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
  37 #include "libavutil/mathematics.h"
  38 #include "mathops.h"
  39 #include "avcodec.h"
  40 #include "put_bits.h"
  41 #include "aac.h"
  42 #include "aacenc.h"
  43 #include "aactab.h"
  44 #include "aacenctab.h"
  45 #include "aacenc_utils.h"
  46 #include "aacenc_quantization.h"
  47 #include "aac_tablegen_decl.h"
  48
  49 #include "aacenc_is.h"
  50 #include "aacenc_tns.h"
  51 #include "aacenc_ltp.h"
  52 #include "aacenc_pred.h"
  53
  54 #include "libavcodec/aaccoder_twoloop.h"
  55
  56 /* Parameter of f(x) = a*(lambda/100), defines the maximum fourier spread
  57  * beyond which no PNS is used (since the SFBs contain tone rather than noise) */
  58 #define NOISE_SPREAD_THRESHOLD 0.5073f
  59
  60 /* Parameter of f(x) = a*(100/lambda), defines how much PNS is allowed to
  61  * replace low energy non zero bands */
  62 #define NOISE_LAMBDA_REPLACE 1.948f
  63
  64 #include "libavcodec/aaccoder_trellis.h"
  65
  66 /**
  67  * structure used in optimal codebook search
  68  */
  69 typedef struct BandCodingPath {
  70     int prev_idx; ///< pointer to the previous path point
  71     float cost;   ///< path cost
  72     int run;
  73 } BandCodingPath;
  74
  75 /**
  76  * Encode band info for single window group bands.
  77  */
  78 static void encode_window_bands_info(AACEncContext *s, SingleChannelElement *sce,
  79                                      int win, int group_len, const float lambda)
  80 {
  81     BandCodingPath path[120][CB_TOT_ALL];
  82     int w, swb, cb, start, size;
  83     int i, j;
  84     const int max_sfb  = sce->ics.max_sfb;
  85     const int run_bits = sce->ics.num_windows == 1 ? 5 : 3;
  86     const int run_esc  = (1 << run_bits) - 1;
  87     int idx, ppos, count;
  88     int stackrun[120], stackcb[120], stack_len;
  89     float next_minrd = INFINITY;
  90     int next_mincb = 0;
  91
  92     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
  93     start = win*128;
  94     for (cb = 0; cb < CB_TOT_ALL; cb++) {
  95         path[0][cb].cost     = 0.0f;
  96         path[0][cb].prev_idx = -1;
  97         path[0][cb].run      = 0;
  98     }
  99     for (swb = 0; swb < max_sfb; swb++) {
 100         size = sce->ics.swb_sizes[swb];
 101         if (sce->zeroes[win*16 + swb]) {
 102             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 103                 path[swb+1][cb].prev_idx = cb;
 104                 path[swb+1][cb].cost     = path[swb][cb].cost;
 105                 path[swb+1][cb].run      = path[swb][cb].run + 1;
 106             }
 107         } else {
 108             float minrd = next_minrd;
 109             int mincb = next_mincb;
 110             next_minrd = INFINITY;
 111             next_mincb = 0;
 112             for (cb = 0; cb < CB_TOT_ALL; cb++) {
 113                 float cost_stay_here, cost_get_here;
 114                 float rd = 0.0f;
 115                 if (cb >= 12 && sce->band_type[win*16+swb] < aac_cb_out_map[cb] ||
 116                     cb  < aac_cb_in_map[sce->band_type[win*16+swb]] && sce->band_type[win*16+swb] > aac_cb_out_map[cb]) {
 117                     path[swb+1][cb].prev_idx = -1;
 118                     path[swb+1][cb].cost     = INFINITY;
 119                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 120                     continue;
 121                 }
 122                 for (w = 0; w < group_len; w++) {
 123                     FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(win+w)*16+swb];
 124                     rd += quantize_band_cost(s, &sce->coeffs[start + w*128],
 125                                              &s->scoefs[start + w*128], size,
 126                                              sce->sf_idx[(win+w)*16+swb], aac_cb_out_map[cb],
 127                                              lambda / band->threshold, INFINITY, NULL, NULL, 0);
 128                 }
 129                 cost_stay_here = path[swb][cb].cost + rd;
 130                 cost_get_here  = minrd              + rd + run_bits + 4;
 131                 if (   run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run]
 132                     != run_value_bits[sce->ics.num_windows == 8][path[swb][cb].run+1])
 133                     cost_stay_here += run_bits;
 134                 if (cost_get_here < cost_stay_here) {
 135                     path[swb+1][cb].prev_idx = mincb;
 136                     path[swb+1][cb].cost     = cost_get_here;
 137                     path[swb+1][cb].run      = 1;
 138                 } else {
 139                     path[swb+1][cb].prev_idx = cb;
 140                     path[swb+1][cb].cost     = cost_stay_here;
 141                     path[swb+1][cb].run      = path[swb][cb].run + 1;
 142                 }
 143                 if (path[swb+1][cb].cost < next_minrd) {
 144                     next_minrd = path[swb+1][cb].cost;
 145                     next_mincb = cb;
 146                 }
 147             }
 148         }
 149         start += sce->ics.swb_sizes[swb];
 150     }
 151
 152     //convert resulting path from backward-linked list
 153     stack_len = 0;
 154     idx       = 0;
 155     for (cb = 1; cb < CB_TOT_ALL; cb++)
 156         if (path[max_sfb][cb].cost < path[max_sfb][idx].cost)
 157             idx = cb;
 158     ppos = max_sfb;
 159     while (ppos > 0) {
 160         av_assert1(idx >= 0);
 161         cb = idx;
 162         stackrun[stack_len] = path[ppos][cb].run;
 163         stackcb [stack_len] = cb;
 164         idx = path[ppos-path[ppos][cb].run+1][cb].prev_idx;
