1 /* -----------------------------------------------------------------------------
2 Software License for The Fraunhofer FDK AAC Codec Library for Android
3
4 © Copyright 1995 - 2020 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 /*!
106 *
107 * \brief Calculate second order autocorrelation using 2 accumulators
108 *
109 */
110 #if !defined(FUNCTION_autoCorr2nd_real)
autoCorr2nd_real(ACORR_COEFS * ac,const FIXP_DBL * reBuffer,const int len)111 INT autoCorr2nd_real(
112 ACORR_COEFS *ac, /*!< Pointer to autocorrelation coeffs */
113 const FIXP_DBL *reBuffer, /*!< Pointer to to real part of input samples */
114 const int len /*!< Number input samples */
115 ) {
116 int j, autoCorrScaling, mScale;
117
118 FIXP_DBL accu1, accu2, accu3, accu4, accu5;
119
120 const FIXP_DBL *pReBuf;
121
122 const FIXP_DBL *realBuf = reBuffer;
123
124 const int len_scale = fMax(DFRACT_BITS - fNormz((FIXP_DBL)(len / 2)), 1);
125 /*
126 r11r,r22r
127 r01r,r12r
128 r02r
129 */
130 pReBuf = realBuf - 2;
131 accu5 =
132 ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3])) >>
133 len_scale);
134 pReBuf++;
135
136 /* len must be even */
137 accu1 = fPow2Div2(pReBuf[0]) >> len_scale;
138 accu3 = fMultDiv2(pReBuf[0], pReBuf[1]) >> len_scale;
139 pReBuf++;
140
141 for (j = (len - 2) >> 1; j != 0; j--, pReBuf += 2) {
142 accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pReBuf[1])) >> len_scale);
143
144 accu3 +=
145 ((fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pReBuf[1], pReBuf[2])) >>
146 len_scale);
147
148 accu5 +=
149 ((fMultDiv2(pReBuf[0], pReBuf[2]) + fMultDiv2(pReBuf[1], pReBuf[3])) >>
150 len_scale);
151 }
152
153 accu2 = (fPow2Div2(realBuf[-2]) >> len_scale);
154 accu2 += accu1;
155
156 accu1 += (fPow2Div2(realBuf[len - 2]) >> len_scale);
157
158 accu4 = (fMultDiv2(realBuf[-1], realBuf[-2]) >> len_scale);
159 accu4 += accu3;
160
161 accu3 += (fMultDiv2(realBuf[len - 1], realBuf[len - 2]) >> len_scale);
162
163 mScale = CntLeadingZeros(
164 (accu1 | accu2 | fAbs(accu3) | fAbs(accu4) | fAbs(accu5))) -
165 1;
166 autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/
167
168 /* Scale to common scale factor */
169 ac->r11r = accu1 << mScale;
170 ac->r22r = accu2 << mScale;
171 ac->r01r = accu3 << mScale;
172 ac->r12r = accu4 << mScale;
173 ac->r02r = accu5 << mScale;
174
175 ac->det = (fMultDiv2(ac->r11r, ac->r22r) - fMultDiv2(ac->r12r, ac->r12r));
176 mScale = CountLeadingBits(fAbs(ac->det));
177
178 ac->det <<= mScale;
179 ac->det_scale = mScale - 1;
180
181 return autoCorrScaling;
182 }
183 #endif
184
185 #if !defined(FUNCTION_autoCorr2nd_cplx)
autoCorr2nd_cplx(ACORR_COEFS * ac,const FIXP_DBL * reBuffer,const FIXP_DBL * imBuffer,const int len)186 INT autoCorr2nd_cplx(
187 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 (should be smaller than 128) */
191 ) {
192 int j, autoCorrScaling, mScale;
193
194 FIXP_DBL accu0, accu1, accu2, accu3, accu4, accu5, accu6, accu7, accu8;
195
196 const FIXP_DBL *pReBuf, *pImBuf;
197
198 const FIXP_DBL *realBuf = reBuffer;
