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   1 /*
   2  * AAC coefficients encoder
   3  * Copyright (C) 2008-2009 Konstantin Shishkov
   4  *
   5  * This file is part of FFmpeg.
   6  *
   7  * FFmpeg is free software; you can redistribute it and/or
   8  * modify it under the terms of the GNU Lesser General Public
   9  * License as published by the Free Software Foundation; either
  10  * version 2.1 of the License, or (at your option) any later version.
  11  *
  12  * FFmpeg is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Lesser General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public
  18  * License along with FFmpeg; if not, write to the Free Software
  19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  20  */
  21
  22 /**
  23  * @file
  24  * AAC coefficients encoder
  25  */
  26
  27 /***********************************
  28  *              TODOs:
  29  * speedup quantizer selection
  30  * add sane pulse detection
  31  ***********************************/
  32
  33 #include "libavutil/libm.h" // brought forward to work around cygwin header breakage
  34
  35 #include <float.h>
  36 #include "libavutil/mathematics.h"
  37 #include "avcodec.h"
  38 #include "put_bits.h"
  39 #include "aac.h"
  40 #include "aacenc.h"
  41 #include "aactab.h"
  42 #include "aacenctab.h"
  43 #include "aacenc_utils.h"
  44 #include "aac_tablegen_decl.h"
  45
  46 /** Frequency in Hz for lower limit of noise substitution **/
  47 #define NOISE_LOW_LIMIT 4500
  48
  49 /* Energy spread threshold value below which no PNS is used, this corresponds to
  50  * typically around 17Khz, after which PNS usage decays ending at 19Khz */
  51 #define NOISE_SPREAD_THRESHOLD 0.5f
  52
  53 /* This constant gets divided by lambda to return ~1.65 which when multiplied
  54  * by the band->threshold and compared to band->energy is the boundary between
  55  * excessive PNS and little PNS usage. */
  56 #define NOISE_LAMBDA_NUMERATOR 252.1f
  57
  58 /** Frequency in Hz for lower limit of intensity stereo   **/
  59 #define INT_STEREO_LOW_LIMIT 6100
  60
  61 /**
  62  * Calculate rate distortion cost for quantizing with given codebook
  63  *
  64  * @return quantization distortion
  65  */
  66 static av_always_inline float quantize_and_encode_band_cost_template(
  67                                 struct AACEncContext *s,
  68                                 PutBitContext *pb, const float *in,
  69                                 const float *scaled, int size, int scale_idx,
  70                                 int cb, const float lambda, const float uplim,
  71                                 int *bits, int BT_ZERO, int BT_UNSIGNED,
  72                                 int BT_PAIR, int BT_ESC, int BT_NOISE, int BT_STEREO,
  73                                 const float ROUNDING)
  74 {
  75     const int q_idx = POW_SF2_ZERO - scale_idx + SCALE_ONE_POS - SCALE_DIV_512;
  76     const float Q   = ff_aac_pow2sf_tab [q_idx];
  77     const float Q34 = ff_aac_pow34sf_tab[q_idx];
  78     const float IQ  = ff_aac_pow2sf_tab [POW_SF2_ZERO + scale_idx - SCALE_ONE_POS + SCALE_DIV_512];
  79     const float CLIPPED_ESCAPE = 165140.0f*IQ;
  80     int i, j;
  81     float cost = 0;
  82     const int dim = BT_PAIR ? 2 : 4;
  83     int resbits = 0;
  84     int off;
  85
  86     if (BT_ZERO || BT_NOISE || BT_STEREO) {
  87         for (i = 0; i < size; i++)
  88             cost += in[i]*in[i];
  89         if (bits)
  90             *bits = 0;
  91         return cost * lambda;
  92     }
  93     if (!scaled) {
  94         abs_pow34_v(s->scoefs, in, size);
  95         scaled = s->scoefs;
  96     }
  97     quantize_bands(s->qcoefs, in, scaled, size, Q34, !BT_UNSIGNED, aac_cb_maxval[cb], ROUNDING);
  98     if (BT_UNSIGNED) {
  99         off = 0;
 100     } else {
 101         off = aac_cb_maxval[cb];
 102     }
 103     for (i = 0; i < size; i += dim) {
 104         const float *vec;
 105         int *quants = s->qcoefs + i;
 106         int curidx = 0;
 107         int curbits;
 108         float rd = 0.0f;
 109         for (j = 0; j < dim; j++) {
 110             curidx *= aac_cb_range[cb];
 111             curidx += quants[j] + off;
 112         }
 113         curbits =  ff_aac_spectral_bits[cb-1][curidx];
 114         vec     = &ff_aac_codebook_vectors[cb-1][curidx*dim];
 115         if (BT_UNSIGNED) {
 116             for (j = 0; j < dim; j++) {
 117                 float t = fabsf(in[i+j]);
 118                 float di;
 119                 if (BT_ESC && vec[j] == 64.0f) { //FIXME: slow
 120                     if (t >= CLIPPED_ESCAPE) {
 121                         di = t - CLIPPED_ESCAPE;
 122                         curbits += 21;
 123                     } else {
 124                         int c = av_clip_uintp2(quant(t, Q, ROUNDING), 13);
 125                         di = t - c*cbrtf(c)*IQ;
 126                         curbits += av_log2(c)*2 - 4 + 1;
 127                     }
 128                 } else {
 129                     di = t - vec[j]*IQ;
 130                 }
 131                 if (vec[j] != 0.0f)
 132                     curbits++;
 133                 rd += di*di;
 134             }
 135         } else {
 136             for (j = 0; j < dim; j++) {
 137                 float di = in[i+j] - vec[j]*IQ;
 138                 rd += di*di;
 139             }
 140         }
 141         cost    += rd * lambda + curbits;
 142         resbits += curbits;
 143         if (cost >= uplim)
 144             return uplim;
 145         if (pb) {
 146             put_bits(pb, ff_aac_spectral_bits[cb-1][curidx], ff_aac_spectral_codes[cb-1][curidx]);
 147             if (BT_UNSIGNED)
 148                 for (j = 0; j < dim; j++)
 149                     if (ff_aac_codebook_vectors[cb-1][curidx*dim+j] != 0.0f)
 150                         put_bits(pb, 1, in[i+j] < 0.0f);
 151             if (BT_ESC) {
 152                 for (j = 0; j < 2; j++) {
 153                     if (ff_aac_codebook_vectors[cb-1][curidx*2+j] == 64.0f) {
 154                         int coef = av_clip_uintp2(quant(fabsf(in[i+j]), Q, ROUNDING), 13);
 155                         int len = av_log2(coef);
 156
 157                         put_bits(pb, len - 4 + 1, (1 << (len - 4 + 1)) - 2);
 158                         put_sbits(pb, len, coef);
 159                     }
 160                 }
 161             }
 162         }
 163     }
 164
 165     if (bits)
 166         *bits = resbits;
 167     return cost;
 168 }
 169
 170 static float quantize_and_encode_band_cost_NONE(struct AACEncContext *s, PutBitContext *pb,