 165         ppos -= path[ppos][cb].run;
 166         stack_len++;
 167     }
 168     //perform actual band info encoding
 169     start = 0;
 170     for (i = stack_len - 1; i >= 0; i--) {
 171         cb = aac_cb_out_map[stackcb[i]];
 172         put_bits(&s->pb, 4, cb);
 173         count = stackrun[i];
 174         memset(sce->zeroes + win*16 + start, !cb, count);
 175         //XXX: memset when band_type is also uint8_t
 176         for (j = 0; j < count; j++) {
 177             sce->band_type[win*16 + start] = cb;
 178             start++;
 179         }
 180         while (count >= run_esc) {
 181             put_bits(&s->pb, run_bits, run_esc);
 182             count -= run_esc;
 183         }
 184         put_bits(&s->pb, run_bits, count);
 185     }
 186 }
 187
 188
 189 typedef struct TrellisPath {
 190     float cost;
 191     int prev;
 192 } TrellisPath;
 193
 194 #define TRELLIS_STAGES 121
 195 #define TRELLIS_STATES (SCALE_MAX_DIFF+1)
 196
 197 static void set_special_band_scalefactors(AACEncContext *s, SingleChannelElement *sce)
 198 {
 199     int w, g, start = 0;
 200     int minscaler_n = sce->sf_idx[0], minscaler_i = sce->sf_idx[0];
 201     int bands = 0;
 202
 203     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 204         start = 0;
 205         for (g = 0;  g < sce->ics.num_swb; g++) {
 206             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 207                 sce->sf_idx[w*16+g] = av_clip(roundf(log2f(sce->is_ener[w*16+g])*2), -155, 100);
 208                 minscaler_i = FFMIN(minscaler_i, sce->sf_idx[w*16+g]);
 209                 bands++;
 210             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 211                 sce->sf_idx[w*16+g] = av_clip(3+ceilf(log2f(sce->pns_ener[w*16+g])*2), -100, 155);
 212                 minscaler_n = FFMIN(minscaler_n, sce->sf_idx[w*16+g]);
 213                 bands++;
 214             }
 215             start += sce->ics.swb_sizes[g];
 216         }
 217     }
 218
 219     if (!bands)
 220         return;
 221
 222     /* Clip the scalefactor indices */
 223     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 224         for (g = 0;  g < sce->ics.num_swb; g++) {
 225             if (sce->band_type[w*16+g] == INTENSITY_BT || sce->band_type[w*16+g] == INTENSITY_BT2) {
 226                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_i, minscaler_i + SCALE_MAX_DIFF);
 227             } else if (sce->band_type[w*16+g] == NOISE_BT) {
 228                 sce->sf_idx[w*16+g] = av_clip(sce->sf_idx[w*16+g], minscaler_n, minscaler_n + SCALE_MAX_DIFF);
 229             }
 230         }
 231     }
 232 }
 233
 234 static void search_for_quantizers_anmr(AVCodecContext *avctx, AACEncContext *s,
 235                                        SingleChannelElement *sce,
 236                                        const float lambda)
 237 {
 238     int q, w, w2, g, start = 0;
 239     int i, j;
 240     int idx;
 241     TrellisPath paths[TRELLIS_STAGES][TRELLIS_STATES];
 242     int bandaddr[TRELLIS_STAGES];
 243     int minq;
 244     float mincost;
 245     float q0f = FLT_MAX, q1f = 0.0f, qnrgf = 0.0f;
 246     int q0, q1, qcnt = 0;
 247
 248     for (i = 0; i < 1024; i++) {
 249         float t = fabsf(sce->coeffs[i]);
 250         if (t > 0.0f) {
 251             q0f = FFMIN(q0f, t);
 252             q1f = FFMAX(q1f, t);
 253             qnrgf += t*t;
 254             qcnt++;
 255         }
 256     }
 257
 258     if (!qcnt) {
 259         memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 260         memset(sce->zeroes, 1, sizeof(sce->zeroes));
 261         return;
 262     }
 263
 264     //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 265     q0 = coef2minsf(q0f);
 266     //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 267     q1 = coef2maxsf(q1f);
 268     if (q1 - q0 > 60) {
 269         int q0low  = q0;
 270         int q1high = q1;
 271         //minimum scalefactor index is when maximum nonzero coefficient after quantizing is not clipped
 272         int qnrg = av_clip_uint8(log2f(sqrtf(qnrgf/qcnt))*4 - 31 + SCALE_ONE_POS - SCALE_DIV_512);
 273         q1 = qnrg + 30;
 274         q0 = qnrg - 30;
 275         if (q0 < q0low) {
 276             q1 += q0low - q0;
 277             q0  = q0low;
 278         } else if (q1 > q1high) {
 279             q0 -= q1 - q1high;
 280             q1  = q1high;
 281         }
 282     }
 283
 284     for (i = 0; i < TRELLIS_STATES; i++) {
 285         paths[0][i].cost    = 0.0f;
 286         paths[0][i].prev    = -1;
 287     }
 288     for (j = 1; j < TRELLIS_STAGES; j++) {
 289         for (i = 0; i < TRELLIS_STATES; i++) {
 290             paths[j][i].cost    = INFINITY;
 291             paths[j][i].prev    = -2;
 292         }
 293     }
 294     idx = 1;
 295     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 296     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 297         start = w*128;
 298         for (g = 0; g < sce->ics.num_swb; g++) {
 299             const float *coefs = &sce->coeffs[start];
 300             float qmin, qmax;
 301             int nz = 0;
 302
 303             bandaddr[idx] = w * 16 + g;
 304             qmin = INT_MAX;
 305             qmax = 0.0f;
 306             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 307                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 308                 if (band->energy <= band->threshold || band->threshold == 0.0f) {
 309                     sce->zeroes[(w+w2)*16+g] = 1;
 310                     continue;
