git.sesse.net Git - ffmpeg/blob - libavcodec/aaccoder.c

   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 "aac_tablegen_decl.h"
  43
  44 /** Frequency in Hz for lower limit of noise substitution **/
  45 #define NOISE_LOW_LIMIT 4500
  46
  47 /* Energy spread threshold value below which no PNS is used, this corresponds to
  48  * typically around 17Khz, after which PNS usage decays ending at 19Khz */
  49 #define NOISE_SPREAD_THRESHOLD 0.5f
  50
  51 /* This constant gets divided by lambda to return ~1.65 which when multiplied
  52  * by the band->threshold and compared to band->energy is the boundary between
  53  * excessive PNS and little PNS usage. */
  54 #define NOISE_LAMBDA_NUMERATOR 252.1f
  55
  56 /** Frequency in Hz for lower limit of intensity stereo   **/
  57 #define INT_STEREO_LOW_LIMIT 6100
  58
  59 /** Total number of usable codebooks **/
  60 #define CB_TOT 12
  61
  62 /** Total number of codebooks, including special ones **/
  63 #define CB_TOT_ALL 15
  64
  65 /** bits needed to code codebook run value for long windows */
  66 static const uint8_t run_value_bits_long[64] = {
  67      5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,
  68      5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5,  5, 10,
  69     10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10,
  70     10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 10, 15
  71 };
  72
  73 /** bits needed to code codebook run value for short windows */
  74 static const uint8_t run_value_bits_short[16] = {
  75     3, 3, 3, 3, 3, 3, 3, 6, 6, 6, 6, 6, 6, 6, 6, 9
  76 };
  77
  78 static const uint8_t * const run_value_bits[2] = {
  79     run_value_bits_long, run_value_bits_short
  80 };
  81
  82 #define ROUND_STANDARD 0.4054f
  83 #define ROUND_TO_ZERO 0.1054f
  84
  85 /** Map to convert values from BandCodingPath index to a codebook index **/
  86 static const uint8_t aac_cb_out_map[CB_TOT_ALL]  = {0,1,2,3,4,5,6,7,8,9,10,11,13,14,15};
  87 /** Inverse map to convert from codebooks to BandCodingPath indices **/
  88 static const uint8_t aac_cb_in_map[CB_TOT_ALL+1] = {0,1,2,3,4,5,6,7,8,9,10,11,0,12,13,14};
  89
  90 /**
  91  * Quantize one coefficient.
  92  * @return absolute value of the quantized coefficient
  93  * @see 3GPP TS26.403 5.6.2 "Scalefactor determination"
  94  */
  95 static av_always_inline int quant(float coef, const float Q, const float rounding)
  96 {
  97     float a = coef * Q;
  98     return sqrtf(a * sqrtf(a)) + rounding;
  99 }
 100
 101 static void quantize_bands(int *out, const float *in, const float *scaled,
 102                            int size, float Q34, int is_signed, int maxval, const float rounding)
 103 {
 104     int i;
 105     double qc;
 106     for (i = 0; i < size; i++) {
 107         qc = scaled[i] * Q34;
 108         out[i] = (int)FFMIN(qc + rounding, (double)maxval);
 109         if (is_signed && in[i] < 0.0f) {
 110             out[i] = -out[i];
 111         }
 112     }
 113 }
 114
 115 static void abs_pow34_v(float *out, const float *in, const int size)
 116 {
 117 #ifndef USE_REALLY_FULL_SEARCH
 118     int i;
 119     for (i = 0; i < size; i++) {
 120         float a = fabsf(in[i]);
 121         out[i] = sqrtf(a * sqrtf(a));
 122     }
 123 #endif /* USE_REALLY_FULL_SEARCH */
 124 }
 125
 126 static const uint8_t aac_cb_range [12] = {0, 3, 3, 3, 3, 9, 9, 8, 8, 13, 13, 17};
 127 static const uint8_t aac_cb_maxval[12] = {0, 1, 1, 2, 2, 4, 4, 7, 7, 12, 12, 16};
 128
 129 /**
 130  * Calculate rate distortion cost for quantizing with given codebook
 131  *
 132  * @return quantization distortion
 133  */
 134 static av_always_inline float quantize_and_encode_band_cost_template(
 135                                 struct AACEncContext *s,
 136                                 PutBitContext *pb, const float *in,
 137                                 const float *scaled, int size, int scale_idx,
 138                                 int cb, const float lambda, const float uplim,
 139                                 int *bits, int BT_ZERO, int BT_UNSIGNED,
 140                                 int BT_PAIR, int BT_ESC, int BT_NOISE, int BT_STEREO,
 141                                 const float ROUNDING)
 142 {
 143     const int q_idx = POW_SF2_ZERO - scale_idx + SCALE_ONE_POS - SCALE_DIV_512;
 144     const float Q   = ff_aac_pow2sf_tab [q_idx];
 145     const float Q34 = ff_aac_pow34sf_tab[q_idx];
 146     const float IQ  = ff_aac_pow2sf_tab [POW_SF2_ZERO + scale_idx - SCALE_ONE_POS + SCALE_DIV_512];
 147     const float CLIPPED_ESCAPE = 165140.0f*IQ;
 148     int i, j;
 149     float cost = 0;
 150     const int dim = BT_PAIR ? 2 : 4;
 151     int resbits = 0;
 152     int off;
 153
 154     if (BT_ZERO || BT_NOISE || BT_STEREO) {
 155         for (i = 0; i < size; i++)
 156             cost += in[i]*in[i];
 157         if (bits)
 158             *bits = 0;
 159         return cost * lambda;
 160     }
 161     if (!scaled) {
 162         abs_pow34_v(s->scoefs, in, size);
 163         scaled = s->scoefs;
 164     }
 165     quantize_bands(s->qcoefs, in, scaled, size, Q34, !BT_UNSIGNED, aac_cb_maxval[cb], ROUNDING);
 166     if (BT_UNSIGNED) {
 167         off = 0;
 168     } else {
 169         off = aac_cb_maxval[cb];
 170     }
 171     for (i = 0; i < size; i += dim) {
 172         const float *vec;
 173         int *quants = s->qcoefs + i;
 174         int curidx = 0;
 175         int curbits;
 176         float rd = 0.0f;
 177         for (j = 0; j < dim; j++) {
 178             curidx *= aac_cb_range[cb];
 179             curidx += quants[j] + off;
 180         }
 181         curbits =  ff_aac_spectral_bits[cb-1][curidx];
 182         vec     = &ff_aac_codebook_vectors[cb-1][curidx*dim];
 183         if (BT_UNSIGNED) {
 184             for (j = 0; j < dim; j++) {
 185                 float t = fabsf(in[i+j]);
 186                 float di;
 187                 if (BT_ESC && vec[j] == 64.0f) { //FIXME: slow
 188                     if (t >= CLIPPED_ESCAPE) {
 189                         di = t - CLIPPED_ESCAPE;
 190                         curbits += 21;
 191                     } else {
 192                         int c = av_clip_uintp2(quant(t, Q, ROUNDING), 13);
 193                         di = t - c*cbrtf(c)*IQ;
 194                         curbits += av_log2(c)*2 - 4 + 1;
 195                     }
 196                 } else {
 197                     di = t - vec[j]*IQ;
 198                 }
 199                 if (vec[j] != 0.0f)
 200                     curbits++;
 201                 rd += di*di;
 202             }
 203         } else {
 204             for (j = 0; j < dim; j++) {
 205                 float di = in[i+j] - vec[j]*IQ;
 206                 rd += di*di;
 207             }
 208         }
 209         cost    += rd * lambda + curbits;
 210         resbits += curbits;
 211         if (cost >= uplim)
 212             return uplim;
 213         if (pb) {
 214             put_bits(pb, ff_aac_spectral_bits[cb-1][curidx], ff_aac_spectral_codes[cb-1][curidx]);
 215             if (BT_UNSIGNED)
 216                 for (j = 0; j < dim; j++)
 217                     if (ff_aac_codebook_vectors[cb-1][curidx*dim+j] != 0.0f)
 218                         put_bits(pb, 1, in[i+j] < 0.0f);
 219             if (BT_ESC) {
 220                 for (j = 0; j < 2; j++) {
 221                     if (ff_aac_codebook_vectors[cb-1][curidx*2+j] == 64.0f) {
 222                         int coef = av_clip_uintp2(quant(fabsf(in[i+j]), Q, ROUNDING), 13);
 223                         int len = av_log2(coef);
 224
 225                         put_bits(pb, len - 4 + 1, (1 << (len - 4 + 1)) - 2);
 226                         put_sbits(pb, len, coef);
 227                     }
