Line data Source code
1 : /******************************************************************************************************
2 :
3 : (C) 2022-2025 IVAS codec Public Collaboration with portions copyright Dolby International AB, Ericsson AB,
4 : Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V., Huawei Technologies Co. LTD.,
5 : Koninklijke Philips N.V., Nippon Telegraph and Telephone Corporation, Nokia Technologies Oy, Orange,
6 : Panasonic Holdings Corporation, Qualcomm Technologies, Inc., VoiceAge Corporation, and other
7 : contributors to this repository. All Rights Reserved.
8 :
9 : This software is protected by copyright law and by international treaties.
10 : The IVAS codec Public Collaboration consisting of Dolby International AB, Ericsson AB,
11 : Fraunhofer-Gesellschaft zur Foerderung der angewandten Forschung e.V., Huawei Technologies Co. LTD.,
12 : Koninklijke Philips N.V., Nippon Telegraph and Telephone Corporation, Nokia Technologies Oy, Orange,
13 : Panasonic Holdings Corporation, Qualcomm Technologies, Inc., VoiceAge Corporation, and other
14 : contributors to this repository retain full ownership rights in their respective contributions in
15 : the software. This notice grants no license of any kind, including but not limited to patent
16 : license, nor is any license granted by implication, estoppel or otherwise.
17 :
18 : Contributors are required to enter into the IVAS codec Public Collaboration agreement before making
19 : contributions.
20 :
21 : This software is provided "AS IS", without any express or implied warranties. The software is in the
22 : development stage. It is intended exclusively for experts who have experience with such software and
23 : solely for the purpose of inspection. All implied warranties of non-infringement, merchantability
24 : and fitness for a particular purpose are hereby disclaimed and excluded.
25 :
26 : Any dispute, controversy or claim arising under or in relation to providing this software shall be
27 : submitted to and settled by the final, binding jurisdiction of the courts of Munich, Germany in
28 : accordance with the laws of the Federal Republic of Germany excluding its conflict of law rules and
29 : the United Nations Convention on Contracts on the International Sales of Goods.
30 :
31 : *******************************************************************************************************/
32 :
33 : /*====================================================================================
34 : EVS Codec 3GPP TS26.443 Nov 04, 2021. Version 12.14.0 / 13.10.0 / 14.6.0 / 15.4.0 / 16.3.0
35 : ====================================================================================*/
36 :
37 : #include <stdint.h>
38 : #include "options.h"
39 : #ifdef DEBUGGING
40 : #include "debug.h"
41 : #endif
42 : #include "prot.h"
43 : #include "rom_com.h"
44 : #include "wmc_auto.h"
45 :
46 : /*-----------------------------------------------------------------*
47 : * Local constants
48 : *-----------------------------------------------------------------*/
49 :
50 : #define N_MAX_FFT 1024
51 :
52 : /*---------------------------------------------------------------------*
53 : * ifft_rel()
54 : *
55 : * Calculate the inverse FFT of a real signal
56 : *
57 : * Based on the FORTRAN code from the article "Real-valued Fast Fourier Transform Algorithms"
58 : * by Sorensen, ... in IEEE Trans. on ASSP, Vol. ASSP-35, No. June 6th 1987.
