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1 | | /* Copyright (c) 2007-2008 CSIRO |
2 | | Copyright (c) 2007-2008 Xiph.Org Foundation |
3 | | Written by Jean-Marc Valin */ |
4 | | /* |
5 | | Redistribution and use in source and binary forms, with or without |
6 | | modification, are permitted provided that the following conditions |
7 | | are met: |
8 | | |
9 | | - Redistributions of source code must retain the above copyright |
10 | | notice, this list of conditions and the following disclaimer. |
11 | | |
12 | | - Redistributions in binary form must reproduce the above copyright |
13 | | notice, this list of conditions and the following disclaimer in the |
14 | | documentation and/or other materials provided with the distribution. |
15 | | |
16 | | THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
17 | | ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
18 | | LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
19 | | A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER |
20 | | OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, |
21 | | EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, |
22 | | PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR |
23 | | PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF |
24 | | LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING |
25 | | NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS |
26 | | SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
27 | | */ |
28 | | |
29 | | /* This is a simple MDCT implementation that uses a N/4 complex FFT |
30 | | to do most of the work. It should be relatively straightforward to |
31 | | plug in pretty much and FFT here. |
32 | | |
33 | | This replaces the Vorbis FFT (and uses the exact same API), which |
34 | | was a bit too messy and that was ending up duplicating code |
35 | | (might as well use the same FFT everywhere). |
36 | | |
37 | | The algorithm is similar to (and inspired from) Fabrice Bellard's |
38 | | MDCT implementation in FFMPEG, but has differences in signs, ordering |
39 | | and scaling in many places. |
40 | | */ |
41 | | |
42 | | #ifndef SKIP_CONFIG_H |
43 | | #ifdef HAVE_CONFIG_H |
44 | | #include "config.h" |
45 | | #endif |
46 | | #endif |
47 | | |
48 | | #include "mdct.h" |
49 | | #include "kiss_fft.h" |
50 | | #include "_kiss_fft_guts.h" |
51 | | #include <math.h> |
52 | | #include "os_support.h" |
53 | | #include "mathops.h" |
54 | | #include "stack_alloc.h" |
55 | | |
56 | | #if defined(MIPSr1_ASM) |
57 | | #include "mips/mdct_mipsr1.h" |
58 | | #endif |
59 | | |
60 | | |
61 | | #ifdef CUSTOM_MODES |
62 | | |
63 | | int clt_mdct_init(mdct_lookup *l,int N, int maxshift, int arch) |
64 | | { |
65 | | int i; |
66 | | kiss_twiddle_scalar *trig; |
67 | | int shift; |
68 | | int N2=N>>1; |
69 | | l->n = N; |
70 | | l->maxshift = maxshift; |
71 | | for (i=0;i<=maxshift;i++) |
72 | | { |
73 | | if (i==0) |
74 | | l->kfft[i] = opus_fft_alloc(N>>2>>i, 0, 0, arch); |
75 | | else |
76 | | l->kfft[i] = opus_fft_alloc_twiddles(N>>2>>i, 0, 0, l->kfft[0], arch); |
77 | | #ifndef ENABLE_TI_DSPLIB55 |
78 | | if (l->kfft[i]==NULL) |
79 | | return 0; |
80 | | #endif |
81 | | } |
