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1 /*
2  * Copyright (c) 2016 Kyle Swanson <k@ylo.ph>.
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 /* http://k.ylo.ph/2016/04/04/loudnorm.html */
22 
23 #include "libavutil/opt.h"
24 #include "avfilter.h"
25 #include "internal.h"
26 #include "audio.h"
27 #include "ebur128.h"
28 
29 enum FrameType {
30     FIRST_FRAME,
31     INNER_FRAME,
32     FINAL_FRAME,
33     LINEAR_MODE,
34     FRAME_NB
35 };
36 
37 enum LimiterState {
38     OUT,
39     ATTACK,
40     SUSTAIN,
41     RELEASE,
42     STATE_NB
43 };
44 
45 enum PrintFormat {
46     NONE,
47     JSON,
48     SUMMARY,
49     PF_NB
50 };
51 
52 typedef struct LoudNormContext {
53     const AVClass *class;
54     double target_i;
55     double target_lra;
56     double target_tp;
57     double measured_i;
58     double measured_lra;
59     double measured_tp;
60     double measured_thresh;
61     double offset;
62     int linear;
63     int dual_mono;
64     enum PrintFormat print_format;
65 
66     double *buf;
67     int buf_size;
68     int buf_index;
69     int prev_buf_index;
70 
71     double delta[30];
72     double weights[21];
73     double prev_delta;
74     int index;
75 
76     double gain_reduction[2];
77     double *limiter_buf;
78     double *prev_smp;
79     int limiter_buf_index;
80     int limiter_buf_size;
81     enum LimiterState limiter_state;
82     int peak_index;
83     int env_index;
84     int env_cnt;
85     int attack_length;
86     int release_length;
87 
88     int64_t pts;
89     enum FrameType frame_type;
90     int above_threshold;
91     int prev_nb_samples;
92     int channels;
93 
94     FFEBUR128State *r128_in;
95     FFEBUR128State *r128_out;
96 } LoudNormContext;
97 
98 #define OFFSET(x) offsetof(LoudNormContext, x)
99 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
100 
101 static const AVOption loudnorm_options[] = {
102     { "I",                "set integrated loudness target",    OFFSET(target_i),         AV_OPT_TYPE_DOUBLE,  {.dbl = -24.},   -70.,       -5.,  FLAGS },
103     { "i",                "set integrated loudness target",    OFFSET(target_i),         AV_OPT_TYPE_DOUBLE,  {.dbl = -24.},   -70.,       -5.,  FLAGS },
104     { "LRA",              "set loudness range target",         OFFSET(target_lra),       AV_OPT_TYPE_DOUBLE,  {.dbl =  7.},     1.,        50.,  FLAGS },
105     { "lra",              "set loudness range target",         OFFSET(target_lra),       AV_OPT_TYPE_DOUBLE,  {.dbl =  7.},     1.,        50.,  FLAGS },
106     { "TP",               "set maximum true peak",             OFFSET(target_tp),        AV_OPT_TYPE_DOUBLE,  {.dbl = -2.},    -9.,         0.,  FLAGS },
107     { "tp",               "set maximum true peak",             OFFSET(target_tp),        AV_OPT_TYPE_DOUBLE,  {.dbl = -2.},    -9.,         0.,  FLAGS },
108     { "measured_I",       "measured IL of input file",         OFFSET(measured_i),       AV_OPT_TYPE_DOUBLE,  {.dbl =  0.},    -99.,        0.,  FLAGS },
109     { "measured_i",       "measured IL of input file",         OFFSET(measured_i),       AV_OPT_TYPE_DOUBLE,  {.dbl =  0.},    -99.,        0.,  FLAGS },
110     { "measured_LRA",     "measured LRA of input file",        OFFSET(measured_lra),     AV_OPT_TYPE_DOUBLE,  {.dbl =  0.},     0.,        99.,  FLAGS },
111     { "measured_lra",     "measured LRA of input file",        OFFSET(measured_lra),     AV_OPT_TYPE_DOUBLE,  {.dbl =  0.},     0.,        99.,  FLAGS },
112     { "measured_TP",      "measured true peak of input file",  OFFSET(measured_tp),      AV_OPT_TYPE_DOUBLE,  {.dbl =  99.},   -99.,       99.,  FLAGS },
113     { "measured_tp",      "measured true peak of input file",  OFFSET(measured_tp),      AV_OPT_TYPE_DOUBLE,  {.dbl =  99.},   -99.,       99.,  FLAGS },
114     { "measured_thresh",  "measured threshold of input file",  OFFSET(measured_thresh),  AV_OPT_TYPE_DOUBLE,  {.dbl = -70.},   -99.,        0.,  FLAGS },
115     { "offset",           "set offset gain",                   OFFSET(offset),           AV_OPT_TYPE_DOUBLE,  {.dbl =  0.},    -99.,       99.,  FLAGS },
116     { "linear",           "normalize linearly if possible",    OFFSET(linear),           AV_OPT_TYPE_BOOL,    {.i64 =  1},        0,         1,  FLAGS },
117     { "dual_mono",        "treat mono input as dual-mono",     OFFSET(dual_mono),        AV_OPT_TYPE_BOOL,    {.i64 =  0},        0,         1,  FLAGS },
