summaryrefslogtreecommitdiff
path: root/libs/libopus/celt/quant_bands.c
blob: 95076e0af2d4ee07b25b5b3330542773e24497b2 (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
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
/* Copyright (c) 2007-2008 CSIRO
   Copyright (c) 2007-2009 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 "quant_bands.h"
#include "laplace.h"
#include <math.h>
#include "os_support.h"
#include "arch.h"
#include "mathops.h"
#include "stack_alloc.h"
#include "rate.h"

#ifdef FIXED_POINT
/* Mean energy in each band quantized in Q4 */
const signed char eMeans[25] = {
      103,100, 92, 85, 81,
       77, 72, 70, 78, 75,
       73, 71, 78, 74, 69,
       72, 70, 74, 76, 71,
       60, 60, 60, 60, 60
};
#else
/* Mean energy in each band quantized in Q4 and converted back to float */
const opus_val16 eMeans[25] = {
      6.437500f, 6.250000f, 5.750000f, 5.312500f, 5.062500f,
      4.812500f, 4.500000f, 4.375000f, 4.875000f, 4.687500f,
      4.562500f, 4.437500f, 4.875000f, 4.625000f, 4.312500f,
      4.500000f, 4.375000f, 4.625000f, 4.750000f, 4.437500f,
      3.750000f, 3.750000f, 3.750000f, 3.750000f, 3.750000f
};
#endif
/* prediction coefficients: 0.9, 0.8, 0.65, 0.5 */
#ifdef FIXED_POINT
static const opus_val16 pred_coef[4] = {29440, 26112, 21248, 16384};
static const opus_val16 beta_coef[4] = {30147, 22282, 12124, 6554};
static const opus_val16 beta_intra = 4915;
#else
static const opus_val16 pred_coef[4] = {29440/32768., 26112/32768., 21248/32768., 16384/32768.};
static const opus_val16 beta_coef[4] = {30147/32768., 22282/32768., 12124/32768., 6554/32768.};
static const opus_val16 beta_intra = 4915/32768.;
#endif

/*Parameters of the Laplace-like probability models used for the coarse energy.
  There is one pair of parameters for each frame size, prediction type
   (inter/intra), and band number.
  The first number of each pair is the probability of 0, and the second is the
   decay rate, both in Q8 precision.*/
static const unsigned char e_prob_model[4][2][42] = {
   /*120 sample frames.*/
   {
      /*Inter*/
      {
          72, 127,  65, 129,  66, 128,  65, 128,  64, 128,  62, 128,  64, 128,
          64, 128,  92,  78,  92,  79,  92,  78,  90,  79, 116,  41, 115,  40,
         114,  40, 132,  26, 132,  26, 145,  17, 161,  12, 176,  10, 177,  11
      },
      /*Intra*/
      {
          24, 179,  48, 138,  54, 135,  54, 132,  53, 134,  56, 133,  55, 132,
          55, 132,  61, 114,  70,  96,  74,  88,  75,  88,  87,  74,  89,  66,
          91,  67, 100,  59, 108,  50, 120,  40, 122,  37,  97,  43,  78,  50
      }
   },
   /*240 sample frames.*/
   {
      /*Inter*/
      {
          83,  78,  84,  81,  88,  75,  86,  74,  87,  71,  90,  73,  93,  74,
          93,  74, 109,  40, 114,  36, 117,  34, 117,  34, 143,  17, 145,  18,
         146,  19, 162,  12, 165,  10, 178,   7, 189,   6, 190,   8, 177,   9
      },
      /*Intra*/
      {
          23, 178,  54, 115,  63, 102,  66,  98,  69,  99,  74,  89,  71,  91,
          73,  91,  78,  89,  86,  80,  92,  66,  93,  64, 102,  59, 103,  60,
         104,  60, 117,  52, 123,  44, 138,  35, 133,  31,  97,  38,  77,  45
      }
   },
   /*480 sample frames.*/
   {
      /*Inter*/
      {
          61,  90,  93,  60, 105,  42, 107,  41, 110,  45, 116,  38, 113,  38,
         112,  38, 124,  26, 132,  27, 136,  19, 140,  20, 155,  14, 159,  16,
         158,  18, 170,  13, 177,  10, 187,   8, 192,   6, 175,   9, 159,  10
      },
      /*Intra*/
      {
          21, 178,  59, 110,  71,  86,  75,  85,  84,  83,  91,  66,  88,  73,
          87,  72,  92,  75,  98,  72, 105,  58, 107,  54, 115,  52, 114,  55,
         112,  56, 129,  51, 132,  40, 150,  33, 140,  29,  98,  35,  77,  42
      }
   },
   /*960 sample frames.*/
   {
      /*Inter*/
      {
          42, 121,  96,  66, 108,  43, 111,  40, 117,  44, 123,  32, 120,  36,
         119,  33, 127,  33, 134,  34, 139,  21, 147,  23, 152,  20, 158,  25,
         154,  26, 166,  21, 173,  16, 184,  13, 184,  10, 150,  13, 139,  15
      },
      /*Intra*/
      {
          22, 178,  63, 114,  74,  82,  84,  83,  92,  82, 103,  62,  96,  72,
          96,  67, 101,  73, 107,  72, 113,  55, 118,  52, 125,  52, 118,  52,
         117,  55, 135,  49, 137,  39, 157,  32, 145,  29,  97,  33,  77,  40
      }
   }
};