 311                 }
 312                 sce->zeroes[(w+w2)*16+g] = 0;
 313                 nz = 1;
 314                 for (i = 0; i < sce->ics.swb_sizes[g]; i++) {
 315                     float t = fabsf(coefs[w2*128+i]);
 316                     if (t > 0.0f)
 317                         qmin = FFMIN(qmin, t);
 318                     qmax = FFMAX(qmax, t);
 319                 }
 320             }
 321             if (nz) {
 322                 int minscale, maxscale;
 323                 float minrd = INFINITY;
 324                 float maxval;
 325                 //minimum scalefactor index is when minimum nonzero coefficient after quantizing is not clipped
 326                 minscale = coef2minsf(qmin);
 327                 //maximum scalefactor index is when maximum coefficient after quantizing is still not zero
 328                 maxscale = coef2maxsf(qmax);
 329                 minscale = av_clip(minscale - q0, 0, TRELLIS_STATES - 1);
 330                 maxscale = av_clip(maxscale - q0, 0, TRELLIS_STATES);
 331                 maxval = find_max_val(sce->ics.group_len[w], sce->ics.swb_sizes[g], s->scoefs+start);
 332                 for (q = minscale; q < maxscale; q++) {
 333                     float dist = 0;
 334                     int cb = find_min_book(maxval, sce->sf_idx[w*16+g]);
 335                     for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 336                         FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 337                         dist += quantize_band_cost(s, coefs + w2*128, s->scoefs + start + w2*128, sce->ics.swb_sizes[g],
 338                                                    q + q0, cb, lambda / band->threshold, INFINITY, NULL, NULL, 0);
 339                     }
 340                     minrd = FFMIN(minrd, dist);
 341
 342                     for (i = 0; i < q1 - q0; i++) {
 343                         float cost;
 344                         cost = paths[idx - 1][i].cost + dist
 345                                + ff_aac_scalefactor_bits[q - i + SCALE_DIFF_ZERO];
 346                         if (cost < paths[idx][q].cost) {
 347                             paths[idx][q].cost    = cost;
 348                             paths[idx][q].prev    = i;
 349                         }
 350                     }
 351                 }
 352             } else {
 353                 for (q = 0; q < q1 - q0; q++) {
 354                     paths[idx][q].cost = paths[idx - 1][q].cost + 1;
 355                     paths[idx][q].prev = q;
 356                 }
 357             }
 358             sce->zeroes[w*16+g] = !nz;
 359             start += sce->ics.swb_sizes[g];
 360             idx++;
 361         }
 362     }
 363     idx--;
 364     mincost = paths[idx][0].cost;
 365     minq    = 0;
 366     for (i = 1; i < TRELLIS_STATES; i++) {
 367         if (paths[idx][i].cost < mincost) {
 368             mincost = paths[idx][i].cost;
 369             minq = i;
 370         }
 371     }
 372     while (idx) {
 373         sce->sf_idx[bandaddr[idx]] = minq + q0;
 374         minq = paths[idx][minq].prev;
 375         idx--;
 376     }
 377     //set the same quantizers inside window groups
 378     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
 379         for (g = 0;  g < sce->ics.num_swb; g++)
 380             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
 381                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
 382 }
 383
 384
 385 static void search_for_quantizers_faac(AVCodecContext *avctx, AACEncContext *s,
 386                                        SingleChannelElement *sce,
 387                                        const float lambda)
 388 {
 389     int start = 0, i, w, w2, g;
 390     float uplim[128], maxq[128];
 391     int minq, maxsf;
 392     float distfact = ((sce->ics.num_windows > 1) ? 85.80 : 147.84) / lambda;
 393     int last = 0, lastband = 0, curband = 0;
 394     float avg_energy = 0.0;
 395     if (sce->ics.num_windows == 1) {
 396         start = 0;
 397         for (i = 0; i < 1024; i++) {
 398             if (i - start >= sce->ics.swb_sizes[curband]) {
 399                 start += sce->ics.swb_sizes[curband];
 400                 curband++;
 401             }
 402             if (sce->coeffs[i]) {
 403                 avg_energy += sce->coeffs[i] * sce->coeffs[i];
 404                 last = i;
 405                 lastband = curband;
 406             }
 407         }
 408     } else {
 409         for (w = 0; w < 8; w++) {
 410             const float *coeffs = &sce->coeffs[w*128];
 411             curband = start = 0;
 412             for (i = 0; i < 128; i++) {
 413                 if (i - start >= sce->ics.swb_sizes[curband]) {
 414                     start += sce->ics.swb_sizes[curband];
 415                     curband++;
 416                 }
 417                 if (coeffs[i]) {
 418                     avg_energy += coeffs[i] * coeffs[i];
 419                     last = FFMAX(last, i);
 420                     lastband = FFMAX(lastband, curband);
 421                 }
 422             }
 423         }
 424     }
 425     last++;
 426     avg_energy /= last;
 427     if (avg_energy == 0.0f) {
 428         for (i = 0; i < FF_ARRAY_ELEMS(sce->sf_idx); i++)
 429             sce->sf_idx[i] = SCALE_ONE_POS;
 430         return;
 431     }
 432     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 433         start = w*128;
 434         for (g = 0; g < sce->ics.num_swb; g++) {
 435             float *coefs   = &sce->coeffs[start];
