1/*
2 * Copyright (c) Lynne
3 *
4 * Power of two FFT:
5 * Copyright (c) Lynne
6 * Copyright (c) 2008 Loren Merritt
7 * Copyright (c) 2002 Fabrice Bellard
8 * Partly based on libdjbfft by D. J. Bernstein
9 *
10 * This file is part of FFmpeg.
11 *
12 * FFmpeg is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU Lesser General Public
14 * License as published by the Free Software Foundation; either
15 * version 2.1 of the License, or (at your option) any later version.
16 *
17 * FFmpeg is distributed in the hope that it will be useful,
18 * but WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
20 * Lesser General Public License for more details.
21 *
22 * You should have received a copy of the GNU Lesser General Public
23 * License along with FFmpeg; if not, write to the Free Software
24 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
25 */
26
27#define TABLE_DEF(name, size) \
28    DECLARE_ALIGNED(32, TXSample, TX_TAB(ff_tx_tab_ ##name))[size]
29
30#define SR_TABLE(len) \
31    TABLE_DEF(len, len/4 + 1)
32
33/* Power of two tables */
34SR_TABLE(8);
35SR_TABLE(16);
36SR_TABLE(32);
37SR_TABLE(64);
38SR_TABLE(128);
39SR_TABLE(256);
40SR_TABLE(512);
41SR_TABLE(1024);
42SR_TABLE(2048);
43SR_TABLE(4096);
44SR_TABLE(8192);
45SR_TABLE(16384);
46SR_TABLE(32768);
47SR_TABLE(65536);
48SR_TABLE(131072);
49
50/* Other factors' tables */
51TABLE_DEF(53, 8);
52TABLE_DEF( 7, 6);
53TABLE_DEF( 9, 8);
54
55typedef struct FFSRTabsInitOnce {
56    void (*func)(void);
57    AVOnce control;
58    int factors[TX_MAX_SUB]; /* Must be sorted high -> low */
59} FFSRTabsInitOnce;
60
61#define INIT_FF_SR_TAB(len)                                        \
62static av_cold void TX_TAB(ff_tx_init_tab_ ##len)(void)            \
63{                                                                  \
64    double freq = 2*M_PI/len;                                      \
65    TXSample *tab = TX_TAB(ff_tx_tab_ ##len);                      \
66                                                                   \
67    for (int i = 0; i < len/4; i++)                                \
68        *tab++ = RESCALE(cos(i*freq));                             \
69                                                                   \
70    *tab = 0;                                                      \
71}
72
73INIT_FF_SR_TAB(8)
74INIT_FF_SR_TAB(16)
75INIT_FF_SR_TAB(32)
76INIT_FF_SR_TAB(64)
77INIT_FF_SR_TAB(128)
78INIT_FF_SR_TAB(256)
79INIT_FF_SR_TAB(512)
80INIT_FF_SR_TAB(1024)
81INIT_FF_SR_TAB(2048)
82INIT_FF_SR_TAB(4096)
83INIT_FF_SR_TAB(8192)
84INIT_FF_SR_TAB(16384)
85INIT_FF_SR_TAB(32768)
86INIT_FF_SR_TAB(65536)
87INIT_FF_SR_TAB(131072)
88
89static FFSRTabsInitOnce sr_tabs_init_once[] = {
90    { TX_TAB(ff_tx_init_tab_8),      AV_ONCE_INIT },
91    { TX_TAB(ff_tx_init_tab_16),     AV_ONCE_INIT },
92    { TX_TAB(ff_tx_init_tab_32),     AV_ONCE_INIT },
93    { TX_TAB(ff_tx_init_tab_64),     AV_ONCE_INIT },
94    { TX_TAB(ff_tx_init_tab_128),    AV_ONCE_INIT },
95    { TX_TAB(ff_tx_init_tab_256),    AV_ONCE_INIT },
96    { TX_TAB(ff_tx_init_tab_512),    AV_ONCE_INIT },
97    { TX_TAB(ff_tx_init_tab_1024),   AV_ONCE_INIT },
98    { TX_TAB(ff_tx_init_tab_2048),   AV_ONCE_INIT },
99    { TX_TAB(ff_tx_init_tab_4096),   AV_ONCE_INIT },
100    { TX_TAB(ff_tx_init_tab_8192),   AV_ONCE_INIT },
101    { TX_TAB(ff_tx_init_tab_16384),  AV_ONCE_INIT },
102    { TX_TAB(ff_tx_init_tab_32768),  AV_ONCE_INIT },
103    { TX_TAB(ff_tx_init_tab_65536),  AV_ONCE_INIT },
104    { TX_TAB(ff_tx_init_tab_131072), AV_ONCE_INIT },
105};
106
107static av_cold void TX_TAB(ff_tx_init_tab_53)(void)
108{
109    TX_TAB(ff_tx_tab_53)[0] = RESCALE(cos(2 * M_PI / 12));
110    TX_TAB(ff_tx_tab_53)[1] = RESCALE(cos(2 * M_PI / 12));
111    TX_TAB(ff_tx_tab_53)[2] = RESCALE(cos(2 * M_PI /  6));
112    TX_TAB(ff_tx_tab_53)[3] = RESCALE(cos(2 * M_PI /  6));
113    TX_TAB(ff_tx_tab_53)[4] = RESCALE(cos(2 * M_PI /  5));
114    TX_TAB(ff_tx_tab_53)[5] = RESCALE(sin(2 * M_PI /  5));
115    TX_TAB(ff_tx_tab_53)[6] = RESCALE(cos(2 * M_PI / 10));
116    TX_TAB(ff_tx_tab_53)[7] = RESCALE(sin(2 * M_PI / 10));
117}
118
119static av_cold void TX_TAB(ff_tx_init_tab_7)(void)
120{
121    TX_TAB(ff_tx_tab_7)[0] = RESCALE(cos(2 * M_PI /  7));
122    TX_TAB(ff_tx_tab_7)[1] = RESCALE(sin(2 * M_PI /  7));
123    TX_TAB(ff_tx_tab_7)[2] = RESCALE(sin(2 * M_PI / 28));
124    TX_TAB(ff_tx_tab_7)[3] = RESCALE(cos(2 * M_PI / 28));
125    TX_TAB(ff_tx_tab_7)[4] = RESCALE(cos(2 * M_PI / 14));
126    TX_TAB(ff_tx_tab_7)[5] = RESCALE(sin(2 * M_PI / 14));
127}
128
129static av_cold void TX_TAB(ff_tx_init_tab_9)(void)
130{
131    TX_TAB(ff_tx_tab_9)[0] = RESCALE(cos(2 * M_PI /  3));
132    TX_TAB(ff_tx_tab_9)[1] = RESCALE(sin(2 * M_PI /  3));
133    TX_TAB(ff_tx_tab_9)[2] = RESCALE(cos(2 * M_PI /  9));
134    TX_TAB(ff_tx_tab_9)[3] = RESCALE(sin(2 * M_PI /  9));
135    TX_TAB(ff_tx_tab_9)[4] = RESCALE(cos(2 * M_PI / 36));
136    TX_TAB(ff_tx_tab_9)[5] = RESCALE(sin(2 * M_PI / 36));
137    TX_TAB(ff_tx_tab_9)[6] = TX_TAB(ff_tx_tab_9)[2] + TX_TAB(ff_tx_tab_9)[5];
138    TX_TAB(ff_tx_tab_9)[7] = TX_TAB(ff_tx_tab_9)[3] - TX_TAB(ff_tx_tab_9)[4];
139}
140
141static FFSRTabsInitOnce nptwo_tabs_init_once[] = {
142    { TX_TAB(ff_tx_init_tab_53),      AV_ONCE_INIT, { 15, 5, 3 } },
143    { TX_TAB(ff_tx_init_tab_9),       AV_ONCE_INIT, {  9 }       },
144    { TX_TAB(ff_tx_init_tab_7),       AV_ONCE_INIT, {  7 }       },
145};
146
147av_cold void TX_TAB(ff_tx_init_tabs)(int len)
148{
149    int factor_2 = ff_ctz(len);
150    if (factor_2) {
151        int idx = factor_2 - 3;
152        for (int i = 0; i <= idx; i++)
153            ff_thread_once(&sr_tabs_init_once[i].control,
154                            sr_tabs_init_once[i].func);
155        len >>= factor_2;
156    }
157
158    for (int i = 0; i < FF_ARRAY_ELEMS(nptwo_tabs_init_once); i++) {
159        int f, f_idx = 0;
160
161        if (len <= 1)
162            return;
163
164        while ((f = nptwo_tabs_init_once[i].factors[f_idx++])) {
165            if (f % len)
166                continue;
167
168            ff_thread_once(&nptwo_tabs_init_once[i].control,
169                            nptwo_tabs_init_once[i].func);
170            len /= f;
171            break;
172        }
173    }
174}
175
176static av_always_inline void fft3(TXComplex *out, TXComplex *in,
177                                  ptrdiff_t stride)
178{
179    TXComplex tmp[2];
180    const TXSample *tab = TX_TAB(ff_tx_tab_53);
181#ifdef TX_INT32
182    int64_t mtmp[4];
183#endif
184
185    BF(tmp[0].re, tmp[1].im, in[1].im, in[2].im);
186    BF(tmp[0].im, tmp[1].re, in[1].re, in[2].re);
187
188    out[0*stride].re = in[0].re + tmp[1].re;
189    out[0*stride].im = in[0].im + tmp[1].im;
190
191#ifdef TX_INT32
192    mtmp[0] = (int64_t)tab[0] * tmp[0].re;
193    mtmp[1] = (int64_t)tab[1] * tmp[0].im;
194    mtmp[2] = (int64_t)tab[2] * tmp[1].re;
195    mtmp[3] = (int64_t)tab[2] * tmp[1].im;
196    out[1*stride].re = in[0].re - (mtmp[2] + mtmp[0] + 0x40000000 >> 31);
197    out[1*stride].im = in[0].im - (mtmp[3] - mtmp[1] + 0x40000000 >> 31);
198    out[2*stride].re = in[0].re - (mtmp[2] - mtmp[0] + 0x40000000 >> 31);
199    out[2*stride].im = in[0].im - (mtmp[3] + mtmp[1] + 0x40000000 >> 31);
200#else
201    tmp[0].re = tab[0] * tmp[0].re;
202    tmp[0].im = tab[1] * tmp[0].im;
203    tmp[1].re = tab[2] * tmp[1].re;
204    tmp[1].im = tab[2] * tmp[1].im;
205    out[1*stride].re = in[0].re - tmp[1].re + tmp[0].re;
206    out[1*stride].im = in[0].im - tmp[1].im - tmp[0].im;
207    out[2*stride].re = in[0].re - tmp[1].re - tmp[0].re;
208    out[2*stride].im = in[0].im - tmp[1].im + tmp[0].im;
209#endif
210}
211
212#define DECL_FFT5(NAME, D0, D1, D2, D3, D4)                         \
213static av_always_inline void NAME(TXComplex *out, TXComplex *in,    \
214                                  ptrdiff_t stride)                 \
215{                                                                   \
216    TXComplex z0[4], t[6];                                          \
217    const TXSample *tab = TX_TAB(ff_tx_tab_53);                     \
218                                                                    \
219    BF(t[1].im, t[0].re, in[1].re, in[4].re);                       \
220    BF(t[1].re, t[0].im, in[1].im, in[4].im);                       \
221    BF(t[3].im, t[2].re, in[2].re, in[3].re);                       \
