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1 /* Copyright (c) 2007-2008 CSIRO
2    Copyright (c) 2007-2009 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 #ifdef HAVE_CONFIG_H
30 #include "config.h"
31 #endif
32 
33 #include "mathops.h"
34 #include "cwrs.h"
35 #include "vq.h"
36 #include "arch.h"
37 #include "os_support.h"
38 #include "bands.h"
39 #include "rate.h"
40 #include "pitch.h"
41 
42 #if defined(MIPSr1_ASM)
43 #include "mips/vq_mipsr1.h"
44 #endif
45 
46 #ifndef OVERRIDE_vq_exp_rotation1
exp_rotation1(celt_norm * X,int len,int stride,opus_val16 c,opus_val16 s)47 static void exp_rotation1(celt_norm *X, int len, int stride, opus_val16 c, opus_val16 s)
48 {
49    int i;
50    opus_val16 ms;
51    celt_norm *Xptr;
52    Xptr = X;
53    ms = NEG16(s);
54    for (i=0;i<len-stride;i++)
55    {
56       celt_norm x1, x2;
57       x1 = Xptr[0];
58       x2 = Xptr[stride];
59       Xptr[stride] = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x2),  s, x1), 15));
60       *Xptr++      = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x1), ms, x2), 15));
61    }
62    Xptr = &X[len-2*stride-1];
63    for (i=len-2*stride-1;i>=0;i--)
64    {
65       celt_norm x1, x2;
66       x1 = Xptr[0];
67       x2 = Xptr[stride];
68       Xptr[stride] = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x2),  s, x1), 15));
69       *Xptr--      = EXTRACT16(PSHR32(MAC16_16(MULT16_16(c, x1), ms, x2), 15));
70    }
71 }
72 #endif /* OVERRIDE_vq_exp_rotation1 */
73 
exp_rotation(celt_norm * X,int len,int dir,int stride,int K,int spread)74 void exp_rotation(celt_norm *X, int len, int dir, int stride, int K, int spread)
75 {
76    static const int SPREAD_FACTOR[3]={15,10,5};
77    int i;
78    opus_val16 c, s;
79    opus_val16 gain, theta;
80    int stride2=0;
81    int factor;
82 
83    if (2*K>=len || spread==SPREAD_NONE)
84       return;
85    factor = SPREAD_FACTOR[spread-1];
86 
87    gain = celt_div((opus_val32)MULT16_16(Q15_ONE,len),(opus_val32)(len+factor*K));
88    theta = HALF16(MULT16_16_Q15(gain,gain));
89 
90    c = celt_cos_norm(EXTEND32(theta));
91    s = celt_cos_norm(EXTEND32(SUB16(Q15ONE,theta))); /*  sin(theta) */
92 
93    if (len>=8*stride)
94    {
95       stride2 = 1;
96       /* This is just a simple (equivalent) way of computing sqrt(len/stride) with rounding.
97          It's basically incrementing long as (stride2+0.5)^2 < len/stride. */
98       while ((stride2*stride2+stride2)*stride + (stride>>2) < len)
99          stride2++;
100    }
101    /*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for
102       extract_collapse_mask().*/
103    len = celt_udiv(len, stride);
104    for (i=0;i<stride;i++)
105    {
106       if (dir < 0)
107       {
108          if (stride2)
109             exp_rotation1(X+i*len, len, stride2, s, c);
110          exp_rotation1(X+i*len, len, 1, c, s);
111       } else {
112          exp_rotation1(X+i*len, len, 1, c, -s);
113          if (stride2)
114             exp_rotation1(X+i*len, len, stride2, s, -c);
115       }
116    }
117 }
118 
119 /** Takes the pitch vector and the decoded residual vector, computes the gain
120     that will give ||p+g*y||=1 and mixes the residual with the pitch. */
normalise_residual(int * OPUS_RESTRICT iy,celt_norm * OPUS_RESTRICT X,int N,opus_val32 Ryy,opus_val16 gain)121 static void normalise_residual(int * OPUS_RESTRICT iy, celt_norm * OPUS_RESTRICT X,
122       int N, opus_val32 Ryy, opus_val16 gain)
123 {