 171                                                 const float *in, const float *scaled,
 172                                                 int size, int scale_idx, int cb,
 173                                                 const float lambda, const float uplim,
 174                                                 int *bits) {
 175     av_assert0(0);
 176     return 0.0f;
 177 }
 178
 179 #define QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NAME, BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO, ROUNDING) \
 180 static float quantize_and_encode_band_cost_ ## NAME(                                         \
 181                                 struct AACEncContext *s,                                     \
 182                                 PutBitContext *pb, const float *in,                          \
 183                                 const float *scaled, int size, int scale_idx,                \
 184                                 int cb, const float lambda, const float uplim,               \
 185                                 int *bits) {                                                 \
 186     return quantize_and_encode_band_cost_template(                                           \
 187                                 s, pb, in, scaled, size, scale_idx,                          \
 188                                 BT_ESC ? ESC_BT : cb, lambda, uplim, bits,                   \
 189                                 BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO,  \
 190                                 ROUNDING);                                                   \
 191 }
 192
 193 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ZERO,  1, 0, 0, 0, 0, 0, ROUND_STANDARD)
 194 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SQUAD, 0, 0, 0, 0, 0, 0, ROUND_STANDARD)
 195 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UQUAD, 0, 1, 0, 0, 0, 0, ROUND_STANDARD)
 196 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SPAIR, 0, 0, 1, 0, 0, 0, ROUND_STANDARD)
 197 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UPAIR, 0, 1, 1, 0, 0, 0, ROUND_STANDARD)
 198 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC,   0, 1, 1, 1, 0, 0, ROUND_STANDARD)
 199 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC_RTZ, 0, 1, 1, 1, 0, 0, ROUND_TO_ZERO)
 200 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NOISE, 0, 0, 0, 0, 1, 0, ROUND_STANDARD)
 201 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(STEREO,0, 0, 0, 0, 0, 1, ROUND_STANDARD)
 202
 203 static float (*const quantize_and_encode_band_cost_arr[])(
 204                                 struct AACEncContext *s,
 205                                 PutBitContext *pb, const float *in,
 206                                 const float *scaled, int size, int scale_idx,
 207                                 int cb, const float lambda, const float uplim,
 208                                 int *bits) = {
 209     quantize_and_encode_band_cost_ZERO,
 210     quantize_and_encode_band_cost_SQUAD,
 211     quantize_and_encode_band_cost_SQUAD,
 212     quantize_and_encode_band_cost_UQUAD,
 213     quantize_and_encode_band_cost_UQUAD,
 214     quantize_and_encode_band_cost_SPAIR,
 215     quantize_and_encode_band_cost_SPAIR,
 216     quantize_and_encode_band_cost_UPAIR,
 217     quantize_and_encode_band_cost_UPAIR,
 218     quantize_and_encode_band_cost_UPAIR,
 219     quantize_and_encode_band_cost_UPAIR,
 220     quantize_and_encode_band_cost_ESC,
 221     quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */
 222     quantize_and_encode_band_cost_NOISE,
 223     quantize_and_encode_band_cost_STEREO,
 224     quantize_and_encode_band_cost_STEREO,
 225 };
 226
 227 static float (*const quantize_and_encode_band_cost_rtz_arr[])(
 228                                 struct AACEncContext *s,
 229                                 PutBitContext *pb, const float *in,
 230                                 const float *scaled, int size, int scale_idx,
 231                                 int cb, const float lambda, const float uplim,
 232                                 int *bits) = {
 233     quantize_and_encode_band_cost_ZERO,
 234     quantize_and_encode_band_cost_SQUAD,
 235     quantize_and_encode_band_cost_SQUAD,
 236     quantize_and_encode_band_cost_UQUAD,
 237     quantize_and_encode_band_cost_UQUAD,
 238     quantize_and_encode_band_cost_SPAIR,
 239     quantize_and_encode_band_cost_SPAIR,
 240     quantize_and_encode_band_cost_UPAIR,
 241     quantize_and_encode_band_cost_UPAIR,
 242     quantize_and_encode_band_cost_UPAIR,
 243     quantize_and_encode_band_cost_UPAIR,
 244     quantize_and_encode_band_cost_ESC_RTZ,
 245     quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */
 246     quantize_and_encode_band_cost_NOISE,
 247     quantize_and_encode_band_cost_STEREO,
 248     quantize_and_encode_band_cost_STEREO,
 249 };
 250
 251 #define quantize_and_encode_band_cost(                                  \
 252                                 s, pb, in, scaled, size, scale_idx, cb, \
 253                                 lambda, uplim, bits, rtz)               \
 254     ((rtz) ? quantize_and_encode_band_cost_rtz_arr : quantize_and_encode_band_cost_arr)[cb]( \
 255                                 s, pb, in, scaled, size, scale_idx, cb, \
 256                                 lambda, uplim, bits)
 257
 258 static float quantize_band_cost(struct AACEncContext *s, const float *in,
 259                                 const float *scaled, int size, int scale_idx,
 260                                 int cb, const float lambda, const float uplim,
 261                                 int *bits, int rtz)
 262 {
 263     return quantize_and_encode_band_cost(s, NULL, in, scaled, size, scale_idx,
 264                                          cb, lambda, uplim, bits, rtz);
 265 }
 266
 267 static void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb,
 268                                      const float *in, int size, int scale_idx,
 269                                      int cb, const float lambda, int rtz)
 270 {
 271     quantize_and_encode_band_cost(s, pb, in, NULL, size, scale_idx, cb, lambda,
 272                                   INFINITY, NULL, rtz);
 273 }
 274
 275 /**
 276  * structure used in optimal codebook search
 277  */
 278 typedef struct BandCodingPath {
 279     int prev_idx; ///< pointer to the previous path point
 280     float cost;   ///< path cost
 281     int run;
 282 } BandCodingPath;
 283
 284 /**
 285  * Encode band info for single window group bands.