118     { "print_format",     "set print format for stats",        OFFSET(print_format),     AV_OPT_TYPE_INT,     {.i64 =  NONE},  NONE,  PF_NB -1,  FLAGS, "print_format" },
119     {     "none",         0,                                   0,                        AV_OPT_TYPE_CONST,   {.i64 =  NONE},     0,         0,  FLAGS, "print_format" },
120     {     "json",         0,                                   0,                        AV_OPT_TYPE_CONST,   {.i64 =  JSON},     0,         0,  FLAGS, "print_format" },
121     {     "summary",      0,                                   0,                        AV_OPT_TYPE_CONST,   {.i64 =  SUMMARY},  0,         0,  FLAGS, "print_format" },
122     { NULL }
123 };
124 
125 AVFILTER_DEFINE_CLASS(loudnorm);
126 
frame_size(int sample_rate,int frame_len_msec)127 static inline int frame_size(int sample_rate, int frame_len_msec)
128 {
129     const int frame_size = round((double)sample_rate * (frame_len_msec / 1000.0));
130     return frame_size + (frame_size % 2);
131 }
132 
init_gaussian_filter(LoudNormContext * s)133 static void init_gaussian_filter(LoudNormContext *s)
134 {
135     double total_weight = 0.0;
136     const double sigma = 3.5;
137     double adjust;
138     int i;
139 
140     const int offset = 21 / 2;
141     const double c1 = 1.0 / (sigma * sqrt(2.0 * M_PI));
142     const double c2 = 2.0 * pow(sigma, 2.0);
143 
144     for (i = 0; i < 21; i++) {
145         const int x = i - offset;
146         s->weights[i] = c1 * exp(-(pow(x, 2.0) / c2));
147         total_weight += s->weights[i];
148     }
149 
150     adjust = 1.0 / total_weight;
151     for (i = 0; i < 21; i++)
152         s->weights[i] *= adjust;
153 }
154 
gaussian_filter(LoudNormContext * s,int index)155 static double gaussian_filter(LoudNormContext *s, int index)
156 {
157     double result = 0.;
158     int i;
159 
160     index = index - 10 > 0 ? index - 10 : index + 20;
161     for (i = 0; i < 21; i++)
162         result += s->delta[((index + i) < 30) ? (index + i) : (index + i - 30)] * s->weights[i];
163 
164     return result;
165 }
166 
detect_peak(LoudNormContext * s,int offset,int nb_samples,int channels,int * peak_delta,double * peak_value)167 static void detect_peak(LoudNormContext *s, int offset, int nb_samples, int channels, int *peak_delta, double *peak_value)
168 {
169     int n, c, i, index;
170     double ceiling;
171     double *buf;
172 
173     *peak_delta = -1;
174     buf = s->limiter_buf;
175     ceiling = s->target_tp;
176 
177     index = s->limiter_buf_index + (offset * channels) + (1920 * channels);
178     if (index >= s->limiter_buf_size)
179         index -= s->limiter_buf_size;
180 
181     if (s->frame_type == FIRST_FRAME) {
182         for (c = 0; c < channels; c++)
183             s->prev_smp[c] = fabs(buf[index + c - channels]);
184     }
185 
186     for (n = 0; n < nb_samples; n++) {
187         for (c = 0; c < channels; c++) {
188             double this, next, max_peak;
189 
190             this = fabs(buf[(index + c) < s->limiter_buf_size ? (index + c) : (index + c - s->limiter_buf_size)]);
191             next = fabs(buf[(index + c + channels) < s->limiter_buf_size ? (index + c + channels) : (index + c + channels - s->limiter_buf_size)]);
192 
193             if ((s->prev_smp[c] <= this) && (next <= this) && (this > ceiling) && (n > 0)) {
194                 int detected;
195 
196                 detected = 1;
197                 for (i = 2; i < 12; i++) {
198                     next = fabs(buf[(index + c + (i * channels)) < s->limiter_buf_size ? (index + c + (i * channels)) : (index + c + (i * channels) - s->limiter_buf_size)]);
199                     if (next > this) {
200                         detected = 0;
201                         break;
202                     }
203                 }
204 
205                 if (!detected)
206                     continue;
207 
208                 for (c = 0; c < channels; c++) {
209                     if (c == 0 || fabs(buf[index + c]) > max_peak)
210                         max_peak = fabs(buf[index + c]);
211 
212                     s->prev_smp[c] = fabs(buf[(index + c) < s->limiter_buf_size ? (index + c) : (index + c - s->limiter_buf_size)]);
213                 }
214 
215                 *peak_delta = n;
216                 s->peak_index = index;
217                 *peak_value = max_peak;
218                 return;
219             }
220 
221             s->prev_smp[c] = this;