124    int i;
125 #ifdef FIXED_POINT
126    int k;
127 #endif
128    opus_val32 t;
129    opus_val16 g;
130 
131 #ifdef FIXED_POINT
132    k = celt_ilog2(Ryy)>>1;
133 #endif
134    t = VSHR32(Ryy, 2*(k-7));
135    g = MULT16_16_P15(celt_rsqrt_norm(t),gain);
136 
137    i=0;
138    do
139       X[i] = EXTRACT16(PSHR32(MULT16_16(g, iy[i]), k+1));
140    while (++i < N);
141 }
142 
extract_collapse_mask(int * iy,int N,int B)143 static unsigned extract_collapse_mask(int *iy, int N, int B)
144 {
145    unsigned collapse_mask;
146    int N0;
147    int i;
148    if (B<=1)
149       return 1;
150    /*NOTE: As a minor optimization, we could be passing around log2(B), not B, for both this and for
151       exp_rotation().*/
152    N0 = celt_udiv(N, B);
153    collapse_mask = 0;
154    i=0; do {
155       int j;
156       unsigned tmp=0;
157       j=0; do {
158          tmp |= iy[i*N0+j];
159       } while (++j<N0);
160       collapse_mask |= (tmp!=0)<<i;
161    } while (++i<B);
162    return collapse_mask;
163 }
164 
op_pvq_search_c(celt_norm * X,int * iy,int K,int N,int arch)165 opus_val16 op_pvq_search_c(celt_norm *X, int *iy, int K, int N, int arch)
166 {
167    VARDECL(celt_norm, y);
168    VARDECL(int, signx);
169    int i, j;
170    int pulsesLeft;
171    opus_val32 sum;
172    opus_val32 xy;
173    opus_val16 yy;
174    SAVE_STACK;
175 
176    (void)arch;
177    ALLOC(y, N, celt_norm);
178    ALLOC(signx, N, int);
179 
180    /* Get rid of the sign */
181    sum = 0;
182    j=0; do {
183       signx[j] = X[j]<0;
184       /* OPT: Make sure the compiler doesn't use a branch on ABS16(). */
185       X[j] = ABS16(X[j]);
186       iy[j] = 0;
187       y[j] = 0;
188    } while (++j<N);
189 
190    xy = yy = 0;
191 
192    pulsesLeft = K;
193 
194    /* Do a pre-search by projecting on the pyramid */
195    if (K > (N>>1))
196    {
197       opus_val16 rcp;
198       j=0; do {
199          sum += X[j];
200       }  while (++j<N);
201 
202       /* If X is too small, just replace it with a pulse at 0 */
203 #ifdef FIXED_POINT
204       if (sum <= K)
205 #else
206       /* Prevents infinities and NaNs from causing too many pulses
207          to be allocated. 64 is an approximation of infinity here. */
208       if (!(sum > EPSILON && sum < 64))
209 #endif
210       {
211          X[0] = QCONST16(1.f,14);
212          j=1; do
213             X[j]=0;
214          while (++j<N);
215          sum = QCONST16(1.f,14);
216       }
217 #ifdef FIXED_POINT
218       rcp = EXTRACT16(MULT16_32_Q16(K, celt_rcp(sum)));
219 #else
220       /* Using K+e with e < 1 guarantees we cannot get more than K pulses. */
221       rcp = EXTRACT16(MULT16_32_Q16(K+0.8f, celt_rcp(sum)));
222 #endif
223       j=0; do {
224 #ifdef FIXED_POINT
225          /* It's really important to round *towards zero* here */
226          iy[j] = MULT16_16_Q15(X[j],rcp);
227 #else
228          iy[j] = (int)floor(rcp*X[j]);
229 #endif
230          y[j] = (celt_norm)iy[j];
231          yy = MAC16_16(yy, y[j],y[j]);
232          xy = MAC16_16(xy, X[j],y[j]);
233          y[j] *= 2;
234          pulsesLeft -= iy[j];
235       }  while (++j<N);
236    }
237    celt_sig_assert(pulsesLeft>=0);
238 
239    /* This should never happen, but just in case it does (e.g. on silence)
240       we fill the first bin with pulses. */
241 #ifdef FIXED_POINT_DEBUG
242    celt_sig_assert(pulsesLeft<=N+3);
243 #endif
244    if (pulsesLeft > N+3)
245    {