82 | | l->trig = trig = (kiss_twiddle_scalar*)opus_alloc((N-(N2>>maxshift))*sizeof(kiss_twiddle_scalar)); |
83 | | if (l->trig==NULL) |
84 | | return 0; |
85 | | for (shift=0;shift<=maxshift;shift++) |
86 | | { |
87 | | /* We have enough points that sine isn't necessary */ |
88 | | #if defined(FIXED_POINT) |
89 | | #if 1 |
90 | | for (i=0;i<N2;i++) |
91 | | trig[i] = TRIG_UPSCALE*celt_cos_norm(DIV32(ADD32(SHL32(EXTEND32(i),17),N2+16384),N)); |
92 | | #else |
93 | | for (i=0;i<N2;i++) |
94 | | trig[i] = (kiss_twiddle_scalar)MAX32(-32767,MIN32(32767,floor(.5+32768*cos(2*M_PI*(i+.125)/N)))); |
95 | | #endif |
96 | | #else |
97 | | for (i=0;i<N2;i++) |
98 | | trig[i] = (kiss_twiddle_scalar)cos(2*PI*(i+.125)/N); |
99 | | #endif |
100 | | trig += N2; |
101 | | N2 >>= 1; |
102 | | N >>= 1; |
103 | | } |
104 | | return 1; |
105 | | } |
106 | | |
107 | | void clt_mdct_clear(mdct_lookup *l, int arch) |
108 | | { |
109 | | int i; |
110 | | for (i=0;i<=l->maxshift;i++) |
111 | | opus_fft_free(l->kfft[i], arch); |
112 | | opus_free((kiss_twiddle_scalar*)l->trig); |
113 | | } |
114 | | |
115 | | #endif /* CUSTOM_MODES */ |
116 | | |
117 | | /* Forward MDCT trashes the input array */ |
118 | | #ifndef OVERRIDE_clt_mdct_forward |
119 | | void clt_mdct_forward_c(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out, |
120 | | const opus_val16 *window, int overlap, int shift, int stride, int arch) |
121 | 0 | { |
122 | 0 | int i; |
123 | 0 | int N, N2, N4; |
124 | 0 | VARDECL(kiss_fft_scalar, f); |
125 | 0 | VARDECL(kiss_fft_cpx, f2); |
126 | 0 | const kiss_fft_state *st = l->kfft[shift]; |
127 | 0 | const kiss_twiddle_scalar *trig; |
128 | 0 | opus_val16 scale; |
129 | | #ifdef FIXED_POINT |
130 | | /* Allows us to scale with MULT16_32_Q16(), which is faster than |
131 | | MULT16_32_Q15() on ARM. */ |
132 | | int scale_shift = st->scale_shift-1; |
133 | | #endif |
134 | 0 | SAVE_STACK; |
135 | 0 | (void)arch; |
136 | 0 | scale = st->scale; |
137 | |
|
138 | 0 | N = l->n; |
139 | 0 | trig = l->trig; |
140 | 0 | for (i=0;i<shift;i++) |
141 | 0 | { |
142 | 0 | N >>= 1; |
143 | 0 | trig += N; |
144 | 0 | } |
145 | 0 | N2 = N>>1; |
146 | 0 | N4 = N>>2; |
147 | |
|
148 | 0 | ALLOC(f, N2, kiss_fft_scalar); |
149 | 0 | ALLOC(f2, N4, kiss_fft_cpx); |
150 | | |
151 | | /* Consider the input to be composed of four blocks: [a, b, c, d] */ |
152 | | /* Window, shuffle, fold */ |
153 | 0 | { |
154 | | /* Temp pointers to make it really clear to the compiler what we're doing */ |
155 | 0 | const kiss_fft_scalar * OPUS_RESTRICT xp1 = in+(overlap>>1); |
156 | 0 | const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+N2-1+(overlap>>1); |
157 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp = f; |
158 | 0 | const opus_val16 * OPUS_RESTRICT wp1 = window+(overlap>>1); |
159 | 0 | const opus_val16 * OPUS_RESTRICT wp2 = window+(overlap>>1)-1; |
160 | 0 | for(i=0;i<((overlap+3)>>2);i++) |
161 | 0 | { |
162 | | /* Real part arranged as -d-cR, Imag part arranged as -b+aR*/ |
163 | 0 | *yp++ = MULT16_32_Q15(*wp2, xp1[N2]) + MULT16_32_Q15(*wp1,*xp2); |
164 | 0 | *yp++ = MULT16_32_Q15(*wp1, *xp1) - MULT16_32_Q15(*wp2, xp2[-N2]); |
165 | 0 | xp1+=2; |
166 | 0 | xp2-=2; |
167 | 0 | wp1+=2; |
168 | 0 | wp2-=2; |
169 | 0 | } |
170 | 0 | wp1 = window; |