222    BF(t[3].re, t[2].im, in[2].im, in[3].im);                       \
223                                                                    \
224    out[D0*stride].re = in[0].re + t[0].re + t[2].re;               \
225    out[D0*stride].im = in[0].im + t[0].im + t[2].im;               \
226                                                                    \
227    SMUL(t[4].re, t[0].re, tab[4], tab[6], t[2].re, t[0].re);       \
228    SMUL(t[4].im, t[0].im, tab[4], tab[6], t[2].im, t[0].im);       \
229    CMUL(t[5].re, t[1].re, tab[5], tab[7], t[3].re, t[1].re);       \
230    CMUL(t[5].im, t[1].im, tab[5], tab[7], t[3].im, t[1].im);       \
231                                                                    \
232    BF(z0[0].re, z0[3].re, t[0].re, t[1].re);                       \
233    BF(z0[0].im, z0[3].im, t[0].im, t[1].im);                       \
234    BF(z0[2].re, z0[1].re, t[4].re, t[5].re);                       \
235    BF(z0[2].im, z0[1].im, t[4].im, t[5].im);                       \
236                                                                    \
237    out[D1*stride].re = in[0].re + z0[3].re;                        \
238    out[D1*stride].im = in[0].im + z0[0].im;                        \
239    out[D2*stride].re = in[0].re + z0[2].re;                        \
240    out[D2*stride].im = in[0].im + z0[1].im;                        \
241    out[D3*stride].re = in[0].re + z0[1].re;                        \
242    out[D3*stride].im = in[0].im + z0[2].im;                        \
243    out[D4*stride].re = in[0].re + z0[0].re;                        \
244    out[D4*stride].im = in[0].im + z0[3].im;                        \
245}
246
247DECL_FFT5(fft5,     0,  1,  2,  3,  4)
248DECL_FFT5(fft5_m1,  0,  6, 12,  3,  9)
249DECL_FFT5(fft5_m2, 10,  1,  7, 13,  4)
250DECL_FFT5(fft5_m3,  5, 11,  2,  8, 14)
251
252static av_always_inline void fft7(TXComplex *out, TXComplex *in,
253                                  ptrdiff_t stride)
254{
255    TXComplex t[6], z[3];
256    const TXComplex *tab = (const TXComplex *)TX_TAB(ff_tx_tab_7);
257#ifdef TX_INT32
258    int64_t mtmp[12];
259#endif
260
261    BF(t[1].re, t[0].re, in[1].re, in[6].re);
262    BF(t[1].im, t[0].im, in[1].im, in[6].im);
263    BF(t[3].re, t[2].re, in[2].re, in[5].re);
264    BF(t[3].im, t[2].im, in[2].im, in[5].im);
265    BF(t[5].re, t[4].re, in[3].re, in[4].re);
266    BF(t[5].im, t[4].im, in[3].im, in[4].im);
267
268    out[0*stride].re = in[0].re + t[0].re + t[2].re + t[4].re;
269    out[0*stride].im = in[0].im + t[0].im + t[2].im + t[4].im;
270
271#ifdef TX_INT32 /* NOTE: it's possible to do this with 16 mults but 72 adds */
272    mtmp[ 0] = ((int64_t)tab[0].re)*t[0].re - ((int64_t)tab[2].re)*t[4].re;
273    mtmp[ 1] = ((int64_t)tab[0].re)*t[4].re - ((int64_t)tab[1].re)*t[0].re;
274    mtmp[ 2] = ((int64_t)tab[0].re)*t[2].re - ((int64_t)tab[2].re)*t[0].re;
275    mtmp[ 3] = ((int64_t)tab[0].re)*t[0].im - ((int64_t)tab[1].re)*t[2].im;
276    mtmp[ 4] = ((int64_t)tab[0].re)*t[4].im - ((int64_t)tab[1].re)*t[0].im;
277    mtmp[ 5] = ((int64_t)tab[0].re)*t[2].im - ((int64_t)tab[2].re)*t[0].im;
278
279    mtmp[ 6] = ((int64_t)tab[2].im)*t[1].im + ((int64_t)tab[1].im)*t[5].im;
280    mtmp[ 7] = ((int64_t)tab[0].im)*t[5].im + ((int64_t)tab[2].im)*t[3].im;
281    mtmp[ 8] = ((int64_t)tab[2].im)*t[5].im + ((int64_t)tab[1].im)*t[3].im;
282    mtmp[ 9] = ((int64_t)tab[0].im)*t[1].re + ((int64_t)tab[1].im)*t[3].re;
283    mtmp[10] = ((int64_t)tab[2].im)*t[3].re + ((int64_t)tab[0].im)*t[5].re;
284    mtmp[11] = ((int64_t)tab[2].im)*t[1].re + ((int64_t)tab[1].im)*t[5].re;
285
286    z[0].re = (int32_t)(mtmp[ 0] - ((int64_t)tab[1].re)*t[2].re + 0x40000000 >> 31);
287    z[1].re = (int32_t)(mtmp[ 1] - ((int64_t)tab[2].re)*t[2].re + 0x40000000 >> 31);
288    z[2].re = (int32_t)(mtmp[ 2] - ((int64_t)tab[1].re)*t[4].re + 0x40000000 >> 31);
289    z[0].im = (int32_t)(mtmp[ 3] - ((int64_t)tab[2].re)*t[4].im + 0x40000000 >> 31);
290    z[1].im = (int32_t)(mtmp[ 4] - ((int64_t)tab[2].re)*t[2].im + 0x40000000 >> 31);
291    z[2].im = (int32_t)(mtmp[ 5] - ((int64_t)tab[1].re)*t[4].im + 0x40000000 >> 31);
292
293    t[0].re = (int32_t)(mtmp[ 6] - ((int64_t)tab[0].im)*t[3].im + 0x40000000 >> 31);
294    t[2].re = (int32_t)(mtmp[ 7] - ((int64_t)tab[1].im)*t[1].im + 0x40000000 >> 31);
295    t[4].re = (int32_t)(mtmp[ 8] + ((int64_t)tab[0].im)*t[1].im + 0x40000000 >> 31);
296    t[0].im = (int32_t)(mtmp[ 9] + ((int64_t)tab[2].im)*t[5].re + 0x40000000 >> 31);
297    t[2].im = (int32_t)(mtmp[10] - ((int64_t)tab[1].im)*t[1].re + 0x40000000 >> 31);
298    t[4].im = (int32_t)(mtmp[11] - ((int64_t)tab[0].im)*t[3].re + 0x40000000 >> 31);
299#else
300    z[0].re = tab[0].re*t[0].re - tab[2].re*t[4].re - tab[1].re*t[2].re;
301    z[1].re = tab[0].re*t[4].re - tab[1].re*t[0].re - tab[2].re*t[2].re;
302    z[2].re = tab[0].re*t[2].re - tab[2].re*t[0].re - tab[1].re*t[4].re;
303    z[0].im = tab[0].re*t[0].im - tab[1].re*t[2].im - tab[2].re*t[4].im;
304    z[1].im = tab[0].re*t[4].im - tab[1].re*t[0].im - tab[2].re*t[2].im;
305    z[2].im = tab[0].re*t[2].im - tab[2].re*t[0].im - tab[1].re*t[4].im;
306
307    /* It's possible to do t[4].re and t[0].im with 2 multiplies only by
308     * multiplying the sum of all with the average of the twiddles */
309
310    t[0].re = tab[2].im*t[1].im + tab[1].im*t[5].im - tab[0].im*t[3].im;
311    t[2].re = tab[0].im*t[5].im + tab[2].im*t[3].im - tab[1].im*t[1].im;
312    t[4].re = tab[2].im*t[5].im + tab[1].im*t[3].im + tab[0].im*t[1].im;
313    t[0].im = tab[0].im*t[1].re + tab[1].im*t[3].re + tab[2].im*t[5].re;
314    t[2].im = tab[2].im*t[3].re + tab[0].im*t[5].re - tab[1].im*t[1].re;
315    t[4].im = tab[2].im*t[1].re + tab[1].im*t[5].re - tab[0].im*t[3].re;
316#endif
317
318    BF(t[1].re, z[0].re, z[0].re, t[4].re);
319    BF(t[3].re, z[1].re, z[1].re, t[2].re);
320    BF(t[5].re, z[2].re, z[2].re, t[0].re);
321    BF(t[1].im, z[0].im, z[0].im, t[0].im);
322    BF(t[3].im, z[1].im, z[1].im, t[2].im);
323    BF(t[5].im, z[2].im, z[2].im, t[4].im);
324
325    out[1*stride].re = in[0].re + z[0].re;
326    out[1*stride].im = in[0].im + t[1].im;
327    out[2*stride].re = in[0].re + t[3].re;
328    out[2*stride].im = in[0].im + z[1].im;
329    out[3*stride].re = in[0].re + z[2].re;
330    out[3*stride].im = in[0].im + t[5].im;
331    out[4*stride].re = in[0].re + t[5].re;
332    out[4*stride].im = in[0].im + z[2].im;
333    out[5*stride].re = in[0].re + z[1].re;
334    out[5*stride].im = in[0].im + t[3].im;
335    out[6*stride].re = in[0].re + t[1].re;
336    out[6*stride].im = in[0].im + z[0].im;
337}
338
339static av_always_inline void fft9(TXComplex *out, TXComplex *in,
340                                  ptrdiff_t stride)
341{
342    const TXComplex *tab = (const TXComplex *)TX_TAB(ff_tx_tab_9);
343    TXComplex t[16], w[4], x[5], y[5], z[2];
344#ifdef TX_INT32
345    int64_t mtmp[12];
346#endif
347
348    BF(t[1].re, t[0].re, in[1].re, in[8].re);
349    BF(t[1].im, t[0].im, in[1].im, in[8].im);
350    BF(t[3].re, t[2].re, in[2].re, in[7].re);
351    BF(t[3].im, t[2].im, in[2].im, in[7].im);
352    BF(t[5].re, t[4].re, in[3].re, in[6].re);
353    BF(t[5].im, t[4].im, in[3].im, in[6].im);
354    BF(t[7].re, t[6].re, in[4].re, in[5].re);
355    BF(t[7].im, t[6].im, in[4].im, in[5].im);
356
357    w[0].re = t[0].re - t[6].re;
358    w[0].im = t[0].im - t[6].im;
359    w[1].re = t[2].re - t[6].re;
360    w[1].im = t[2].im - t[6].im;
361    w[2].re = t[1].re - t[7].re;
362    w[2].im = t[1].im - t[7].im;
363    w[3].re = t[3].re + t[7].re;
364    w[3].im = t[3].im + t[7].im;
365
366    z[0].re = in[0].re + t[4].re;
367    z[0].im = in[0].im + t[4].im;
368
369    z[1].re = t[0].re + t[2].re + t[6].re;
370    z[1].im = t[0].im + t[2].im + t[6].im;
371
372    out[0*stride].re = z[0].re + z[1].re;
373    out[0*stride].im = z[0].im + z[1].im;
374
375#ifdef TX_INT32
376    mtmp[0] = t[1].re - t[3].re + t[7].re;
377    mtmp[1] = t[1].im - t[3].im + t[7].im;
378
379    y[3].re = (int32_t)(((int64_t)tab[0].im)*mtmp[0] + 0x40000000 >> 31);
380    y[3].im = (int32_t)(((int64_t)tab[0].im)*mtmp[1] + 0x40000000 >> 31);
381
382    mtmp[0] = (int32_t)(((int64_t)tab[0].re)*z[1].re + 0x40000000 >> 31);
383    mtmp[1] = (int32_t)(((int64_t)tab[0].re)*z[1].im + 0x40000000 >> 31);
384    mtmp[2] = (int32_t)(((int64_t)tab[0].re)*t[4].re + 0x40000000 >> 31);
385    mtmp[3] = (int32_t)(((int64_t)tab[0].re)*t[4].im + 0x40000000 >> 31);
386