246       opus_val16 tmp = (opus_val16)pulsesLeft;
247       yy = MAC16_16(yy, tmp, tmp);
248       yy = MAC16_16(yy, tmp, y[0]);
249       iy[0] += pulsesLeft;
250       pulsesLeft=0;
251    }
252 
253    for (i=0;i<pulsesLeft;i++)
254    {
255       opus_val16 Rxy, Ryy;
256       int best_id;
257       opus_val32 best_num;
258       opus_val16 best_den;
259 #ifdef FIXED_POINT
260       int rshift;
261 #endif
262 #ifdef FIXED_POINT
263       rshift = 1+celt_ilog2(K-pulsesLeft+i+1);
264 #endif
265       best_id = 0;
266       /* The squared magnitude term gets added anyway, so we might as well
267          add it outside the loop */
268       yy = ADD16(yy, 1);
269 
270       /* Calculations for position 0 are out of the loop, in part to reduce
271          mispredicted branches (since the if condition is usually false)
272          in the loop. */
273       /* Temporary sums of the new pulse(s) */
274       Rxy = EXTRACT16(SHR32(ADD32(xy, EXTEND32(X[0])),rshift));
275       /* We're multiplying y[j] by two so we don't have to do it here */
276       Ryy = ADD16(yy, y[0]);
277 
278       /* Approximate score: we maximise Rxy/sqrt(Ryy) (we're guaranteed that
279          Rxy is positive because the sign is pre-computed) */
280       Rxy = MULT16_16_Q15(Rxy,Rxy);
281       best_den = Ryy;
282       best_num = Rxy;
283       j=1;
284       do {
285          /* Temporary sums of the new pulse(s) */
286          Rxy = EXTRACT16(SHR32(ADD32(xy, EXTEND32(X[j])),rshift));
287          /* We're multiplying y[j] by two so we don't have to do it here */
288          Ryy = ADD16(yy, y[j]);
289 
290          /* Approximate score: we maximise Rxy/sqrt(Ryy) (we're guaranteed that
291             Rxy is positive because the sign is pre-computed) */
292          Rxy = MULT16_16_Q15(Rxy,Rxy);
293          /* The idea is to check for num/den >= best_num/best_den, but that way
294             we can do it without any division */
295          /* OPT: It's not clear whether a cmov is faster than a branch here
296             since the condition is more often false than true and using
297             a cmov introduces data dependencies across iterations. The optimal
298             choice may be architecture-dependent. */
299          if (opus_unlikely(MULT16_16(best_den, Rxy) > MULT16_16(Ryy, best_num)))
300          {
301             best_den = Ryy;
302             best_num = Rxy;
303             best_id = j;
304          }
305       } while (++j<N);
306 
307       /* Updating the sums of the new pulse(s) */
308       xy = ADD32(xy, EXTEND32(X[best_id]));
309       /* We're multiplying y[j] by two so we don't have to do it here */
310       yy = ADD16(yy, y[best_id]);
311 
312       /* Only now that we've made the final choice, update y/iy */
313       /* Multiplying y[j] by 2 so we don't have to do it everywhere else */
314       y[best_id] += 2;
315       iy[best_id]++;
316    }
317 
318    /* Put the original sign back */
319    j=0;
320    do {
321       /*iy[j] = signx[j] ? -iy[j] : iy[j];*/
322       /* OPT: The is more likely to be compiled without a branch than the code above
323          but has the same performance otherwise. */
324       iy[j] = (iy[j]^-signx[j]) + signx[j];
325    } while (++j<N);
326    RESTORE_STACK;
327    return yy;
328 }
329 
alg_quant(celt_norm * X,int N,int K,int spread,int B,ec_enc * enc,opus_val16 gain,int resynth,int arch)330 unsigned alg_quant(celt_norm *X, int N, int K, int spread, int B, ec_enc *enc,