 436             const int size = sce->ics.swb_sizes[g];
 437             int start2 = start, end2 = start + size, peakpos = start;
 438             float maxval = -1, thr = 0.0f, t;
 439             maxq[w*16+g] = 0.0f;
 440             if (g > lastband) {
 441                 maxq[w*16+g] = 0.0f;
 442                 start += size;
 443                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++)
 444                     memset(coefs + w2*128, 0, sizeof(coefs[0])*size);
 445                 continue;
 446             }
 447             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 448                 for (i = 0; i < size; i++) {
 449                     float t = coefs[w2*128+i]*coefs[w2*128+i];
 450                     maxq[w*16+g] = FFMAX(maxq[w*16+g], fabsf(coefs[w2*128 + i]));
 451                     thr += t;
 452                     if (sce->ics.num_windows == 1 && maxval < t) {
 453                         maxval  = t;
 454                         peakpos = start+i;
 455                     }
 456                 }
 457             }
 458             if (sce->ics.num_windows == 1) {
 459                 start2 = FFMAX(peakpos - 2, start2);
 460                 end2   = FFMIN(peakpos + 3, end2);
 461             } else {
 462                 start2 -= start;
 463                 end2   -= start;
 464             }
 465             start += size;
 466             thr = pow(thr / (avg_energy * (end2 - start2)), 0.3 + 0.1*(lastband - g) / lastband);
 467             t   = 1.0 - (1.0 * start2 / last);
 468             uplim[w*16+g] = distfact / (1.4 * thr + t*t*t + 0.075);
 469         }
 470     }
 471     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 472     abs_pow34_v(s->scoefs, sce->coeffs, 1024);
 473     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 474         start = w*128;
 475         for (g = 0;  g < sce->ics.num_swb; g++) {
 476             const float *coefs  = &sce->coeffs[start];
 477             const float *scaled = &s->scoefs[start];
 478             const int size      = sce->ics.swb_sizes[g];
 479             int scf, prev_scf, step;
 480             int min_scf = -1, max_scf = 256;
 481             float curdiff;
 482             if (maxq[w*16+g] < 21.544) {
 483                 sce->zeroes[w*16+g] = 1;
 484                 start += size;
 485                 continue;
 486             }
 487             sce->zeroes[w*16+g] = 0;
 488             scf  = prev_scf = av_clip(SCALE_ONE_POS - SCALE_DIV_512 - log2f(1/maxq[w*16+g])*16/3, 60, 218);
 489             for (;;) {
 490                 float dist = 0.0f;
 491                 int quant_max;
 492
 493                 for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 494                     int b;
 495                     dist += quantize_band_cost(s, coefs + w2*128,
 496                                                scaled + w2*128,
 497                                                sce->ics.swb_sizes[g],
 498                                                scf,
 499                                                ESC_BT,
 500                                                lambda,
 501                                                INFINITY,
 502                                                &b, NULL,
 503                                                0);
 504                     dist -= b;
 505                 }
 506                 dist *= 1.0f / 512.0f / lambda;
 507                 quant_max = quant(maxq[w*16+g], ff_aac_pow2sf_tab[POW_SF2_ZERO - scf + SCALE_ONE_POS - SCALE_DIV_512], ROUND_STANDARD);
 508                 if (quant_max >= 8191) { // too much, return to the previous quantizer
 509                     sce->sf_idx[w*16+g] = prev_scf;
 510                     break;
 511                 }
 512                 prev_scf = scf;
 513                 curdiff = fabsf(dist - uplim[w*16+g]);
 514                 if (curdiff <= 1.0f)
 515                     step = 0;
 516                 else
 517                     step = log2f(curdiff);
 518                 if (dist > uplim[w*16+g])
 519                     step = -step;
 520                 scf += step;
 521                 scf = av_clip_uint8(scf);
 522                 step = scf - prev_scf;
 523                 if (FFABS(step) <= 1 || (step > 0 && scf >= max_scf) || (step < 0 && scf <= min_scf)) {
 524                     sce->sf_idx[w*16+g] = av_clip(scf, min_scf, max_scf);
 525                     break;
 526                 }
 527                 if (step > 0)
 528                     min_scf = prev_scf;
 529                 else
 530                     max_scf = prev_scf;
 531             }
 532             start += size;
 533         }
 534     }
 535     minq = sce->sf_idx[0] ? sce->sf_idx[0] : INT_MAX;
 536     for (i = 1; i < 128; i++) {
 537         if (!sce->sf_idx[i])
 538             sce->sf_idx[i] = sce->sf_idx[i-1];
 539         else
 540             minq = FFMIN(minq, sce->sf_idx[i]);
 541     }
 542     if (minq == INT_MAX)
 543         minq = 0;
 544     minq = FFMIN(minq, SCALE_MAX_POS);
 545     maxsf = FFMIN(minq + SCALE_MAX_DIFF, SCALE_MAX_POS);
 546     for (i = 126; i >= 0; i--) {
 547         if (!sce->sf_idx[i])
 548             sce->sf_idx[i] = sce->sf_idx[i+1];
 549         sce->sf_idx[i] = av_clip(sce->sf_idx[i], minq, maxsf);
 550     }
 551 }
 552
 553 static void search_for_quantizers_fast(AVCodecContext *avctx, AACEncContext *s,
 554                                        SingleChannelElement *sce,
 555                                        const float lambda)
 556 {
 557     int i, w, w2, g;
