summaryrefslogtreecommitdiffstats
path: root/media/libopus/celt/celt_lpc.c
blob: b410a21c5f6bf095f2f16c7350a9b471141fed89 (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
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
/* Copyright (c) 2009-2010 Xiph.Org Foundation
   Written by Jean-Marc Valin */
/*
   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.
*/

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

#include "celt_lpc.h"
#include "stack_alloc.h"
#include "mathops.h"
#include "pitch.h"

void _celt_lpc(
      opus_val16       *_lpc, /* out: [0...p-1] LPC coefficients      */
const opus_val32 *ac,  /* in:  [0...p] autocorrelation values  */
int          p
)
{
   int i, j;
   opus_val32 r;
   opus_val32 error = ac[0];
#ifdef FIXED_POINT
   opus_val32 lpc[LPC_ORDER];
#else
   float *lpc = _lpc;
#endif

   OPUS_CLEAR(lpc, p);
   if (ac[0] != 0)
   {
      for (i = 0; i < p; i++) {
         /* Sum up this iteration's reflection coefficient */
         opus_val32 rr = 0;
         for (j = 0; j < i; j++)
            rr += MULT32_32_Q31(lpc[j],ac[i - j]);
         rr += SHR32(ac[i + 1],3);
         r = -frac_div32(SHL32(rr,3), error);
         /*  Update LPC coefficients and total error */
         lpc[i] = SHR32(r,3);
         for (j = 0; j < (i+1)>>1; j++)
         {
            opus_val32 tmp1, tmp2;
            tmp1 = lpc[j];
            tmp2 = lpc[i-1-j];
            lpc[j]     = tmp1 + MULT32_32_Q31(r,tmp2);
            lpc[i-1-j] = tmp2 + MULT32_32_Q31(r,tmp1);
         }

         error = error - MULT32_32_Q31(MULT32_32_Q31(r,r),error);
         /* Bail out once we get 30 dB gain */
#ifdef FIXED_POINT
         if (error<SHR32(ac[0],10))
            break;
#else
         if (error<.001f*ac[0])
            break;
#endif
      }
   }
#ifdef FIXED_POINT
   for (i=0;i<p;i++)
      _lpc[i] = ROUND16(lpc[i],16);
#endif
}


void celt_fir_c(
         const opus_val16 *_x,
         const opus_val16 *num,
         opus_val16 *_y,
         int N,
         int ord,
         opus_val16 *mem,
         int arch)
{
   int i,j;
   VARDECL(opus_val16, rnum);
   VARDECL(opus_val16, x);
   SAVE_STACK;

   ALLOC(rnum, ord, opus_val16);
   ALLOC(x, N+ord, opus_val16);
   for(i=0;i<ord;i++)
      rnum[i] = num[ord-i-1];
   for(i=0;i<ord;i++)
      x[i] = mem[ord-i-1];
   for (i=0;i<N;i++)
      x[i+ord]=_x[i];
   for(i=0;i<ord;i++)
      mem[i] = _x[N-i-1];
#ifdef SMALL_FOOTPRINT
   (void)arch;
   for (i=0;i<N;i++)
   {
      opus_val32 sum = SHL32(EXTEND32(_x[i]), SIG_SHIFT);
      for (j=0;j<ord;j++)
      {
         sum = MAC16_16(sum,rnum[j],x[i+j]);
      }
      _y[i] = SATURATE16(PSHR32(sum, SIG_SHIFT));
   }
#else
   for (i=0;i<N-3;i+=4)
   {
      opus_val32 sum[4]={0,0,0,0};
      xcorr_kernel(rnum, x+i, sum, ord, arch);
      _y[i  ] = SATURATE16(ADD32(EXTEND32(_x[i  ]), PSHR32(sum[0], SIG_SHIFT)));
      _y[i+1] = SATURATE16(ADD32(EXTEND32(_x[i+1]), PSHR32(sum[1], SIG_SHIFT)));
      _y[i+2] = SATURATE16(ADD32(EXTEND32(_x[i+2]), PSHR32(sum[2], SIG_SHIFT)));
      _y[i+3] = SATURATE16(ADD32(EXTEND32(_x[i+3]), PSHR32(sum[3], SIG_SHIFT)));
   }
   for (;i<N;i++)
   {
      opus_val32 sum = 0;
      for (j=0;j<ord;j++)
         sum = MAC16_16(sum,rnum[j],x[i+j]);
      _y[i] = SATURATE16(ADD32(EXTEND32(_x[i]), PSHR32(sum, SIG_SHIFT)));
   }
#endif
   RESTORE_STACK;
}

void celt_iir(const opus_val32 *_x,
         const opus_val16 *den,
         opus_val32 *_y,
         int N,
         int ord,
         opus_val16 *mem,
         int arch)
{
#ifdef SMALL_FOOTPRINT
   int i,j;
   (void)arch;
   for (i=0;i<N;i++)
   {
      opus_val32 sum = _x[i];
      for (j=0;j<ord;j++)
      {
         sum -= MULT16_16(den[j],mem[j]);
      }
      for (j=ord-1;j>=1;j--)
      {
         mem[j]=mem[j-1];
      }
      mem[0] = ROUND16(sum,SIG_SHIFT);
      _y[i] = sum;
   }
#else
   int i,j;
   VARDECL(opus_val16, rden);
   VARDECL(opus_val16, y);
   SAVE_STACK;