387    x[3].re = z[0].re  + (int32_t)mtmp[0];
388    x[3].im = z[0].im  + (int32_t)mtmp[1];
389    z[0].re = in[0].re + (int32_t)mtmp[2];
390    z[0].im = in[0].im + (int32_t)mtmp[3];
391
392    mtmp[0] = ((int64_t)tab[1].re)*w[0].re;
393    mtmp[1] = ((int64_t)tab[1].re)*w[0].im;
394    mtmp[2] = ((int64_t)tab[2].im)*w[0].re;
395    mtmp[3] = ((int64_t)tab[2].im)*w[0].im;
396    mtmp[4] = ((int64_t)tab[1].im)*w[2].re;
397    mtmp[5] = ((int64_t)tab[1].im)*w[2].im;
398    mtmp[6] = ((int64_t)tab[2].re)*w[2].re;
399    mtmp[7] = ((int64_t)tab[2].re)*w[2].im;
400
401    x[1].re = (int32_t)(mtmp[0] + ((int64_t)tab[2].im)*w[1].re + 0x40000000 >> 31);
402    x[1].im = (int32_t)(mtmp[1] + ((int64_t)tab[2].im)*w[1].im + 0x40000000 >> 31);
403    x[2].re = (int32_t)(mtmp[2] - ((int64_t)tab[3].re)*w[1].re + 0x40000000 >> 31);
404    x[2].im = (int32_t)(mtmp[3] - ((int64_t)tab[3].re)*w[1].im + 0x40000000 >> 31);
405    y[1].re = (int32_t)(mtmp[4] + ((int64_t)tab[2].re)*w[3].re + 0x40000000 >> 31);
406    y[1].im = (int32_t)(mtmp[5] + ((int64_t)tab[2].re)*w[3].im + 0x40000000 >> 31);
407    y[2].re = (int32_t)(mtmp[6] - ((int64_t)tab[3].im)*w[3].re + 0x40000000 >> 31);
408    y[2].im = (int32_t)(mtmp[7] - ((int64_t)tab[3].im)*w[3].im + 0x40000000 >> 31);
409
410    y[0].re = (int32_t)(((int64_t)tab[0].im)*t[5].re + 0x40000000 >> 31);
411    y[0].im = (int32_t)(((int64_t)tab[0].im)*t[5].im + 0x40000000 >> 31);
412
413#else
414    y[3].re = tab[0].im*(t[1].re - t[3].re + t[7].re);
415    y[3].im = tab[0].im*(t[1].im - t[3].im + t[7].im);
416
417    x[3].re = z[0].re  + tab[0].re*z[1].re;
418    x[3].im = z[0].im  + tab[0].re*z[1].im;
419    z[0].re = in[0].re + tab[0].re*t[4].re;
420    z[0].im = in[0].im + tab[0].re*t[4].im;
421
422    x[1].re = tab[1].re*w[0].re + tab[2].im*w[1].re;
423    x[1].im = tab[1].re*w[0].im + tab[2].im*w[1].im;
424    x[2].re = tab[2].im*w[0].re - tab[3].re*w[1].re;
425    x[2].im = tab[2].im*w[0].im - tab[3].re*w[1].im;
426    y[1].re = tab[1].im*w[2].re + tab[2].re*w[3].re;
427    y[1].im = tab[1].im*w[2].im + tab[2].re*w[3].im;
428    y[2].re = tab[2].re*w[2].re - tab[3].im*w[3].re;
429    y[2].im = tab[2].re*w[2].im - tab[3].im*w[3].im;
430
431    y[0].re = tab[0].im*t[5].re;
432    y[0].im = tab[0].im*t[5].im;
433#endif
434
435    x[4].re = x[1].re + x[2].re;
436    x[4].im = x[1].im + x[2].im;
437
438    y[4].re = y[1].re - y[2].re;
439    y[4].im = y[1].im - y[2].im;
440    x[1].re = z[0].re + x[1].re;
441    x[1].im = z[0].im + x[1].im;
442    y[1].re = y[0].re + y[1].re;
443    y[1].im = y[0].im + y[1].im;
444    x[2].re = z[0].re + x[2].re;
445    x[2].im = z[0].im + x[2].im;
446    y[2].re = y[2].re - y[0].re;
447    y[2].im = y[2].im - y[0].im;
448    x[4].re = z[0].re - x[4].re;
449    x[4].im = z[0].im - x[4].im;
450    y[4].re = y[0].re - y[4].re;
451    y[4].im = y[0].im - y[4].im;
452
453    out[1*stride] = (TXComplex){ x[1].re + y[1].im, x[1].im - y[1].re };
454    out[2*stride] = (TXComplex){ x[2].re + y[2].im, x[2].im - y[2].re };
455    out[3*stride] = (TXComplex){ x[3].re + y[3].im, x[3].im - y[3].re };
456    out[4*stride] = (TXComplex){ x[4].re + y[4].im, x[4].im - y[4].re };
457    out[5*stride] = (TXComplex){ x[4].re - y[4].im, x[4].im + y[4].re };
458    out[6*stride] = (TXComplex){ x[3].re - y[3].im, x[3].im + y[3].re };
459    out[7*stride] = (TXComplex){ x[2].re - y[2].im, x[2].im + y[2].re };
460    out[8*stride] = (TXComplex){ x[1].re - y[1].im, x[1].im + y[1].re };
461}
462
463static av_always_inline void fft15(TXComplex *out, TXComplex *in,
464                                   ptrdiff_t stride)
465{
466    TXComplex tmp[15];
467
468    for (int i = 0; i < 5; i++)
469        fft3(tmp + i, in + i*3, 5);
470
471    fft5_m1(out, tmp +  0, stride);
472    fft5_m2(out, tmp +  5, stride);
473    fft5_m3(out, tmp + 10, stride);
474}
475
476#define BUTTERFLIES(a0, a1, a2, a3)            \
477    do {                                       \
478        r0=a0.re;                              \
479        i0=a0.im;                              \
480        r1=a1.re;                              \
481        i1=a1.im;                              \
482        BF(t3, t5, t5, t1);                    \
483        BF(a2.re, a0.re, r0, t5);              \
484        BF(a3.im, a1.im, i1, t3);              \
485        BF(t4, t6, t2, t6);                    \
486        BF(a3.re, a1.re, r1, t4);              \
487        BF(a2.im, a0.im, i0, t6);              \
488    } while (0)
489
490#define TRANSFORM(a0, a1, a2, a3, wre, wim)    \
491    do {                                       \
492        CMUL(t1, t2, a2.re, a2.im, wre, -wim); \
493        CMUL(t5, t6, a3.re, a3.im, wre,  wim); \
494        BUTTERFLIES(a0, a1, a2, a3);           \
495    } while (0)
496
497/* z[0...8n-1], w[1...2n-1] */
498static inline void TX_NAME(ff_tx_fft_sr_combine)(TXComplex *z,
499                                                 const TXSample *cos, int len)
500{
501    int o1 = 2*len;
502    int o2 = 4*len;
503    int o3 = 6*len;
504    const TXSample *wim = cos + o1 - 7;
505    TXUSample t1, t2, t3, t4, t5, t6, r0, i0, r1, i1;
506
507    for (int i = 0; i < len; i += 4) {
508        TRANSFORM(z[0], z[o1 + 0], z[o2 + 0], z[o3 + 0], cos[0], wim[7]);
509        TRANSFORM(z[2], z[o1 + 2], z[o2 + 2], z[o3 + 2], cos[2], wim[5]);
510        TRANSFORM(z[4], z[o1 + 4], z[o2 + 4], z[o3 + 4], cos[4], wim[3]);
511        TRANSFORM(z[6], z[o1 + 6], z[o2 + 6], z[o3 + 6], cos[6], wim[1]);
512
513        TRANSFORM(z[1], z[o1 + 1], z[o2 + 1], z[o3 + 1], cos[1], wim[6]);
514        TRANSFORM(z[3], z[o1 + 3], z[o2 + 3], z[o3 + 3], cos[3], wim[4]);
515        TRANSFORM(z[5], z[o1 + 5], z[o2 + 5], z[o3 + 5], cos[5], wim[2]);
516        TRANSFORM(z[7], z[o1 + 7], z[o2 + 7], z[o3 + 7], cos[7], wim[0]);
517
518        z   += 2*4;
519        cos += 2*4;
520        wim -= 2*4;
521    }
522}
523
524static av_cold int TX_NAME(ff_tx_fft_sr_codelet_init)(AVTXContext *s,
525                                                      const FFTXCodelet *cd,
526                                                      uint64_t flags,
527                                                      FFTXCodeletOptions *opts,
528                                                      int len, int inv,
529                                                      const void *scale)
530{
531    TX_TAB(ff_tx_init_tabs)(len);
532    return ff_tx_gen_ptwo_revtab(s, opts ? opts->invert_lookup : 1);
533}
534
535#define DECL_SR_CODELET_DEF(n)                              \
536static const FFTXCodelet TX_NAME(ff_tx_fft##n##_ns_def) = { \
537    .name       = TX_NAME_STR("fft" #n "_ns"),              \
538    .function   = TX_NAME(ff_tx_fft##n##_ns),               \
539    .type       = TX_TYPE(FFT),                             \
540    .flags      = AV_TX_INPLACE | AV_TX_UNALIGNED |         \
541                  FF_TX_PRESHUFFLE,                         \
542    .factors[0] = 2,                                        \
543    .min_len    = n,                                        \
544    .max_len    = n,                                        \
545    .init       = TX_NAME(ff_tx_fft_sr_codelet_init),       \
546    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,                      \
547    .prio       = FF_TX_PRIO_BASE,                          \
548};
549
550#define DECL_SR_CODELET(n, n2, n4)                                   \
551static void TX_NAME(ff_tx_fft##n##_ns)(AVTXContext *s, void *dst,    \
552                                        void *src, ptrdiff_t stride) \
553{                                                                    \
554    TXComplex *z = dst;                                              \
555    const TXSample *cos = TX_TAB(ff_tx_tab_##n);                     \
556                                                                     \
557    TX_NAME(ff_tx_fft##n2##_ns)(s, z,        z,        stride);      \
558    TX_NAME(ff_tx_fft##n4##_ns)(s, z + n4*2, z + n4*2, stride);      \
559    TX_NAME(ff_tx_fft##n4##_ns)(s, z + n4*3, z + n4*3, stride);      \
560    TX_NAME(ff_tx_fft_sr_combine)(z, cos, n4 >> 1);                  \
561}                                                                    \
562                                                                     \
563DECL_SR_CODELET_DEF(n)
564
565static void TX_NAME(ff_tx_fft2_ns)(AVTXContext *s, void *dst,
