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