static const unsigned char small_energy_icdf[3]={2,1,0};

static opus_val32 loss_distortion(const opus_val16 *eBands, opus_val16 *oldEBands, int start, int end, int len, int C)
{
   int c, i;
   opus_val32 dist = 0;
   c=0; do {
      for (i=start;i<end;i++)
      {
         opus_val16 d = SUB16(SHR16(eBands[i+c*len], 3), SHR16(oldEBands[i+c*len], 3));
         dist = MAC16_16(dist, d,d);
      }
   } while (++c<C);
   return MIN32(200,SHR32(dist,2*DB_SHIFT-6));
}

static int quant_coarse_energy_impl(const CELTMode *m, int start, int end,
      const opus_val16 *eBands, opus_val16 *oldEBands,
      opus_int32 budget, opus_int32 tell,
      const unsigned char *prob_model, opus_val16 *error, ec_enc *enc,
      int C, int LM, int intra, opus_val16 max_decay, int lfe)
{
   int i, c;
   int badness = 0;
   opus_val32 prev[2] = {0,0};
   opus_val16 coef;
   opus_val16 beta;

   if (tell+3 <= budget)
      ec_enc_bit_logp(enc, intra, 3);
   if (intra)
   {
      coef = 0;
      beta = beta_intra;
   } else {
      beta = beta_coef[LM];
      coef = pred_coef[LM];
   }

   /* Encode at a fixed coarse resolution */
   for (i=start;i<end;i++)
   {
      c=0;
      do {
         int bits_left;
         int qi, qi0;
         opus_val32 q;
         opus_val16 x;
         opus_val32 f, tmp;
         opus_val16 oldE;
         opus_val16 decay_bound;
         x = eBands[i+c*m->nbEBands];
         oldE = MAX16(-QCONST16(9.f,DB_SHIFT), oldEBands[i+c*m->nbEBands]);
#ifdef FIXED_POINT
         f = SHL32(EXTEND32(x),7) - PSHR32(MULT16_16(coef,oldE), 8) - prev[c];
         /* Rounding to nearest integer here is really important! */
         qi = (f+QCONST32(.5f,DB_SHIFT+7))>>(DB_SHIFT+7);
         decay_bound = EXTRACT16(MAX32(-QCONST16(28.f,DB_SHIFT),
               SUB32((opus_val32)oldEBands[i+c*m->nbEBands],max_decay)));
#else
         f = x-coef*oldE-prev[c];
         /* Rounding to nearest integer here is really important! */
         qi = (int)floor(.5f+f);
         decay_bound = MAX16(-QCONST16(28.f,DB_SHIFT), oldEBands[i+c*m->nbEBands]) - max_decay;
#endif
         /* Prevent the energy from going down too quickly (e.g. for bands
            that have just one bin) */
         if (qi < 0 && x < decay_bound)
         {
            qi += (int)SHR16(SUB16(decay_bound,x), DB_SHIFT);
            if (qi > 0)
               qi = 0;
         }
         qi0 = qi;
         /* If we don't have enough bits to encode all the energy, just assume
             something safe. */
         tell = ec_tell(enc);
         bits_left = budget-tell-3*C*(end-i);
         if (i!=start && bits_left < 30)
         {
            if (bits_left < 24)
               qi = IMIN(1, qi);
            if (bits_left < 16)
               qi = IMAX(-1, qi);
         }
         if (lfe && i>=2)
            qi = IMIN(qi, 0);
         if (budget-tell >= 15)
         {
            int pi;
            pi = 2*IMIN(i,20);
            ec_laplace_encode(enc, &qi,
                  prob_model[pi]<<7, prob_model[pi+1]<<6);
         }
         else if(budget-tell >= 2)
         {
            qi = IMAX(-1, IMIN(qi, 1));
            ec_enc_icdf(enc, 2*qi^-(qi<0), small_energy_icdf, 2);
         }
         else if(budget-tell >= 1)
         {
            qi = IMIN(0, qi);
            ec_enc_bit_logp(enc, -qi, 1);
         }
         else
            qi = -1;
         error[i+c*m->nbEBands] = PSHR32(f,7) - SHL16(qi,DB_SHIFT);
         badness += abs(qi0-qi);
         q = (opus_val32)SHL32(EXTEND32(qi),DB_SHIFT);

