1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3 
4 © Copyright  1995 - 2018 Fraunhofer-Gesellschaft zur Förderung der angewandten
5 Forschung e.V. All rights reserved.
6 
7  1.    INTRODUCTION
8 The Fraunhofer FDK AAC Codec Library for Android ("FDK AAC Codec") is software
9 that implements the MPEG Advanced Audio Coding ("AAC") encoding and decoding
10 scheme for digital audio. This FDK AAC Codec software is intended to be used on
11 a wide variety of Android devices.
12 
13 AAC's HE-AAC and HE-AAC v2 versions are regarded as today's most efficient
14 general perceptual audio codecs. AAC-ELD is considered the best-performing
15 full-bandwidth communications codec by independent studies and is widely
16 deployed. AAC has been standardized by ISO and IEC as part of the MPEG
17 specifications.
18 
19 Patent licenses for necessary patent claims for the FDK AAC Codec (including
20 those of Fraunhofer) may be obtained through Via Licensing
21 (www.vialicensing.com) or through the respective patent owners individually for
22 the purpose of encoding or decoding bit streams in products that are compliant
23 with the ISO/IEC MPEG audio standards. Please note that most manufacturers of
24 Android devices already license these patent claims through Via Licensing or
25 directly from the patent owners, and therefore FDK AAC Codec software may
26 already be covered under those patent licenses when it is used for those
27 licensed purposes only.
28 
29 Commercially-licensed AAC software libraries, including floating-point versions
30 with enhanced sound quality, are also available from Fraunhofer. Users are
31 encouraged to check the Fraunhofer website for additional applications
32 information and documentation.
33 
34 2.    COPYRIGHT LICENSE
35 
36 Redistribution and use in source and binary forms, with or without modification,
37 are permitted without payment of copyright license fees provided that you
38 satisfy the following conditions:
39 
40 You must retain the complete text of this software license in redistributions of
41 the FDK AAC Codec or your modifications thereto in source code form.
42 
43 You must retain the complete text of this software license in the documentation
44 and/or other materials provided with redistributions of the FDK AAC Codec or
45 your modifications thereto in binary form. You must make available free of
46 charge copies of the complete source code of the FDK AAC Codec and your
47 modifications thereto to recipients of copies in binary form.
48 
49 The name of Fraunhofer may not be used to endorse or promote products derived
50 from this library without prior written permission.
51 
52 You may not charge copyright license fees for anyone to use, copy or distribute
53 the FDK AAC Codec software or your modifications thereto.
54 
55 Your modified versions of the FDK AAC Codec must carry prominent notices stating
56 that you changed the software and the date of any change. For modified versions
57 of the FDK AAC Codec, the term "Fraunhofer FDK AAC Codec Library for Android"
58 must be replaced by the term "Third-Party Modified Version of the Fraunhofer FDK
59 AAC Codec Library for Android."
60 
61 3.    NO PATENT LICENSE
62 
63 NO EXPRESS OR IMPLIED LICENSES TO ANY PATENT CLAIMS, including without
64 limitation the patents of Fraunhofer, ARE GRANTED BY THIS SOFTWARE LICENSE.
65 Fraunhofer provides no warranty of patent non-infringement with respect to this
66 software.
67 
68 You may use this FDK AAC Codec software or modifications thereto only for
69 purposes that are authorized by appropriate patent licenses.
70 
71 4.    DISCLAIMER
72 
73 This FDK AAC Codec software is provided by Fraunhofer on behalf of the copyright
74 holders and contributors "AS IS" and WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES,
75 including but not limited to the implied warranties of merchantability and
76 fitness for a particular purpose. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR
77 CONTRIBUTORS BE LIABLE for any direct, indirect, incidental, special, exemplary,
78 or consequential damages, including but not limited to procurement of substitute
79 goods or services; loss of use, data, or profits, or business interruption,
80 however caused and on any theory of liability, whether in contract, strict
81 liability, or tort (including negligence), arising in any way out of the use of
82 this software, even if advised of the possibility of such damage.