 286  */
 287 static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce,
 288                                      int win, int group_len, const float lambda)
 289 {
 290     BandCodingPath path[120][CB_TOT_ALL];
 291     int w, swb, cb, start, size;
 292     int i, j;
 293     const int max_sfb  = sce->ics.max_sfb;
 294     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
 295     const int run_esc  = (1 << run_bits) - 1;
 296     int idx, ppos, count;
 297     int stackrun[120], stackcb[120], stack_len;
 298     float next_minrd = INFINITY;
 299     int next_mincb = 0;
 300
 301     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 302     start = win*128;
 303     for (cb = 0; cb < CB_TOT_ALL; cb++) {
 304         path[0][cb].cost     = 0.0f;
 305         path[0][cb].prev_idx = -1;
 306         path[0][cb].run      = 0;
 307     }
 308     for (swb = 0; swb < max_sfb; swb++) {
 309         size = sce->ics.swb_sizes[swb];
 310         if (sce->zeroes[win*16 + swb]) {
 311             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 312                 path[swb+1][cb].prev_idx = cb;
 313                 path[swb+1][cb].cost     = path[swb][cb].cost;
 314                 path[swb+1][cb].run      = path[swb][cb].run + 1;
 315             }
 316         } else {
 317             float minrd = next_minrd;
 318             int mincb = next_mincb;
 319             next_minrd = INFINITY;
 320             next_mincb = 0;
 321             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 322                 float cost_stay_here, cost_get_here;
 323                 float rd = 0.0f;
 324                 if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] ||
 325                     cb  < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) {
 326                     path[swb+1][cb].prev_idx = -1;
 327                     path[swb+1][cb].cost     = INFINITY;
 328                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 329                     continue;
 330                 }
 331                 for (w = 0; w < group_len; w++) {
 332                     FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb];
 333                     rd += quantize_band_cost(s, sce->coeffs + start + w*128,
 334                                              s->scoefs + start + w*128, size,
 335                                              sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb],
 336                                              lambda / band->threshold, INFINITY, NULL, 0);
 337                 }
 338                 cost_stay_here = path[swb][cb].cost + rd;
 339                 cost_get_here  = minrd              + rd + run_bits + 4;
 340                 if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
 341                     != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
 342                     cost_stay_here += run_bits;
 343                 if (cost_get_here < cost_stay_here) {
 344                     path[swb+1][cb].prev_idx = mincb;
 345                     path[swb+1][cb].cost     = cost_get_here;
 346                     path[swb+1][cb].run      = 1;
 347                 } else {
 348                     path[swb+1][cb].prev_idx = cb;
 349                     path[swb+1][cb].cost     = cost_stay_here;
 350                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 351                 }
 352                 if (path[swb+1][cb].cost < next_minrd) {
 353                     next_minrd = path[swb+1][cb].cost;
 354                     next_mincb = cb;
 355                 }
 356             }
 357         }
 358         start += sce->ics.swb_sizes[swb];
 359     }
 360
 361     //convert resulting path from backward-linked list
 362     stack_len = 0;
 363     idx       = 0;
 364     for (cb = 1; cb < CB_TOT_ALL; cb++)
 365         if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
 366             idx = cb;
 367     ppos = max_sfb;
 368     while (ppos > 0) {
 369         av_assert1(idx >= 0);
 370         cb = idx;
 371         stackrun[stack_len] = path[ppos][cb].run;
 372         stackcb [stack_len] = cb;
 373         idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
 374         ppos -= path[ppos][cb].run;
 375         stack_len++;
 376     }
 377     //perform actual band info encoding
 378     start = 0;
 379     for (i = stack_len - 1; i >= 0; i--) {
 380         cb = aac_cb_out_map[stackcb[i]];
 381         put_bits(&s->pb, 4, cb);
 382         count = stackrun[i];
 383         memset(sce->zeroes + win*16 + start, !cb, count);
 384         //XXX: memset when band_type is also uint8_t
 385         for (j = 0; j < count; j++) {
 386             sce->band_type[win*16 + start] = cb;
 387             start++;
 388         }
 389         while (count >= run_esc) {
 390             put_bits(&s->pb, run_bits, run_esc);
 391             count -= run_esc;
 392         }
 393         put_bits(&s->pb, run_bits, count);
 394     }
 395 }
 396
 397 static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
 398                                   int win, int group_len, const float lambda)
 399 {
 400     BandCodingPath path[120][CB_TOT_ALL];
 401     int w, swb, cb, start, size;
 402     int i, j;
 403     const int max_sfb  = sce->ics.max_sfb;
 404     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
 405     const int run_esc  = (1 << run_bits) - 1;
 406     int idx, ppos, count;
 407     int stackrun[120], stackcb[120], stack_len;
 408     float next_minbits = INFINITY;
 409     int next_mincb = 0;
 410
 411     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 412     start = win*128;
 413     for (cb = 0; cb < CB_TOT_ALL; cb++) {
 414         path[0][cb].cost     = run_bits+4;
 415         path[0][cb].prev_idx = -1;
 416         path[0][cb].run      = 0;
 417     }
 418     for (swb = 0; swb < max_sfb; swb++) {
 419         size = sce->ics.swb_sizes[swb];
 420         if (sce->zeroes[win*16 + swb]) {
 421             float cost_stay_here = path[swb][0].cost;
 422             float cost_get_here  = next_minbits + run_bits + 4;
 423             if (   run_value_bits[sce->ics.num_windows == 8][path[swb][0].run]
 424                 != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1])
 425                 cost_stay_here += run_bits;
 426             if (cost_get_here < cost_stay_here) {
 427                 path[swb+1][0].prev_idx = next_mincb;
 428                 path[swb+1][0].cost     = cost_get_here;
 429                 path[swb+1][0].run      = 1;
 430             } else {
 431                 path[swb+1][0].prev_idx = 0;
 432                 path[swb+1][0].cost     = cost_stay_here;
 433                 path[swb+1][0].run      = path[swb][0].run + 1;
 434             }
 435             next_minbits = path[swb+1][0].cost;
 436             next_mincb = 0;
 437             for (cb = 1; cb < CB_TOT_ALL; cb++) {
 438                 path[swb+1][cb].cost = 61450;
 439                 path[swb+1][cb].prev_idx = -1;
 440                 path[swb+1][cb].run = 0;
 441             }
 442         } else {
 443             float minbits = next_minbits;
 444             int mincb = next_mincb;
 445             int startcb = sce->band_type[win*16+swb];
 446             startcb = aac_cb_in_map[startcb];
 447             next_minbits = INFINITY;
 448             next_mincb = 0;
 449             for (cb = 0; cb < startcb; cb++) {
 450                 path[swb+1][cb].cost = 61450;
 451                 path[swb+1][cb].prev_idx = -1;
 452                 path[swb+1][cb].run = 0;
 453             }
 454             for (cb = startcb; cb < CB_TOT_ALL; cb++) {
 455                 float cost_stay_here, cost_get_here;
 456                 float bits = 0.0f;
 457                 if (cb >= 12 && sce->band_type[win*16+swb] != aac_cb_out_map[cb]) {
 458                     path[swb+1][cb].cost = 61450;
