScale
;
258 ac
->r22r
= (FIXP_DBL
)accu2
<< mScale
;
259 ac
->r01r
= (FIXP_DBL
)accu3
<< mScale
;
260 ac
->r12r
= (FIXP_DBL
)accu4
<< mScale
;
261 ac
->r01i
= (FIXP_DBL
)accu5
<< mScale
;
262 ac
->r12i
= (FIXP_DBL
)accu6
<< mScale
;
263 ac
->r02r
= (FIXP_DBL
)accu7
<< mScale
;
264 ac
->r02i
= (FIXP_DBL
)accu8
<< mScale
;
266 ac
->det
= ( fMultDiv2(ac
->r11r
,ac
->r22r
) >> 1 ) -
267 ( (fMultDiv2(ac
->r12r
,ac
->r12r
) + fMultDiv2(ac
->r12i
,ac
->r12i
)) >> 1 );
268 mScale
= CountLeadingBits(fAbs(ac
->det
));
271 ac
->det_scale
= mScale
- 2;
273 return autoCorrScaling
;
275 #endif /* FUNCTION_autoCorr2nd_cplx */
276 #endif /* LOW_POWER_SBR_ONLY */