 228                 }
 229             }
 230         }
 231     }
 232
 233     if (bits)
 234         *bits = resbits;
 235     return cost;
 236 }
 237
 238 static float quantize_and_encode_band_cost_NONE(struct AACEncContext *s, PutBitContext *pb,
 239                                                 const float *in, const float *scaled,
 240                                                 int size, int scale_idx, int cb,
 241                                                 const float lambda, const float uplim,
 242                                                 int *bits) {
 243     av_assert0(0);
 244     return 0.0f;
 245 }
 246
 247 #define QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NAME, BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO, ROUNDING) \
 248 static float quantize_and_encode_band_cost_ ## NAME(                                         \
 249                                 struct AACEncContext *s,                                     \
 250                                 PutBitContext *pb, const float *in,                          \
 251                                 const float *scaled, int size, int scale_idx,                \
 252                                 int cb, const float lambda, const float uplim,               \
 253                                 int *bits) {                                                 \
 254     return quantize_and_encode_band_cost_template(                                           \
 255                                 s, pb, in, scaled, size, scale_idx,                          \
 256                                 BT_ESC ? ESC_BT : cb, lambda, uplim, bits,                   \
 257                                 BT_ZERO, BT_UNSIGNED, BT_PAIR, BT_ESC, BT_NOISE, BT_STEREO,  \
 258                                 ROUNDING);                                                   \
 259 }
 260
 261 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ZERO,  1, 0, 0, 0, 0, 0, ROUND_STANDARD)
 262 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SQUAD, 0, 0, 0, 0, 0, 0, ROUND_STANDARD)
 263 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UQUAD, 0, 1, 0, 0, 0, 0, ROUND_STANDARD)
 264 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(SPAIR, 0, 0, 1, 0, 0, 0, ROUND_STANDARD)
 265 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(UPAIR, 0, 1, 1, 0, 0, 0, ROUND_STANDARD)
 266 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC,   0, 1, 1, 1, 0, 0, ROUND_STANDARD)
 267 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(ESC_RTZ, 0, 1, 1, 1, 0, 0, ROUND_TO_ZERO)
 268 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(NOISE, 0, 0, 0, 0, 1, 0, ROUND_STANDARD)
 269 QUANTIZE_AND_ENCODE_BAND_COST_FUNC(STEREO,0, 0, 0, 0, 0, 1, ROUND_STANDARD)
 270
 271 static float (*const quantize_and_encode_band_cost_arr[])(
 272                                 struct AACEncContext *s,
 273                                 PutBitContext *pb, const float *in,
 274                                 const float *scaled, int size, int scale_idx,
 275                                 int cb, const float lambda, const float uplim,
 276                                 int *bits) = {
 277     quantize_and_encode_band_cost_ZERO,
 278     quantize_and_encode_band_cost_SQUAD,
 279     quantize_and_encode_band_cost_SQUAD,
 280     quantize_and_encode_band_cost_UQUAD,
 281     quantize_and_encode_band_cost_UQUAD,
 282     quantize_and_encode_band_cost_SPAIR,
 283     quantize_and_encode_band_cost_SPAIR,
 284     quantize_and_encode_band_cost_UPAIR,
 285     quantize_and_encode_band_cost_UPAIR,
 286     quantize_and_encode_band_cost_UPAIR,
 287     quantize_and_encode_band_cost_UPAIR,
 288     quantize_and_encode_band_cost_ESC,
 289     quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */
 290     quantize_and_encode_band_cost_NOISE,
 291     quantize_and_encode_band_cost_STEREO,
 292     quantize_and_encode_band_cost_STEREO,
 293 };
 294
 295 static float (*const quantize_and_encode_band_cost_rtz_arr[])(
 296                                 struct AACEncContext *s,
 297                                 PutBitContext *pb, const float *in,
 298                                 const float *scaled, int size, int scale_idx,
 299                                 int cb, const float lambda, const float uplim,
 300                                 int *bits) = {
 301     quantize_and_encode_band_cost_ZERO,
 302     quantize_and_encode_band_cost_SQUAD,
 303     quantize_and_encode_band_cost_SQUAD,
 304     quantize_and_encode_band_cost_UQUAD,
 305     quantize_and_encode_band_cost_UQUAD,
 306     quantize_and_encode_band_cost_SPAIR,
 307     quantize_and_encode_band_cost_SPAIR,
 308     quantize_and_encode_band_cost_UPAIR,
 309     quantize_and_encode_band_cost_UPAIR,
 310     quantize_and_encode_band_cost_UPAIR,
 311     quantize_and_encode_band_cost_UPAIR,
 312     quantize_and_encode_band_cost_ESC_RTZ,
 313     quantize_and_encode_band_cost_NONE,     /* CB 12 doesn't exist */
 314     quantize_and_encode_band_cost_NOISE,
 315     quantize_and_encode_band_cost_STEREO,
 316     quantize_and_encode_band_cost_STEREO,
 317 };
 318
 319 #define quantize_and_encode_band_cost(                                  \
 320                                 s, pb, in, scaled, size, scale_idx, cb, \
 321                                 lambda, uplim, bits, rtz)               \
 322     ((rtz) ? quantize_and_encode_band_cost_rtz_arr : quantize_and_encode_band_cost_arr)[cb]( \
 323                                 s, pb, in, scaled, size, scale_idx, cb, \
 324                                 lambda, uplim, bits)
 325
 326 static float quantize_band_cost(struct AACEncContext *s, const float *in,
 327                                 const float *scaled, int size, int scale_idx,
 328                                 int cb, const float lambda, const float uplim,
 329                                 int *bits, int rtz)
 330 {
 331     return quantize_and_encode_band_cost(s, NULL, in, scaled, size, scale_idx,
 332                                          cb, lambda, uplim, bits, rtz);
 333 }
 334
 335 static void quantize_and_encode_band(struct AACEncContext *s, PutBitContext *pb,
 336                                      const float *in, int size, int scale_idx,
 337                                      int cb, const float lambda, int rtz)
 338 {
 339     quantize_and_encode_band_cost(s, pb, in, NULL, size, scale_idx, cb, lambda,
 340                                   INFINITY, NULL, rtz);
 341 }
 342
 343 static float find_max_val(int group_len, int swb_size, const float *scaled) {
 344     float maxval = 0.0f;
 345     int w2, i;
 346     for (w2 = 0; w2 < group_len; w2++) {
 347         for (i = 0; i < swb_size; i++) {
 348             maxval = FFMAX(maxval, scaled[w2*128+i]);
 349         }
 350     }
 351     return maxval;
 352 }
 353
 354 static int find_min_book(float maxval, int sf) {
 355     float Q = ff_aac_pow2sf_tab[POW_SF2_ZERO - sf + SCALE_ONE_POS - SCALE_DIV_512];
 356     float Q34 = sqrtf(Q * sqrtf(Q));
 357     int qmaxval, cb;
 358     qmaxval = maxval * Q34 + 0.4054f;
 359     if      (qmaxval ==  0) cb = 0;
 360     else if (qmaxval ==  1) cb = 1;
 361     else if (qmaxval ==  2) cb = 3;
 362     else if (qmaxval <=  4) cb = 5;
 363     else if (qmaxval <=  7) cb = 7;
 364     else if (qmaxval <= 12) cb = 9;
 365     else                    cb = 11;
 366     return cb;
 367 }
 368
 369 /**
 370  * structure used in optimal codebook search
 371  */
 372 typedef struct BandCodingPath {
 373     int prev_idx; ///< pointer to the previous path point
 374     float cost;   ///< path cost
 375     int run;
 376 } BandCodingPath;
 377
 378 /**
 379  * Encode band info for single window group bands.