199 const FIXP_DBL *imagBuf = imBuffer;
200
201 const int len_scale = fMax(DFRACT_BITS - fNormz((FIXP_DBL)len), 1);
202 /*
203 r00r,
204 r11r,r22r
205 r01r,r12r
206 r01i,r12i
207 r02r,r02i
208 */
209 accu1 = accu3 = accu5 = accu7 = accu8 = FL2FXCONST_DBL(0.0f);
210
211 pReBuf = realBuf - 2, pImBuf = imagBuf - 2;
212 accu7 +=
213 ((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
214 len_scale);
215 accu8 +=
216 ((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
217 len_scale);
218
219 pReBuf = realBuf - 1, pImBuf = imagBuf - 1;
220 for (j = (len - 1); j != 0; j--, pReBuf++, pImBuf++) {
221 accu1 += ((fPow2Div2(pReBuf[0]) + fPow2Div2(pImBuf[0])) >> len_scale);
222 accu3 +=
223 ((fMultDiv2(pReBuf[0], pReBuf[1]) + fMultDiv2(pImBuf[0], pImBuf[1])) >>
224 len_scale);
225 accu5 +=
226 ((fMultDiv2(pImBuf[1], pReBuf[0]) - fMultDiv2(pReBuf[1], pImBuf[0])) >>
227 len_scale);
228 accu7 +=
229 ((fMultDiv2(pReBuf[2], pReBuf[0]) + fMultDiv2(pImBuf[2], pImBuf[0])) >>
230 len_scale);
231 accu8 +=
232 ((fMultDiv2(pImBuf[2], pReBuf[0]) - fMultDiv2(pReBuf[2], pImBuf[0])) >>
233 len_scale);
234 }
235
236 accu2 = ((fPow2Div2(realBuf[-2]) + fPow2Div2(imagBuf[-2])) >> len_scale);
237 accu2 += accu1;
238
239 accu1 += ((fPow2Div2(realBuf[len - 2]) + fPow2Div2(imagBuf[len - 2])) >>
240 len_scale);
241 accu0 = ((fPow2Div2(realBuf[len - 1]) + fPow2Div2(imagBuf[len - 1])) >>
242 len_scale) -
243 ((fPow2Div2(realBuf[-1]) + fPow2Div2(imagBuf[-1])) >> len_scale);
244 accu0 += accu1;
245
246 accu4 = ((fMultDiv2(realBuf[-1], realBuf[-2]) +
247 fMultDiv2(imagBuf[-1], imagBuf[-2])) >>
248 len_scale);
249 accu4 += accu3;
250
251 accu3 += ((fMultDiv2(realBuf[len - 1], realBuf[len - 2]) +
252 fMultDiv2(imagBuf[len - 1], imagBuf[len - 2])) >>
253 len_scale);
254
255 accu6 = ((fMultDiv2(imagBuf[-1], realBuf[-2]) -
256 fMultDiv2(realBuf[-1], imagBuf[-2])) >>
257 len_scale);
258 accu6 += accu5;
259
260 accu5 += ((fMultDiv2(imagBuf[len - 1], realBuf[len - 2]) -
261 fMultDiv2(realBuf[len - 1], imagBuf[len - 2])) >>
262 len_scale);
263
264 mScale =
265 CntLeadingZeros((accu0 | accu1 | accu2 | fAbs(accu3) | fAbs(accu4) |
266 fAbs(accu5) | fAbs(accu6) | fAbs(accu7) | fAbs(accu8))) -
267 1;
268 autoCorrScaling = mScale - 1 - len_scale; /* -1 because of fMultDiv2*/
269
270 /* Scale to common scale factor */
271 ac->r00r = (FIXP_DBL)accu0 << mScale;
272 ac->r11r = (FIXP_DBL)accu1 << mScale;
273 ac->r22r = (FIXP_DBL)accu2 << mScale;
274 ac->r01r = (FIXP_DBL)accu3 << mScale;
275 ac->r12r = (FIXP_DBL)accu4 << mScale;
276 ac->r01i = (FIXP_DBL)accu5 << mScale;
277 ac->r12i = (FIXP_DBL)accu6 << mScale;
278 ac->r02r = (FIXP_DBL)accu7 << mScale;
279 ac->r02i = (FIXP_DBL)accu8 << mScale;
280
281 ac->det =
282 (fMultDiv2(ac->r11r, ac->r22r) >> 1) -
283 ((fMultDiv2(ac->r12r, ac->r12r) + fMultDiv2(ac->r12i, ac->r12i)) >> 1);
284 mScale = CntLeadingZeros(fAbs(ac->det)) - 1;
285
286 ac->det <<= mScale;
287 ac->det_scale = mScale - 2;
288
289 return autoCorrScaling;
290 }
291
292 #endif /* FUNCTION_autoCorr2nd_cplx */
293