summaryrefslogtreecommitdiffstats
path: root/media/libopus/celt/arm/celt_ne10_mdct.c
blob: 293c3efd7a242a35df2ae26fd890ce8c26761930 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
/* Copyright (c) 2015 Xiph.Org Foundation
   Written by Viswanath Puttagunta */
/**
   @file celt_ne10_mdct.c
   @brief ARM Neon optimizations for mdct using NE10 library
 */

/*
   Redistribution and use in source and binary forms, with or without
   modification, are permitted provided that the following conditions
   are met:

   - Redistributions of source code must retain the above copyright
   notice, this list of conditions and the following disclaimer.

   - Redistributions in binary form must reproduce the above copyright
   notice, this list of conditions and the following disclaimer in the
   documentation and/or other materials provided with the distribution.

   THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
   ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
   LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
   A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER
   OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
   EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
   PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
   PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
   LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
   NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/

#ifndef SKIP_CONFIG_H
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#endif

#include "kiss_fft.h"
#include "_kiss_fft_guts.h"
#include "mdct.h"
#include "stack_alloc.h"

void clt_mdct_forward_neon(const mdct_lookup *l,
                           kiss_fft_scalar *in,
                           kiss_fft_scalar * OPUS_RESTRICT out,
                           const opus_val16 *window,
                           int overlap, int shift, int stride, int arch)
{
   int i;
   int N, N2, N4;
   VARDECL(kiss_fft_scalar, f);
   VARDECL(kiss_fft_cpx, f2);
   const kiss_fft_state *st = l->kfft[shift];
   const kiss_twiddle_scalar *trig;

   SAVE_STACK;

   N = l->n;
   trig = l->trig;
   for (i=0;i<shift;i++)
   {
      N >>= 1;
      trig += N;
   }
   N2 = N>>1;
   N4 = N>>2;

   ALLOC(f, N2, kiss_fft_scalar);
   ALLOC(f2, N4, kiss_fft_cpx);

   /* Consider the input to be composed of four blocks: [a, b, c, d] */
   /* Window, shuffle, fold */
   {
      /* Temp pointers to make it really clear to the compiler what we're doing */
      const kiss_fft_scalar * OPUS_RESTRICT xp1 = in+(overlap>>1);
      const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+N2-1+(overlap>>1);
      kiss_fft_scalar * OPUS_RESTRICT yp = f;
      const opus_val16 * OPUS_RESTRICT wp1 = window+(overlap>>1);
      const opus_val16 * OPUS_RESTRICT wp2 = window+(overlap>>1)-1;
      for(i=0;i<((overlap+3)>>2);i++)
      {
         /* Real part arranged as -d-cR, Imag part arranged as -b+aR*/
         *yp++ = MULT16_32_Q15(*wp2, xp1[N2]) + MULT16_32_Q15(*wp1,*xp2);
         *yp++ = MULT16_32_Q15(*wp1, *xp1)    - MULT16_32_Q15(*wp2, xp2[-N2]);
         xp1+=2;
         xp2-=2;
         wp1+=2;
         wp2-=2;
      }
      wp1 = window;
      wp2 = window+overlap-1;
      for(;i<N4-((overlap+3)>>2);i++)
      {
         /* Real part arranged as a-bR, Imag part arranged as -c-dR */
         *yp++ = *xp2;
         *yp++ = *xp1;
         xp1+=2;
         xp2-=2;
      }
      for(;i<N4;i++)
      {
         /* Real part arranged as a-bR, Imag part arranged as -c-dR */
         *yp++ =  -MULT16_32_Q15(*wp1, xp1[-N2]) + MULT16_32_Q15(*wp2, *xp2);
         *yp++ = MULT16_32_Q15(*wp2, *xp1)     + MULT16_32_Q15(*wp1, xp2[N2]);
         xp1+=2;
         xp2-=2;
         wp1+=2;
         wp2-=2;
      }
   }
   /* Pre-rotation */
   {
      kiss_fft_scalar * OPUS_RESTRICT yp = f;
      const kiss_twiddle_scalar *t = &trig[0];
      for(i=0;i<N4;i++)
      {
         kiss_fft_cpx yc;
         kiss_twiddle_scalar t0, t1;
         kiss_fft_scalar re, im, yr, yi;
         t0 = t[i];
         t1 = t[N4+i];
         re = *yp++;
         im = *yp++;
         yr = S_MUL(re,t0)  -  S_MUL(im,t1);
         yi = S_MUL(im,t0)  +  S_MUL(re,t1);
         yc.r = yr;
         yc.i = yi;
         f2[i] = yc;
      }
   }

   opus_fft(st, f2, (kiss_fft_cpx *)f, arch);