83 
84 5.    CONTACT INFORMATION
85 
86 Fraunhofer Institute for Integrated Circuits IIS
87 Attention: Audio and Multimedia Departments - FDK AAC LL
88 Am Wolfsmantel 33
89 91058 Erlangen, Germany
90 
91 www.iis.fraunhofer.de/amm
92 amm-info@iis.fraunhofer.de
93 ----------------------------------------------------------------------------- */
94 
95 /******************* Library for basic calculation routines ********************
96 
97    Author(s):   M. Lohwasser
98 
99    Description: auto-correlation functions
100 
101 *******************************************************************************/
102 
103 #include "autocorr2nd.h"
104 
105 /*  If the accumulator does not provide enough overflow bits,
106     products have to be shifted down in the autocorrelation below. */
107 #define SHIFT_FACTOR (5)
108 #define SHIFT >> (SHIFT_FACTOR)
109 
110 /*!
111  *
112  * \brief Calculate second order autocorrelation using 2 accumulators
113  *
114  */
115 #if !defined(FUNCTION_autoCorr2nd_real)
116 INT autoCorr2nd_real(
117     ACORR_COEFS *ac,          /*!< Pointer to autocorrelation coeffs */
118     const FIXP_DBL *reBuffer, /*!< Pointer to to real part of input samples */
119     const int len             /*!< Number input samples */
120 ) {
121   int j, autoCorrScaling, mScale;
122 
123   FIXP_DBL accu1, accu2, accu3, accu4, accu5;
124 
125   const FIXP_DBL *pReBuf;
126 
127   const FIXP_DBL *realBuf = reBuffer;
128 
129   /*
130     r11r,r22r
131     r01r,r12r
132     r02r
133   */
134   pReBuf = realBuf - 2;
135   accu5 = ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3]))
136                SHIFT);
137   pReBuf++;
138 
139   /* len must be even */
140   accu1 = fPow2Div2(pReBuf[0]) SHIFT;
141   accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) SHIFT;
142   pReBuf++;
143 
144   for (j = (len - 2) >> 1; j != 0; j--, pReBuf += 2) {
145     accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pReBuf[1])) SHIFT);
146 
147     accu3 += ((fMultDiv2(pReBuf[0], pReBuf[1]) +
148                fMultDiv2(pReBuf[1], pReBuf[2])) SHIFT);
149 
150     accu5 += ((fMultDiv2(pReBuf[0], pReBuf[2]) +
151                fMultDiv2(pReBuf[1], pReBuf[3])) SHIFT);
152   }
153 
154   accu2 = (fPow2Div2(realBuf[-2]) SHIFT);
155   accu2 += accu1;
156 
157   accu1 += (fPow2Div2(realBuf[len - 2]) SHIFT);
158 
159   accu4 = (fMultDiv2(realBuf[-1], realBuf[-2]) SHIFT);
160   accu4 += accu3;
161 
162   accu3 += (fMultDiv2(realBuf[len - 1], realBuf[len - 2]) SHIFT);
163 
164   mScale = CntLeadingZeros(
165                (accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5))) -
166            1;
167   autoCorrScaling = mScale - 1 - SHIFT_FACTOR; /* -1 because of fMultDiv2*/
168 
169   /* Scale to common scale factor */
170   ac->r11r = accu1 << mScale;
171   ac->r22r = accu2 << mScale;
172   ac->r01r = accu3 << mScale;
173   ac->r12r = accu4 << mScale;
174   ac->r02r = accu5 << mScale;
175 
176   ac->det = (fMultDiv2(ac->r11r, ac->r22r) - fMultDiv2(ac->r12r, ac->r12r));
177   mScale = CountLeadingBits(fAbs(ac->det));
178 
179   ac->det <<= mScale;
180   ac->det_scale = mScale - 1;
181 
182   return autoCorrScaling;
183 }
184 #endif
185 
186 #if !defined(FUNCTION_autoCorr2nd_cplx)
187 INT autoCorr2nd_cplx(
188     ACORR_COEFS *ac,          /*!< Pointer to autocorrelation coeffs */
189     const FIXP_DBL *reBuffer, /*!< Pointer to real part of input samples */
190     const FIXP_DBL *imBuffer, /*!< Pointer to imag part of input samples */
191     const int len /*!< Number of input samples (should be smaller than 128) */
192 ) {