 380  */
 381 static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce,
 382                                      int win, int group_len, const float lambda)
 383 {
 384     BandCodingPath path[120][CB_TOT_ALL];
 385     int w, swb, cb, start, size;
 386     int i, j;
 387     const int max_sfb  = sce->ics.max_sfb;
 388     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
 389     const int run_esc  = (1 << run_bits) - 1;
 390     int idx, ppos, count;
 391     int stackrun[120], stackcb[120], stack_len;
 392     float next_minrd = INFINITY;
 393     int next_mincb = 0;
 394
 395     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 396     start = win*128;
 397     for (cb = 0; cb < CB_TOT_ALL; cb++) {
 398         path[0][cb].cost     = 0.0f;
 399         path[0][cb].prev_idx = -1;
 400         path[0][cb].run      = 0;
 401     }
 402     for (swb = 0; swb < max_sfb; swb++) {
 403         size = sce->ics.swb_sizes[swb];
 404         if (sce->zeroes[win*16 + swb]) {
 405             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 406                 path[swb+1][cb].prev_idx = cb;
 407                 path[swb+1][cb].cost     = path[swb][cb].cost;
 408                 path[swb+1][cb].run      = path[swb][cb].run + 1;
 409             }
 410         } else {
 411             float minrd = next_minrd;
 412             int mincb = next_mincb;
 413             next_minrd = INFINITY;
 414             next_mincb = 0;
 415             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 416                 float cost_stay_here, cost_get_here;
 417                 float rd = 0.0f;
 418                 if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] ||
 419                     cb  < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) {
 420                     path[swb+1][cb].prev_idx = -1;
 421                     path[swb+1][cb].cost     = INFINITY;
 422                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 423                     continue;
 424                 }
 425                 for (w = 0; w < group_len; w++) {
 426                     FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb];
 427                     rd += quantize_band_cost(s, sce->coeffs + start + w*128,
 428                                              s->scoefs + start + w*128, size,
 429                                              sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb],
 430                                              lambda / band->threshold, INFINITY, NULL, 0);
 431                 }
 432                 cost_stay_here = path[swb][cb].cost + rd;
 433                 cost_get_here  = minrd              + rd + run_bits + 4;
 434                 if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
 435                     != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
 436                     cost_stay_here += run_bits;
 437                 if (cost_get_here < cost_stay_here) {
 438                     path[swb+1][cb].prev_idx = mincb;
 439                     path[swb+1][cb].cost     = cost_get_here;
 440                     path[swb+1][cb].run      = 1;
 441                 } else {
 442                     path[swb+1][cb].prev_idx = cb;
 443                     path[swb+1][cb].cost     = cost_stay_here;
 444                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 445                 }
 446                 if (path[swb+1][cb].cost < next_minrd) {
 447                     next_minrd = path[swb+1][cb].cost;
 448                     next_mincb = cb;
 449                 }
 450             }
 451         }
 452         start += sce->ics.swb_sizes[swb];
 453     }
 454
 455     //convert resulting path from backward-linked list
 456     stack_len = 0;
 457     idx       = 0;
 458     for (cb = 1; cb < CB_TOT_ALL; cb++)
 459         if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
 460             idx = cb;
 461     ppos = max_sfb;
 462     while (ppos > 0) {
 463         av_assert1(idx >= 0);
 464         cb = idx;
 465         stackrun[stack_len] = path[ppos][cb].run;
 466         stackcb [stack_len] = cb;
 467         idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
 468         ppos -= path[ppos][cb].run;
 469         stack_len++;
 470     }
 471     //perform actual band info encoding
 472     start = 0;
 473     for (i = stack_len - 1; i >= 0; i--) {
 474         cb = aac_cb_out_map[stackcb[i]];
 475         put_bits(&s->pb, 4, cb);
 476         count = stackrun[i];
 477         memset(sce->zeroes + win*16 + start, !cb, count);
 478         //XXX: memset when band_type is also uint8_t
 479         for (j = 0; j < count; j++) {
 480             sce->band_type[win*16 + start] = cb;
 481             start++;
 482         }
 483         while (count >= run_esc) {
 484             put_bits(&s->pb, run_bits, run_esc);
 485             count -= run_esc;
 486         }
 487         put_bits(&s->pb, run_bits, count);
 488     }
 489 }
 490
 491 static void codebook_trellis_rate(AACEncContext *s, SingleChannelElement *sce,
 492                                   int win, int group_len, const float lambda)
 493 {
 494     BandCodingPath path[120][CB_TOT_ALL];
 495     int w, swb, cb, start, size;
 496     int i, j;
 497     const int max_sfb  = sce->ics.max_sfb;
 498     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
 499     const int run_esc  = (1 << run_bits) - 1;
 500     int idx, ppos, count;
 501     int stackrun[120], stackcb[120], stack_len;
 502     float next_minbits = INFINITY;
 503     int next_mincb = 0;
 504
 505     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 506     start = win*128;
 507     for (cb = 0; cb < CB_TOT_ALL; cb++) {
 508         path[0][cb].cost     = run_bits+4;
 509         path[0][cb].prev_idx = -1;
 510         path[0][cb].run      = 0;
 511     }
 512     for (swb = 0; swb < max_sfb; swb++) {
 513         size = sce->ics.swb_sizes[swb];
 514         if (sce->zeroes[win*16 + swb]) {
 515             float cost_stay_here = path[swb][0].cost;
 516             float cost_get_here  = next_minbits + run_bits + 4;
 517             if (   run_value_bits[sce->ics.num_windows == 8][path[swb][0].run]
 518                 != run_value_bits[sce->ics.num_windows == 8][path[swb][0].run+1])
 519                 cost_stay_here += run_bits;
 520             if (cost_get_here < cost_stay_here) {
 521                 path[swb+1][0].prev_idx = next_mincb;
 522                 path[swb+1][0].cost     = cost_get_here;
 523                 path[swb+1][0].run      = 1;
 524             } else {
 525                 path[swb+1][0].prev_idx = 0;
 526                 path[swb+1][0].cost     = cost_stay_here;
 527                 path[swb+1][0].run      = path[swb][0].run + 1;
 528             }
 529             next_minbits = path[swb+1][0].cost;
 530             next_mincb = 0;
 531             for (cb = 1; cb < CB_TOT_ALL; cb++) {
 532                 path[swb+1][cb].cost = 61450;
 533                 path[swb+1][cb].prev_idx = -1;
 534                 path[swb+1][cb].run = 0;
 535             }
 536         } else {
 537             float minbits = next_minbits;
 538             int mincb = next_mincb;
 539             int startcb = sce->band_type[win*16+swb];
 540             startcb = aac_cb_in_map[startcb];
 541             next_minbits = INFINITY;
 542             next_mincb = 0;
 543             for (cb = 0; cb < startcb; cb++) {
 544                 path[swb+1][cb].cost = 61450;
 545                 path[swb+1][cb].prev_idx = -1;
 546                 path[swb+1][cb].run = 0;
 547             }
 548             for (cb = startcb; cb < CB_TOT_ALL; cb++) {
 549                 float cost_stay_here, cost_get_here;
 550                 float bits = 0.0f;
 551                 if (cb >= 12 && sce->band_type[win*16+swb] != aac_cb_out_map[cb]) {
 552                     path[swb+1][cb].cost = 61450;
 553                     path[swb+1][cb].prev_idx = -1;