 558     int minq = 255;
 559
 560     memset(sce->sf_idx, 0, sizeof(sce->sf_idx));
 561     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 562         for (g = 0; g < sce->ics.num_swb; g++) {
 563             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 564                 FFPsyBand *band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 565                 if (band->energy <= band->threshold) {
 566                     sce->sf_idx[(w+w2)*16+g] = 218;
 567                     sce->zeroes[(w+w2)*16+g] = 1;
 568                 } else {
 569                     sce->sf_idx[(w+w2)*16+g] = av_clip(SCALE_ONE_POS - SCALE_DIV_512 + log2f(band->threshold), 80, 218);
 570                     sce->zeroes[(w+w2)*16+g] = 0;
 571                 }
 572                 minq = FFMIN(minq, sce->sf_idx[(w+w2)*16+g]);
 573             }
 574         }
 575     }
 576     for (i = 0; i < 128; i++) {
 577         sce->sf_idx[i] = 140;
 578         //av_clip(sce->sf_idx[i], minq, minq + SCALE_MAX_DIFF - 1);
 579     }
 580     //set the same quantizers inside window groups
 581     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w])
 582         for (g = 0;  g < sce->ics.num_swb; g++)
 583             for (w2 = 1; w2 < sce->ics.group_len[w]; w2++)
 584                 sce->sf_idx[(w+w2)*16+g] = sce->sf_idx[w*16+g];
 585 }
 586
 587 static void search_for_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
 588 {
 589     FFPsyBand *band;
 590     int w, g, w2, i;
 591     int wlen = 1024 / sce->ics.num_windows;
 592     int bandwidth, cutoff;
 593     float *PNS = &s->scoefs[0*128], *PNS34 = &s->scoefs[1*128];
 594     float *NOR34 = &s->scoefs[3*128];
 595     const float lambda = s->lambda;
 596     const float freq_mult = avctx->sample_rate*0.5f/wlen;
 597     const float thr_mult = NOISE_LAMBDA_REPLACE*(100.0f/lambda);
 598     const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f));
 599     const float dist_bias = av_clipf(4.f * 120 / lambda, 0.25f, 4.0f);
 600     const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f);
 601
 602     int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate
 603         / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels)
 604         * (lambda / 120.f);
 605
 606     /** Keep this in sync with twoloop's cutoff selection */
 607     float rate_bandwidth_multiplier = 1.5f;
 608     int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE)
 609         ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024)
 610         : (avctx->bit_rate / avctx->channels);
 611
 612     frame_bit_rate *= 1.15f;
 613
 614     if (avctx->cutoff > 0) {
 615         bandwidth = avctx->cutoff;
 616     } else {
 617         bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate));
 618     }
 619
 620     cutoff = bandwidth * 2 * wlen / avctx->sample_rate;
 621
 622     memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type));
 623     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 624         int wstart = w*128;
 625         for (g = 0;  g < sce->ics.num_swb; g++) {
 626             int noise_sfi;
 627             float dist1 = 0.0f, dist2 = 0.0f, noise_amp;
 628             float pns_energy = 0.0f, pns_tgt_energy, energy_ratio, dist_thresh;
 629             float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f;
 630             float min_energy = -1.0f, max_energy = 0.0f;
 631             const int start = wstart+sce->ics.swb_offset[g];
 632             const float freq = (start-wstart)*freq_mult;
 633             const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
 634             if (freq < NOISE_LOW_LIMIT || (start-wstart) >= cutoff)
 635                 continue;
 636             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 637                 band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 638                 sfb_energy += band->energy;
 639                 spread     = FFMIN(spread, band->spread);
 640                 threshold  += band->threshold;
 641                 if (!w2) {
 642                     min_energy = max_energy = band->energy;
 643                 } else {
 644                     min_energy = FFMIN(min_energy, band->energy);
 645                     max_energy = FFMAX(max_energy, band->energy);
 646                 }
 647             }
 648
 649             /* Ramps down at ~8000Hz and loosens the dist threshold */
 650             dist_thresh = av_clipf(2.5f*NOISE_LOW_LIMIT/freq, 0.5f, 2.5f) * dist_bias;
 651
 652             /* PNS is acceptable when all of these are true:
 653              * 1. high spread energy (noise-like band)
 654              * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed)
 655              * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS)
 656              *
 657              * At this stage, point 2 is relaxed for zeroed bands near the noise threshold (hole avoidance is more important)
 658              */
 659             if (((sce->zeroes[w*16+g] || !sce->band_alt[w*16+g]) && sfb_energy < threshold*sqrtf(1.5f/freq_boost)) || spread < spread_threshold ||
 660                 (!sce->zeroes[w*16+g] && sce->band_alt[w*16+g] && sfb_energy > threshold*thr_mult*freq_boost) ||
 661                 min_energy < pns_transient_energy_r * max_energy ) {
 662                 sce->pns_ener[w*16+g] = sfb_energy;
 663                 continue;
 664             }
 665
 666             pns_tgt_energy = sfb_energy*FFMIN(1.0f, spread*spread);
 667             noise_sfi = av_clip(roundf(log2f(pns_tgt_energy)*2), -100, 155); /* Quantize */