171 | 0 | wp2 = window+overlap-1; |
172 | 0 | for(;i<N4-((overlap+3)>>2);i++) |
173 | 0 | { |
174 | | /* Real part arranged as a-bR, Imag part arranged as -c-dR */ |
175 | 0 | *yp++ = *xp2; |
176 | 0 | *yp++ = *xp1; |
177 | 0 | xp1+=2; |
178 | 0 | xp2-=2; |
179 | 0 | } |
180 | 0 | for(;i<N4;i++) |
181 | 0 | { |
182 | | /* Real part arranged as a-bR, Imag part arranged as -c-dR */ |
183 | 0 | *yp++ = -MULT16_32_Q15(*wp1, xp1[-N2]) + MULT16_32_Q15(*wp2, *xp2); |
184 | 0 | *yp++ = MULT16_32_Q15(*wp2, *xp1) + MULT16_32_Q15(*wp1, xp2[N2]); |
185 | 0 | xp1+=2; |
186 | 0 | xp2-=2; |
187 | 0 | wp1+=2; |
188 | 0 | wp2-=2; |
189 | 0 | } |
190 | 0 | } |
191 | | /* Pre-rotation */ |
192 | 0 | { |
193 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp = f; |
194 | 0 | const kiss_twiddle_scalar *t = &trig[0]; |
195 | 0 | for(i=0;i<N4;i++) |
196 | 0 | { |
197 | 0 | kiss_fft_cpx yc; |
198 | 0 | kiss_twiddle_scalar t0, t1; |
199 | 0 | kiss_fft_scalar re, im, yr, yi; |
200 | 0 | t0 = t[i]; |
201 | 0 | t1 = t[N4+i]; |
202 | 0 | re = *yp++; |
203 | 0 | im = *yp++; |
204 | 0 | yr = S_MUL(re,t0) - S_MUL(im,t1); |
205 | 0 | yi = S_MUL(im,t0) + S_MUL(re,t1); |
206 | 0 | yc.r = yr; |
207 | 0 | yc.i = yi; |
208 | 0 | yc.r = PSHR32(MULT16_32_Q16(scale, yc.r), scale_shift); |
209 | 0 | yc.i = PSHR32(MULT16_32_Q16(scale, yc.i), scale_shift); |
210 | 0 | f2[st->bitrev[i]] = yc; |
211 | 0 | } |
212 | 0 | } |
213 | | |
214 | | /* N/4 complex FFT, does not downscale anymore */ |
215 | 0 | opus_fft_impl(st, f2); |
216 | | |
217 | | /* Post-rotate */ |
218 | 0 | { |
219 | | /* Temp pointers to make it really clear to the compiler what we're doing */ |
220 | 0 | const kiss_fft_cpx * OPUS_RESTRICT fp = f2; |
221 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp1 = out; |
222 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1); |
223 | 0 | const kiss_twiddle_scalar *t = &trig[0]; |
224 | | /* Temp pointers to make it really clear to the compiler what we're doing */ |
225 | 0 | for(i=0;i<N4;i++) |
226 | 0 | { |
227 | 0 | kiss_fft_scalar yr, yi; |
228 | 0 | yr = S_MUL(fp->i,t[N4+i]) - S_MUL(fp->r,t[i]); |
229 | 0 | yi = S_MUL(fp->r,t[N4+i]) + S_MUL(fp->i,t[i]); |
230 | 0 | *yp1 = yr; |
231 | 0 | *yp2 = yi; |
232 | 0 | fp++; |
233 | 0 | yp1 += 2*stride; |
234 | 0 | yp2 -= 2*stride; |
235 | 0 | } |
236 | 0 | } |
237 | 0 | RESTORE_STACK; |
238 | 0 | } |
239 | | #endif /* OVERRIDE_clt_mdct_forward */ |
240 | | |
241 | | #ifndef OVERRIDE_clt_mdct_backward |
242 | | void clt_mdct_backward_c(const mdct_lookup *l, kiss_fft_scalar *in, kiss_fft_scalar * OPUS_RESTRICT out, |
243 | | const opus_val16 * OPUS_RESTRICT window, int overlap, int shift, int stride, int arch) |
244 | 0 | { |
245 | 0 | int i; |
246 | 0 | int N, N2, N4; |
247 | 0 | const kiss_twiddle_scalar *trig; |
248 | 0 | (void) arch; |
249 | |
|
250 | 0 | N = l->n; |
251 | 0 | trig = l->trig; |
252 | 0 | for (i=0;i<shift;i++) |
253 | 0 | { |
254 | 0 | N >>= 1; |
255 | 0 | trig += N; |
256 | 0 | } |
257 | 0 | N2 = N>>1; |
258 | 0 | N4 = N>>2; |
259 | | |
260 | | /* Pre-rotate */ |
261 | 0 | { |
262 | | /* Temp pointers to make it really clear to the compiler what we're doing */ |
263 | 0 | const kiss_fft_scalar * OPUS_RESTRICT xp1 = in; |