 554                     path[swb+1][cb].run = 0;
 555                     continue;
 556                 }
 557                 for (w = 0; w < group_len; w++) {
 558                     bits += quantize_band_cost(s, sce->coeffs + start + w*128,
 559                                                s->scoefs + start + w*128, size,
 560                                                sce->sf_idx[win*16+swb],
 561                                                aac_cb_out_map[cb],
 562                                                0, INFINITY, NULL, 0);
 563                 }
 564                 cost_stay_here = path[swb][cb].cost + bits;
 565                 cost_get_here  = minbits            + bits + run_bits + 4;
 566                 if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
 567                     != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
 568                     cost_stay_here += run_bits;
 569                 if (cost_get_here < cost_stay_here) {
 570                     path[swb+1][cb].prev_idx = mincb;
 571                     path[swb+1][cb].cost     = cost_get_here;
 572                     path[swb+1][cb].run      = 1;
 573                 } else {
 574                     path[swb+1][cb].prev_idx = cb;
 575                     path[swb+1][cb].cost     = cost_stay_here;
 576                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 577                 }
 578                 if (path[swb+1][cb].cost < next_minbits) {
 579                     next_minbits = path[swb+1][cb].cost;
 580                     next_mincb = cb;
 581                 }
 582             }
 583         }
 584         start += sce->ics.swb_sizes[swb];
 585     }
 586
 587     //convert resulting path from backward-linked list
 588     stack_len = 0;
 589     idx       = 0;
 590     for (cb = 1; cb < CB_TOT_ALL; cb++)
 591         if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
 592             idx = cb;
 593     ppos = max_sfb;
 594     while (ppos > 0) {
 595         av_assert1(idx >= 0);
 596         cb = idx;
 597         stackrun[stack_len] = path[ppos][cb].run;
 598         stackcb [stack_len] = cb;
 599         idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
 600         ppos -= path[ppos][cb].run;
 601         stack_len++;
 602     }
 603     //perform actual band info encoding
 604     start = 0;
 605     for (i = stack_len - 1; i >= 0; i--) {
 606         cb = aac_cb_out_map[stackcb[i]];
 607         put_bits(&s->pb, 4, cb);
 608         count = stackrun[i];
 609         memset(sce->zeroes + win*16 + start, !cb, count);
 610         //XXX: memset when band_type is also uint8_t
 611         for (j = 0; j < count; j++) {
 612             sce->band_type[win*16 + start] = cb;
 613             start++;
 614         }
 615         while (count >= run_esc) {
 616             put_bits(&s->pb, run_bits, run_esc);
 617             count -= run_esc;
 618         }
 619         put_bits(&s->pb, run_bits, count);
 620     }
 621 }
 622
 623 /** Return the minimum scalefactor where the quantized coef does not clip. */
 624 static av_always_inline uint8_t coef2minsf(float coef) {
 625     return av_clip_uint8(log2f(coef)*4 - 69 + SCALE_ONE_POS - SCALE_DIV_512);
 626 }
 627
 628 /** Return the maximum scalefactor where the quantized coef is not zero. */
 629 static av_always_inline uint8_t coef2maxsf(float coef) {
 630     return av_clip_uint8(log2f(coef)*4 +  6 + SCALE_ONE_POS - SCALE_DIV_512);
 631 }
 632
 633 typedef struct TrellisPath {
 634     float cost;
 635     int prev;
 636 } TrellisPath;
 637
 638 #define TRELLIS_STAGES 121
 639 #define TRELLIS_STATES (SCALE_MAX_DIFF+1)
 640
 641 static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce)
 642 {
 643     int w, g, start = 0;
 644     int minscaler_n = sce->sf_idx[0], minscaler_i = sce->sf_idx[0];
 645     int bands = 0;
 646
 647     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 648         start = 0;
 649         for (g = 0;  g < sce->ics.num_swb; g++) {
 650             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 651                 sce->sf_idx[w*16+g] = av_clip(ceilf(log2f(sce->is_ener[w*16+g])*2), -155, 100);
 652                 minscaler_i = FFMIN(minscaler_i, sce->sf_idx[w*16+g]);
 653                 bands++;
 654             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 655                 sce->sf_idx[w*16+g] = av_clip(4+log2f(sce->pns_ener[w*16+g])*2, -100, 155);
 656                 minscaler_n = FFMIN(minscaler_n, sce->sf_idx[w*16+g]);
 657                 bands++;
 658             }
 659             start += sce->ics.swb_sizes[g];
 660         }
 661     }
 662
 663     if (!bands)
 664         return;
 665
 666     /* Clip the scalefactor indices */
 667     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 668         for (g = 0;  g < sce->ics.num_swb; g++) {
 669             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 670                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_i, minscaler_i + SCALE_MAX_DIFF);
 671             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 672                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_n, minscaler_n + SCALE_MAX_DIFF);
 673             }
 674         }
 675     }
 676 }
 677
 678 static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
 679                                        SingleChannelElement *sce,
 680                                        const float lambda)
 681 {
 682     int q, w, w2, g, start = 0;
 683     int i, j;
 684     int idx;
 685     TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
 686     int bandaddr[TRELLIS_STAGES];
 687     int minq;
 688     float mincost;
 689     float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f;
 690     int q0, q1, qcnt = 0;
 691
 692     for (i = 0; i < 1024; i++) {
 693         float t = fabsf(sce->coeffs[i]);
 694         if (t > 0.0f) {
 695             q0f = FFMIN(q0f, t);
 696             q1f = FFMAX(q1f, t);
 697             qnrgf += t*t;
 698             qcnt++;
 699         }
 700     }
 701
 702     if (!qcnt) {
 703         memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 704         memset(sce->zeroes, 1, sizeof(sce->zeroes));
 705         return;
 706     }
 707
 708     //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 709     q0 = coef2minsf(q0f);
 710     //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 711     q1 = coef2maxsf(q1f);
 712     if (q1 - q0 > 60) {
 713         int q0low  = q0;
 714         int q1high = q1;
 715         //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped
 716         int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512);
 717         q1 = qnrg + 30;
 718         q0 = qnrg - 30;
 719         if (q0 < q0low) {
 720             q1 += q0low - q0;
 721             q0  = q0low;
 722         } else if (q1 > q1high) {
 723             q0 -= q1 - q1high;
 724             q1  = q1high;
 725         }
 726     }
 727
 728     for (i = 0; i < TRELLIS_STATES; i++) {
 729         paths[0][i].cost    = 0.0f;
 730         paths[0][i].prev    = -1;
 731     }
 732     for (j = 1; j < TRELLIS_STAGES; j++) {
 733         for (i = 0; i < TRELLIS_STATES; i++) {
 734             paths[j][i].cost    = INFINITY;
 735             paths[j][i].prev    = -2;
 736         }
 737     }
 738     idx = 1;
 739     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 740     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 741         start = w*128;
 742         for (g = 0; g < sce->ics.num_swb; g++) {
 743             const float *coefs = sce->coeffs + start;
 744             float qmin, qmax;
 745             int nz = 0;
 746
 747             bandaddr[idx] = w * 16 + g;
 748             qmin = INT_MAX;
 749             qmax = 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                 if (band->energy <= band->threshold || band->threshold == 0.0f) {