 459                     path[swb+1][cb].prev_idx = -1;
 460                     path[swb+1][cb].run = 0;
 461                     continue;
 462                 }
 463                 for (w = 0; w < group_len; w++) {
 464                     bits += quantize_band_cost(s, sce->coeffs + start + w*128,
 465                                                s->scoefs + start + w*128, size,
 466                                                sce->sf_idx[win*16+swb],
 467                                                aac_cb_out_map[cb],
 468                                                0, INFINITY, NULL, 0);
 469                 }
 470                 cost_stay_here = path[swb][cb].cost + bits;
 471                 cost_get_here  = minbits            + bits + run_bits + 4;
 472                 if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
 473                     != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
 474                     cost_stay_here += run_bits;
 475                 if (cost_get_here < cost_stay_here) {
 476                     path[swb+1][cb].prev_idx = mincb;
 477                     path[swb+1][cb].cost     = cost_get_here;
 478                     path[swb+1][cb].run      = 1;
 479                 } else {
 480                     path[swb+1][cb].prev_idx = cb;
 481                     path[swb+1][cb].cost     = cost_stay_here;
 482                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 483                 }
 484                 if (path[swb+1][cb].cost < next_minbits) {
 485                     next_minbits = path[swb+1][cb].cost;
 486                     next_mincb = cb;
 487                 }
 488             }
 489         }
 490         start += sce->ics.swb_sizes[swb];
 491     }
 492
 493     //convert resulting path from backward-linked list
 494     stack_len = 0;
 495     idx       = 0;
 496     for (cb = 1; cb < CB_TOT_ALL; cb++)
 497         if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
 498             idx = cb;
 499     ppos = max_sfb;
 500     while (ppos > 0) {
 501         av_assert1(idx >= 0);
 502         cb = idx;
 503         stackrun[stack_len] = path[ppos][cb].run;
 504         stackcb [stack_len] = cb;
 505         idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
 506         ppos -= path[ppos][cb].run;
 507         stack_len++;
 508     }
 509     //perform actual band info encoding
 510     start = 0;
 511     for (i = stack_len - 1; i >= 0; i--) {
 512         cb = aac_cb_out_map[stackcb[i]];
 513         put_bits(&s->pb, 4, cb);
 514         count = stackrun[i];
 515         memset(sce->zeroes + win*16 + start, !cb, count);
 516         //XXX: memset when band_type is also uint8_t
 517         for (j = 0; j < count; j++) {
 518             sce->band_type[win*16 + start] = cb;
 519             start++;
 520         }
 521         while (count >= run_esc) {
 522             put_bits(&s->pb, run_bits, run_esc);
 523             count -= run_esc;
 524         }
 525         put_bits(&s->pb, run_bits, count);
 526     }
 527 }
 528
 529 typedef struct TrellisPath {
 530     float cost;
 531     int prev;
 532 } TrellisPath;
 533
 534 #define TRELLIS_STAGES 121
 535 #define TRELLIS_STATES (SCALE_MAX_DIFF+1)
 536
 537 static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce)
 538 {
 539     int w, g, start = 0;
 540     int minscaler_n = sce->sf_idx[0], minscaler_i = sce->sf_idx[0];
 541     int bands = 0;
 542
 543     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 544         start = 0;
 545         for (g = 0;  g < sce->ics.num_swb; g++) {
 546             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 547                 sce->sf_idx[w*16+g] = av_clip(ceilf(log2f(sce->is_ener[w*16+g])*2), -155, 100);
 548                 minscaler_i = FFMIN(minscaler_i, sce->sf_idx[w*16+g]);
 549                 bands++;
 550             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 551                 sce->sf_idx[w*16+g] = av_clip(4+log2f(sce->pns_ener[w*16+g])*2, -100, 155);
 552                 minscaler_n = FFMIN(minscaler_n, sce->sf_idx[w*16+g]);
 553                 bands++;
 554             }
 555             start += sce->ics.swb_sizes[g];
 556         }
 557     }
 558
 559     if (!bands)
 560         return;
 561
 562     /* Clip the scalefactor indices */
 563     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 564         for (g = 0;  g < sce->ics.num_swb; g++) {
 565             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 566                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_i, minscaler_i + SCALE_MAX_DIFF);
 567             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 568                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_n, minscaler_n + SCALE_MAX_DIFF);
 569             }
 570         }
 571     }
 572 }
 573
 574 static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
 575                                        SingleChannelElement *sce,
 576                                        const float lambda)
 577 {
 578     int q, w, w2, g, start = 0;
 579     int i, j;
 580     int idx;
 581     TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
 582     int bandaddr[TRELLIS_STAGES];
 583     int minq;
 584     float mincost;
 585     float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f;
 586     int q0, q1, qcnt = 0;
 587
 588     for (i = 0; i < 1024; i++) {
 589         float t = fabsf(sce->coeffs[i]);
 590         if (t > 0.0f) {
 591             q0f = FFMIN(q0f, t);
 592             q1f = FFMAX(q1f, t);
 593             qnrgf += t*t;
 594             qcnt++;
 595         }
 596     }
 597
 598     if (!qcnt) {
 599         memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 600         memset(sce->zeroes, 1, sizeof(sce->zeroes));
 601         return;
 602     }
 603
 604     //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 605     q0 = coef2minsf(q0f);
 606     //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 607     q1 = coef2maxsf(q1f);
 608     if (q1 - q0 > 60) {
 609         int q0low  = q0;
 610         int q1high = q1;
 611         //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped
 612         int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512);
 613         q1 = qnrg + 30;
 614         q0 = qnrg - 30;
 615         if (q0 < q0low) {
 616             q1 += q0low - q0;
 617             q0  = q0low;
 618         } else if (q1 > q1high) {
 619             q0 -= q1 - q1high;
 620             q1  = q1high;
 621         }
 622     }
 623
 624     for (i = 0; i < TRELLIS_STATES; i++) {
 625         paths[0][i].cost    = 0.0f;
 626         paths[0][i].prev    = -1;
 627     }
 628     for (j = 1; j < TRELLIS_STAGES; j++) {
 629         for (i = 0; i < TRELLIS_STATES; i++) {
 630             paths[j][i].cost    = INFINITY;
 631             paths[j][i].prev    = -2;
 632         }
 633     }
 634     idx = 1;
 635     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 636     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 637         start = w*128;
 638         for (g = 0; g < sce->ics.num_swb; g++) {
 639             const float *coefs = sce->coeffs + start;
 640             float qmin, qmax;
 641             int nz = 0;
 642
 643             bandaddr[idx] = w * 16 + g;
 644             qmin = INT_MAX;
 645             qmax = 0.0f;
 646             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 647                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 648                 if (band->energy <= band->threshold || band->threshold == 0.0f) {
 649                     sce->zeroes[(w+w2)*16+g] = 1;
 650                     continue;
 651                 }
 652                 sce->zeroes[(w+w2)*16+g] = 0;
 653                 nz = 1;
 654                 for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