222         }
223 
224         index += channels;
225         if (index >= s->limiter_buf_size)
226             index -= s->limiter_buf_size;
227     }
228 }
229 
true_peak_limiter(LoudNormContext * s,double * out,int nb_samples,int channels)230 static void true_peak_limiter(LoudNormContext *s, double *out, int nb_samples, int channels)
231 {
232     int n, c, index, peak_delta, smp_cnt;
233     double ceiling, peak_value;
234     double *buf;
235 
236     buf = s->limiter_buf;
237     ceiling = s->target_tp;
238     index = s->limiter_buf_index;
239     smp_cnt = 0;
240 
241     if (s->frame_type == FIRST_FRAME) {
242         double max;
243 
244         max = 0.;
245         for (n = 0; n < 1920; n++) {
246             for (c = 0; c < channels; c++) {
247               max = fabs(buf[c]) > max ? fabs(buf[c]) : max;
248             }
249             buf += channels;
250         }
251 
252         if (max > ceiling) {
253             s->gain_reduction[1] = ceiling / max;
254             s->limiter_state = SUSTAIN;
255             buf = s->limiter_buf;
256 
257             for (n = 0; n < 1920; n++) {
258                 for (c = 0; c < channels; c++) {
259                     double env;
260                     env = s->gain_reduction[1];
261                     buf[c] *= env;
262                 }
263                 buf += channels;
264             }
265         }
266 
267         buf = s->limiter_buf;
268     }
269 
270     do {
271 
272         switch(s->limiter_state) {
273         case OUT:
274             detect_peak(s, smp_cnt, nb_samples - smp_cnt, channels, &peak_delta, &peak_value);
275             if (peak_delta != -1) {
276                 s->env_cnt = 0;
277                 smp_cnt += (peak_delta - s->attack_length);
278                 s->gain_reduction[0] = 1.;
279                 s->gain_reduction[1] = ceiling / peak_value;
280                 s->limiter_state = ATTACK;
281 
282                 s->env_index = s->peak_index - (s->attack_length * channels);
283                 if (s->env_index < 0)
284                     s->env_index += s->limiter_buf_size;
285 
286                 s->env_index += (s->env_cnt * channels);
287                 if (s->env_index > s->limiter_buf_size)
288                     s->env_index -= s->limiter_buf_size;
289 
290             } else {
291                 smp_cnt = nb_samples;
292             }
293             break;
294 
295         case ATTACK:
296             for (; s->env_cnt < s->attack_length; s->env_cnt++) {
297                 for (c = 0; c < channels; c++) {
298                     double env;
299                     env = s->gain_reduction[0] - ((double) s->env_cnt / (s->attack_length - 1) * (s->gain_reduction[0] - s->gain_reduction[1]));
300                     buf[s->env_index + c] *= env;
301                 }
302 
303                 s->env_index += channels;
304                 if (s->env_index >= s->limiter_buf_size)
305                     s->env_index -= s->limiter_buf_size;
306 
307                 smp_cnt++;
308                 if (smp_cnt >= nb_samples) {
309                     s->env_cnt++;
310                     break;
311                 }
312             }
313 
314             if (smp_cnt < nb_samples) {
315                 s->env_cnt = 0;
316                 s->attack_length = 1920;
317                 s->limiter_state = SUSTAIN;
318             }
319             break;
320 
321         case SUSTAIN:
322             detect_peak(s, smp_cnt, nb_samples, channels, &peak_delta, &peak_value);
323             if (peak_delta == -1) {
324                 s->limiter_state = RELEASE;
325                 s->gain_reduction[0] = s->gain_reduction[1];
326                 s->gain_reduction[1] = 1.;
327                 s->env_cnt = 0;
328                 break;
329             } else {
330                 double gain_reduction;
331                 gain_reduction = ceiling / peak_value;
332 
333                 if (gain_reduction < s->gain_reduction[1]) {
334                     s->limiter_state = ATTACK;
335 
336                     s->attack_length = peak_delta;
337                     if (s->attack_length <= 1)
338                         s->attack_length =  2;
339 
340                     s->gain_reduction[0] = s->gain_reduction[1];
341                     s->gain_reduction[1] = gain_reduction;
342                     s->env_cnt = 0;
343                     break;
344                 }
345 