 753                     sce->zeroes[(w+w2)*16+g] = 1;
 754                     continue;
 755                 }
 756                 sce->zeroes[(w+w2)*16+g] = 0;
 757                 nz = 1;
 758                 for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
 759                     float t = fabsf(coefs[w2*128+i]);
 760                     if (t > 0.0f)
 761                         qmin = FFMIN(qmin, t);
 762                     qmax = FFMAX(qmax, t);
 763                 }
 764             }
 765             if (nz) {
 766                 int minscale, maxscale;
 767                 float minrd = INFINITY;
 768                 float maxval;
 769                 //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 770                 minscale = coef2minsf(qmin);
 771                 //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 772                 maxscale = coef2maxsf(qmax);
 773                 minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
 774                 maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
 775                 maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
 776                 for (q = minscale; q < maxscale; q++) {
 777                     float dist = 0;
 778                     int cb = find_min_book(maxval, sce->sf_idx[w*16+g]);
 779                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 780                         FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 781                         dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
 782                                                    q + q0, cb, lambda / band->threshold, INFINITY, NULL, 0);
 783                     }
 784                     minrd = FFMIN(minrd, dist);
 785
 786                     for (i = 0; i < q1 - q0; i++) {
 787                         float cost;
 788                         cost = paths[idx - 1][i].cost + dist
 789                                + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
 790                         if (cost < paths[idx][q].cost) {
 791                             paths[idx][q].cost    = cost;
 792                             paths[idx][q].prev    = i;
 793                         }
 794                     }
 795                 }
 796             } else {
 797                 for (q = 0; q < q1 - q0; q++) {
 798                     paths[idx][q].cost = paths[idx - 1][q].cost + 1;
 799                     paths[idx][q].prev = q;
 800                 }
 801             }
 802             sce->zeroes[w*16+g] = !nz;
 803             start += sce->ics.swb_sizes[g];
 804             idx++;
 805         }
 806     }
 807     idx--;
 808     mincost = paths[idx][0].cost;
 809     minq    = 0;
 810     for (i = 1; i < TRELLIS_STATES; i++) {
 811         if (paths[idx][i].cost < mincost) {
 812             mincost = paths[idx][i].cost;
 813             minq = i;
 814         }
 815     }
 816     while (idx) {
 817         sce->sf_idx[bandaddr[idx]] = minq + q0;
 818         minq = paths[idx][minq].prev;
 819         idx--;
 820     }
 821     //set the same quantizers inside window groups
 822     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
 823         for (g = 0;  g < sce->ics.num_swb; g++)
 824             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
 825                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
 826 }
 827
 828 /**
 829  * two-loop quantizers search taken from ISO 13818-7 Appendix C
 830  */
 831 static void search_for_quantizers_twoloop(AVCodecContext *avctx,
 832                                           AACEncContext *s,
 833                                           SingleChannelElement *sce,
 834                                           const float lambda)
 835 {
 836     int start = 0, i, w, w2, g;
 837     int destbits = avctx->bit_rate * 1024.0 / avctx->sample_rate / avctx->channels * (lambda / 120.f);
 838     float dists[128] = { 0 }, uplims[128] = { 0 };
 839     float maxvals[128];
 840     int fflag, minscaler;
 841     int its  = 0;
 842     int allz = 0;
 843     float minthr = INFINITY;
 844
 845     // for values above this the decoder might end up in an endless loop
 846     // due to always having more bits than what can be encoded.
 847     destbits = FFMIN(destbits, 5800);
 848     //XXX: some heuristic to determine initial quantizers will reduce search time
 849     //determine zero bands and upper limits
 850     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 851         for (g = 0;  g < sce->ics.num_swb; g++) {
 852             int nz = 0;
 853             float uplim = 0.0f, energy = 0.0f;
 854             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 855                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 856                 uplim  += band->threshold;
 857                 energy += band->energy;
 858                 if (band->energy <= band->threshold || band->threshold == 0.0f) {
 859                     sce->zeroes[(w+w2)*16+g] = 1;
 860                     continue;
 861                 }
 862                 nz = 1;
 863             }
 864             uplims[w*16+g] = uplim *512;
 865             sce->zeroes[w*16+g] = !nz;
 866             if (nz)
 867                 minthr = FFMIN(minthr, uplim);
 868             allz |= nz;
 869         }
 870     }
 871     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 872         for (g = 0;  g < sce->ics.num_swb; g++) {
 873             if (sce->zeroes[w*16+g]) {
 874                 sce->sf_idx[w*16+g] = SCALE_ONE_POS;
 875                 continue;
 876             }
 877             sce->sf_idx[w*16+g] = SCALE_ONE_POS + FFMIN(log2f(uplims[w*16+g]/minthr)*4,59);
 878         }
 879     }
 880
 881     if (!allz)
 882         return;
 883     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 884
 885     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 886         start = w*128;
 887         for (g = 0;  g < sce->ics.num_swb; g++) {
 888             const float *scaled = s->scoefs + start;
 889             maxvals[w*16+g] = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], scaled);
 890             start += sce->ics.swb_sizes[g];
 891         }
 892     }
 893
 894     //perform two-loop search
 895     //outer loop - improve quality
 896     do {
 897         int tbits, qstep;
 898         minscaler = sce->sf_idx[0];
 899         //inner loop - quantize spectrum to fit into given number of bits
 900         qstep = its ? 1 : 32;
 901         do {
 902             int prev = -1;
 903             tbits = 0;
 904             for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 905                 start = w*128;
 906                 for (g = 0;  g < sce->ics.num_swb; g++) {
 907                     const float *coefs = sce->coeffs + start;
 908                     const float *scaled = s->scoefs + start;
 909                     int bits = 0;
 910                     int cb;
 911                     float dist = 0.0f;
 912
 913                     if (sce->zeroes[w*16+g] || sce->sf_idx[w*16+g] >= 218) {
 914                         start += sce->ics.swb_sizes[g];
 915                         continue;
 916                     }
 917                     minscaler = FFMIN(minscaler, sce->sf_idx[w*16+g]);
 918                     cb = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
 919                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 920                         int b;
 921                         dist += quantize_band_cost(s, coefs + w2*128,
 922                                                    scaled + w2*128,
 923                                                    sce->ics.swb_sizes[g],
 924                                                    sce->sf_idx[w*16+g],
 925                                                    cb,
 926                                                    1.0f,
 927                                                    INFINITY,