 655                     float t = fabsf(coefs[w2*128+i]);
 656                     if (t > 0.0f)
 657                         qmin = FFMIN(qmin, t);
 658                     qmax = FFMAX(qmax, t);
 659                 }
 660             }
 661             if (nz) {
 662                 int minscale, maxscale;
 663                 float minrd = INFINITY;
 664                 float maxval;
 665                 //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 666                 minscale = coef2minsf(qmin);
 667                 //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 668                 maxscale = coef2maxsf(qmax);
 669                 minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
 670                 maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
 671                 maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
 672                 for (q = minscale; q < maxscale; q++) {
 673                     float dist = 0;
 674                     int cb = find_min_book(maxval, sce->sf_idx[w*16+g]);
 675                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 676                         FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 677                         dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
 678                                                    q + q0, cb, lambda / band->threshold, INFINITY, NULL, 0);
 679                     }
 680                     minrd = FFMIN(minrd, dist);
 681
 682                     for (i = 0; i < q1 - q0; i++) {
 683                         float cost;
 684                         cost = paths[idx - 1][i].cost + dist
 685                                + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
 686                         if (cost < paths[idx][q].cost) {
 687                             paths[idx][q].cost    = cost;
 688                             paths[idx][q].prev    = i;
 689                         }
 690                     }
 691                 }
 692             } else {
 693                 for (q = 0; q < q1 - q0; q++) {
 694                     paths[idx][q].cost = paths[idx - 1][q].cost + 1;
 695                     paths[idx][q].prev = q;
 696                 }
 697             }
 698             sce->zeroes[w*16+g] = !nz;
 699             start += sce->ics.swb_sizes[g];
 700             idx++;
 701         }
 702     }
 703     idx--;
 704     mincost = paths[idx][0].cost;
 705     minq    = 0;
 706     for (i = 1; i < TRELLIS_STATES; i++) {
 707         if (paths[idx][i].cost < mincost) {
 708             mincost = paths[idx][i].cost;
 709             minq = i;
 710         }
 711     }
 712     while (idx) {
 713         sce->sf_idx[bandaddr[idx]] = minq + q0;
 714         minq = paths[idx][minq].prev;
 715         idx--;
 716     }
 717     //set the same quantizers inside window groups
 718     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
 719         for (g = 0;  g < sce->ics.num_swb; g++)
 720             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
 721                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
 722 }
 723
 724 /**
 725  * two-loop quantizers search taken from ISO 13818-7 Appendix C
 726  */
 727 static void search_for_quantizers_twoloop(AVCodecContext *avctx,
 728                                           AACEncContext *s,
 729                                           SingleChannelElement *sce,
 730                                           const float lambda)
 731 {
 732     int start = 0, i, w, w2, g;
 733     int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / avctx->channels * (lambda / 120.f);
 734     float dists[128] = { 0 }, uplims[128] = { 0 };
 735     float maxvals[128];
 736     int fflag, minscaler;
 737     int its  = 0;
 738     int allz = 0;
 739     float minthr = INFINITY;
 740
 741     // for values above this the decoder might end up in an endless loop
 742     // due to always having more bits than what can be encoded.
 743     destbits = FFMIN(destbits, 5800);
 744     //XXX: some heuristic to determine initial quantizers will reduce search time
 745     //determine zero bands and upper limits
 746     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 747         for (g = 0;  g < sce->ics.num_swb; g++) {
 748             int nz = 0;
 749             float uplim = 0.0f, energy = 0.0f;
 750             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 751                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 752                 uplim  += band->threshold;
 753                 energy += band->energy;
 754                 if (band->energy <= band->threshold || band->threshold == 0.0f) {
 755                     sce->zeroes[(w+w2)*16+g] = 1;
 756                     continue;
 757                 }
 758                 nz = 1;
 759             }
 760             uplims[w*16+g] = uplim *512;
 761             sce->zeroes[w*16+g] = !nz;
 762             if (nz)
 763                 minthr = FFMIN(minthr, uplim);
 764             allz |= nz;
 765         }
 766     }
 767     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 768         for (g = 0;  g < sce->ics.num_swb; g++) {
 769             if (sce->zeroes[w*16+g]) {
 770                 sce->sf_idx[w*16+g] = SCALE_ONE_POS;
 771                 continue;
 772             }
 773             sce->sf_idx[w*16+g] = SCALE_ONE_POS + FFMIN(log2f(uplims[w*16+g]/minthr)*4,59);
 774         }
 775     }
 776
 777     if (!allz)
 778         return;
 779     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 780
 781     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 782         start = w*128;
 783         for (g = 0;  g < sce->ics.num_swb; g++) {
 784             const float *scaled = s->scoefs + start;
 785             maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled);
 786             start += sce->ics.swb_sizes[g];
 787         }
 788     }
 789
 790     //perform two-loop search
 791     //outer loop - improve quality
 792     do {
 793         int tbits, qstep;
 794         minscaler = sce->sf_idx[0];
 795         //inner loop - quantize spectrum to fit into given number of bits
 796         qstep = its ? 1 : 32;
 797         do {
 798             int prev = -1;
 799             tbits = 0;
 800             for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 801                 start = w*128;
 802                 for (g = 0;  g < sce->ics.num_swb; g++) {
 803                     const float *coefs = sce->coeffs + start;
 804                     const float *scaled = s->scoefs + start;
 805                     int bits = 0;
 806                     int cb;
 807                     float dist = 0.0f;
 808
 809                     if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) {
 810                         start += sce->ics.swb_sizes[g];
 811                         continue;
 812                     }
 813                     minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]);
 814                     cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
 815                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 816                         int b;
 817                         dist += quantize_band_cost(s, coefs + w2*128,
 818                                                    scaled + w2*128,
 819                                                    sce->ics.swb_sizes[g],
 820                                                    sce->sf_idx[w*16+g],
 821                                                    cb,
 822                                                    1.0f,
 823                                                    INFINITY,
 824                                                    &b,
 825                                                    0);
 826                         bits += b;
 827                     }