566                                   void *src, ptrdiff_t stride)
567{
568    TXComplex *z = dst;
569    TXComplex tmp;
570
571    BF(tmp.re, z[0].re, z[0].re, z[1].re);
572    BF(tmp.im, z[0].im, z[0].im, z[1].im);
573    z[1] = tmp;
574}
575
576static void TX_NAME(ff_tx_fft4_ns)(AVTXContext *s, void *dst,
577                                   void *src, ptrdiff_t stride)
578{
579    TXComplex *z = dst;
580    TXSample t1, t2, t3, t4, t5, t6, t7, t8;
581
582    BF(t3, t1, z[0].re, z[1].re);
583    BF(t8, t6, z[3].re, z[2].re);
584    BF(z[2].re, z[0].re, t1, t6);
585    BF(t4, t2, z[0].im, z[1].im);
586    BF(t7, t5, z[2].im, z[3].im);
587    BF(z[3].im, z[1].im, t4, t8);
588    BF(z[3].re, z[1].re, t3, t7);
589    BF(z[2].im, z[0].im, t2, t5);
590}
591
592static void TX_NAME(ff_tx_fft8_ns)(AVTXContext *s, void *dst,
593                                   void *src, ptrdiff_t stride)
594{
595    TXComplex *z = dst;
596    TXSample t1, t2, t3, t4, t5, t6, r0, i0, r1, i1;
597    const TXSample cos = TX_TAB(ff_tx_tab_8)[1];
598
599    TX_NAME(ff_tx_fft4_ns)(s, z, z, stride);
600
601    BF(t1, z[5].re, z[4].re, -z[5].re);
602    BF(t2, z[5].im, z[4].im, -z[5].im);
603    BF(t5, z[7].re, z[6].re, -z[7].re);
604    BF(t6, z[7].im, z[6].im, -z[7].im);
605
606    BUTTERFLIES(z[0], z[2], z[4], z[6]);
607    TRANSFORM(z[1], z[3], z[5], z[7], cos, cos);
608}
609
610static void TX_NAME(ff_tx_fft16_ns)(AVTXContext *s, void *dst,
611                                    void *src, ptrdiff_t stride)
612{
613    TXComplex *z = dst;
614    const TXSample *cos = TX_TAB(ff_tx_tab_16);
615
616    TXSample t1, t2, t3, t4, t5, t6, r0, i0, r1, i1;
617    TXSample cos_16_1 = cos[1];
618    TXSample cos_16_2 = cos[2];
619    TXSample cos_16_3 = cos[3];
620
621    TX_NAME(ff_tx_fft8_ns)(s, z +  0, z +  0, stride);
622    TX_NAME(ff_tx_fft4_ns)(s, z +  8, z +  8, stride);
623    TX_NAME(ff_tx_fft4_ns)(s, z + 12, z + 12, stride);
624
625    t1 = z[ 8].re;
626    t2 = z[ 8].im;
627    t5 = z[12].re;
628    t6 = z[12].im;
629    BUTTERFLIES(z[0], z[4], z[8], z[12]);
630
631    TRANSFORM(z[ 2], z[ 6], z[10], z[14], cos_16_2, cos_16_2);
632    TRANSFORM(z[ 1], z[ 5], z[ 9], z[13], cos_16_1, cos_16_3);
633    TRANSFORM(z[ 3], z[ 7], z[11], z[15], cos_16_3, cos_16_1);
634}
635
636DECL_SR_CODELET_DEF(2)
637DECL_SR_CODELET_DEF(4)
638DECL_SR_CODELET_DEF(8)
639DECL_SR_CODELET_DEF(16)
640DECL_SR_CODELET(32,16,8)
641DECL_SR_CODELET(64,32,16)
642DECL_SR_CODELET(128,64,32)
643DECL_SR_CODELET(256,128,64)
644DECL_SR_CODELET(512,256,128)
645DECL_SR_CODELET(1024,512,256)
646DECL_SR_CODELET(2048,1024,512)
647DECL_SR_CODELET(4096,2048,1024)
648DECL_SR_CODELET(8192,4096,2048)
649DECL_SR_CODELET(16384,8192,4096)
650DECL_SR_CODELET(32768,16384,8192)
651DECL_SR_CODELET(65536,32768,16384)
652DECL_SR_CODELET(131072,65536,32768)
653
654static av_cold int TX_NAME(ff_tx_fft_sr_init)(AVTXContext *s,
655                                              const FFTXCodelet *cd,
656                                              uint64_t flags,
657                                              FFTXCodeletOptions *opts,
658                                              int len, int inv,
659                                              const void *scale)
660{
661    int ret;
662    int is_inplace = !!(flags & AV_TX_INPLACE);
663    FFTXCodeletOptions sub_opts = { .invert_lookup = !is_inplace };
664
665    flags &= ~FF_TX_OUT_OF_PLACE; /* We want the subtransform to be */
666    flags |=  AV_TX_INPLACE;      /* in-place */
667    flags |=  FF_TX_PRESHUFFLE;   /* This function handles the permute step */
668
669    if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, &sub_opts, len, inv, scale)))
670        return ret;
671
672    if (is_inplace && (ret = ff_tx_gen_ptwo_inplace_revtab_idx(s)))
673        return ret;
674
675    return 0;
676}
677
678static void TX_NAME(ff_tx_fft_sr)(AVTXContext *s, void *_dst,
679                                  void *_src, ptrdiff_t stride)
680{
681    TXComplex *src = _src;
682    TXComplex *dst = _dst;
683    int *map = s->sub[0].map;
684    int len = s->len;
685
686    /* Compilers can't vectorize this anyway without assuming AVX2, which they
687     * generally don't, at least without -march=native -mtune=native */
688    for (int i = 0; i < len; i++)
689        dst[i] = src[map[i]];
690
691    s->fn[0](&s->sub[0], dst, dst, stride);
692}
693
694static void TX_NAME(ff_tx_fft_sr_inplace)(AVTXContext *s, void *_dst,
695                                          void *_src, ptrdiff_t stride)
696{
697    TXComplex *dst = _dst;
698    TXComplex tmp;
699    const int *map = s->sub->map;
700    const int *inplace_idx = s->map;
701    int src_idx, dst_idx;
702
703    src_idx = *inplace_idx++;
704    do {
705        tmp = dst[src_idx];
706        dst_idx = map[src_idx];
707        do {
708            FFSWAP(TXComplex, tmp, dst[dst_idx]);
709            dst_idx = map[dst_idx];
710        } while (dst_idx != src_idx); /* Can be > as well, but was less predictable */
711        dst[dst_idx] = tmp;
712    } while ((src_idx = *inplace_idx++));
713
714    s->fn[0](&s->sub[0], dst, dst, stride);
715}
716
717static const FFTXCodelet TX_NAME(ff_tx_fft_sr_def) = {
718    .name       = TX_NAME_STR("fft_sr"),
719    .function   = TX_NAME(ff_tx_fft_sr),
720    .type       = TX_TYPE(FFT),
721    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE,
722    .factors[0] = 2,
723    .min_len    = 2,
724    .max_len    = TX_LEN_UNLIMITED,
725    .init       = TX_NAME(ff_tx_fft_sr_init),
726    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
727    .prio       = FF_TX_PRIO_BASE,
728};
729
730static const FFTXCodelet TX_NAME(ff_tx_fft_sr_inplace_def) = {
731    .name       = TX_NAME_STR("fft_sr_inplace"),
732    .function   = TX_NAME(ff_tx_fft_sr_inplace),
733    .type       = TX_TYPE(FFT),
734    .flags      = AV_TX_UNALIGNED | AV_TX_INPLACE,
735    .factors[0] = 2,
736    .min_len    = 2,
737    .max_len    = TX_LEN_UNLIMITED,
738    .init       = TX_NAME(ff_tx_fft_sr_init),
739    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
740    .prio       = FF_TX_PRIO_BASE,
741};
742
743static void TX_NAME(ff_tx_fft_naive)(AVTXContext *s, void *_dst, void *_src,
744                                     ptrdiff_t stride)
745{
746    TXComplex *src = _src;
747    TXComplex *dst = _dst;
748    const int n = s->len;
749    double phase = s->inv ? 2.0*M_PI/n : -2.0*M_PI/n;
750
751    for(int i = 0; i < n; i++) {
752        TXComplex tmp = { 0 };
753        for(int j = 0; j < n; j++) {
754            const double factor = phase*i*j;
755            const TXComplex mult = {
756                RESCALE(cos(factor)),
757                RESCALE(sin(factor)),
758            };
759            TXComplex res;
760            CMUL3(res, src[j], mult);
761            tmp.re += res.re;
762            tmp.im += res.im;
763        }
764        dst[i] = tmp;
765    }
766}
767
768static const FFTXCodelet TX_NAME(ff_tx_fft_naive_def) = {
769    .name       = TX_NAME_STR("fft_naive"),
770    .function   = TX_NAME(ff_tx_fft_naive),
771    .type       = TX_TYPE(FFT),
772    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE,
773    .factors[0] = TX_FACTOR_ANY,
774    .min_len    = 2,
775    .max_len    = TX_LEN_UNLIMITED,
776    .init       = NULL,
777    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
778    .prio       = FF_TX_PRIO_MIN,
779};
780
781static av_cold int TX_NAME(ff_tx_fft_pfa_init)(AVTXContext *s,
782                                               const FFTXCodelet *cd,
783                                               uint64_t flags,
784                                               FFTXCodeletOptions *opts,
785                                               int len, int inv,
786                                               const void *scale)
787{
788    int ret;
789    int sub_len = len / cd->factors[0];
790    FFTXCodeletOptions sub_opts = { .invert_lookup = 0 };
791
792    flags &= ~FF_TX_OUT_OF_PLACE; /* We want the subtransform to be */
793    flags |=  AV_TX_INPLACE;      /* in-place */
794    flags |=  FF_TX_PRESHUFFLE;   /* This function handles the permute step */
795
796    if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, &sub_opts,
797                                sub_len, inv, scale)))
798        return ret;
799
800    if ((ret = ff_tx_gen_compound_mapping(s, cd->factors[0], sub_len)))
801        return ret;
802