 928                                                    &b,
 929                                                    0);
 930                         bits += b;
 931                     }
 932                     dists[w*16+g] = dist - bits;
 933                     if (prev != -1) {
 934                         bits += ff_aac_scalefactor_bits[sce->sf_idx[w*16+g] - prev + SCALE_DIFF_ZERO];
 935                     }
 936                     tbits += bits;
 937                     start += sce->ics.swb_sizes[g];
 938                     prev = sce->sf_idx[w*16+g];
 939                 }
 940             }
 941             if (tbits > destbits) {
 942                 for (i = 0; i < 128; i++)
 943                     if (sce->sf_idx[i] < 218 - qstep)
 944                         sce->sf_idx[i] += qstep;
 945             } else {
 946                 for (i = 0; i < 128; i++)
 947                     if (sce->sf_idx[i] > 60 - qstep)
 948                         sce->sf_idx[i] -= qstep;
 949             }
 950             qstep >>= 1;
 951             if (!qstep && tbits > destbits*1.02 && sce->sf_idx[0] < 217)
 952                 qstep = 1;
 953         } while (qstep);
 954
 955         fflag = 0;
 956         minscaler = av_clip(minscaler, 60, 255 - SCALE_MAX_DIFF);
 957
 958         for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 959             for (g = 0; g < sce->ics.num_swb; g++) {
 960                 int prevsc = sce->sf_idx[w*16+g];
 961                 if (dists[w*16+g] > uplims[w*16+g] && sce->sf_idx[w*16+g] > 60) {
 962                     if (find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]-1))
 963                         sce->sf_idx[w*16+g]--;
 964                     else //Try to make sure there is some energy in every band
 965                         sce->sf_idx[w*16+g]-=2;
 966                 }
 967                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler, minscaler + SCALE_MAX_DIFF);
 968                 sce->sf_idx[w*16+g] = FFMIN(sce->sf_idx[w*16+g], 219);
 969                 if (sce->sf_idx[w*16+g] != prevsc)
 970                     fflag = 1;
 971                 sce->band_type[w*16+g] = find_min_book(maxvals[w*16+g], sce->sf_idx[w*16+g]);
 972             }
 973         }
 974         its++;
 975     } while (fflag && its < 10);
 976 }
 977
 978 static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s,
 979                                        SingleChannelElement *sce,
 980                                        const float lambda)
 981 {
 982     int start = 0, i, w, w2, g;
 983     float uplim[128], maxq[128];
 984     int minq, maxsf;
 985     float distfact = ((sce->ics.num_windows > 1) ? 85.80 : 147.84) / lambda;
 986     int last = 0, lastband = 0, curband = 0;
 987     float avg_energy = 0.0;
 988     if (sce->ics.num_windows == 1) {
 989         start = 0;
 990         for (i = 0; i < 1024; i++) {
 991             if (i - start >= sce->ics.swb_sizes[curband]) {
 992                 start += sce->ics.swb_sizes[curband];
 993                 curband++;
 994             }
 995             if (sce->coeffs[i]) {
 996                 avg_energy += sce->coeffs[i] * sce->coeffs[i];
 997                 last = i;
 998                 lastband = curband;
 999             }
1000         }
1001     } else {
1002         for (w = 0; w < 8; w++) {
1003             const float *coeffs = sce->coeffs + w*128;
1004             curband = start = 0;
1005             for (i = 0; i < 128; i++) {
1006                 if (i - start >= sce->ics.swb_sizes[curband]) {
1007                     start += sce->ics.swb_sizes[curband];
1008                     curband++;
1009                 }
1010                 if (coeffs[i]) {
1011                     avg_energy += coeffs[i] * coeffs[i];
1012                     last = FFMAX(last, i);
1013                     lastband = FFMAX(lastband, curband);
1014                 }
1015             }
1016         }
1017     }
1018     last++;
1019     avg_energy /= last;
1020     if (avg_energy == 0.0f) {
1021         for (i = 0; i < FF_ARRAY_ELEMS(sce->sf_idx); i++)
1022             sce->sf_idx[i] = SCALE_ONE_POS;
1023         return;
1024     }
1025     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1026         start = w*128;
1027         for (g = 0; g < sce->ics.num_swb; g++) {
1028             float *coefs   = sce->coeffs + start;
1029             const int size = sce->ics.swb_sizes[g];
1030             int start2 = start, end2 = start + size, peakpos = start;
1031             float maxval = -1, thr = 0.0f, t;
1032             maxq[w*16+g] = 0.0f;
1033             if (g > lastband) {
1034                 maxq[w*16+g] = 0.0f;
1035                 start += size;
1036                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
1037                     memset(coefs + w2*128, 0, sizeof(coefs[0])*size);
1038                 continue;
1039             }
1040             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1041                 for (i = 0; i < size; i++) {
1042                     float t = coefs[w2*128+i]*coefs[w2*128+i];
1043                     maxq[w*16+g] = FFMAX(maxq[w*16+g], fabsf(coefs[w2*128 + i]));
1044                     thr += t;
1045                     if (sce->ics.num_windows == 1 && maxval < t) {
1046                         maxval  = t;
1047                         peakpos = start+i;
1048                     }
1049                 }
1050             }
1051             if (sce->ics.num_windows == 1) {
1052                 start2 = FFMAX(peakpos - 2, start2);
1053                 end2   = FFMIN(peakpos + 3, end2);
1054             } else {
1055                 start2 -= start;
1056                 end2   -= start;
1057             }
1058             start += size;
1059             thr = pow(thr / (avg_energy * (end2 - start2)), 0.3 + 0.1*(lastband - g) / lastband);
1060             t   = 1.0 - (1.0 * start2 / last);
1061             uplim[w*16+g] = distfact / (1.4 * thr + t*t*t + 0.075);
1062         }
1063     }
1064     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
1065     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
1066     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1067         start = w*128;
1068         for (g = 0;  g < sce->ics.num_swb; g++) {
1069             const float *coefs  = sce->coeffs + start;
1070             const float *scaled = s->scoefs   + start;
1071             const int size      = sce->ics.swb_sizes[g];
1072             int scf, prev_scf, step;
1073             int min_scf = -1, max_scf = 256;
1074             float curdiff;
1075             if (maxq[w*16+g] < 21.544) {
1076                 sce->zeroes[w*16+g] = 1;
1077                 start += size;
1078                 continue;
1079             }
1080             sce->zeroes[w*16+g] = 0;
1081             scf  = prev_scf = av_clip(SCALE_ONE_POS - SCALE_DIV_512 - log2f(1/maxq[w*16+g])*16/3, 60, 218);
1082             for (;;) {
1083                 float dist = 0.0f;
1084                 int quant_max;
1085
1086                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1087                     int b;
1088                     dist += quantize_band_cost(s, coefs + w2*128,
1089                                                scaled + w2*128,
1090                                                sce->ics.swb_sizes[g],
1091                                                scf,
1092                                                ESC_BT,
1093                                                lambda,
1094                                                INFINITY,
1095                                                &b,
1096                                                0);
1097                     dist -= b;
1098                 }
1099                 dist *= 1.0f / 512.0f / lambda;
1100                 quant_max = quant(maxq[w*16+g], ff_aac_pow2sf_tab[POW_SF2_ZERO - scf + SCALE_ONE_POS - SCALE_DIV_512], ROUND_STANDARD);