346                 for (s->env_cnt = 0; s->env_cnt < peak_delta; s->env_cnt++) {
347                     for (c = 0; c < channels; c++) {
348                         double env;
349                         env = s->gain_reduction[1];
350                         buf[s->env_index + c] *= env;
351                     }
352 
353                     s->env_index += channels;
354                     if (s->env_index >= s->limiter_buf_size)
355                         s->env_index -= s->limiter_buf_size;
356 
357                     smp_cnt++;
358                     if (smp_cnt >= nb_samples) {
359                         s->env_cnt++;
360                         break;
361                     }
362                 }
363             }
364             break;
365 
366         case RELEASE:
367             for (; s->env_cnt < s->release_length; s->env_cnt++) {
368                 for (c = 0; c < channels; c++) {
369                     double env;
370                     env = s->gain_reduction[0] + (((double) s->env_cnt / (s->release_length - 1)) * (s->gain_reduction[1] - s->gain_reduction[0]));
371                     buf[s->env_index + c] *= env;
372                 }
373 
374                 s->env_index += channels;
375                 if (s->env_index >= s->limiter_buf_size)
376                     s->env_index -= s->limiter_buf_size;
377 
378                 smp_cnt++;
379                 if (smp_cnt >= nb_samples) {
380                     s->env_cnt++;
381                     break;
382                 }
383             }
384 
385             if (smp_cnt < nb_samples) {
386                 s->env_cnt = 0;
387                 s->limiter_state = OUT;
388             }
389 
390             break;
391         }
392 
393     } while (smp_cnt < nb_samples);
394 
395     for (n = 0; n < nb_samples; n++) {
396         for (c = 0; c < channels; c++) {
397             out[c] = buf[index + c];
398             if (fabs(out[c]) > ceiling) {
399                 out[c] = ceiling * (out[c] < 0 ? -1 : 1);
400             }
401         }
402         out += channels;
403         index += channels;
404         if (index >= s->limiter_buf_size)
405             index -= s->limiter_buf_size;
406     }
407 }
408 
filter_frame(AVFilterLink * inlink,AVFrame * in)409 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
410 {
411     AVFilterContext *ctx = inlink->dst;
412     LoudNormContext *s = ctx->priv;
413     AVFilterLink *outlink = ctx->outputs[0];
414     AVFrame *out;
415     const double *src;
416     double *dst;
417     double *buf;
418     double *limiter_buf;
419     int i, n, c, subframe_length, src_index;
420     double gain, gain_next, env_global, env_shortterm,
421     global, shortterm, lra, relative_threshold;
422 
423     if (av_frame_is_writable(in)) {
424         out = in;
425     } else {
426         out = ff_get_audio_buffer(outlink, in->nb_samples);
427         if (!out) {
428             av_frame_free(&in);
429             return AVERROR(ENOMEM);
430         }
431         av_frame_copy_props(out, in);
432     }
433 
434     if (s->pts == AV_NOPTS_VALUE)
435         s->pts = in->pts;
436 
437     out->pts = s->pts;
438     src = (const double *)in->data[0];
439     dst = (double *)out->data[0];
440     buf = s->buf;
441     limiter_buf = s->limiter_buf;
442 
443     ff_ebur128_add_frames_double(s->r128_in, src, in->nb_samples);
444 
445     if (s->frame_type == FIRST_FRAME && in->nb_samples < frame_size(inlink->sample_rate, 3000)) {
446         double offset, offset_tp, true_peak;
447 
448         ff_ebur128_loudness_global(s->r128_in, &global);
449         for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
450             double tmp;
451             ff_ebur128_sample_peak(s->r128_in, c, &tmp);
452             if (c == 0 || tmp > true_peak)
453                 true_peak = tmp;
454         }
455 
456         offset    = pow(10., (s->target_i - global) / 20.);
457         offset_tp = true_peak * offset;
458         s->offset = offset_tp < s->target_tp ? offset : s->target_tp - true_peak;
459         s->frame_type = LINEAR_MODE;
460     }
461 
462     switch (s->frame_type) {
463     case FIRST_FRAME:
464         for (n = 0; n < in->nb_samples; n++) {
465             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
466                 buf[s->buf_index + c] = src[c];
467             }
468             src += inlink->ch_layout.nb_channels;