803    if (!(s->tmp = av_malloc(len*sizeof(*s->tmp))))
804        return AVERROR(ENOMEM);
805
806    TX_TAB(ff_tx_init_tabs)(len / sub_len);
807
808    return 0;
809}
810
811#define DECL_COMP_FFT(N)                                                       \
812static void TX_NAME(ff_tx_fft_pfa_##N##xM)(AVTXContext *s, void *_out,         \
813                                           void *_in, ptrdiff_t stride)        \
814{                                                                              \
815    const int m = s->sub->len;                                                 \
816    const int *in_map = s->map, *out_map = in_map + s->len;                    \
817    const int *sub_map = s->sub->map;                                          \
818    TXComplex *in = _in;                                                       \
819    TXComplex *out = _out;                                                     \
820    TXComplex fft##N##in[N];                                                   \
821                                                                               \
822    for (int i = 0; i < m; i++) {                                              \
823        for (int j = 0; j < N; j++)                                            \
824            fft##N##in[j] = in[in_map[i*N + j]];                               \
825        fft##N(s->tmp + sub_map[i], fft##N##in, m);                            \
826    }                                                                          \
827                                                                               \
828    for (int i = 0; i < N; i++)                                                \
829        s->fn[0](&s->sub[0], s->tmp + m*i, s->tmp + m*i, sizeof(TXComplex));   \
830                                                                               \
831    for (int i = 0; i < N*m; i++)                                              \
832        out[i] = s->tmp[out_map[i]];                                           \
833}                                                                              \
834                                                                               \
835static const FFTXCodelet TX_NAME(ff_tx_fft_pfa_##N##xM_def) = {                \
836    .name       = TX_NAME_STR("fft_pfa_" #N "xM"),                             \
837    .function   = TX_NAME(ff_tx_fft_pfa_##N##xM),                              \
838    .type       = TX_TYPE(FFT),                                                \
839    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE,                        \
840    .factors    = { N, TX_FACTOR_ANY },                                        \
841    .min_len    = N*2,                                                         \
842    .max_len    = TX_LEN_UNLIMITED,                                            \
843    .init       = TX_NAME(ff_tx_fft_pfa_init),                                 \
844    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,                                         \
845    .prio       = FF_TX_PRIO_BASE,                                             \
846};
847
848DECL_COMP_FFT(3)
849DECL_COMP_FFT(5)
850DECL_COMP_FFT(7)
851DECL_COMP_FFT(9)
852DECL_COMP_FFT(15)
853
854static av_cold int TX_NAME(ff_tx_mdct_naive_init)(AVTXContext *s,
855                                                  const FFTXCodelet *cd,
856                                                  uint64_t flags,
857                                                  FFTXCodeletOptions *opts,
858                                                  int len, int inv,
859                                                  const void *scale)
860{
861    s->scale_d = *((SCALE_TYPE *)scale);
862    s->scale_f = s->scale_d;
863    return 0;
864}
865
866static void TX_NAME(ff_tx_mdct_naive_fwd)(AVTXContext *s, void *_dst,
867                                          void *_src, ptrdiff_t stride)
868{
869    TXSample *src = _src;
870    TXSample *dst = _dst;
871    double scale = s->scale_d;
872    int len = s->len;
873    const double phase = M_PI/(4.0*len);
874
875    stride /= sizeof(*dst);
876
877    for (int i = 0; i < len; i++) {
878        double sum = 0.0;
879        for (int j = 0; j < len*2; j++) {
880            int a = (2*j + 1 + len) * (2*i + 1);
881            sum += UNSCALE(src[j]) * cos(a * phase);
882        }
883        dst[i*stride] = RESCALE(sum*scale);
884    }
885}
886
887static void TX_NAME(ff_tx_mdct_naive_inv)(AVTXContext *s, void *_dst,
888                                          void *_src, ptrdiff_t stride)
889{
890    TXSample *src = _src;
891    TXSample *dst = _dst;
892    double scale = s->scale_d;
893    int len = s->len >> 1;
894    int len2 = len*2;
895    const double phase = M_PI/(4.0*len2);
896
897    stride /= sizeof(*src);
898
899    for (int i = 0; i < len; i++) {
900        double sum_d = 0.0;
901        double sum_u = 0.0;
902        double i_d = phase * (4*len  - 2*i - 1);
903        double i_u = phase * (3*len2 + 2*i + 1);
904        for (int j = 0; j < len2; j++) {
905            double a = (2 * j + 1);
906            double a_d = cos(a * i_d);
907            double a_u = cos(a * i_u);
908            double val = UNSCALE(src[j*stride]);
909            sum_d += a_d * val;
910            sum_u += a_u * val;
911        }
912        dst[i +   0] = RESCALE( sum_d*scale);
913        dst[i + len] = RESCALE(-sum_u*scale);
914    }
915}
916
917static const FFTXCodelet TX_NAME(ff_tx_mdct_naive_fwd_def) = {
918    .name       = TX_NAME_STR("mdct_naive_fwd"),
919    .function   = TX_NAME(ff_tx_mdct_naive_fwd),
920    .type       = TX_TYPE(MDCT),
921    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_FORWARD_ONLY,
922    .factors    = { 2, TX_FACTOR_ANY }, /* MDCTs need an even length */
923    .min_len    = 2,
924    .max_len    = TX_LEN_UNLIMITED,
925    .init       = TX_NAME(ff_tx_mdct_naive_init),
926    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
927    .prio       = FF_TX_PRIO_MIN,
928};
929
930static const FFTXCodelet TX_NAME(ff_tx_mdct_naive_inv_def) = {
931    .name       = TX_NAME_STR("mdct_naive_inv"),
932    .function   = TX_NAME(ff_tx_mdct_naive_inv),
933    .type       = TX_TYPE(MDCT),
934    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY,
935    .factors    = { 2, TX_FACTOR_ANY },
936    .min_len    = 2,
937    .max_len    = TX_LEN_UNLIMITED,
938    .init       = TX_NAME(ff_tx_mdct_naive_init),
939    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
940    .prio       = FF_TX_PRIO_MIN,
941};
942
943static av_cold int TX_NAME(ff_tx_mdct_sr_init)(AVTXContext *s,
944                                               const FFTXCodelet *cd,
945                                               uint64_t flags,
946                                               FFTXCodeletOptions *opts,
947                                               int len, int inv,
948                                               const void *scale)
949{
950    int ret;
951    FFTXCodeletOptions sub_opts = { .invert_lookup = 0 };
952
953    s->scale_d = *((SCALE_TYPE *)scale);
954    s->scale_f = s->scale_d;
955
956    flags &= ~FF_TX_OUT_OF_PLACE; /* We want the subtransform to be */
957    flags |=  AV_TX_INPLACE;      /* in-place */
958    flags |=  FF_TX_PRESHUFFLE;   /* This function handles the permute step */
959
960    if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, &sub_opts, len >> 1,
961                                inv, scale)))
962        return ret;
963
964    if ((ret = TX_TAB(ff_tx_mdct_gen_exp)(s)))
965        return ret;
966
967    return 0;
968}
969
970static void TX_NAME(ff_tx_mdct_sr_fwd)(AVTXContext *s, void *_dst, void *_src,
971                                       ptrdiff_t stride)
972{
973    TXSample *src = _src, *dst = _dst;
974    TXComplex *exp = s->exp, tmp, *z = _dst;
975    const int len2 = s->len >> 1;
976    const int len4 = s->len >> 2;
977    const int len3 = len2 * 3;
978    const int *sub_map = s->sub->map;
979
980    stride /= sizeof(*dst);
981
982    for (int i = 0; i < len2; i++) { /* Folding and pre-reindexing */
983        const int k = 2*i;
984        const int idx = sub_map[i];
985        if (k < len2) {
986            tmp.re = FOLD(-src[ len2 + k],  src[1*len2 - 1 - k]);
987            tmp.im = FOLD(-src[ len3 + k], -src[1*len3 - 1 - k]);
988        } else {
989            tmp.re = FOLD(-src[ len2 + k], -src[5*len2 - 1 - k]);