   /* Post-rotate */
   {
      /* Temp pointers to make it really clear to the compiler what we're doing */
      const kiss_fft_cpx * OPUS_RESTRICT fp = (kiss_fft_cpx *)f;
      kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
      kiss_fft_scalar * OPUS_RESTRICT yp2 = out+stride*(N2-1);
      const kiss_twiddle_scalar *t = &trig[0];
      /* Temp pointers to make it really clear to the compiler what we're doing */
      for(i=0;i<N4;i++)
      {
         kiss_fft_scalar yr, yi;
         yr = S_MUL(fp->i,t[N4+i]) - S_MUL(fp->r,t[i]);
         yi = S_MUL(fp->r,t[N4+i]) + S_MUL(fp->i,t[i]);
         *yp1 = yr;
         *yp2 = yi;
         fp++;
         yp1 += 2*stride;
         yp2 -= 2*stride;
      }
   }
   RESTORE_STACK;
}

void clt_mdct_backward_neon(const mdct_lookup *l,
                            kiss_fft_scalar *in,
                            kiss_fft_scalar * OPUS_RESTRICT out,
                            const opus_val16 * OPUS_RESTRICT window,
                            int overlap, int shift, int stride, int arch)
{
   int i;
   int N, N2, N4;
   VARDECL(kiss_fft_scalar, f);
   const kiss_twiddle_scalar *trig;
   const kiss_fft_state *st = l->kfft[shift];

   N = l->n;
   trig = l->trig;
   for (i=0;i<shift;i++)
   {
      N >>= 1;
      trig += N;
   }
   N2 = N>>1;
   N4 = N>>2;

   ALLOC(f, N2, kiss_fft_scalar);

   /* Pre-rotate */
   {
      /* Temp pointers to make it really clear to the compiler what we're doing */
      const kiss_fft_scalar * OPUS_RESTRICT xp1 = in;
      const kiss_fft_scalar * OPUS_RESTRICT xp2 = in+stride*(N2-1);
      kiss_fft_scalar * OPUS_RESTRICT yp = f;
      const kiss_twiddle_scalar * OPUS_RESTRICT t = &trig[0];
      for(i=0;i<N4;i++)
      {
         kiss_fft_scalar yr, yi;
         yr = S_MUL(*xp2, t[i]) + S_MUL(*xp1, t[N4+i]);
         yi = S_MUL(*xp1, t[i]) - S_MUL(*xp2, t[N4+i]);
         yp[2*i] = yr;
         yp[2*i+1] = yi;
         xp1+=2*stride;
         xp2-=2*stride;
      }
   }

   opus_ifft(st, (kiss_fft_cpx *)f, (kiss_fft_cpx*)(out+(overlap>>1)), arch);

   /* Post-rotate and de-shuffle from both ends of the buffer at once to make
      it in-place. */
   {
      kiss_fft_scalar * yp0 = out+(overlap>>1);
      kiss_fft_scalar * yp1 = out+(overlap>>1)+N2-2;
      const kiss_twiddle_scalar *t = &trig[0];
      /* Loop to (N4+1)>>1 to handle odd N4. When N4 is odd, the
         middle pair will be computed twice. */
      for(i=0;i<(N4+1)>>1;i++)
      {
         kiss_fft_scalar re, im, yr, yi;
         kiss_twiddle_scalar t0, t1;
         re = yp0[0];
         im = yp0[1];
         t0 = t[i];
         t1 = t[N4+i];
         /* We'd scale up by 2 here, but instead it's done when mixing the windows */
         yr = S_MUL(re,t0) + S_MUL(im,t1);
         yi = S_MUL(re,t1) - S_MUL(im,t0);
         re = yp1[0];
         im = yp1[1];
         yp0[0] = yr;
         yp1[1] = yi;

         t0 = t[(N4-i-1)];
         t1 = t[(N2-i-1)];
         /* We'd scale up by 2 here, but instead it's done when mixing the windows */
         yr = S_MUL(re,t0) + S_MUL(im,t1);
         yi = S_MUL(re,t1) - S_MUL(im,t0);
         yp1[0] = yr;
         yp0[1] = yi;
         yp0 += 2;
         yp1 -= 2;
      }
   }

   /* Mirror on both sides for TDAC */
   {
      kiss_fft_scalar * OPUS_RESTRICT xp1 = out+overlap-1;
      kiss_fft_scalar * OPUS_RESTRICT yp1 = out;
      const opus_val16 * OPUS_RESTRICT wp1 = window;
      const opus_val16 * OPUS_RESTRICT wp2 = window+overlap-1;

      for(i = 0; i < overlap/2; i++)
      {
         kiss_fft_scalar x1, x2;
         x1 = *xp1;
         x2 = *yp1;
         *yp1++ = MULT16_32_Q15(*wp2, x2) - MULT16_32_Q15(*wp1, x1);
         *xp1-- = MULT16_32_Q15(*wp1, x2) + MULT16_32_Q15(*wp2, x1);
         wp1++;
         wp2--;
      }
   }
   RESTORE_STACK;
}