469             s->buf_index += inlink->ch_layout.nb_channels;
470         }
471 
472         ff_ebur128_loudness_shortterm(s->r128_in, &shortterm);
473 
474         if (shortterm < s->measured_thresh) {
475             s->above_threshold = 0;
476             env_shortterm = shortterm <= -70. ? 0. : s->target_i - s->measured_i;
477         } else {
478             s->above_threshold = 1;
479             env_shortterm = shortterm <= -70. ? 0. : s->target_i - shortterm;
480         }
481 
482         for (n = 0; n < 30; n++)
483             s->delta[n] = pow(10., env_shortterm / 20.);
484         s->prev_delta = s->delta[s->index];
485 
486         s->buf_index =
487         s->limiter_buf_index = 0;
488 
489         for (n = 0; n < (s->limiter_buf_size / inlink->ch_layout.nb_channels); n++) {
490             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
491                 limiter_buf[s->limiter_buf_index + c] = buf[s->buf_index + c] * s->delta[s->index] * s->offset;
492             }
493             s->limiter_buf_index += inlink->ch_layout.nb_channels;
494             if (s->limiter_buf_index >= s->limiter_buf_size)
495                 s->limiter_buf_index -= s->limiter_buf_size;
496 
497             s->buf_index += inlink->ch_layout.nb_channels;
498         }
499 
500         subframe_length = frame_size(inlink->sample_rate, 100);
501         true_peak_limiter(s, dst, subframe_length, inlink->ch_layout.nb_channels);
502         ff_ebur128_add_frames_double(s->r128_out, dst, subframe_length);
503 
504         s->pts +=
505         out->nb_samples =
506         inlink->min_samples =
507         inlink->max_samples = subframe_length;
508 
509         s->frame_type = INNER_FRAME;
510         break;
511 
512     case INNER_FRAME:
513         gain      = gaussian_filter(s, s->index + 10 < 30 ? s->index + 10 : s->index + 10 - 30);
514         gain_next = gaussian_filter(s, s->index + 11 < 30 ? s->index + 11 : s->index + 11 - 30);
515 
516         for (n = 0; n < in->nb_samples; n++) {
517             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
518                 buf[s->prev_buf_index + c] = src[c];
519                 limiter_buf[s->limiter_buf_index + c] = buf[s->buf_index + c] * (gain + (((double) n / in->nb_samples) * (gain_next - gain))) * s->offset;
520             }
521             src += inlink->ch_layout.nb_channels;
522 
523             s->limiter_buf_index += inlink->ch_layout.nb_channels;
524             if (s->limiter_buf_index >= s->limiter_buf_size)
525                 s->limiter_buf_index -= s->limiter_buf_size;
526 
527             s->prev_buf_index += inlink->ch_layout.nb_channels;
528             if (s->prev_buf_index >= s->buf_size)
529                 s->prev_buf_index -= s->buf_size;
530 
531             s->buf_index += inlink->ch_layout.nb_channels;
532             if (s->buf_index >= s->buf_size)
533                 s->buf_index -= s->buf_size;
534         }
535 
536         subframe_length = (frame_size(inlink->sample_rate, 100) - in->nb_samples) * inlink->ch_layout.nb_channels;
537         s->limiter_buf_index = s->limiter_buf_index + subframe_length < s->limiter_buf_size ? s->limiter_buf_index + subframe_length : s->limiter_buf_index + subframe_length - s->limiter_buf_size;
538 
539         true_peak_limiter(s, dst, in->nb_samples, inlink->ch_layout.nb_channels);
540         ff_ebur128_add_frames_double(s->r128_out, dst, in->nb_samples);
541 
542         ff_ebur128_loudness_range(s->r128_in, &lra);
543         ff_ebur128_loudness_global(s->r128_in, &global);
544         ff_ebur128_loudness_shortterm(s->r128_in, &shortterm);
545         ff_ebur128_relative_threshold(s->r128_in, &relative_threshold);
546 
547         if (s->above_threshold == 0) {
548             double shortterm_out;
549 
550             if (shortterm > s->measured_thresh)
551                 s->prev_delta *= 1.0058;
552 
553             ff_ebur128_loudness_shortterm(s->r128_out, &shortterm_out);
554             if (shortterm_out >= s->target_i)
555                 s->above_threshold = 1;
556         }
557 
558         if (shortterm < relative_threshold || shortterm <= -70. || s->above_threshold == 0) {
559             s->delta[s->index] = s->prev_delta;
560         } else {
561             env_global = fabs(shortterm - global) < (s->target_lra / 2.) ? shortterm - global : (s->target_lra / 2.) * ((shortterm - global) < 0 ? -1 : 1);
562             env_shortterm = s->target_i - shortterm;