 828                     dists[w*16+g] = dist - bits;
 829                     if (prev != -1) {
 830                         bits += ff_aac_scalefactor_bits[sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO];
 831                     }
 832                     tbits += bits;
 833                     start += sce->ics.swb_sizes[g];
 834                     prev = sce->sf_idx[w*16+g];
 835                 }
 836             }
 837             if (tbits > destbits) {
 838                 for (i = 0; i < 128; i++)
 839                     if (sce->sf_idx[i] < 218 - qstep)
 840                         sce->sf_idx[i] += qstep;
 841             } else {
 842                 for (i = 0; i < 128; i++)
 843                     if (sce->sf_idx[i] > 60 - qstep)
 844                         sce->sf_idx[i] -= qstep;
 845             }
 846             qstep >>= 1;
 847             if (!qstep && tbits > destbits*1.02 && sce->sf_idx[0] < 217)
 848                 qstep = 1;
 849         } while (qstep);
 850
 851         fflag = 0;
 852         minscaler = av_clip(minscaler, 60, 255 - SCALE_MAX_DIFF);
 853
 854         for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 855             for (g = 0; g < sce->ics.num_swb; g++) {
 856                 int prevsc = sce->sf_idx[w*16+g];
 857                 if (dists[w*16+g] > uplims[w*16+g] && sce->sf_idx[w*16+g] > 60) {
 858                     if (find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1))
 859                         sce->sf_idx[w*16+g]--;
 860                     else //Try to make sure there is some energy in every band
 861                         sce->sf_idx[w*16+g]-=2;
 862                 }
 863                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF);
 864                 sce->sf_idx[w*16+g] = FFMIN(sce->sf_idx[w*16+g], 219);
 865                 if (sce->sf_idx[w*16+g] != prevsc)
 866                     fflag = 1;
 867                 sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
 868             }
 869         }
 870         its++;
 871     } while (fflag && its < 10);
 872 }
 873
 874 static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s,
 875                                        SingleChannelElement *sce,
 876                                        const float lambda)
 877 {
 878     int start = 0, i, w, w2, g;
 879     float uplim[128], maxq[128];
 880     int minq, maxsf;
 881     float distfact = ((sce->ics.num_windows > 1) ? 85.80 : 147.84) / lambda;
 882     int last = 0, lastband = 0, curband = 0;
 883     float avg_energy = 0.0;
 884     if (sce->ics.num_windows == 1) {
 885         start = 0;
 886         for (i = 0; i < 1024; i++) {
 887             if (i - start >= sce->ics.swb_sizes[curband]) {
 888                 start += sce->ics.swb_sizes[curband];
 889                 curband++;
 890             }
 891             if (sce->coeffs[i]) {
 892                 avg_energy += sce->coeffs[i] * sce->coeffs[i];
 893                 last = i;
 894                 lastband = curband;
 895             }
 896         }
 897     } else {
 898         for (w = 0; w < 8; w++) {
 899             const float *coeffs = sce->coeffs + w*128;
 900             curband = start = 0;
 901             for (i = 0; i < 128; i++) {
 902                 if (i - start >= sce->ics.swb_sizes[curband]) {
 903                     start += sce->ics.swb_sizes[curband];
 904                     curband++;
 905                 }
 906                 if (coeffs[i]) {
 907                     avg_energy += coeffs[i] * coeffs[i];
 908                     last = FFMAX(last, i);
 909                     lastband = FFMAX(lastband, curband);
 910                 }
 911             }
 912         }
 913     }
 914     last++;
 915     avg_energy /= last;
 916     if (avg_energy == 0.0f) {
 917         for (i = 0; i < FF_ARRAY_ELEMS(sce->sf_idx); i++)
 918             sce->sf_idx[i] = SCALE_ONE_POS;
 919         return;
 920     }
 921     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 922         start = w*128;
 923         for (g = 0; g < sce->ics.num_swb; g++) {
 924             float *coefs   = sce->coeffs + start;
 925             const int size = sce->ics.swb_sizes[g];
 926             int start2 = start, end2 = start + size, peakpos = start;
 927             float maxval = -1, thr = 0.0f, t;
 928             maxq[w*16+g] = 0.0f;
 929             if (g > lastband) {
 930                 maxq[w*16+g] = 0.0f;
 931                 start += size;
 932                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
 933                     memset(coefs + w2*128, 0, sizeof(coefs[0])*size);
 934                 continue;
 935             }
 936             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 937                 for (i = 0; i < size; i++) {
 938                     float t = coefs[w2*128+i]*coefs[w2*128+i];
 939                     maxq[w*16+g] = FFMAX(maxq[w*16+g], fabsf(coefs[w2*128 + i]));
 940                     thr += t;
 941                     if (sce->ics.num_windows == 1 && maxval < t) {
 942                         maxval  = t;
 943                         peakpos = start+i;
 944                     }
 945                 }
 946             }
 947             if (sce->ics.num_windows == 1) {
 948                 start2 = FFMAX(peakpos - 2, start2);
 949                 end2   = FFMIN(peakpos + 3, end2);
 950             } else {
 951                 start2 -= start;
 952                 end2   -= start;
 953             }
 954             start += size;
 955             thr = pow(thr / (avg_energy * (end2 - start2)), 0.3 + 0.1*(lastband - g) / lastband);
 956             t   = 1.0 - (1.0 * start2 / last);
 957             uplim[w*16+g] = distfact / (1.4 * thr + t*t*t + 0.075);
 958         }
 959     }
 960     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 961     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 962     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 963         start = w*128;
 964         for (g = 0;  g < sce->ics.num_swb; g++) {
 965             const float *coefs  = sce->coeffs + start;
 966             const float *scaled = s->scoefs   + start;
 967             const int size      = sce->ics.swb_sizes[g];
 968             int scf, prev_scf, step;
 969             int min_scf = -1, max_scf = 256;
 970             float curdiff;
 971             if (maxq[w*16+g] < 21.544) {
 972                 sce->zeroes[w*16+g] = 1;
 973                 start += size;
 974                 continue;
 975             }
 976             sce->zeroes[w*16+g] = 0;
 977             scf  = prev_scf = av_clip(SCALE_ONE_POS - SCALE_DIV_512 - log2f(1/maxq[w*16+g])*16/3, 60, 218);
 978             for (;;) {
 979                 float dist = 0.0f;
 980                 int quant_max;
 981
 982                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 983                     int b;
 984                     dist += quantize_band_cost(s, coefs + w2*128,
 985                                                scaled + w2*128,
 986                                                sce->ics.swb_sizes[g],
 987                                                scf,
 988                                                ESC_BT,
 989                                                lambda,
 990                                                INFINITY,
 991                                                &b,
 992                                                0);
 993                     dist -= b;
 994                 }
 995                 dist *= 1.0f / 512.0f / lambda;
 996                 quant_max = quant(maxq[w*16+g], ff_aac_pow2sf_tab[POW_SF2_ZERO - scf + SCALE_ONE_POS - SCALE_DIV_512], ROUND_STANDARD);
 997                 if (quant_max >= 8191) { // too much, return to the previous quantizer
 998                     sce->sf_idx[w*16+g] = prev_scf;