         tmp = PSHR32(MULT16_16(coef,oldE),8) + prev[c] + SHL32(q,7);
#ifdef FIXED_POINT
         tmp = MAX32(-QCONST32(28.f, DB_SHIFT+7), tmp);
#endif
         oldEBands[i+c*m->nbEBands] = PSHR32(tmp, 7);
         prev[c] = prev[c] + SHL32(q,7) - MULT16_16(beta,PSHR32(q,8));
      } while (++c < C);
   }
   return lfe ? 0 : badness;
}

void quant_coarse_energy(const CELTMode *m, int start, int end, int effEnd,
      const opus_val16 *eBands, opus_val16 *oldEBands, opus_uint32 budget,
      opus_val16 *error, ec_enc *enc, int C, int LM, int nbAvailableBytes,
      int force_intra, opus_val32 *delayedIntra, int two_pass, int loss_rate, int lfe)
{
   int intra;
   opus_val16 max_decay;
   VARDECL(opus_val16, oldEBands_intra);
   VARDECL(opus_val16, error_intra);
   ec_enc enc_start_state;
   opus_uint32 tell;
   int badness1=0;
   opus_int32 intra_bias;
   opus_val32 new_distortion;
   SAVE_STACK;

   intra = force_intra || (!two_pass && *delayedIntra>2*C*(end-start) && nbAvailableBytes > (end-start)*C);
   intra_bias = (opus_int32)((budget**delayedIntra*loss_rate)/(C*512));
   new_distortion = loss_distortion(eBands, oldEBands, start, effEnd, m->nbEBands, C);

   tell = ec_tell(enc);
   if (tell+3 > budget)
      two_pass = intra = 0;

   max_decay = QCONST16(16.f,DB_SHIFT);
   if (end-start>10)
   {
#ifdef FIXED_POINT
      max_decay = MIN32(max_decay, SHL32(EXTEND32(nbAvailableBytes),DB_SHIFT-3));
#else
      max_decay = MIN32(max_decay, .125f*nbAvailableBytes);
#endif
   }
   if (lfe)
      max_decay = QCONST16(3.f,DB_SHIFT);
   enc_start_state = *enc;

   ALLOC(oldEBands_intra, C*m->nbEBands, opus_val16);
   ALLOC(error_intra, C*m->nbEBands, opus_val16);
   OPUS_COPY(oldEBands_intra, oldEBands, C*m->nbEBands);

   if (two_pass || intra)
   {
      badness1 = quant_coarse_energy_impl(m, start, end, eBands, oldEBands_intra, budget,
            tell, e_prob_model[LM][1], error_intra, enc, C, LM, 1, max_decay, lfe);
   }

   if (!intra)
   {
      unsigned char *intra_buf;
      ec_enc enc_intra_state;
      opus_int32 tell_intra;
      opus_uint32 nstart_bytes;
      opus_uint32 nintra_bytes;
      opus_uint32 save_bytes;
      int badness2;
      VARDECL(unsigned char, intra_bits);

      tell_intra = ec_tell_frac(enc);

      enc_intra_state = *enc;

      nstart_bytes = ec_range_bytes(&enc_start_state);
      nintra_bytes = ec_range_bytes(&enc_intra_state);
      intra_buf = ec_get_buffer(&enc_intra_state) + nstart_bytes;
      save_bytes = nintra_bytes-nstart_bytes;
      if (save_bytes == 0)
         save_bytes = ALLOC_NONE;
      ALLOC(intra_bits, save_bytes, unsigned char);
      /* Copy bits from intra bit-stream */
      OPUS_COPY(intra_bits, intra_buf, nintra_bytes - nstart_bytes);