563             s->delta[s->index] = pow(10., (env_global + env_shortterm) / 20.);
564         }
565 
566         s->prev_delta = s->delta[s->index];
567         s->index++;
568         if (s->index >= 30)
569             s->index -= 30;
570         s->prev_nb_samples = in->nb_samples;
571         s->pts += in->nb_samples;
572         break;
573 
574     case FINAL_FRAME:
575         gain = gaussian_filter(s, s->index + 10 < 30 ? s->index + 10 : s->index + 10 - 30);
576         s->limiter_buf_index = 0;
577         src_index = 0;
578 
579         for (n = 0; n < s->limiter_buf_size / inlink->ch_layout.nb_channels; n++) {
580             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
581                 s->limiter_buf[s->limiter_buf_index + c] = src[src_index + c] * gain * s->offset;
582             }
583             src_index += inlink->ch_layout.nb_channels;
584 
585             s->limiter_buf_index += inlink->ch_layout.nb_channels;
586             if (s->limiter_buf_index >= s->limiter_buf_size)
587                 s->limiter_buf_index -= s->limiter_buf_size;
588         }
589 
590         subframe_length = frame_size(inlink->sample_rate, 100);
591         for (i = 0; i < in->nb_samples / subframe_length; i++) {
592             true_peak_limiter(s, dst, subframe_length, inlink->ch_layout.nb_channels);
593 
594             for (n = 0; n < subframe_length; n++) {
595                 for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
596                     if (src_index < (in->nb_samples * inlink->ch_layout.nb_channels)) {
597                         limiter_buf[s->limiter_buf_index + c] = src[src_index + c] * gain * s->offset;
598                     } else {
599                         limiter_buf[s->limiter_buf_index + c] = 0.;
600                     }
601                 }
602 
603                 if (src_index < (in->nb_samples * inlink->ch_layout.nb_channels))
604                     src_index += inlink->ch_layout.nb_channels;
605 
606                 s->limiter_buf_index += inlink->ch_layout.nb_channels;
607                 if (s->limiter_buf_index >= s->limiter_buf_size)
608                     s->limiter_buf_index -= s->limiter_buf_size;
609             }
610 
611             dst += (subframe_length * inlink->ch_layout.nb_channels);
612         }
613 
614         dst = (double *)out->data[0];
615         ff_ebur128_add_frames_double(s->r128_out, dst, in->nb_samples);
616         break;
617 
618     case LINEAR_MODE:
619         for (n = 0; n < in->nb_samples; n++) {
620             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
621                 dst[c] = src[c] * s->offset;
622             }
623             src += inlink->ch_layout.nb_channels;
624             dst += inlink->ch_layout.nb_channels;
625         }
626 
627         dst = (double *)out->data[0];
628         ff_ebur128_add_frames_double(s->r128_out, dst, in->nb_samples);
629         s->pts += in->nb_samples;
630         break;
631     }
632 
633     if (in != out)
634         av_frame_free(&in);
635 
636     return ff_filter_frame(outlink, out);
637 }
638 
request_frame(AVFilterLink * outlink)639 static int request_frame(AVFilterLink *outlink)
640 {
641     int ret;
642     AVFilterContext *ctx = outlink->src;
643     AVFilterLink *inlink = ctx->inputs[0];
644     LoudNormContext *s = ctx->priv;
645 
646     ret = ff_request_frame(inlink);
647     if (ret == AVERROR_EOF && s->frame_type == INNER_FRAME) {
648         double *src;
649         double *buf;
650         int nb_samples, n, c, offset;
651         AVFrame *frame;
652 
653         nb_samples  = (s->buf_size / inlink->ch_layout.nb_channels) - s->prev_nb_samples;
654         nb_samples -= (frame_size(inlink->sample_rate, 100) - s->prev_nb_samples);
655 
656         frame = ff_get_audio_buffer(outlink, nb_samples);
657         if (!frame)
658             return AVERROR(ENOMEM);
659         frame->nb_samples = nb_samples;
660 
661         buf = s->buf;
662         src = (double *)frame->data[0];
663 
664         offset  = ((s->limiter_buf_size / inlink->ch_layout.nb_channels) - s->prev_nb_samples) * inlink->ch_layout.nb_channels;
665         offset -= (frame_size(inlink->sample_rate, 100) - s->prev_nb_samples) * inlink->ch_layout.nb_channels;
666         s->buf_index = s->buf_index - offset < 0 ? s->buf_index - offset + s->buf_size : s->buf_index - offset;
667 
668         for (n = 0; n < nb_samples; n++) {