   celt_assert((ord&3)==0);
   ALLOC(rden, ord, opus_val16);
   ALLOC(y, N+ord, opus_val16);
   for(i=0;i<ord;i++)
      rden[i] = den[ord-i-1];
   for(i=0;i<ord;i++)
      y[i] = -mem[ord-i-1];
   for(;i<N+ord;i++)
      y[i]=0;
   for (i=0;i<N-3;i+=4)
   {
      /* Unroll by 4 as if it were an FIR filter */
      opus_val32 sum[4];
      sum[0]=_x[i];
      sum[1]=_x[i+1];
      sum[2]=_x[i+2];
      sum[3]=_x[i+3];
      xcorr_kernel(rden, y+i, sum, ord, arch);

      /* Patch up the result to compensate for the fact that this is an IIR */
      y[i+ord  ] = -ROUND16(sum[0],SIG_SHIFT);
      _y[i  ] = sum[0];
      sum[1] = MAC16_16(sum[1], y[i+ord  ], den[0]);
      y[i+ord+1] = -ROUND16(sum[1],SIG_SHIFT);
      _y[i+1] = sum[1];
      sum[2] = MAC16_16(sum[2], y[i+ord+1], den[0]);
      sum[2] = MAC16_16(sum[2], y[i+ord  ], den[1]);
      y[i+ord+2] = -ROUND16(sum[2],SIG_SHIFT);
      _y[i+2] = sum[2];

      sum[3] = MAC16_16(sum[3], y[i+ord+2], den[0]);
      sum[3] = MAC16_16(sum[3], y[i+ord+1], den[1]);
      sum[3] = MAC16_16(sum[3], y[i+ord  ], den[2]);
      y[i+ord+3] = -ROUND16(sum[3],SIG_SHIFT);
      _y[i+3] = sum[3];
   }
   for (;i<N;i++)
   {
      opus_val32 sum = _x[i];
      for (j=0;j<ord;j++)
         sum -= MULT16_16(rden[j],y[i+j]);
      y[i+ord] = ROUND16(sum,SIG_SHIFT);
      _y[i] = sum;
   }
   for(i=0;i<ord;i++)
      mem[i] = _y[N-i-1];
   RESTORE_STACK;
#endif
}

int _celt_autocorr(
                   const opus_val16 *x,   /*  in: [0...n-1] samples x   */
                   opus_val32       *ac,  /* out: [0...lag-1] ac values */
                   const opus_val16       *window,
                   int          overlap,
                   int          lag,
                   int          n,
                   int          arch
                  )
{
   opus_val32 d;
   int i, k;
   int fastN=n-lag;
   int shift;
   const opus_val16 *xptr;
   VARDECL(opus_val16, xx);
   SAVE_STACK;
   ALLOC(xx, n, opus_val16);
   celt_assert(n>0);
   celt_assert(overlap>=0);
   if (overlap == 0)
   {
      xptr = x;
   } else {
      for (i=0;i<n;i++)
         xx[i] = x[i];
      for (i=0;i<overlap;i++)
      {
         xx[i] = MULT16_16_Q15(x[i],window[i]);
         xx[n-i-1] = MULT16_16_Q15(x[n-i-1],window[i]);
      }
      xptr = xx;
   }
   shift=0;
#ifdef FIXED_POINT
   {
      opus_val32 ac0;
      ac0 = 1+(n<<7);
      if (n&1) ac0 += SHR32(MULT16_16(xptr[0],xptr[0]),9);
      for(i=(n&1);i<n;i+=2)
      {
         ac0 += SHR32(MULT16_16(xptr[i],xptr[i]),9);
         ac0 += SHR32(MULT16_16(xptr[i+1],xptr[i+1]),9);
      }

      shift = celt_ilog2(ac0)-30+10;
      shift = (shift)/2;
      if (shift>0)
      {
         for(i=0;i<n;i++)
            xx[i] = PSHR32(xptr[i], shift);
         xptr = xx;
      } else
         shift = 0;
   }
#endif
   celt_pitch_xcorr(xptr, xptr, ac, fastN, lag+1, arch);
   for (k=0;k<=lag;k++)
   {
      for (i = k+fastN, d = 0; i < n; i++)
         d = MAC16_16(d, xptr[i], xptr[i-k]);
      ac[k] += d;
   }
#ifdef FIXED_POINT
   shift = 2*shift;
   if (shift<=0)
      ac[0] += SHL32((opus_int32)1, -shift);
   if (ac[0] < 268435456)
   {
      int shift2 = 29 - EC_ILOG(ac[0]);
      for (i=0;i<=lag;i++)
         ac[i] = SHL32(ac[i], shift2);
      shift -= shift2;
   } else if (ac[0] >= 536870912)
   {
      int shift2=1;
      if (ac[0] >= 1073741824)
         shift2++;
      for (i=0;i<=lag;i++)
         ac[i] = SHR32(ac[i], shift2);
      shift += shift2;
   }
#endif

   RESTORE_STACK;
   return shift;
}