193   int j, autoCorrScaling, mScale, len_scale;
194 
195   FIXP_DBL accu0, accu1, accu2, accu3, accu4, accu5, accu6, accu7, accu8;
196 
197   const FIXP_DBL *pReBuf, *pImBuf;
198 
199   const FIXP_DBL *realBuf = reBuffer;
200   const FIXP_DBL *imagBuf = imBuffer;
201 
202   (len > 64) ? (len_scale = 6) : (len_scale = 5);
203   /*
204     r00r,
205     r11r,r22r
206     r01r,r12r
207     r01i,r12i
208     r02r,r02i
209   */
210   accu1 = accu3 = accu5 = accu7 = accu8 = FL2FXCONST_DBL(0.0f);
211 
212   pReBuf = realBuf - 2, pImBuf = imagBuf - 2;
213   accu7 +=
214       ((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
215        len_scale);
216   accu8 +=
217       ((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
218        len_scale);
219 
220   pReBuf = realBuf - 1, pImBuf = imagBuf - 1;
221   for (j = (len - 1); j != 0; j--, pReBuf++, pImBuf++) {
222     accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pImBuf[0])) >> len_scale);
223     accu3 +=
224         ((fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pImBuf[0], pImBuf[1])) >>
225          len_scale);
226     accu5 +=
227         ((fMultDiv2(pImBuf[1], pReBuf[0]) - fMultDiv2(pReBuf[1], pImBuf[0])) >>
228          len_scale);
229     accu7 +=
230         ((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
231          len_scale);
232     accu8 +=
233         ((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
234          len_scale);
235   }
236 
237   accu2 = ((fPow2Div2(realBuf[-2]) + fPow2Div2(imagBuf[-2])) >> len_scale);
238   accu2 += accu1;
239 
240   accu1 += ((fPow2Div2(realBuf[len - 2]) + fPow2Div2(imagBuf[len - 2])) >>
241             len_scale);
242   accu0 = ((fPow2Div2(realBuf[len - 1]) + fPow2Div2(imagBuf[len - 1])) >>
243            len_scale) -
244           ((fPow2Div2(realBuf[-1]) + fPow2Div2(imagBuf[-1])) >> len_scale);
245   accu0 += accu1;
246 
247   accu4 = ((fMultDiv2(realBuf[-1], realBuf[-2]) +
248             fMultDiv2(imagBuf[-1], imagBuf[-2])) >>
249            len_scale);
250   accu4 += accu3;
251 
252   accu3 += ((fMultDiv2(realBuf[len - 1], realBuf[len - 2]) +
253              fMultDiv2(imagBuf[len - 1], imagBuf[len - 2])) >>
254             len_scale);
255 
256   accu6 = ((fMultDiv2(imagBuf[-1], realBuf[-2]) -
257             fMultDiv2(realBuf[-1], imagBuf[-2])) >>
258            len_scale);
259   accu6 += accu5;
260 
261   accu5 += ((fMultDiv2(imagBuf[len - 1], realBuf[len - 2]) -
262              fMultDiv2(realBuf[len - 1], imagBuf[len - 2])) >>
263             len_scale);
264 
265   mScale =
266       CntLeadingZeros((accu0 | accu1 | accu2 | fAbs(accu3) | fAbs(accu4) |
267                        fAbs(accu5) | fAbs(accu6) | fAbs(accu7) | fAbs(accu8))) -
268       1;
269   autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/
270 
271   /* Scale to common scale factor */
272   ac->r00r = (FIXP_DBL)accu0 << mScale;
273   ac->r11r = (FIXP_DBL)accu1 << mScale;
274   ac->r22r = (FIXP_DBL)accu2 << mScale;
275   ac->r01r = (FIXP_DBL)accu3 << mScale;
276   ac->r12r = (FIXP_DBL)accu4 << mScale;
277   ac->r01i = (FIXP_DBL)accu5 << mScale;
278   ac->r12i = (FIXP_DBL)accu6 << mScale;
279   ac->r02r = (FIXP_DBL)accu7 << mScale;
280   ac->r02i = (FIXP_DBL)accu8 << mScale;
281 
282   ac->det =
283       (fMultDiv2(ac->r11r, ac->r22r) >> 1) -
284       ((fMultDiv2(ac->r12r, ac->r12r) + fMultDiv2(ac->r12i, ac->r12i)) >> 1);
285   mScale = CntLeadingZeros(fAbs(ac->det)) - 1;
286 
287   ac->det <<= mScale;
288   ac->det_scale = mScale - 2;
289 
290   return autoCorrScaling;
291 }
292 
293 #endif /* FUNCTION_autoCorr2nd_cplx */
294