990            tmp.im = FOLD( src[-len2 + k], -src[1*len3 - 1 - k]);
991        }
992        CMUL(z[idx].im, z[idx].re, tmp.re, tmp.im, exp[i].re, exp[i].im);
993    }
994
995    s->fn[0](&s->sub[0], z, z, sizeof(TXComplex));
996
997    for (int i = 0; i < len4; i++) {
998        const int i0 = len4 + i, i1 = len4 - i - 1;
999        TXComplex src1 = { z[i1].re, z[i1].im };
1000        TXComplex src0 = { z[i0].re, z[i0].im };
1001
1002        CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], src0.re, src0.im,
1003             exp[i0].im, exp[i0].re);
1004        CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], src1.re, src1.im,
1005             exp[i1].im, exp[i1].re);
1006    }
1007}
1008
1009static void TX_NAME(ff_tx_mdct_sr_inv)(AVTXContext *s, void *_dst, void *_src,
1010                                       ptrdiff_t stride)
1011{
1012    TXComplex *z = _dst, *exp = s->exp;
1013    const TXSample *src = _src, *in1, *in2;
1014    const int len2 = s->len >> 1;
1015    const int len4 = s->len >> 2;
1016    const int *sub_map = s->sub->map;
1017
1018    stride /= sizeof(*src);
1019    in1 = src;
1020    in2 = src + ((len2*2) - 1) * stride;
1021
1022    for (int i = 0; i < len2; i++) {
1023        TXComplex tmp = { in2[-2*i*stride], in1[2*i*stride] };
1024        CMUL3(z[sub_map[i]], tmp, exp[i]);
1025    }
1026
1027    s->fn[0](&s->sub[0], z, z, sizeof(TXComplex));
1028
1029    for (int i = 0; i < len4; i++) {
1030        const int i0 = len4 + i, i1 = len4 - i - 1;
1031        TXComplex src1 = { z[i1].im, z[i1].re };
1032        TXComplex src0 = { z[i0].im, z[i0].re };
1033
1034        CMUL(z[i1].re, z[i0].im, src1.re, src1.im, exp[i1].im, exp[i1].re);
1035        CMUL(z[i0].re, z[i1].im, src0.re, src0.im, exp[i0].im, exp[i0].re);
1036    }
1037}
1038
1039static const FFTXCodelet TX_NAME(ff_tx_mdct_sr_fwd_def) = {
1040    .name       = TX_NAME_STR("mdct_sr_fwd"),
1041    .function   = TX_NAME(ff_tx_mdct_sr_fwd),
1042    .type       = TX_TYPE(MDCT),
1043    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_FORWARD_ONLY,
1044    .factors[0] = 2,
1045    .min_len    = 2,
1046    .max_len    = TX_LEN_UNLIMITED,
1047    .init       = TX_NAME(ff_tx_mdct_sr_init),
1048    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
1049    .prio       = FF_TX_PRIO_BASE,
1050};
1051
1052static const FFTXCodelet TX_NAME(ff_tx_mdct_sr_inv_def) = {
1053    .name       = TX_NAME_STR("mdct_sr_inv"),
1054    .function   = TX_NAME(ff_tx_mdct_sr_inv),
1055    .type       = TX_TYPE(MDCT),
1056    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY,
1057    .factors[0] = 2,
1058    .min_len    = 2,
1059    .max_len    = TX_LEN_UNLIMITED,
1060    .init       = TX_NAME(ff_tx_mdct_sr_init),
1061    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
1062    .prio       = FF_TX_PRIO_BASE,
1063};
1064
1065static av_cold int TX_NAME(ff_tx_mdct_inv_full_init)(AVTXContext *s,
1066                                                     const FFTXCodelet *cd,
1067                                                     uint64_t flags,
1068                                                     FFTXCodeletOptions *opts,
1069                                                     int len, int inv,
1070                                                     const void *scale)
1071{
1072    int ret;
1073
1074    s->scale_d = *((SCALE_TYPE *)scale);
1075    s->scale_f = s->scale_d;
1076
1077    flags &= ~AV_TX_FULL_IMDCT;
1078
1079    if ((ret = ff_tx_init_subtx(s, TX_TYPE(MDCT), flags, NULL, len, 1, scale)))
1080        return ret;
1081
1082    return 0;
1083}
1084
1085static void TX_NAME(ff_tx_mdct_inv_full)(AVTXContext *s, void *_dst,
1086                                         void *_src, ptrdiff_t stride)
1087{
1088    int len  = s->len << 1;
1089    int len2 = len >> 1;
1090    int len4 = len >> 2;
1091    TXSample *dst = _dst;
1092
1093    s->fn[0](&s->sub[0], dst + len4, _src, stride);
1094
1095    stride /= sizeof(*dst);
1096
1097    for (int i = 0; i < len4; i++) {
1098        dst[            i*stride] = -dst[(len2 - i - 1)*stride];
1099        dst[(len - i - 1)*stride] =  dst[(len2 + i + 0)*stride];
1100    }
1101}
1102
1103static const FFTXCodelet TX_NAME(ff_tx_mdct_inv_full_def) = {
1104    .name       = TX_NAME_STR("mdct_inv_full"),
1105    .function   = TX_NAME(ff_tx_mdct_inv_full),
1106    .type       = TX_TYPE(MDCT),
1107    .flags      = AV_TX_UNALIGNED | AV_TX_INPLACE |
1108                  FF_TX_OUT_OF_PLACE | AV_TX_FULL_IMDCT,
1109    .factors    = { 2, TX_FACTOR_ANY },
1110    .min_len    = 2,
1111    .max_len    = TX_LEN_UNLIMITED,
1112    .init       = TX_NAME(ff_tx_mdct_inv_full_init),
1113    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
1114    .prio       = FF_TX_PRIO_BASE,
1115};
1116
1117static av_cold int TX_NAME(ff_tx_mdct_pfa_init)(AVTXContext *s,
1118                                                const FFTXCodelet *cd,
1119                                                uint64_t flags,
1120                                                FFTXCodeletOptions *opts,
1121                                                int len, int inv,
1122                                                const void *scale)
1123{
1124    int ret, sub_len;
1125    FFTXCodeletOptions sub_opts = { .invert_lookup = 0 };
1126
1127    len >>= 1;
1128    sub_len = len / cd->factors[0];
1129
1130    s->scale_d = *((SCALE_TYPE *)scale);
1131    s->scale_f = s->scale_d;
1132
1133    flags &= ~FF_TX_OUT_OF_PLACE; /* We want the subtransform to be */
1134    flags |=  AV_TX_INPLACE;      /* in-place */
1135    flags |=  FF_TX_PRESHUFFLE;   /* This function handles the permute step */
1136
1137    if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, &sub_opts,
1138                                sub_len, inv, scale)))
1139        return ret;
1140
1141    if ((ret = ff_tx_gen_compound_mapping(s, cd->factors[0], sub_len)))
1142        return ret;
1143
1144    if ((ret = TX_TAB(ff_tx_mdct_gen_exp)(s)))
1145        return ret;
1146
1147    if (!(s->tmp = av_malloc(len*sizeof(*s->tmp))))
1148        return AVERROR(ENOMEM);
1149
1150    TX_TAB(ff_tx_init_tabs)(len / sub_len);
1151
1152    return 0;
1153}
1154
1155#define DECL_COMP_IMDCT(N)                                                     \
1156static void TX_NAME(ff_tx_mdct_pfa_##N##xM_inv)(AVTXContext *s, void *_dst,    \
1157                                                void *_src, ptrdiff_t stride)  \
1158{                                                                              \
1159    TXComplex fft##N##in[N];                                                   \
1160    TXComplex *z = _dst, *exp = s->exp;                                        \
1161    const TXSample *src = _src, *in1, *in2;                                    \
1162    const int len4 = s->len >> 2;                                              \
1163    const int m = s->sub->len;                                                 \
1164    const int *in_map = s->map, *out_map = in_map + N*m;                       \
1165    const int *sub_map = s->sub->map;                                          \
1166                                                                               \
1167    stride /= sizeof(*src); /* To convert it from bytes */                     \
1168    in1 = src;                                                                 \
1169    in2 = src + ((N*m*2) - 1) * stride;                                        \
1170                                                                               \
1171    for (int i = 0; i < m; i++) {                                              \
1172        for (int j = 0; j < N; j++) {                                          \
1173            const int k = in_map[i*N + j];                                     \
1174            TXComplex tmp = { in2[-k*stride], in1[k*stride] };                 \
1175            CMUL3(fft##N##in[j], tmp, exp[k >> 1]);                            \
1176        }                                                                      \
1177        fft##N(s->tmp + sub_map[i], fft##N##in, m);                            \
1178    }                                                                          \
1179                                                                               \
1180    for (int i = 0; i < N; i++)                                                \