1101                 if (quant_max >= 8191) { // too much, return to the previous quantizer
1102                     sce->sf_idx[w*16+g] = prev_scf;
1103                     break;
1104                 }
1105                 prev_scf = scf;
1106                 curdiff = fabsf(dist - uplim[w*16+g]);
1107                 if (curdiff <= 1.0f)
1108                     step = 0;
1109                 else
1110                     step = log2f(curdiff);
1111                 if (dist > uplim[w*16+g])
1112                     step = -step;
1113                 scf += step;
1114                 scf = av_clip_uint8(scf);
1115                 step = scf - prev_scf;
1116                 if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) {
1117                     sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf);
1118                     break;
1119                 }
1120                 if (step > 0)
1121                     min_scf = prev_scf;
1122                 else
1123                     max_scf = prev_scf;
1124             }
1125             start += size;
1126         }
1127     }
1128     minq = sce->sf_idx[0] ? sce->sf_idx[0] : INT_MAX;
1129     for (i = 1; i < 128; i++) {
1130         if (!sce->sf_idx[i])
1131             sce->sf_idx[i] = sce->sf_idx[i-1];
1132         else
1133             minq = FFMIN(minq, sce->sf_idx[i]);
1134     }
1135     if (minq == INT_MAX)
1136         minq = 0;
1137     minq = FFMIN(minq, SCALE_MAX_POS);
1138     maxsf = FFMIN(minq + SCALE_MAX_DIFF, SCALE_MAX_POS);
1139     for (i = 126; i >= 0; i--) {
1140         if (!sce->sf_idx[i])
1141             sce->sf_idx[i] = sce->sf_idx[i+1];
1142         sce->sf_idx[i] = av_clip(sce->sf_idx[i], minq, maxsf);
1143     }
1144 }
1145
1146 static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s,
1147                                        SingleChannelElement *sce,
1148                                        const float lambda)
1149 {
1150     int i, w, w2, g;
1151     int minq = 255;
1152
1153     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
1154     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1155         for (g = 0; g < sce->ics.num_swb; g++) {
1156             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1157                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
1158                 if (band->energy <= band->threshold) {
1159                     sce->sf_idx[(w+w2)*16+g] = 218;
1160                     sce->zeroes[(w+w2)*16+g] = 1;
1161                 } else {
1162                     sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218);
1163                     sce->zeroes[(w+w2)*16+g] = 0;
1164                 }
1165                 minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]);
1166             }
1167         }
1168     }
1169     for (i = 0; i < 128; i++) {
1170         sce->sf_idx[i] = 140;
1171         //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1);
1172     }
1173     //set the same quantizers inside window groups
1174     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
1175         for (g = 0;  g < sce->ics.num_swb; g++)
1176             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
1177                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
1178 }
1179
1180 static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
1181 {
1182     int start = 0, w, w2, g;
1183     const float lambda = s->lambda;
1184     const float freq_mult = avctx->sample_rate/(1024.0f/sce->ics.num_windows)/2.0f;
1185     const float spread_threshold = NOISE_SPREAD_THRESHOLD*(lambda/120.f);
1186     const float thr_mult = NOISE_LAMBDA_NUMERATOR/lambda;
1187
1188     /* Coders !twoloop don't reset the band_types */
1189     for (w = 0; w < 128; w++)
1190         if (sce->band_type[w] == NOISE_BT)
1191             sce->band_type[w] = 0;
1192
1193     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
1194         start = 0;
1195         for (g = 0;  g < sce->ics.num_swb; g++) {
1196             if (start*freq_mult > NOISE_LOW_LIMIT*(lambda/170.0f)) {
1197                 float energy = 0.0f, threshold = 0.0f, spread = 0.0f;
1198                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
1199                     FFPsyBand *band = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1200                     energy += band->energy;
1201                     threshold += band->threshold;
1202                     spread += band->spread;
1203                 }
1204                 if (spread > spread_threshold*sce->ics.group_len[w] &&
1205                     ((sce->zeroes[w*16+g] && energy >= threshold) ||
1206                     energy < threshold*thr_mult*sce->ics.group_len[w])) {
1207                     sce->band_type[w*16+g] = NOISE_BT;
1208                     sce->pns_ener[w*16+g] = energy / sce->ics.group_len[w];
1209                     sce->zeroes[w*16+g] = 0;
1210                 }
1211             }
1212             start += sce->ics.swb_sizes[g];
1213         }
1214     }
1215 }
1216
1217 static void search_for_is(AACEncContext *s, AVCodecContext *avctx, ChannelElement *cpe)
1218 {
1219     float IS[128];
1220     float *L34  = s->scoefs + 128*0, *R34  = s->scoefs + 128*1;
1221     float *I34  = s->scoefs + 128*2;
1222     SingleChannelElement *sce0 = &cpe->ch[0];
1223     SingleChannelElement *sce1 = &cpe->ch[1];
1224     int start = 0, count = 0, i, w, w2, g;
1225     const float freq_mult = avctx->sample_rate/(1024.0f/sce0->ics.num_windows)/2.0f;
1226     const float lambda = s->lambda;
1227
1228     for (w = 0; w < 128; w++)
1229         if (sce1->band_type[w] >= INTENSITY_BT2)
1230             sce1->band_type[w] = 0;
1231
1232     if (!cpe->common_window)
1233         return;
1234     for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
1235         start = 0;
1236         for (g = 0;  g < sce0->ics.num_swb; g++) {
1237             if (start*freq_mult > INT_STEREO_LOW_LIMIT*(lambda/170.0f) &&
1238                 cpe->ch[0].band_type[w*16+g] != NOISE_BT && !cpe->ch[0].zeroes[w*16+g] &&
1239                 cpe->ch[1].band_type[w*16+g] != NOISE_BT && !cpe->ch[1].zeroes[w*16+g]) {
1240                 int phase = 0;
1241                 float ener0 = 0.0f, ener1 = 0.0f, ener01 = 0.0f;
1242                 float dist1 = 0.0f, dist2 = 0.0f;
1243                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1244                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1245                         float coef0 = sce0->pcoeffs[start+(w+w2)*128+i];
1246                         float coef1 = sce1->pcoeffs[start+(w+w2)*128+i];
1247                         phase += coef0*coef1 >= 0.0f ? 1 : -1;
1248                         ener0 += coef0*coef0;
1249                         ener1 += coef1*coef1;
1250                         ener01 += (coef0 + coef1)*(coef0 + coef1);
1251                     }
1252                 }
1253                 if (!phase) { /* Too much phase difference between channels */
1254                     start += sce0->ics.swb_sizes[g];
1255                     continue;
1256                 }
1257                 phase = av_clip(phase, -1, 1);
1258                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1259                     FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1260                     FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
1261                     int is_band_type, is_sf_idx = FFMAX(1, sce0->sf_idx[(w+w2)*16+g]-4);
1262                     float e01_34 = phase*pow(sqrt(ener1/ener0), 3.0/4.0);
1263                     float maxval, dist_spec_err = 0.0f;
1264                     float minthr = FFMIN(band0->threshold, band1->threshold);
1265                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++)
1266                         IS[i] = (sce0->pcoeffs[start+(w+w2)*128+i] + phase*sce1->pcoeffs[start+(w+w2)*128+i]) * sqrt(ener0/ener01);