 668             noise_amp = -ff_aac_pow2sf_tab[noise_sfi + POW_SF2_ZERO];    /* Dequantize */
 669             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 670                 float band_energy, scale, pns_senergy;
 671                 const int start_c = (w+w2)*128+sce->ics.swb_offset[g];
 672                 band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 673                 for (i = 0; i < sce->ics.swb_sizes[g]; i++)
 674                     PNS[i] = s->random_state = lcg_random(s->random_state);
 675                 band_energy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
 676                 scale = noise_amp/sqrtf(band_energy);
 677                 s->fdsp->vector_fmul_scalar(PNS, PNS, scale, sce->ics.swb_sizes[g]);
 678                 pns_senergy = s->fdsp->scalarproduct_float(PNS, PNS, sce->ics.swb_sizes[g]);
 679                 pns_energy += pns_senergy;
 680                 abs_pow34_v(NOR34, &sce->coeffs[start_c], sce->ics.swb_sizes[g]);
 681                 abs_pow34_v(PNS34, PNS, sce->ics.swb_sizes[g]);
 682                 dist1 += quantize_band_cost(s, &sce->coeffs[start_c],
 683                                             NOR34,
 684                                             sce->ics.swb_sizes[g],
 685                                             sce->sf_idx[(w+w2)*16+g],
 686                                             sce->band_alt[(w+w2)*16+g],
 687                                             lambda/band->threshold, INFINITY, NULL, NULL, 0);
 688                 /* Estimate rd on average as 5 bits for SF, 4 for the CB, plus spread energy * lambda/thr */
 689                 dist2 += band->energy/(band->spread*band->spread)*lambda*dist_thresh/band->threshold;
 690             }
 691             if (g && sce->sf_idx[(w+w2)*16+g-1] == NOISE_BT) {
 692                 dist2 += 5;
 693             } else {
 694                 dist2 += 9;
 695             }
 696             energy_ratio = pns_tgt_energy/pns_energy; /* Compensates for quantization error */
 697             sce->pns_ener[w*16+g] = energy_ratio*pns_tgt_energy;
 698             if (sce->zeroes[w*16+g] || !sce->band_alt[w*16+g] || (energy_ratio > 0.85f && energy_ratio < 1.25f && dist2 < dist1)) {
 699                 sce->band_type[w*16+g] = NOISE_BT;
 700                 sce->zeroes[w*16+g] = 0;
 701             }
 702         }
 703     }
 704 }
 705
 706 static void mark_pns(AACEncContext *s, AVCodecContext *avctx, SingleChannelElement *sce)
 707 {
 708     FFPsyBand *band;
 709     int w, g, w2;
 710     int wlen = 1024 / sce->ics.num_windows;
 711     int bandwidth, cutoff;
 712     const float lambda = s->lambda;
 713     const float freq_mult = avctx->sample_rate*0.5f/wlen;
 714     const float spread_threshold = FFMIN(0.75f, NOISE_SPREAD_THRESHOLD*FFMAX(0.5f, lambda/100.f));
 715     const float pns_transient_energy_r = FFMIN(0.7f, lambda / 140.f);
 716
 717     int refbits = avctx->bit_rate * 1024.0 / avctx->sample_rate
 718         / ((avctx->flags & CODEC_FLAG_QSCALE) ? 2.0f : avctx->channels)
 719         * (lambda / 120.f);
 720
 721     /** Keep this in sync with twoloop's cutoff selection */
 722     float rate_bandwidth_multiplier = 1.5f;
 723     int frame_bit_rate = (avctx->flags & CODEC_FLAG_QSCALE)
 724         ? (refbits * rate_bandwidth_multiplier * avctx->sample_rate / 1024)
 725         : (avctx->bit_rate / avctx->channels);
 726
 727     frame_bit_rate *= 1.15f;
 728
 729     if (avctx->cutoff > 0) {
 730         bandwidth = avctx->cutoff;
 731     } else {
 732         bandwidth = FFMAX(3000, AAC_CUTOFF_FROM_BITRATE(frame_bit_rate, 1, avctx->sample_rate));
 733     }
 734
 735     cutoff = bandwidth * 2 * wlen / avctx->sample_rate;
 736
 737     memcpy(sce->band_alt, sce->band_type, sizeof(sce->band_type));
 738     for (w = 0; w < sce->ics.num_windows; w += sce->ics.group_len[w]) {
 739         for (g = 0;  g < sce->ics.num_swb; g++) {
 740             float sfb_energy = 0.0f, threshold = 0.0f, spread = 2.0f;
 741             float min_energy = -1.0f, max_energy = 0.0f;
 742             const int start = sce->ics.swb_offset[g];
 743             const float freq = start*freq_mult;
 744             const float freq_boost = FFMAX(0.88f*freq/NOISE_LOW_LIMIT, 1.0f);
 745             if (freq < NOISE_LOW_LIMIT || start >= cutoff) {
 746                 sce->can_pns[w*16+g] = 0;
 747                 continue;
 748             }
 749             for (w2 = 0; w2 < sce->ics.group_len[w]; w2++) {
 750                 band = &s->psy.ch[s->cur_channel].psy_bands[(w+w2)*16+g];
 751                 sfb_energy += band->energy;
 752                 spread     = FFMIN(spread, band->spread);
 753                 threshold  += band->threshold;
 754                 if (!w2) {
 755                     min_energy = max_energy = band->energy;
 756                 } else {
 757                     min_energy = FFMIN(min_energy, band->energy);
 758                     max_energy = FFMAX(max_energy, band->energy);
 759                 }
 760             }
 761
 762             /* PNS is acceptable when all of these are true:
 763              * 1. high spread energy (noise-like band)
 764              * 2. near-threshold energy (high PE means the random nature of PNS content will be noticed)
 765              * 3. on short window groups, all windows have similar energy (variations in energy would be destroyed by PNS)
 766              */
 767             sce->pns_ener[w*16+g] = sfb_energy;
 768             if (sfb_energy < threshold*sqrtf(1.5f/freq_boost) || spread < spread_threshold || min_energy < pns_transient_energy_r * max_energy) {