      *enc = enc_start_state;

      badness2 = quant_coarse_energy_impl(m, start, end, eBands, oldEBands, budget,
            tell, e_prob_model[LM][intra], error, enc, C, LM, 0, max_decay, lfe);

      if (two_pass && (badness1 < badness2 || (badness1 == badness2 && ((opus_int32)ec_tell_frac(enc))+intra_bias > tell_intra)))
      {
         *enc = enc_intra_state;
         /* Copy intra bits to bit-stream */
         OPUS_COPY(intra_buf, intra_bits, nintra_bytes - nstart_bytes);
         OPUS_COPY(oldEBands, oldEBands_intra, C*m->nbEBands);
         OPUS_COPY(error, error_intra, C*m->nbEBands);
         intra = 1;
      }
   } else {
      OPUS_COPY(oldEBands, oldEBands_intra, C*m->nbEBands);
      OPUS_COPY(error, error_intra, C*m->nbEBands);
   }

   if (intra)
      *delayedIntra = new_distortion;
   else
      *delayedIntra = ADD32(MULT16_32_Q15(MULT16_16_Q15(pred_coef[LM], pred_coef[LM]),*delayedIntra),
            new_distortion);

   RESTORE_STACK;
}

void quant_fine_energy(const CELTMode *m, int start, int end, opus_val16 *oldEBands, opus_val16 *error, int *fine_quant, ec_enc *enc, int C)
{
   int i, c;

   /* Encode finer resolution */
   for (i=start;i<end;i++)
   {
      opus_int16 frac = 1<<fine_quant[i];
      if (fine_quant[i] <= 0)
         continue;
      c=0;
      do {
         int q2;
         opus_val16 offset;
#ifdef FIXED_POINT
         /* Has to be without rounding */
         q2 = (error[i+c*m->nbEBands]+QCONST16(.5f,DB_SHIFT))>>(DB_SHIFT-fine_quant[i]);
#else
         q2 = (int)floor((error[i+c*m->nbEBands]+.5f)*frac);
#endif
         if (q2 > frac-1)
            q2 = frac-1;
         if (q2<0)
            q2 = 0;
         ec_enc_bits(enc, q2, fine_quant[i]);
#ifdef FIXED_POINT
         offset = SUB16(SHR32(SHL32(EXTEND32(q2),DB_SHIFT)+QCONST16(.5f,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
#else
         offset = (q2+.5f)*(1<<(14-fine_quant[i]))*(1.f/16384) - .5f;
#endif
         oldEBands[i+c*m->nbEBands] += offset;
         error[i+c*m->nbEBands] -= offset;
         /*printf ("%f ", error[i] - offset);*/
      } while (++c < C);
   }
}

void quant_energy_finalise(const CELTMode *m, int start, int end, opus_val16 *oldEBands, opus_val16 *error, int *fine_quant, int *fine_priority, int bits_left, ec_enc *enc, int C)
{
   int i, prio, c;

   /* Use up the remaining bits */
   for (prio=0;prio<2;prio++)
   {
      for (i=start;i<end && bits_left>=C ;i++)
      {
         if (fine_quant[i] >= MAX_FINE_BITS || fine_priority[i]!=prio)
            continue;
         c=0;
         do {
            int q2;
            opus_val16 offset;
            q2 = error[i+c*m->nbEBands]<0 ? 0 : 1;
            ec_enc_bits(enc, q2, 1);
#ifdef FIXED_POINT
            offset = SHR16(SHL16(q2,DB_SHIFT)-QCONST16(.5f,DB_SHIFT),fine_quant[i]+1);
#else
            offset = (q2-.5f)*(1<<(14-fine_quant[i]-1))*(1.f/16384);
#endif
            oldEBands[i+c*m->nbEBands] += offset;
            bits_left--;
         } while (++c < C);
      }
   }
}

void unquant_coarse_energy(const CELTMode *m, int start, int end, opus_val16 *oldEBands, int intra, ec_dec *dec, int C, int LM)
{
   const unsigned char *prob_model = e_prob_model[LM][intra];
   int i, c;
   opus_val32 prev[2] = {0, 0};
   opus_val16 coef;
   opus_val16 beta;
   opus_int32 budget;
   opus_int32 tell;

   if (intra)
   {
      coef = 0;
      beta = beta_intra;
   } else {
      beta = beta_coef[LM];
      coef = pred_coef[LM];
   }

   budget = dec->storage*8;