59 : *
60 : * Input: the io[] signal containing the spectrum in the following order :
61 : *
62 : * Re[0], Re[1], .. Re[n/2], Im[n/2-1], .. Im[1]
63 : *---------------------------------------------------------------------*/
64 :
65 142379 : void ifft_rel(
66 : float io[], /* i/o: input/output vector */
67 : const int16_t n, /* i : vector length */
68 : const int16_t m /* i : log2 of vector length */
69 : )
70 : {
71 : int16_t i, j, k;
72 : int16_t step;
73 : int16_t n2, n4, n8, i0;
74 : int16_t is, id;
75 : float *x, *xi0, *xi1, *xi2, *xi3, *xi4, *xup1, *xdn6, *xup3, *xdn8;
76 : float xt;
77 : float r1;
78 : float t1, t2, t3, t4, t5;
79 : float cc1, cc3, ss1, ss3;
80 : const float *s, *s3, *c, *c3;
81 : const int16_t *idx;
82 : float temp[512];
83 : float n_inv;
84 :
85 142379 : n_inv = 1.0f / n;
86 :
87 : /*-----------------------------------------------------------------*
88 : * IFFT
89 : *-----------------------------------------------------------------*/
90 :
91 142379 : x = &io[-1];
92 142379 : n2 = 2 * n;
93 986360 : for ( k = 1; k < m; k++ )
94 : {
95 843981 : is = 0;
96 843981 : id = n2;
97 843981 : n2 = n2 >> 1;
98 843981 : n4 = n2 >> 2;
99 843981 : n8 = n4 >> 1;
100 2716467 : while ( is < n - 1 )
101 : {
102 1872486 : xi1 = x + is + 1;
103 1872486 : xi2 = xi1 + n4;
104 1872486 : xi3 = xi2 + n4;
105 1872486 : xi4 = xi3 + n4;
106 :
107 14829541 : for ( i = is; i < n; i += id )
108 : {
109 12957055 : t1 = *xi1 - *xi3;
110 12957055 : *xi1 += *xi3;
111 12957055 : *xi2 = 2.0f * *xi2;
112 12957055 : *xi3 = t1 - 2.0f * *xi4;
113 12957055 : *xi4 = t1 + 2.0f * *xi4;
114 12957055 : if ( n4 != 1 )
115 : {
116 6455302 : t1 = ( *( xi2 + n8 ) - *( xi1 + n8 ) ) * INV_SQRT_2;
117 6455302 : t2 = ( *( xi4 + n8 ) + *( xi3 + n8 ) ) * INV_SQRT_2;
118 :
119 6455302 : *( xi1 + n8 ) += *( xi2 + n8 );
120 6455302 : *( xi2 + n8 ) = *( xi4 + n8 ) - *( xi3 + n8 );
121 6455302 : *( xi3 + n8 ) = (float) ( 2.0f * ( -t2 - t1 ) );
122 6455302 : *( xi4 + n8 ) = (float) ( 2.0f * ( -t2 + t1 ) );
123 : }
124 12957055 : xi1 += id;
125 12957055 : xi2 += id;
126 12957055 : xi3 += id;
127 12957055 : xi4 += id;
128 : }
129 1872486 : is = 2 * id - n2;
130 1872486 : id = 4 * id;
131 : }
132 843981 : step = N_MAX_FFT / n2;
133 :
134 843981 : s = sincos_t_ext + step;
135 843981 : c = s + N_MAX_FFT / 4;
136 843981 : s3 = sincos_t_ext + 3 * step;
137 843981 : c3 = s3 + N_MAX_FFT / 4;
138 9777368 : for ( j = 2; j <= n8; j++ )
139 : {
140 8933387 : cc1 = *c;
141 8933387 : ss1 = *s;
142 8933387 : cc3 = *c3;
143 8933387 : ss3 = *s3;
144 :
145 8933387 : is = 0;
146 8933387 : id = 2 * n2;
147 :
148 8933387 : c += step;
149 8933387 : s += step;
150 :
151 8933387 : c3 += 3 * step;
152 8933387 : s3 += 3 * step;
153 20017956 : while ( is < n - 1 )
154 : {
155 11084569 : xup1 = x + j + is;
156 11084569 : xup3 = xup1 + 2 * n4;
157 11084569 : xdn6 = xup3 - 2 * j + 2;
158 11084569 : xdn8 = xdn6 + 2 * n4;
159 :
160 27675136 : for ( i = is; i < n; i += id )
161 : {
162 16590567 : t1 = *xup1 - *xdn6;
163 16590567 : *xup1 = *xup1 + *xdn6;
164 16590567 : xup1 += n4;
165 16590567 : xdn6 -= n4;