 769                 sce->can_pns[w*16+g] = 0;
 770             } else {
 771                 sce->can_pns[w*16+g] = 1;
 772             }
 773         }
 774     }
 775 }
 776
 777 static void search_for_ms(AACEncContext *s, ChannelElement *cpe)
 778 {
 779     int start = 0, i, w, w2, g, sid_sf_boost;
 780     float M[128], S[128];
 781     float *L34 = s->scoefs, *R34 = s->scoefs + 128, *M34 = s->scoefs + 128*2, *S34 = s->scoefs + 128*3;
 782     const float lambda = s->lambda;
 783     const float mslambda = FFMIN(1.0f, lambda / 120.f);
 784     SingleChannelElement *sce0 = &cpe->ch[0];
 785     SingleChannelElement *sce1 = &cpe->ch[1];
 786     if (!cpe->common_window)
 787         return;
 788     for (w = 0; w < sce0->ics.num_windows; w += sce0->ics.group_len[w]) {
 789         int min_sf_idx_mid = SCALE_MAX_POS;
 790         int min_sf_idx_side = SCALE_MAX_POS;
 791         for (g = 0; g < sce0->ics.num_swb; g++) {
 792             if (!sce0->zeroes[w*16+g] && sce0->band_type[w*16+g] < RESERVED_BT)
 793                 min_sf_idx_mid = FFMIN(min_sf_idx_mid, sce0->sf_idx[w*16+g]);
 794             if (!sce1->zeroes[w*16+g] && sce1->band_type[w*16+g] < RESERVED_BT)
 795                 min_sf_idx_side = FFMIN(min_sf_idx_side, sce1->sf_idx[w*16+g]);
 796         }
 797
 798         start = 0;
 799         for (g = 0;  g < sce0->ics.num_swb; g++) {
 800             float bmax = bval2bmax(g * 17.0f / sce0->ics.num_swb) / 0.0045f;
 801             cpe->ms_mask[w*16+g] = 0;
 802             if (!cpe->ch[0].zeroes[w*16+g] && !cpe->ch[1].zeroes[w*16+g]) {
 803                 float Mmax = 0.0f, Smax = 0.0f;
 804
 805                 /* Must compute mid/side SF and book for the whole window group */
 806                 for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
 807                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
 808                         M[i] = (sce0->coeffs[start+(w+w2)*128+i]
 809                               + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
 810                         S[i] =  M[i]
 811                               - sce1->coeffs[start+(w+w2)*128+i];
 812                     }
 813                     abs_pow34_v(M34, M, sce0->ics.swb_sizes[g]);
 814                     abs_pow34_v(S34, S, sce0->ics.swb_sizes[g]);
 815                     for (i = 0; i < sce0->ics.swb_sizes[g]; i++ ) {
 816                         Mmax = FFMAX(Mmax, M34[i]);
 817                         Smax = FFMAX(Smax, S34[i]);
 818                     }
 819                 }
 820
 821                 for (sid_sf_boost = 0; sid_sf_boost < 4; sid_sf_boost++) {
 822                     float dist1 = 0.0f, dist2 = 0.0f;
 823                     int B0 = 0, B1 = 0;
 824                     int minidx;
 825                     int mididx, sididx;
 826                     int midcb, sidcb;
 827
 828                     minidx = FFMIN(sce0->sf_idx[w*16+g], sce1->sf_idx[w*16+g]);
 829                     mididx = av_clip(minidx, min_sf_idx_mid, min_sf_idx_mid + SCALE_MAX_DIFF);
 830                     sididx = av_clip(minidx - sid_sf_boost * 3, min_sf_idx_side, min_sf_idx_side + SCALE_MAX_DIFF);
 831                     midcb = find_min_book(Mmax, mididx);
 832                     sidcb = find_min_book(Smax, sididx);
 833
 834                     if ((mididx > minidx) || (sididx > minidx)) {
 835                         /* scalefactor range violation, bad stuff, will decrease quality unacceptably */
 836                         continue;
 837                     }
 838
 839                     /* No CB can be zero */
 840                     midcb = FFMAX(1,midcb);
 841                     sidcb = FFMAX(1,sidcb);
 842
 843                     for (w2 = 0; w2 < sce0->ics.group_len[w]; w2++) {
 844                         FFPsyBand *band0 = &s->psy.ch[s->cur_channel+0].psy_bands[(w+w2)*16+g];
 845                         FFPsyBand *band1 = &s->psy.ch[s->cur_channel+1].psy_bands[(w+w2)*16+g];
 846                         float minthr = FFMIN(band0->threshold, band1->threshold);
 847                         int b1,b2,b3,b4;
 848                         for (i = 0; i < sce0->ics.swb_sizes[g]; i++) {
 849                             M[i] = (sce0->coeffs[start+(w+w2)*128+i]
 850                                   + sce1->coeffs[start+(w+w2)*128+i]) * 0.5;
 851                             S[i] =  M[i]
 852                                   - sce1->coeffs[start+(w+w2)*128+i];
 853                         }
 854
 855                         abs_pow34_v(L34, sce0->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
 856                         abs_pow34_v(R34, sce1->coeffs+start+(w+w2)*128, sce0->ics.swb_sizes[g]);
 857                         abs_pow34_v(M34, M,                         sce0->ics.swb_sizes[g]);
 858                         abs_pow34_v(S34, S,                         sce0->ics.swb_sizes[g]);
 859                         dist1 += quantize_band_cost(s, &sce0->coeffs[start + (w+w2)*128],
 860                                                     L34,
 861                                                     sce0->ics.swb_sizes[g],
 862                                                     sce0->sf_idx[(w+w2)*16+g],
 863                                                     sce0->band_type[(w+w2)*16+g],
 864                                                     lambda / band0->threshold, INFINITY, &b1, NULL, 0);
 865                         dist1 += quantize_band_cost(s, &sce1->coeffs[start + (w+w2)*128],