   /* Decode at a fixed coarse resolution */
   for (i=start;i<end;i++)
   {
      c=0;
      do {
         int qi;
         opus_val32 q;
         opus_val32 tmp;
         /* It would be better to express this invariant as a
            test on C at function entry, but that isn't enough
            to make the static analyzer happy. */
         celt_assert(c<2);
         tell = ec_tell(dec);
         if(budget-tell>=15)
         {
            int pi;
            pi = 2*IMIN(i,20);
            qi = ec_laplace_decode(dec,
                  prob_model[pi]<<7, prob_model[pi+1]<<6);
         }
         else if(budget-tell>=2)
         {
            qi = ec_dec_icdf(dec, small_energy_icdf, 2);
            qi = (qi>>1)^-(qi&1);
         }
         else if(budget-tell>=1)
         {
            qi = -ec_dec_bit_logp(dec, 1);
         }
         else
            qi = -1;
         q = (opus_val32)SHL32(EXTEND32(qi),DB_SHIFT);

         oldEBands[i+c*m->nbEBands] = MAX16(-QCONST16(9.f,DB_SHIFT), oldEBands[i+c*m->nbEBands]);
         tmp = PSHR32(MULT16_16(coef,oldEBands[i+c*m->nbEBands]),8) + prev[c] + SHL32(q,7);
#ifdef FIXED_POINT
         tmp = MAX32(-QCONST32(28.f, DB_SHIFT+7), tmp);
#endif
         oldEBands[i+c*m->nbEBands] = PSHR32(tmp, 7);
         prev[c] = prev[c] + SHL32(q,7) - MULT16_16(beta,PSHR32(q,8));
      } while (++c < C);
   }
}

void unquant_fine_energy(const CELTMode *m, int start, int end, opus_val16 *oldEBands, int *fine_quant, ec_dec *dec, int C)
{
   int i, c;
   /* Decode finer resolution */
   for (i=start;i<end;i++)
   {
      if (fine_quant[i] <= 0)
         continue;
      c=0;
      do {
         int q2;
         opus_val16 offset;
         q2 = ec_dec_bits(dec, fine_quant[i]);
#ifdef FIXED_POINT
         offset = SUB16(SHR32(SHL32(EXTEND32(q2),DB_SHIFT)+QCONST16(.5f,DB_SHIFT),fine_quant[i]),QCONST16(.5f,DB_SHIFT));
#else
         offset = (q2+.5f)*(1<<(14-fine_quant[i]))*(1.f/16384) - .5f;
#endif
         oldEBands[i+c*m->nbEBands] += offset;
      } while (++c < C);
   }
}

void unquant_energy_finalise(const CELTMode *m, int start, int end, opus_val16 *oldEBands, int *fine_quant,  int *fine_priority, int bits_left, ec_dec *dec, int C)
{
   int i, prio, c;

   /* Use up the remaining bits */
   for (prio=0;prio<2;prio++)
   {
      for (i=start;i<end && bits_left>=C ;i++)
      {
         if (fine_quant[i] >= MAX_FINE_BITS || fine_priority[i]!=prio)
            continue;
         c=0;
         do {
            int q2;
            opus_val16 offset;
            q2 = ec_dec_bits(dec, 1);
#ifdef FIXED_POINT
            offset = SHR16(SHL16(q2,DB_SHIFT)-QCONST16(.5f,DB_SHIFT),fine_quant[i]+1);
#else
            offset = (q2-.5f)*(1<<(14-fine_quant[i]-1))*(1.f/16384);
#endif
            oldEBands[i+c*m->nbEBands] += offset;
            bits_left--;
         } while (++c < C);
      }
   }
}

void amp2Log2(const CELTMode *m, int effEnd, int end,
      celt_ener *bandE, opus_val16 *bandLogE, int C)
{
   int c, i;
   c=0;
   do {
      for (i=0;i<effEnd;i++)
         bandLogE[i+c*m->nbEBands] =
               celt_log2(SHL32(bandE[i+c*m->nbEBands],2))
               - SHL16((opus_val16)eMeans[i],6);
      for (i=effEnd;i<end;i++)
         bandLogE[c*m->nbEBands+i] = -QCONST16(14.f,DB_SHIFT);
   } while (++c < C);
}