331       opus_val16 gain, int resynth, int arch)
332 {
333    VARDECL(int, iy);
334    opus_val16 yy;
335    unsigned collapse_mask;
336    SAVE_STACK;
337 
338    celt_assert2(K>0, "alg_quant() needs at least one pulse");
339    celt_assert2(N>1, "alg_quant() needs at least two dimensions");
340 
341    /* Covers vectorization by up to 4. */
342    ALLOC(iy, N+3, int);
343 
344    exp_rotation(X, N, 1, B, K, spread);
345 
346    yy = op_pvq_search(X, iy, K, N, arch);
347 
348    encode_pulses(iy, N, K, enc);
349 
350    if (resynth)
351    {
352       normalise_residual(iy, X, N, yy, gain);
353       exp_rotation(X, N, -1, B, K, spread);
354    }
355 
356    collapse_mask = extract_collapse_mask(iy, N, B);
357    RESTORE_STACK;
358    return collapse_mask;
359 }
360 
361 /** Decode pulse vector and combine the result with the pitch vector to produce
362     the final normalised signal in the current band. */
alg_unquant(celt_norm * X,int N,int K,int spread,int B,ec_dec * dec,opus_val16 gain)363 unsigned alg_unquant(celt_norm *X, int N, int K, int spread, int B,
364       ec_dec *dec, opus_val16 gain)
365 {
366    opus_val32 Ryy;
367    unsigned collapse_mask;
368    VARDECL(int, iy);
369    SAVE_STACK;
370 
371    celt_assert2(K>0, "alg_unquant() needs at least one pulse");
372    celt_assert2(N>1, "alg_unquant() needs at least two dimensions");
373    ALLOC(iy, N, int);
374    Ryy = decode_pulses(iy, N, K, dec);
375    normalise_residual(iy, X, N, Ryy, gain);
376    exp_rotation(X, N, -1, B, K, spread);
377    collapse_mask = extract_collapse_mask(iy, N, B);
378    RESTORE_STACK;
379    return collapse_mask;
380 }
381 
382 #ifndef OVERRIDE_renormalise_vector
renormalise_vector(celt_norm * X,int N,opus_val16 gain,int arch)383 void renormalise_vector(celt_norm *X, int N, opus_val16 gain, int arch)
384 {
385    int i;
386 #ifdef FIXED_POINT
387    int k;
388 #endif
389    opus_val32 E;
390    opus_val16 g;
391    opus_val32 t;
392    celt_norm *xptr;
393    E = EPSILON + celt_inner_prod(X, X, N, arch);
394 #ifdef FIXED_POINT
395    k = celt_ilog2(E)>>1;
396 #endif
397    t = VSHR32(E, 2*(k-7));
398    g = MULT16_16_P15(celt_rsqrt_norm(t),gain);
399 
400    xptr = X;
401    for (i=0;i<N;i++)
402    {
403       *xptr = EXTRACT16(PSHR32(MULT16_16(g, *xptr), k+1));
404       xptr++;
405    }
406    /*return celt_sqrt(E);*/
407 }
408 #endif /* OVERRIDE_renormalise_vector */
409 
stereo_itheta(const celt_norm * X,const celt_norm * Y,int stereo,int N,int arch)410 int stereo_itheta(const celt_norm *X, const celt_norm *Y, int stereo, int N, int arch)
411 {
412    int i;
413    int itheta;
414    opus_val16 mid, side;
415    opus_val32 Emid, Eside;
416 
417    Emid = Eside = EPSILON;
418    if (stereo)
419    {
420       for (i=0;i<N;i++)
421       {
422          celt_norm m, s;
423          m = ADD16(SHR16(X[i],1),SHR16(Y[i],1));
424          s = SUB16(SHR16(X[i],1),SHR16(Y[i],1));
425          Emid = MAC16_16(Emid, m, m);
426          Eside = MAC16_16(Eside, s, s);
427       }
428    } else {
429       Emid += celt_inner_prod(X, X, N, arch);
430       Eside += celt_inner_prod(Y, Y, N, arch);
431    }
432    mid = celt_sqrt(Emid);
433    side = celt_sqrt(Eside);
434 #ifdef FIXED_POINT
435    /* 0.63662 = 2/pi */
436    itheta = MULT16_16_Q15(QCONST16(0.63662f,15),celt_atan2p(side, mid));
437 #else
438    itheta = (int)floor(.5f+16384*0.63662f*fast_atan2f(side,mid));
439 #endif
440 
441    return itheta;
442 }
443