 999                     break;
1000                 }
1001                 prev_scf = scf;
1002                 curdiff = fabsf(dist - uplim[w*16+g]);
1003                 if (curdiff <= 1.0f)
1004                     step = 0;
1005                 else
1006                     step = log2f(curdiff);
1007                 if (dist > uplim[w*16+g])
1008                     step = -step;
1009                 scf += step;
1010                 scf = av_clip_uint8(scf);
1011                 step = scf - prev_scf;
1012                 if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) {
1013                     sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf);
1014                     break;
1015                 }
1016                 if (step > 0)
1017                     min_scf = prev_scf;
1018                 else
1019                     max_scf = prev_scf;
1020             }
1021             start += size;
1022         }
1023     }
1024     minq = sce->sf_idx[0] ? sce->sf_idx[0] : INT_MAX;
1025     for (i = 1; i < 128; i++) {
1026         if (!sce->sf_idx[i])
1027             sce->sf_idx[i] = sce->sf_idx[i-1];
1028         else
1029             minq = FFMIN(minq, sce->sf_idx[i]);
1030     }
1031     if (minq == INT_MAX)
1032         minq = 0;
1033     minq = FFMIN(minq, SCALE_MAX_POS);
1034     maxsf = FFMIN(minq + SCALE_MAX_DIFF, SCALE_MAX_POS);
1035     for (i = 126; i >= 0; i--) {
1036         if (!sce->sf_idx[i])
1037             sce->sf_idx[i] = sce->sf_idx[i+1];
1038         sce->sf_idx[i] = av_clip(sce->sf_idx[i], minq, maxsf);
1039     }
1040 }
1041
1042 static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s,
1043                                        SingleChannelElement *sce,
1044                                        const float lambda)
1045 {
1046     int i, w, w2, g;
1047     int minq = 255;
1048
1049     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
1050     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1051         for (g = 0; g < sce->ics.num_swb; g++) {
1052             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1053                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
1054                 if (band->energy <= band->threshold) {
1055                     sce->sf_idx[(w+w2)*16+g] = 218;
1056                     sce->zeroes[(w+w2)*16+g] = 1;
1057                 } else {
1058                     sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218);
1059                     sce->zeroes[(w+w2)*16+g] = 0;
1060                 }
1061                 minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]);
1062             }
1063         }
1064     }
1065     for (i = 0; i < 128; i++) {
1066         sce->sf_idx[i] = 140;
1067         //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1);
1068     }
1069     //set the same quantizers inside window groups
1070     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
1071         for (g = 0;  g < sce->ics.num_swb; g++)
1072             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
1073                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
1074 }
1075
1076 static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
1077 {
1078     int start = 0, w, w2, g;
1079     const float lambda = s->lambda;
1080     const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f;
1081     const float spread_threshold = NOISE_SPREAD_THRESHOLD*(lambda/120.f);
1082     const float thr_mult = NOISE_LAMBDA_NUMERATOR/lambda;
1083
1084     /* Coders !twoloop don't reset the band_types */
1085     for (w = 0; w < 128; w++)
1086         if (sce->band_type[w] == NOISE_BT)
1087             sce->band_type[w] = 0;
1088
1089     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1090         start = 0;
1091         for (g = 0;  g < sce->ics.num_swb; g++) {
1092             if (start*freq_mult > NOISE_LOW_LIMIT*(lambda/170.0f)) {
1093                 float energy = 0.0f, threshold = 0.0f, spread = 0.0f;
1094                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1095                     FFPsyBand *band = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1096                     energy += band->energy;
1097                     threshold += band->threshold;
1098                     spread += band->spread;
1099                 }
1100                 if (spread > spread_threshold*sce->ics.group_len[w] &&
1101                     ((sce->zeroes[w*16+g] && energy >= threshold) ||
1102                     energy < threshold*thr_mult*sce->ics.group_len[w])) {
1103                     sce->band_type[w*16+g] = NOISE_BT;
1104                     sce->pns_ener[w*16+g] = energy / sce->ics.group_len[w];
1105                     sce->zeroes[w*16+g] = 0;
1106                 }
1107             }
1108             start += sce->ics.swb_sizes[g];
1109         }
1110     }
1111 }
1112
1113 static void search_for_is(AACEncContext *s, AVCodecContext *avctx, ChannelElement *cpe)
1114 {
1115     float IS[128];
1116     float *L34  = s->scoefs + 128*0, *R34  = s->scoefs + 128*1;
1117     float *I34  = s->scoefs + 128*2;
1118     SingleChannelElement *sce0 = &cpe->ch[0];
1119     SingleChannelElement *sce1 = &cpe->ch[1];
1120     int start = 0, count = 0, i, w, w2, g;
1121     const float freq_mult = avctx->sample_rate/(1024.0f/sce0->ics.num_windows)/2.0f;
1122     const float lambda = s->lambda;
1123
1124     for (w = 0; w < 128; w++)
1125         if (sce1->band_type[w] >= INTENSITY_BT2)
1126             sce1->band_type[w] = 0;
1127
1128     if (!cpe->common_window)
1129         return;
1130     for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
1131         start = 0;
1132         for (g = 0;  g < sce0->ics.num_swb; g++) {
1133             if (start*freq_mult > INT_STEREO_LOW_LIMIT*(lambda/170.0f) &&
1134                 cpe->ch[0].band_type[w*16+g] != NOISE_BT && !cpe->ch[0].zeroes[w*16+g] &&
1135                 cpe->ch[1].band_type[w*16+g] != NOISE_BT && !cpe->ch[1].zeroes[w*16+g]) {
1136                 int phase = 0;
1137                 float ener0 = 0.0f, ener1 = 0.0f, ener01 = 0.0f;
1138                 float dist1 = 0.0f, dist2 = 0.0f;
1139                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1140                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1141                         float coef0 = sce0->pcoeffs[start+(w+w2)*128+i];
1142                         float coef1 = sce1->pcoeffs[start+(w+w2)*128+i];
1143                         phase += coef0*coef1 >= 0.0f ? 1 : -1;
1144                         ener0 += coef0*coef0;
1145                         ener1 += coef1*coef1;
1146                         ener01 += (coef0 + coef1)*(coef0 + coef1);
1147                     }
1148                 }
1149                 if (!phase) { /* Too much phase difference between channels */
1150                     start += sce0->ics.swb_sizes[g];
1151                     continue;
1152                 }
1153                 phase = av_clip(phase, -1, 1);
1154                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1155                     FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1156                     FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
1157                     int is_band_type, is_sf_idx = FFMAX(1, sce0->sf_idx[(w+w2)*16+g]-4);
1158                     float e01_34 = phase*pow(sqrt(ener1/ener0), 3.0/4.0);
1159                     float maxval, dist_spec_err = 0.0f;
1160                     float minthr = FFMIN(band0->threshold, band1->threshold);
1161                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++)
1162                         IS[i] = (sce0->pcoeffs[start+(w+w2)*128+i] + phase*sce1->pcoeffs[start+(w+w2)*128+i]) * sqrt(ener0/ener01);