669             for (c = 0; c < inlink->ch_layout.nb_channels; c++) {
670                 src[c] = buf[s->buf_index + c];
671             }
672             src += inlink->ch_layout.nb_channels;
673             s->buf_index += inlink->ch_layout.nb_channels;
674             if (s->buf_index >= s->buf_size)
675                 s->buf_index -= s->buf_size;
676         }
677 
678         s->frame_type = FINAL_FRAME;
679         ret = filter_frame(inlink, frame);
680     }
681     return ret;
682 }
683 
query_formats(AVFilterContext * ctx)684 static int query_formats(AVFilterContext *ctx)
685 {
686     LoudNormContext *s = ctx->priv;
687     AVFilterFormats *formats;
688     AVFilterLink *inlink = ctx->inputs[0];
689     AVFilterLink *outlink = ctx->outputs[0];
690     static const int input_srate[] = {192000, -1};
691     static const enum AVSampleFormat sample_fmts[] = {
692         AV_SAMPLE_FMT_DBL,
693         AV_SAMPLE_FMT_NONE
694     };
695     int ret = ff_set_common_all_channel_counts(ctx);
696     if (ret < 0)
697         return ret;
698 
699     ret = ff_set_common_formats_from_list(ctx, sample_fmts);
700     if (ret < 0)
701         return ret;
702 
703     if (s->frame_type != LINEAR_MODE) {
704         formats = ff_make_format_list(input_srate);
705         if (!formats)
706             return AVERROR(ENOMEM);
707         ret = ff_formats_ref(formats, &inlink->outcfg.samplerates);
708         if (ret < 0)
709             return ret;
710         ret = ff_formats_ref(formats, &outlink->incfg.samplerates);
711         if (ret < 0)
712             return ret;
713     }
714 
715     return 0;
716 }
717 
config_input(AVFilterLink * inlink)718 static int config_input(AVFilterLink *inlink)
719 {
720     AVFilterContext *ctx = inlink->dst;
721     LoudNormContext *s = ctx->priv;
722 
723     s->r128_in = ff_ebur128_init(inlink->ch_layout.nb_channels, inlink->sample_rate, 0, FF_EBUR128_MODE_I | FF_EBUR128_MODE_S | FF_EBUR128_MODE_LRA | FF_EBUR128_MODE_SAMPLE_PEAK);
724     if (!s->r128_in)
725         return AVERROR(ENOMEM);
726 
727     s->r128_out = ff_ebur128_init(inlink->ch_layout.nb_channels, inlink->sample_rate, 0, FF_EBUR128_MODE_I | FF_EBUR128_MODE_S | FF_EBUR128_MODE_LRA | FF_EBUR128_MODE_SAMPLE_PEAK);
728     if (!s->r128_out)
729         return AVERROR(ENOMEM);
730 
731     if (inlink->ch_layout.nb_channels == 1 && s->dual_mono) {
732         ff_ebur128_set_channel(s->r128_in,  0, FF_EBUR128_DUAL_MONO);
733         ff_ebur128_set_channel(s->r128_out, 0, FF_EBUR128_DUAL_MONO);
734     }
735 
736     s->buf_size = frame_size(inlink->sample_rate, 3000) * inlink->ch_layout.nb_channels;
737     s->buf = av_malloc_array(s->buf_size, sizeof(*s->buf));
738     if (!s->buf)
739         return AVERROR(ENOMEM);
740 
741     s->limiter_buf_size = frame_size(inlink->sample_rate, 210) * inlink->ch_layout.nb_channels;
742     s->limiter_buf = av_malloc_array(s->buf_size, sizeof(*s->limiter_buf));
743     if (!s->limiter_buf)
744         return AVERROR(ENOMEM);
745 
746     s->prev_smp = av_malloc_array(inlink->ch_layout.nb_channels, sizeof(*s->prev_smp));
747     if (!s->prev_smp)
748         return AVERROR(ENOMEM);
749 
750     init_gaussian_filter(s);
751 
752     if (s->frame_type != LINEAR_MODE) {
753         inlink->min_samples =
754         inlink->max_samples = frame_size(inlink->sample_rate, 3000);
755     }
756 
757     s->pts = AV_NOPTS_VALUE;
758     s->buf_index =
759     s->prev_buf_index =
760     s->limiter_buf_index = 0;
761     s->channels = inlink->ch_layout.nb_channels;
762     s->index = 1;
763     s->limiter_state = OUT;
764     s->offset = pow(10., s->offset / 20.);
765     s->target_tp = pow(10., s->target_tp / 20.);
766     s->attack_length = frame_size(inlink->sample_rate, 10);
767     s->release_length = frame_size(inlink->sample_rate, 100);
768 
769     return 0;
770 }
771 
init(AVFilterContext * ctx)772 static av_cold int init(AVFilterContext *ctx)
773 {
774     LoudNormContext *s = ctx->priv;
775     s->frame_type = FIRST_FRAME;
776 
777     if (s->linear) {
778         double offset, offset_tp;
779         offset    = s->target_i - s->measured_i;
780         offset_tp = s->measured_tp + offset;
781 
782         if (s->measured_tp != 99 && s->measured_thresh != -70 && s->measured_lra != 0 && s->measured_i != 0) {
783             if ((offset_tp <= s->target_tp) && (s->measured_lra <= s->target_lra)) {
784                 s->frame_type = LINEAR_MODE;