1267                     abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1268                     abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1269                     abs_pow34_v(I34, IS,                            sce0->ics.swb_sizes[g]);
1270                     maxval = find_max_val(1, sce0->ics.swb_sizes[g], I34);
1271                     is_band_type = find_min_book(maxval, is_sf_idx);
1272                     dist1 += quantize_band_cost(s, sce0->coeffs + start + (w+w2)*128,
1273                                                 L34,
1274                                                 sce0->ics.swb_sizes[g],
1275                                                 sce0->sf_idx[(w+w2)*16+g],
1276                                                 sce0->band_type[(w+w2)*16+g],
1277                                                 lambda / band0->threshold, INFINITY, NULL, 0);
1278                     dist1 += quantize_band_cost(s, sce1->coeffs + start + (w+w2)*128,
1279                                                 R34,
1280                                                 sce1->ics.swb_sizes[g],
1281                                                 sce1->sf_idx[(w+w2)*16+g],
1282                                                 sce1->band_type[(w+w2)*16+g],
1283                                                 lambda / band1->threshold, INFINITY, NULL, 0);
1284                     dist2 += quantize_band_cost(s, IS,
1285                                                 I34,
1286                                                 sce0->ics.swb_sizes[g],
1287                                                 is_sf_idx,
1288                                                 is_band_type,
1289                                                 lambda / minthr, INFINITY, NULL, 0);
1290                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1291                         dist_spec_err += (L34[i] - I34[i])*(L34[i] - I34[i]);
1292                         dist_spec_err += (R34[i] - I34[i]*e01_34)*(R34[i] - I34[i]*e01_34);
1293                     }
1294                     dist_spec_err *= lambda / minthr;
1295                     dist2 += dist_spec_err;
1296                 }
1297                 if (dist2 <= dist1) {
1298                     cpe->is_mask[w*16+g] = 1;
1299                     cpe->ms_mask[w*16+g] = 0;
1300                     cpe->ch[0].is_ener[w*16+g] = sqrt(ener0/ener01);
1301                     cpe->ch[1].is_ener[w*16+g] = ener0/ener1;
1302                     if (phase)
1303                         cpe->ch[1].band_type[w*16+g] = INTENSITY_BT;
1304                     else
1305                         cpe->ch[1].band_type[w*16+g] = INTENSITY_BT2;
1306                     count++;
1307                 }
1308             }
1309             start += sce0->ics.swb_sizes[g];
1310         }
1311     }
1312     cpe->is_mode = !!count;
1313 }
1314
1315 static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
1316 {
1317     int start = 0, i, w, w2, g;
1318     float M[128], S[128];
1319     float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
1320     const float lambda = s->lambda;
1321     SingleChannelElement *sce0 = &cpe->ch[0];
1322     SingleChannelElement *sce1 = &cpe->ch[1];
1323     if (!cpe->common_window)
1324         return;
1325     for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
1326         start = 0;
1327         for (g = 0;  g < sce0->ics.num_swb; g++) {
1328             if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g] && !cpe->is_mask[w*16+g]) {
1329                 float dist1 = 0.0f, dist2 = 0.0f;
1330                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
1331                     FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
1332                     FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
1333                     float minthr = FFMIN(band0->threshold, band1->threshold);
1334                     float maxthr = FFMAX(band0->threshold, band1->threshold);
1335                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
1336                         M[i] = (sce0->pcoeffs[start+(w+w2)*128+i]
1337                               + sce1->pcoeffs[start+(w+w2)*128+i]) * 0.5;
1338                         S[i] =  M[i]
1339                               - sce1->pcoeffs[start+(w+w2)*128+i];
1340                     }
1341                     abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1342                     abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
1343                     abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
1344                     abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
1345                     dist1 += quantize_band_cost(s, sce0->coeffs + start + (w+w2)*128,
1346                                                 L34,
1347                                                 sce0->ics.swb_sizes[g],
1348                                                 sce0->sf_idx[(w+w2)*16+g],
1349                                                 sce0->band_type[(w+w2)*16+g],
1350                                                 lambda / band0->threshold, INFINITY, NULL, 0);
1351                     dist1 += quantize_band_cost(s, sce1->coeffs + start + (w+w2)*128,
1352                                                 R34,
1353                                                 sce1->ics.swb_sizes[g],
1354                                                 sce1->sf_idx[(w+w2)*16+g],
1355                                                 sce1->band_type[(w+w2)*16+g],
1356                                                 lambda / band1->threshold, INFINITY, NULL, 0);
1357                     dist2 += quantize_band_cost(s, M,
1358                                                 M34,
1359                                                 sce0->ics.swb_sizes[g],
1360                                                 sce0->sf_idx[(w+w2)*16+g],
1361                                                 sce0->band_type[(w+w2)*16+g],
1362                                                 lambda / maxthr, INFINITY, NULL, 0);
1363                     dist2 += quantize_band_cost(s, S,
1364                                                 S34,
1365                                                 sce1->ics.swb_sizes[g],
1366                                                 sce1->sf_idx[(w+w2)*16+g],
1367                                                 sce1->band_type[(w+w2)*16+g],
1368                                                 lambda / minthr, INFINITY, NULL, 0);
1369                 }
1370                 cpe->ms_mask[w*16+g] = dist2 < dist1;
1371             }
1372             start += sce0->ics.swb_sizes[g];
1373         }
1374     }
1375 }
1376
1377 AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB] = {
1378     [AAC_CODER_FAAC] = {
1379         search_for_quantizers_faac,
1380         encode_window_bands_info,
1381         quantize_and_encode_band,
1382         set_special_band_scalefactors,
1383         search_for_pns,
1384         search_for_ms,
1385         search_for_is,
1386     },
1387     [AAC_CODER_ANMR] = {
1388         search_for_quantizers_anmr,
1389         encode_window_bands_info,
1390         quantize_and_encode_band,
1391         set_special_band_scalefactors,
1392         search_for_pns,
1393         search_for_ms,
1394         search_for_is,
1395     },
1396     [AAC_CODER_TWOLOOP] = {
1397         search_for_quantizers_twoloop,
1398         codebook_trellis_rate,
1399         quantize_and_encode_band,
1400         set_special_band_scalefactors,
1401         search_for_pns,
1402         search_for_ms,
1403         search_for_is,
1404     },
1405     [AAC_CODER_FAST] = {
1406         search_for_quantizers_fast,
1407         encode_window_bands_info,
1408         quantize_and_encode_band,
1409         set_special_band_scalefactors,
1410         search_for_pns,
1411         search_for_ms,
1412         search_for_is,
1413     },
1414 };