1181        s->fn[0](&s->sub[0], s->tmp + m*i, s->tmp + m*i, sizeof(TXComplex));   \
1182                                                                               \
1183    for (int i = 0; i < len4; i++) {                                           \
1184        const int i0 = len4 + i, i1 = len4 - i - 1;                            \
1185        const int s0 = out_map[i0], s1 = out_map[i1];                          \
1186        TXComplex src1 = { s->tmp[s1].im, s->tmp[s1].re };                     \
1187        TXComplex src0 = { s->tmp[s0].im, s->tmp[s0].re };                     \
1188                                                                               \
1189        CMUL(z[i1].re, z[i0].im, src1.re, src1.im, exp[i1].im, exp[i1].re);    \
1190        CMUL(z[i0].re, z[i1].im, src0.re, src0.im, exp[i0].im, exp[i0].re);    \
1191    }                                                                          \
1192}                                                                              \
1193                                                                               \
1194static const FFTXCodelet TX_NAME(ff_tx_mdct_pfa_##N##xM_inv_def) = {           \
1195    .name       = TX_NAME_STR("mdct_pfa_" #N "xM_inv"),                        \
1196    .function   = TX_NAME(ff_tx_mdct_pfa_##N##xM_inv),                         \
1197    .type       = TX_TYPE(MDCT),                                               \
1198    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY,   \
1199    .factors    = { N, TX_FACTOR_ANY },                                        \
1200    .min_len    = N*2,                                                         \
1201    .max_len    = TX_LEN_UNLIMITED,                                            \
1202    .init       = TX_NAME(ff_tx_mdct_pfa_init),                                \
1203    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,                                         \
1204    .prio       = FF_TX_PRIO_BASE,                                             \
1205};
1206
1207DECL_COMP_IMDCT(3)
1208DECL_COMP_IMDCT(5)
1209DECL_COMP_IMDCT(7)
1210DECL_COMP_IMDCT(9)
1211DECL_COMP_IMDCT(15)
1212
1213#define DECL_COMP_MDCT(N)                                                      \
1214static void TX_NAME(ff_tx_mdct_pfa_##N##xM_fwd)(AVTXContext *s, void *_dst,    \
1215                                                void *_src, ptrdiff_t stride)  \
1216{                                                                              \
1217    TXComplex fft##N##in[N];                                                   \
1218    TXSample *src = _src, *dst = _dst;                                         \
1219    TXComplex *exp = s->exp, tmp;                                              \
1220    const int m = s->sub->len;                                                 \
1221    const int len4 = N*m;                                                      \
1222    const int len3 = len4 * 3;                                                 \
1223    const int len8 = s->len >> 2;                                              \
1224    const int *in_map = s->map, *out_map = in_map + N*m;                       \
1225    const int *sub_map = s->sub->map;                                          \
1226                                                                               \
1227    stride /= sizeof(*dst);                                                    \
1228                                                                               \
1229    for (int i = 0; i < m; i++) { /* Folding and pre-reindexing */             \
1230        for (int j = 0; j < N; j++) {                                          \
1231            const int k = in_map[i*N + j];                                     \
1232            if (k < len4) {                                                    \
1233                tmp.re = FOLD(-src[ len4 + k],  src[1*len4 - 1 - k]);          \
1234                tmp.im = FOLD(-src[ len3 + k], -src[1*len3 - 1 - k]);          \
1235            } else {                                                           \
1236                tmp.re = FOLD(-src[ len4 + k], -src[5*len4 - 1 - k]);          \
1237                tmp.im = FOLD( src[-len4 + k], -src[1*len3 - 1 - k]);          \
1238            }                                                                  \
1239            CMUL(fft##N##in[j].im, fft##N##in[j].re, tmp.re, tmp.im,           \
1240                 exp[k >> 1].re, exp[k >> 1].im);                              \
1241        }                                                                      \
1242        fft##N(s->tmp + sub_map[i], fft##N##in, m);                            \
1243    }                                                                          \
1244                                                                               \
1245    for (int i = 0; i < N; i++)                                                \
1246        s->fn[0](&s->sub[0], s->tmp + m*i, s->tmp + m*i, sizeof(TXComplex));   \
1247                                                                               \
1248    for (int i = 0; i < len8; i++) {                                           \
1249        const int i0 = len8 + i, i1 = len8 - i - 1;                            \
1250        const int s0 = out_map[i0], s1 = out_map[i1];                          \
1251        TXComplex src1 = { s->tmp[s1].re, s->tmp[s1].im };                     \
1252        TXComplex src0 = { s->tmp[s0].re, s->tmp[s0].im };                     \
1253                                                                               \
1254        CMUL(dst[2*i1*stride + stride], dst[2*i0*stride], src0.re, src0.im,    \
1255             exp[i0].im, exp[i0].re);                                          \
1256        CMUL(dst[2*i0*stride + stride], dst[2*i1*stride], src1.re, src1.im,    \
1257             exp[i1].im, exp[i1].re);                                          \
1258    }                                                                          \
1259}                                                                              \
1260                                                                               \
1261static const FFTXCodelet TX_NAME(ff_tx_mdct_pfa_##N##xM_fwd_def) = {           \
1262    .name       = TX_NAME_STR("mdct_pfa_" #N "xM_fwd"),                        \
1263    .function   = TX_NAME(ff_tx_mdct_pfa_##N##xM_fwd),                         \
1264    .type       = TX_TYPE(MDCT),                                               \
1265    .flags      = AV_TX_UNALIGNED | FF_TX_OUT_OF_PLACE | FF_TX_FORWARD_ONLY,   \
1266    .factors    = { N, TX_FACTOR_ANY },                                        \
1267    .min_len    = N*2,                                                         \
1268    .max_len    = TX_LEN_UNLIMITED,                                            \
1269    .init       = TX_NAME(ff_tx_mdct_pfa_init),                                \
1270    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,                                         \
1271    .prio       = FF_TX_PRIO_BASE,                                             \
1272};
1273
1274DECL_COMP_MDCT(3)
1275DECL_COMP_MDCT(5)
1276DECL_COMP_MDCT(7)
1277DECL_COMP_MDCT(9)
1278DECL_COMP_MDCT(15)
1279
1280static av_cold int TX_NAME(ff_tx_rdft_init)(AVTXContext *s,
1281                                            const FFTXCodelet *cd,
1282                                            uint64_t flags,
1283                                            FFTXCodeletOptions *opts,
1284                                            int len, int inv,
1285                                            const void *scale)
1286{
1287    int ret;
1288    double f, m;
1289    TXSample *tab;
1290
1291    s->scale_d = *((SCALE_TYPE *)scale);
1292    s->scale_f = s->scale_d;
1293
1294    if ((ret = ff_tx_init_subtx(s, TX_TYPE(FFT), flags, NULL, len >> 1, inv, scale)))
1295        return ret;
1296
1297    if (!(s->exp = av_mallocz((8 + (len >> 2) - 1)*sizeof(*s->exp))))
1298        return AVERROR(ENOMEM);
1299
1300    tab = (TXSample *)s->exp;
1301
1302    f = 2*M_PI/len;
1303
1304    m = (inv ? 2*s->scale_d : s->scale_d);
1305
1306    *tab++ = RESCALE((inv ? 0.5 : 1.0) * m);
1307    *tab++ = RESCALE(inv ? 0.5*m : 1.0);
1308    *tab++ = RESCALE( m);
1309    *tab++ = RESCALE(-m);
1310