264 | 0 | const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+stride*(N2-1); |
265 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp = out+(overlap>>1); |
266 | 0 | const kiss_twiddle_scalar * OPUS_RESTRICT t = &trig[0]; |
267 | 0 | const opus_int16 * OPUS_RESTRICT bitrev = l->kfft[shift]->bitrev; |
268 | 0 | for(i=0;i<N4;i++) |
269 | 0 | { |
270 | 0 | int rev; |
271 | 0 | kiss_fft_scalar yr, yi; |
272 | 0 | rev = *bitrev++; |
273 | 0 | yr = ADD32_ovflw(S_MUL(*xp2, t[i]), S_MUL(*xp1, t[N4+i])); |
274 | 0 | yi = SUB32_ovflw(S_MUL(*xp1, t[i]), S_MUL(*xp2, t[N4+i])); |
275 | | /* We swap real and imag because we use an FFT instead of an IFFT. */ |
276 | 0 | yp[2*rev+1] = yr; |
277 | 0 | yp[2*rev] = yi; |
278 | | /* Storing the pre-rotation directly in the bitrev order. */ |
279 | 0 | xp1+=2*stride; |
280 | 0 | xp2-=2*stride; |
281 | 0 | } |
282 | 0 | } |
283 | |
|
284 | 0 | opus_fft_impl(l->kfft[shift], (kiss_fft_cpx*)(out+(overlap>>1))); |
285 | | |
286 | | /* Post-rotate and de-shuffle from both ends of the buffer at once to make |
287 | | it in-place. */ |
288 | 0 | { |
289 | 0 | kiss_fft_scalar * yp0 = out+(overlap>>1); |
290 | 0 | kiss_fft_scalar * yp1 = out+(overlap>>1)+N2-2; |
291 | 0 | const kiss_twiddle_scalar *t = &trig[0]; |
292 | | /* Loop to (N4+1)>>1 to handle odd N4. When N4 is odd, the |
293 | | middle pair will be computed twice. */ |
294 | 0 | for(i=0;i<(N4+1)>>1;i++) |
295 | 0 | { |
296 | 0 | kiss_fft_scalar re, im, yr, yi; |
297 | 0 | kiss_twiddle_scalar t0, t1; |
298 | | /* We swap real and imag because we're using an FFT instead of an IFFT. */ |
299 | 0 | re = yp0[1]; |
300 | 0 | im = yp0[0]; |
301 | 0 | t0 = t[i]; |
302 | 0 | t1 = t[N4+i]; |
303 | | /* We'd scale up by 2 here, but instead it's done when mixing the windows */ |
304 | 0 | yr = ADD32_ovflw(S_MUL(re,t0), S_MUL(im,t1)); |
305 | 0 | yi = SUB32_ovflw(S_MUL(re,t1), S_MUL(im,t0)); |
306 | | /* We swap real and imag because we're using an FFT instead of an IFFT. */ |
307 | 0 | re = yp1[1]; |
308 | 0 | im = yp1[0]; |
309 | 0 | yp0[0] = yr; |
310 | 0 | yp1[1] = yi; |
311 | |
|
312 | 0 | t0 = t[(N4-i-1)]; |
313 | 0 | t1 = t[(N2-i-1)]; |
314 | | /* We'd scale up by 2 here, but instead it's done when mixing the windows */ |
315 | 0 | yr = ADD32_ovflw(S_MUL(re,t0), S_MUL(im,t1)); |
316 | 0 | yi = SUB32_ovflw(S_MUL(re,t1), S_MUL(im,t0)); |
317 | 0 | yp1[0] = yr; |
318 | 0 | yp0[1] = yi; |
319 | 0 | yp0 += 2; |
320 | 0 | yp1 -= 2; |
321 | 0 | } |
322 | 0 | } |
323 | | |
324 | | /* Mirror on both sides for TDAC */ |
325 | 0 | { |
326 | 0 | kiss_fft_scalar * OPUS_RESTRICT xp1 = out+overlap-1; |
327 | 0 | kiss_fft_scalar * OPUS_RESTRICT yp1 = out; |
328 | 0 | const opus_val16 * OPUS_RESTRICT wp1 = window; |
329 | 0 | const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1; |
330 | |
|
331 | 0 | for(i = 0; i < overlap/2; i++) |
332 | 0 | { |
333 | 0 | kiss_fft_scalar x1, x2; |
334 | 0 | x1 = *xp1; |
335 | 0 | x2 = *yp1; |
336 | 0 | *yp1++ = SUB32_ovflw(MULT16_32_Q15(*wp2, x2), MULT16_32_Q15(*wp1, x1)); |
337 | 0 | *xp1-- = ADD32_ovflw(MULT16_32_Q15(*wp1, x2), MULT16_32_Q15(*wp2, x1)); |
338 | 0 | wp1++; |
339 | 0 | wp2--; |
340 | 0 | } |
341 | 0 | } |
342 | 0 | } |
343 | | #endif /* OVERRIDE_clt_mdct_backward */ |