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)
autoCorr2nd_real(ACORR_COEFS * ac,const FIXP_DBL * reBuffer,const int len)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)
autoCorr2nd_cplx(ACORR_COEFS * ac,const FIXP_DBL * reBuffer,const FIXP_DBL * imBuffer,const int len)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