1311    *tab++ = RESCALE( (0.5 - 0.0) * m);
1312    *tab++ = RESCALE( (0.0 - 0.5) * m);
1313    *tab++ = RESCALE( (0.5 - inv) * m);
1314    *tab++ = RESCALE(-(0.5 - inv) * m);
1315
1316    for (int i = 0; i < len >> 2; i++)
1317        *tab++ = RESCALE(cos(i*f));
1318    for (int i = len >> 2; i >= 0; i--)
1319        *tab++ = RESCALE(cos(i*f) * (inv ? +1.0 : -1.0));
1320
1321    return 0;
1322}
1323
1324#define DECL_RDFT(name, inv)                                                   \
1325static void TX_NAME(ff_tx_rdft_ ##name)(AVTXContext *s, void *_dst,            \
1326                                       void *_src, ptrdiff_t stride)           \
1327{                                                                              \
1328    const int len2 = s->len >> 1;                                              \
1329    const int len4 = s->len >> 2;                                              \
1330    const TXSample *fact = (void *)s->exp;                                     \
1331    const TXSample *tcos = fact + 8;                                           \
1332    const TXSample *tsin = tcos + len4;                                        \
1333    TXComplex *data = inv ? _src : _dst;                                       \
1334    TXComplex t[3];                                                            \
1335                                                                               \
1336    if (!inv)                                                                  \
1337        s->fn[0](&s->sub[0], data, _src, sizeof(TXComplex));                   \
1338    else                                                                       \
1339        data[0].im = data[len2].re;                                            \
1340                                                                               \
1341    /* The DC value's both components are real, but we need to change them     \
1342     * into complex values. Also, the middle of the array is special-cased.    \
1343     * These operations can be done before or after the loop. */               \
1344    t[0].re = data[0].re;                                                      \
1345    data[0].re = t[0].re + data[0].im;                                         \
1346    data[0].im = t[0].re - data[0].im;                                         \
1347    data[   0].re = MULT(fact[0], data[   0].re);                              \
1348    data[   0].im = MULT(fact[1], data[   0].im);                              \
1349    data[len4].re = MULT(fact[2], data[len4].re);                              \
1350    data[len4].im = MULT(fact[3], data[len4].im);                              \
1351                                                                               \
1352    for (int i = 1; i < len4; i++) {                                           \
1353        /* Separate even and odd FFTs */                                       \
1354        t[0].re = MULT(fact[4], (data[i].re + data[len2 - i].re));             \
1355        t[0].im = MULT(fact[5], (data[i].im - data[len2 - i].im));             \
1356        t[1].re = MULT(fact[6], (data[i].im + data[len2 - i].im));             \
1357        t[1].im = MULT(fact[7], (data[i].re - data[len2 - i].re));             \
1358                                                                               \
1359        /* Apply twiddle factors to the odd FFT and add to the even FFT */     \
1360        CMUL(t[2].re, t[2].im, t[1].re, t[1].im, tcos[i], tsin[i]);            \
1361                                                                               \
1362        data[       i].re = t[0].re + t[2].re;                                 \
1363        data[       i].im = t[2].im - t[0].im;                                 \
1364        data[len2 - i].re = t[0].re - t[2].re;                                 \
1365        data[len2 - i].im = t[2].im + t[0].im;                                 \
1366    }                                                                          \
1367                                                                               \
1368    if (inv) {                                                                 \
1369        s->fn[0](&s->sub[0], _dst, data, sizeof(TXComplex));                   \
1370    } else {                                                                   \
1371        /* Move [0].im to the last position, as convention requires */         \
1372        data[len2].re = data[0].im;                                            \
1373        data[   0].im = 0;                                                     \
1374    }                                                                          \
1375}
1376
1377DECL_RDFT(r2c, 0)
1378DECL_RDFT(c2r, 1)
1379
1380static const FFTXCodelet TX_NAME(ff_tx_rdft_r2c_def) = {
1381    .name       = TX_NAME_STR("rdft_r2c"),
1382    .function   = TX_NAME(ff_tx_rdft_r2c),
1383    .type       = TX_TYPE(RDFT),
1384    .flags      = AV_TX_UNALIGNED | AV_TX_INPLACE |
1385                  FF_TX_OUT_OF_PLACE | FF_TX_FORWARD_ONLY,
1386    .factors    = { 2, TX_FACTOR_ANY },
1387    .min_len    = 2,
1388    .max_len    = TX_LEN_UNLIMITED,
1389    .init       = TX_NAME(ff_tx_rdft_init),
1390    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
1391    .prio       = FF_TX_PRIO_BASE,
1392};
1393
1394static const FFTXCodelet TX_NAME(ff_tx_rdft_c2r_def) = {
1395    .name       = TX_NAME_STR("rdft_c2r"),
1396    .function   = TX_NAME(ff_tx_rdft_c2r),
1397    .type       = TX_TYPE(RDFT),
1398    .flags      = AV_TX_UNALIGNED | AV_TX_INPLACE |
1399                  FF_TX_OUT_OF_PLACE | FF_TX_INVERSE_ONLY,
1400    .factors    = { 2, TX_FACTOR_ANY },
1401    .min_len    = 2,
1402    .max_len    = TX_LEN_UNLIMITED,
1403    .init       = TX_NAME(ff_tx_rdft_init),
1404    .cpu_flags  = FF_TX_CPU_FLAGS_ALL,
1405    .prio       = FF_TX_PRIO_BASE,
1406};
1407
1408int TX_TAB(ff_tx_mdct_gen_exp)(AVTXContext *s)
1409{
1410    int len4 = s->len >> 1;
1411    double scale = s->scale_d;
1412    const double theta = (scale < 0 ? len4 : 0) + 1.0/8.0;
1413
1414    if (!(s->exp = av_malloc_array(len4, sizeof(*s->exp))))
1415        return AVERROR(ENOMEM);
1416
1417    scale = sqrt(fabs(scale));
1418    for (int i = 0; i < len4; i++) {
1419        const double alpha = M_PI_2 * (i + theta) / len4;
1420        s->exp[i].re = RESCALE(cos(alpha) * scale);
1421        s->exp[i].im = RESCALE(sin(alpha) * scale);
1422    }
1423
1424    return 0;
1425}
1426
1427const FFTXCodelet * const TX_NAME(ff_tx_codelet_list)[] = {
1428    /* Split-Radix codelets */
1429    &TX_NAME(ff_tx_fft2_ns_def),
1430    &TX_NAME(ff_tx_fft4_ns_def),
1431    &TX_NAME(ff_tx_fft8_ns_def),
1432    &TX_NAME(ff_tx_fft16_ns_def),
1433    &TX_NAME(ff_tx_fft32_ns_def),
1434    &TX_NAME(ff_tx_fft64_ns_def),
1435    &TX_NAME(ff_tx_fft128_ns_def),
1436    &TX_NAME(ff_tx_fft256_ns_def),
1437    &TX_NAME(ff_tx_fft512_ns_def),
1438    &TX_NAME(ff_tx_fft1024_ns_def),
1439    &TX_NAME(ff_tx_fft2048_ns_def),
1440    &TX_NAME(ff_tx_fft4096_ns_def),
1441    &TX_NAME(ff_tx_fft8192_ns_def),
1442    &TX_NAME(ff_tx_fft16384_ns_def),
1443    &TX_NAME(ff_tx_fft32768_ns_def),
1444    &TX_NAME(ff_tx_fft65536_ns_def),
1445    &TX_NAME(ff_tx_fft131072_ns_def),
1446
1447    /* Standalone transforms */
1448    &TX_NAME(ff_tx_fft_sr_def),
1449    &TX_NAME(ff_tx_fft_sr_inplace_def),
1450    &TX_NAME(ff_tx_fft_pfa_3xM_def),
1451    &TX_NAME(ff_tx_fft_pfa_5xM_def),
1452    &TX_NAME(ff_tx_fft_pfa_7xM_def),
1453    &TX_NAME(ff_tx_fft_pfa_9xM_def),
1454    &TX_NAME(ff_tx_fft_pfa_15xM_def),
1455    &TX_NAME(ff_tx_fft_naive_def),
1456    &TX_NAME(ff_tx_mdct_sr_fwd_def),
1457    &TX_NAME(ff_tx_mdct_sr_inv_def),
1458    &TX_NAME(ff_tx_mdct_pfa_3xM_fwd_def),
1459    &TX_NAME(ff_tx_mdct_pfa_5xM_fwd_def),
1460    &TX_NAME(ff_tx_mdct_pfa_7xM_fwd_def),
1461    &TX_NAME(ff_tx_mdct_pfa_9xM_fwd_def),
1462    &TX_NAME(ff_tx_mdct_pfa_15xM_fwd_def),
1463    &TX_NAME(ff_tx_mdct_pfa_3xM_inv_def),
1464    &TX_NAME(ff_tx_mdct_pfa_5xM_inv_def),
1465    &TX_NAME(ff_tx_mdct_pfa_7xM_inv_def),
1466    &TX_NAME(ff_tx_mdct_pfa_9xM_inv_def),
1467    &TX_NAME(ff_tx_mdct_pfa_15xM_inv_def),
1468    &TX_NAME(ff_tx_mdct_naive_fwd_def),
1469    &TX_NAME(ff_tx_mdct_naive_inv_def),
1470    &TX_NAME(ff_tx_mdct_inv_full_def),
1471    &TX_NAME(ff_tx_rdft_r2c_def),
1472    &TX_NAME(ff_tx_rdft_c2r_def),
1473
1474    NULL,
1475};
1476