785                 s->offset = offset;
786             }
787         }
788     }
789 
790     return 0;
791 }
792 
uninit(AVFilterContext * ctx)793 static av_cold void uninit(AVFilterContext *ctx)
794 {
795     LoudNormContext *s = ctx->priv;
796     double i_in, i_out, lra_in, lra_out, thresh_in, thresh_out, tp_in, tp_out;
797     int c;
798 
799     if (!s->r128_in || !s->r128_out)
800         goto end;
801 
802     ff_ebur128_loudness_range(s->r128_in, &lra_in);
803     ff_ebur128_loudness_global(s->r128_in, &i_in);
804     ff_ebur128_relative_threshold(s->r128_in, &thresh_in);
805     for (c = 0; c < s->channels; c++) {
806         double tmp;
807         ff_ebur128_sample_peak(s->r128_in, c, &tmp);
808         if ((c == 0) || (tmp > tp_in))
809             tp_in = tmp;
810     }
811 
812     ff_ebur128_loudness_range(s->r128_out, &lra_out);
813     ff_ebur128_loudness_global(s->r128_out, &i_out);
814     ff_ebur128_relative_threshold(s->r128_out, &thresh_out);
815     for (c = 0; c < s->channels; c++) {
816         double tmp;
817         ff_ebur128_sample_peak(s->r128_out, c, &tmp);
818         if ((c == 0) || (tmp > tp_out))
819             tp_out = tmp;
820     }
821 
822     switch(s->print_format) {
823     case NONE:
824         break;
825 
826     case JSON:
827         av_log(ctx, AV_LOG_INFO,
828             "\n{\n"
829             "\t\"input_i\" : \"%.2f\",\n"
830             "\t\"input_tp\" : \"%.2f\",\n"
831             "\t\"input_lra\" : \"%.2f\",\n"
832             "\t\"input_thresh\" : \"%.2f\",\n"
833             "\t\"output_i\" : \"%.2f\",\n"
834             "\t\"output_tp\" : \"%+.2f\",\n"
835             "\t\"output_lra\" : \"%.2f\",\n"
836             "\t\"output_thresh\" : \"%.2f\",\n"
837             "\t\"normalization_type\" : \"%s\",\n"
838             "\t\"target_offset\" : \"%.2f\"\n"
839             "}\n",
840             i_in,
841             20. * log10(tp_in),
842             lra_in,
843             thresh_in,
844             i_out,
845             20. * log10(tp_out),
846             lra_out,
847             thresh_out,
848             s->frame_type == LINEAR_MODE ? "linear" : "dynamic",
849             s->target_i - i_out
850         );
851         break;
852 
853     case SUMMARY:
854         av_log(ctx, AV_LOG_INFO,
855             "\n"
856             "Input Integrated:   %+6.1f LUFS\n"
857             "Input True Peak:    %+6.1f dBTP\n"
858             "Input LRA:          %6.1f LU\n"
859             "Input Threshold:    %+6.1f LUFS\n"
860             "\n"
861             "Output Integrated:  %+6.1f LUFS\n"
862             "Output True Peak:   %+6.1f dBTP\n"
863             "Output LRA:         %6.1f LU\n"
864             "Output Threshold:   %+6.1f LUFS\n"
865             "\n"
866             "Normalization Type:   %s\n"
867             "Target Offset:      %+6.1f LU\n",
868             i_in,
869             20. * log10(tp_in),
870             lra_in,
871             thresh_in,
872             i_out,
873             20. * log10(tp_out),
874             lra_out,
875             thresh_out,
876             s->frame_type == LINEAR_MODE ? "Linear" : "Dynamic",
877             s->target_i - i_out
878         );
879         break;
880     }
881 
882 end:
883     if (s->r128_in)
884         ff_ebur128_destroy(&s->r128_in);
885     if (s->r128_out)
886         ff_ebur128_destroy(&s->r128_out);
887     av_freep(&s->limiter_buf);
888     av_freep(&s->prev_smp);
889     av_freep(&s->buf);
890 }
891 
892 static const AVFilterPad avfilter_af_loudnorm_inputs[] = {
893     {
894         .name         = "default",
895         .type         = AVMEDIA_TYPE_AUDIO,
896         .config_props = config_input,
897         .filter_frame = filter_frame,
898     },
899 };
900 
901 static const AVFilterPad avfilter_af_loudnorm_outputs[] = {
902     {
903         .name          = "default",
904         .request_frame = request_frame,
905         .type          = AVMEDIA_TYPE_AUDIO,
906     },
907 };
908 
909 const AVFilter ff_af_loudnorm = {
910     .name          = "loudnorm",
911     .description   = NULL_IF_CONFIG_SMALL("EBU R128 loudness normalization"),
912     .priv_size     = sizeof(LoudNormContext),
913     .priv_class    = &loudnorm_class,
914     .init          = init,
915     .uninit        = uninit,
916     FILTER_INPUTS(avfilter_af_loudnorm_inputs),
917     FILTER_OUTPUTS(avfilter_af_loudnorm_outputs),
918     FILTER_QUERY_FUNC(query_formats),
919 };
920