1163                     abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1164                     abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1165                     abs_pow34_v(I34, IS,                            sce0->ics.swb_sizes[g]);
1166                     maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34);
1167                     is_band_type = find_min_book(maxval, is_sf_idx);
1168                     dist1 += quantize_band_cost(s, sce0->coeffs + start + (w+w2)*128,
1169                                                 L34,
1170                                                 sce0->ics.swb_sizes[g],
1171                                                 sce0->sf_idx[(w+w2)*16+g],
1172                                                 sce0->band_type[(w+w2)*16+g],
1173                                                 lambda / band0->threshold, INFINITY, NULL, 0);
1174                     dist1 += quantize_band_cost(s, sce1->coeffs + start + (w+w2)*128,
1175                                                 R34,
1176                                                 sce1->ics.swb_sizes[g],
1177                                                 sce1->sf_idx[(w+w2)*16+g],
1178                                                 sce1->band_type[(w+w2)*16+g],
1179                                                 lambda / band1->threshold, INFINITY, NULL, 0);
1180                     dist2 += quantize_band_cost(s, IS,
1181                                                 I34,
1182                                                 sce0->ics.swb_sizes[g],
1183                                                 is_sf_idx,
1184                                                 is_band_type,
1185                                                 lambda / minthr, INFINITY, NULL, 0);
1186                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1187                         dist_spec_err += (L34[i] - I34[i])*(L34[i] - I34[i]);
1188                         dist_spec_err += (R34[i] - I34[i]*e01_34)*(R34[i] - I34[i]*e01_34);
1189                     }
1190                     dist_spec_err *= lambda / minthr;
1191                     dist2 += dist_spec_err;
1192                 }
1193                 if (dist2 <= dist1) {
1194                     cpe->is_mask[w*16+g] = 1;
1195                     cpe->ms_mask[w*16+g] = 0;
1196                     cpe->ch[0].is_ener[w*16+g] = sqrt(ener0/ener01);
1197                     cpe->ch[1].is_ener[w*16+g] = ener0/ener1;
1198                     if (phase)
1199                         cpe->ch[1].band_type[w*16+g] = INTENSITY_BT;
1200                     else
1201                         cpe->ch[1].band_type[w*16+g] = INTENSITY_BT2;
1202                     count++;
1203                 }
1204             }
1205             start += sce0->ics.swb_sizes[g];
1206         }
1207     }
1208     cpe->is_mode = !!count;
1209 }
1210
1211 static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
1212 {
1213     int start = 0, i, w, w2, g;
1214     float M[128], S[128];
1215     float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
1216     const float lambda = s->lambda;
1217     SingleChannelElement *sce0 = &cpe->ch[0];
1218     SingleChannelElement *sce1 = &cpe->ch[1];
1219     if (!cpe->common_window)
1220         return;
1221     for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
1222         start = 0;
1223         for (g = 0;  g < sce0->ics.num_swb; g++) {
1224             if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g] && !cpe->is_mask[w*16+g]) {
1225                 float dist1 = 0.0f, dist2 = 0.0f;
1226                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1227                     FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1228                     FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
1229                     float minthr = FFMIN(band0->threshold, band1->threshold);
1230                     float maxthr = FFMAX(band0->threshold, band1->threshold);
1231                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1232                         M[i] = (sce0->pcoeffs[start+(w+w2)*128+i]
1233                               + sce1->pcoeffs[start+(w+w2)*128+i]) * 0.5;
1234                         S[i] =  M[i]
1235                               - sce1->pcoeffs[start+(w+w2)*128+i];
1236                     }
1237                     abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1238                     abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1239                     abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
1240                     abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
1241                     dist1 += quantize_band_cost(s, sce0->coeffs + start + (w+w2)*128,
1242                                                 L34,
1243                                                 sce0->ics.swb_sizes[g],
1244                                                 sce0->sf_idx[(w+w2)*16+g],
1245                                                 sce0->band_type[(w+w2)*16+g],
1246                                                 lambda / band0->threshold, INFINITY, NULL, 0);
1247                     dist1 += quantize_band_cost(s, sce1->coeffs + start + (w+w2)*128,
1248                                                 R34,
1249                                                 sce1->ics.swb_sizes[g],
1250                                                 sce1->sf_idx[(w+w2)*16+g],
1251                                                 sce1->band_type[(w+w2)*16+g],
1252                                                 lambda / band1->threshold, INFINITY, NULL, 0);
1253                     dist2 += quantize_band_cost(s, M,
1254                                                 M34,
1255                                                 sce0->ics.swb_sizes[g],
1256                                                 sce0->sf_idx[(w+w2)*16+g],
1257                                                 sce0->band_type[(w+w2)*16+g],
1258                                                 lambda / maxthr, INFINITY, NULL, 0);
1259                     dist2 += quantize_band_cost(s, S,
1260                                                 S34,
1261                                                 sce1->ics.swb_sizes[g],
1262                                                 sce1->sf_idx[(w+w2)*16+g],
1263                                                 sce1->band_type[(w+w2)*16+g],
1264                                                 lambda / minthr, INFINITY, NULL, 0);
1265                 }
1266                 cpe->ms_mask[w*16+g] = dist2 < dist1;
1267             }
1268             start += sce0->ics.swb_sizes[g];
1269         }
1270     }
1271 }
1272
1273 AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB] = {
1274     [AAC_CODER_FAAC] = {
1275         search_for_quantizers_faac,
1276         encode_window_bands_info,
1277         quantize_and_encode_band,
1278         set_special_band_scalefactors,
1279         search_for_pns,
1280         search_for_ms,
1281         search_for_is,
1282     },
1283     [AAC_CODER_ANMR] = {
1284         search_for_quantizers_anmr,
1285         encode_window_bands_info,
1286         quantize_and_encode_band,
1287         set_special_band_scalefactors,
1288         search_for_pns,
1289         search_for_ms,
1290         search_for_is,
1291     },
1292     [AAC_CODER_TWOLOOP] = {
1293         search_for_quantizers_twoloop,
1294         codebook_trellis_rate,
1295         quantize_and_encode_band,
1296         set_special_band_scalefactors,
1297         search_for_pns,
1298         search_for_ms,
1299         search_for_is,
1300     },
1301     [AAC_CODER_FAST] = {
1302         search_for_quantizers_fast,
1303         encode_window_bands_info,
1304         quantize_and_encode_band,
1305         set_special_band_scalefactors,
1306         search_for_pns,
1307         search_for_ms,
1308         search_for_is,
1309     },
1310 };