 866                                                     R34,
 867                                                     sce1->ics.swb_sizes[g],
 868                                                     sce1->sf_idx[(w+w2)*16+g],
 869                                                     sce1->band_type[(w+w2)*16+g],
 870                                                     lambda / band1->threshold, INFINITY, &b2, NULL, 0);
 871                         dist2 += quantize_band_cost(s, M,
 872                                                     M34,
 873                                                     sce0->ics.swb_sizes[g],
 874                                                     sce0->sf_idx[(w+w2)*16+g],
 875                                                     sce0->band_type[(w+w2)*16+g],
 876                                                     lambda / minthr, INFINITY, &b3, NULL, 0);
 877                         dist2 += quantize_band_cost(s, S,
 878                                                     S34,
 879                                                     sce1->ics.swb_sizes[g],
 880                                                     sce1->sf_idx[(w+w2)*16+g],
 881                                                     sce1->band_type[(w+w2)*16+g],
 882                                                     mslambda / (minthr * bmax), INFINITY, &b4, NULL, 0);
 883                         B0 += b1+b2;
 884                         B1 += b3+b4;
 885                         dist1 -= B0;
 886                         dist2 -= B1;
 887                     }
 888                     cpe->ms_mask[w*16+g] = dist2 <= dist1 && B1 < B0;
 889                     if (cpe->ms_mask[w*16+g]) {
 890                         /* Setting the M/S mask is useful with I/S, but only the flag */
 891                         if (!cpe->is_mask[w*16+g]) {
 892                             sce0->sf_idx[w*16+g] = mididx;
 893                             sce1->sf_idx[w*16+g] = sididx;
 894                             sce0->band_type[w*16+g] = midcb;
 895                             sce1->band_type[w*16+g] = sidcb;
 896                         }
 897                         break;
 898                     } else if (B1 > B0) {
 899                         /* More boost won't fix this */
 900                         break;
 901                     }
 902                 }
 903             }
 904             start += sce0->ics.swb_sizes[g];
 905         }
 906     }
 907 }
 908
 909 AACCoefficientsEncoder ff_aac_coders[AAC_CODER_NB] = {
 910     [AAC_CODER_FAAC] = {
 911         search_for_quantizers_faac,
 912         encode_window_bands_info,
 913         quantize_and_encode_band,
 914         ff_aac_encode_tns_info,
 915         ff_aac_encode_ltp_info,
 916         ff_aac_encode_main_pred,
 917         ff_aac_adjust_common_pred,
 918         ff_aac_adjust_common_ltp,
 919         ff_aac_apply_main_pred,
 920         ff_aac_apply_tns,
 921         ff_aac_update_ltp,
 922         ff_aac_ltp_insert_new_frame,
 923         set_special_band_scalefactors,
 924         search_for_pns,
 925         mark_pns,
 926         ff_aac_search_for_tns,
 927         ff_aac_search_for_ltp,
 928         search_for_ms,
 929         ff_aac_search_for_is,
 930         ff_aac_search_for_pred,
 931     },
 932     [AAC_CODER_ANMR] = {
 933         search_for_quantizers_anmr,
 934         encode_window_bands_info,
 935         quantize_and_encode_band,
 936         ff_aac_encode_tns_info,
 937         ff_aac_encode_ltp_info,
 938         ff_aac_encode_main_pred,
 939         ff_aac_adjust_common_pred,
 940         ff_aac_adjust_common_ltp,
 941         ff_aac_apply_main_pred,
 942         ff_aac_apply_tns,
 943         ff_aac_update_ltp,
 944         ff_aac_ltp_insert_new_frame,
 945         set_special_band_scalefactors,
 946         search_for_pns,
 947         mark_pns,
 948         ff_aac_search_for_tns,
 949         ff_aac_search_for_ltp,
 950         search_for_ms,
 951         ff_aac_search_for_is,
 952         ff_aac_search_for_pred,
 953     },
 954     [AAC_CODER_TWOLOOP] = {
 955         search_for_quantizers_twoloop,
 956         codebook_trellis_rate,
 957         quantize_and_encode_band,
 958         ff_aac_encode_tns_info,
 959         ff_aac_encode_ltp_info,
 960         ff_aac_encode_main_pred,
 961         ff_aac_adjust_common_pred,
 962         ff_aac_adjust_common_ltp,
 963         ff_aac_apply_main_pred,
 964         ff_aac_apply_tns,
 965         ff_aac_update_ltp,
 966         ff_aac_ltp_insert_new_frame,
 967         set_special_band_scalefactors,
 968         search_for_pns,
 969         mark_pns,
 970         ff_aac_search_for_tns,
 971         ff_aac_search_for_ltp,
 972         search_for_ms,
 973         ff_aac_search_for_is,
 974         ff_aac_search_for_pred,
 975     },
 976     [AAC_CODER_FAST] = {
 977         search_for_quantizers_fast,
 978         encode_window_bands_info,
 979         quantize_and_encode_band,
 980         ff_aac_encode_tns_info,
 981         ff_aac_encode_ltp_info,
 982         ff_aac_encode_main_pred,
 983         ff_aac_adjust_common_pred,
 984         ff_aac_adjust_common_ltp,
 985         ff_aac_apply_main_pred,
 986         ff_aac_apply_tns,
 987         ff_aac_update_ltp,
 988         ff_aac_ltp_insert_new_frame,
 989         set_special_band_scalefactors,
 990         search_for_pns,
 991         mark_pns,
 992         ff_aac_search_for_tns,
 993         ff_aac_search_for_ltp,
 994         search_for_ms,
 995         ff_aac_search_for_is,
 996         ff_aac_search_for_pred,
 997     },
 998 };