166 :
167 16590567 : t2 = *xdn6 - *xup1;
168 16590567 : *xdn6 = *xup1 + *xdn6;
169 :
170 16590567 : xdn6 += n4;
171 16590567 : t3 = *xdn8 + *xup3;
172 16590567 : *xdn6 = *xdn8 - *xup3;
173 :
174 16590567 : xup3 += n4;
175 16590567 : xdn8 -= n4;
176 :
177 16590567 : t4 = *xup3 + *xdn8;
178 16590567 : *xup1 = *xup3 - *xdn8;
179 :
180 16590567 : t5 = t1 - t4;
181 16590567 : t1 = t1 + t4;
182 16590567 : t4 = t2 - t3;
183 16590567 : t2 = t2 + t3;
184 16590567 : *xup3 = t1 * cc3 - t2 * ss3;
185 16590567 : xup3 -= n4;
186 16590567 : *xup3 = t5 * cc1 + t4 * ss1;
187 16590567 : *xdn8 = -t4 * cc1 + t5 * ss1;
188 :
189 16590567 : xdn8 += n4;
190 16590567 : *xdn8 = t2 * cc3 + t1 * ss3;
191 :
192 16590567 : xup1 -= n4;
193 16590567 : xup1 += id;
194 16590567 : xup3 += id;
195 16590567 : xdn6 += id;
196 16590567 : xdn8 += id;
197 : }
198 11084569 : is = 2 * id - n2;
199 11084569 : id = 4 * id;
200 : }
201 : }
202 : }
203 :
204 : /*-----------------------------------------------------------------*
205 : * Length two butterflies
206 : *-----------------------------------------------------------------*/
207 :
208 142379 : is = 1;
209 142379 : id = 4;
210 683523 : while ( is < n )
211 : {
212 541144 : xi0 = x + is;
213 541144 : xi1 = xi0 + 1;
214 :
215 13594127 : for ( i0 = is; i0 <= n; i0 += id )
216 : {
217 13052983 : r1 = *xi0;
218 13052983 : *xi0 = r1 + *xi1;
219 13052983 : *xi1 = r1 - *xi1;
220 13052983 : xi0 += id;
221 13052983 : xi1 += id;
222 : }
223 541144 : is = 2 * id - 1;
224 541144 : id = 4 * id;
225 : }
226 :
227 : /*-----------------------------------------------------------------*
228 : * Digit reverse counter
229 : *-----------------------------------------------------------------*/
230 :
231 142379 : idx = fft256_read_indexes;
232 142379 : xi0 = &temp[0] - 1;
233 142379 : if ( n == 128 )
234 : {
235 0 : for ( i = 0; i < n; i++ )
236 : {
237 0 : j = *idx++;
238 0 : temp[i] = x[1 + ( j >> 1 )];
239 : }
240 : }
241 142379 : else if ( n == 256 )
242 : {
243 704437 : for ( i = 0; i < n; i++ )
244 : {
245 701696 : j = *idx++;
246 701696 : temp[i] = x[1 + j];
247 : }
248 : }
249 139638 : else if ( n == 512 )
250 : {
251 17740196 : for ( i = 0; i < 256; i++ )
252 : {
253 17671168 : j = *idx++;
254 17671168 : temp[i] = x[1 + 2 * j];
255 17671168 : temp[i + 256] = x[2 + 2 * j];
256 : }
257 : }
258 : else
259 : {
260 70610 : xi0 = x;
261 70610 : j = 1;
262 3065440 : for ( i = 1; i < n; i++ )
263 : {
264 2994830 : if ( i < j )
265 : {
266 1303420 : xt = x[j];
267 1303420 : x[j] = x[i];
268 1303420 : x[i] = xt;
269 : }
270 2994830 : k = n >> 1;
271 5646480 : while ( k < j )
272 : {
273 2651650 : j = j - k;
274 2651650 : k = k >> 1;
275 : }
276 2994830 : j = j + k;
277 : }
278 : }
279 :
280 : /*-----------------------------------------------------------------*
281 : * Normalization
282 : *-----------------------------------------------------------------*/
283 :
284 39251851 : for ( i = 1; i <= n; i++ )
285 : {
286 39109472 : x[i] = xi0[i] * n_inv;
287 : }
288 :
289 142379 : return;
290 : }
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