• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1 /*
2  * Copyright (c) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen and others
3  * Copyright (c) 2015 Paul B Mahol
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 #include "libavutil/intreadwrite.h"
23 #include "libavutil/avstring.h"
24 #include "libavutil/ffmath.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/parseutils.h"
27 #include "avfilter.h"
28 #include "internal.h"
29 #include "audio.h"
30 
31 #define FILTER_ORDER 4
32 
33 enum FilterType {
34     BUTTERWORTH,
35     CHEBYSHEV1,
36     CHEBYSHEV2,
37     NB_TYPES
38 };
39 
40 typedef struct FoSection {
41     double a0, a1, a2, a3, a4;
42     double b0, b1, b2, b3, b4;
43 
44     double num[4];
45     double denum[4];
46 } FoSection;
47 
48 typedef struct EqualizatorFilter {
49     int ignore;
50     int channel;
51     int type;
52 
53     double freq;
54     double gain;
55     double width;
56 
57     FoSection section[2];
58 } EqualizatorFilter;
59 
60 typedef struct AudioNEqualizerContext {
61     const AVClass *class;
62     char *args;
63     char *colors;
64     int draw_curves;
65     int w, h;
66 
67     double mag;
68     int fscale;
69     int nb_filters;
70     int nb_allocated;
71     EqualizatorFilter *filters;
72     AVFrame *video;
73 } AudioNEqualizerContext;
74 
75 #define OFFSET(x) offsetof(AudioNEqualizerContext, x)
76 #define A AV_OPT_FLAG_AUDIO_PARAM
77 #define V AV_OPT_FLAG_VIDEO_PARAM
78 #define F AV_OPT_FLAG_FILTERING_PARAM
79 
80 static const AVOption anequalizer_options[] = {
81     { "params", NULL,                             OFFSET(args),        AV_OPT_TYPE_STRING,     {.str=""}, 0, 0, A|F },
82     { "curves", "draw frequency response curves", OFFSET(draw_curves), AV_OPT_TYPE_BOOL,       {.i64=0}, 0, 1, V|F },
83     { "size",   "set video size",                 OFFSET(w),           AV_OPT_TYPE_IMAGE_SIZE, {.str = "hd720"}, 0, 0, V|F },
84     { "mgain",  "set max gain",                   OFFSET(mag),         AV_OPT_TYPE_DOUBLE,     {.dbl=60}, -900, 900, V|F },
85     { "fscale", "set frequency scale",            OFFSET(fscale),      AV_OPT_TYPE_INT,        {.i64=1}, 0, 1, V|F, "fscale" },
86         { "lin",  "linear",                       0,                   AV_OPT_TYPE_CONST,      {.i64=0}, 0, 0, V|F, "fscale" },
87         { "log",  "logarithmic",                  0,                   AV_OPT_TYPE_CONST,      {.i64=1}, 0, 0, V|F, "fscale" },
88     { "colors", "set channels curves colors",     OFFSET(colors),      AV_OPT_TYPE_STRING,     {.str = "red|green|blue|yellow|orange|lime|pink|magenta|brown" }, 0, 0, V|F },
89     { NULL }
90 };
91 
92 AVFILTER_DEFINE_CLASS(anequalizer);
93 
draw_curves(AVFilterContext * ctx,AVFilterLink * inlink,AVFrame * out)94 static void draw_curves(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *out)
95 {
96     AudioNEqualizerContext *s = ctx->priv;
97     char *colors, *color, *saveptr = NULL;
98     int ch, i, n;
99 
100     colors = av_strdup(s->colors);
101     if (!colors)
102         return;
103 
104     memset(out->data[0], 0, s->h * out->linesize[0]);
105 
106     for (ch = 0; ch < inlink->channels; ch++) {
107         uint8_t fg[4] = { 0xff, 0xff, 0xff, 0xff };
108         int prev_v = -1;
109         double f;
110 
111         color = av_strtok(ch == 0 ? colors : NULL, " |", &saveptr);
112         if (color)
113             av_parse_color(fg, color, -1, ctx);
114 
115         for (f = 0; f < s->w; f++) {
116             double zr, zi, zr2, zi2;
117             double Hr, Hi;
118             double Hmag = 1;
119             double w;
120             int v, y, x;
121 
122             w = M_PI * (s->fscale ? pow(s->w - 1, f / s->w) : f) / (s->w - 1);
123             zr = cos(w);
124             zr2 = zr * zr;
125             zi = -sin(w);
126             zi2 = zi * zi;
127 
128             for (n = 0; n < s->nb_filters; n++) {
129                 if (s->filters[n].channel != ch ||
130                     s->filters[n].ignore)
131                     continue;
132 
133                 for (i = 0; i < FILTER_ORDER / 2; i++) {
134                     FoSection *S = &s->filters[n].section[i];
135 
136                     /* H *= (((((S->b4 * z + S->b3) * z + S->b2) * z + S->b1) * z + S->b0) /
137                           ((((S->a4 * z + S->a3) * z + S->a2) * z + S->a1) * z + S->a0)); */
138 
139                     Hr = S->b4*(1-8*zr2*zi2) + S->b2*(zr2-zi2) + zr*(S->b1+S->b3*(zr2-3*zi2))+ S->b0;
140                     Hi = zi*(S->b3*(3*zr2-zi2) + S->b1 + 2*zr*(2*S->b4*(zr2-zi2) + S->b2));
141                     Hmag *= hypot(Hr, Hi);
142                     Hr = S->a4*(1-8*zr2*zi2) + S->a2*(zr2-zi2) + zr*(S->a1+S->a3*(zr2-3*zi2))+ S->a0;
143                     Hi = zi*(S->a3*(3*zr2-zi2) + S->a1 + 2*zr*(2*S->a4*(zr2-zi2) + S->a2));
144                     Hmag /= hypot(Hr, Hi);
145                 }
146             }
147 
148             v = av_clip((1. + -20 * log10(Hmag) / s->mag) * s->h / 2, 0, s->h - 1);
149             x = lrint(f);
150             if (prev_v == -1)
151                 prev_v = v;
152             if (v <= prev_v) {
153                 for (y = v; y <= prev_v; y++)
154                     AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
155             } else {
156                 for (y = prev_v; y <= v; y++)
157                     AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
158             }
159 
160             prev_v = v;
161         }
162     }
163 
164     av_free(colors);
165 }
166 
config_video(AVFilterLink * outlink)167 static int config_video(AVFilterLink *outlink)
168 {
169     AVFilterContext *ctx = outlink->src;
170     AudioNEqualizerContext *s = ctx->priv;
171     AVFilterLink *inlink = ctx->inputs[0];
172     AVFrame *out;
173 
174     outlink->w = s->w;
175     outlink->h = s->h;
176 
177     av_frame_free(&s->video);
178     s->video = out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
179     if (!out)
180         return AVERROR(ENOMEM);
181     outlink->sample_aspect_ratio = (AVRational){1,1};
182 
183     draw_curves(ctx, inlink, out);
184 
185     return 0;
186 }
187 
init(AVFilterContext * ctx)188 static av_cold int init(AVFilterContext *ctx)
189 {
190     AudioNEqualizerContext *s = ctx->priv;
191     AVFilterPad pad, vpad;
192     int ret;
193 
194     pad = (AVFilterPad){
195         .name         = "out0",
196         .type         = AVMEDIA_TYPE_AUDIO,
197     };
198 
199     ret = ff_insert_outpad(ctx, 0, &pad);
200     if (ret < 0)
201         return ret;
202 
203     if (s->draw_curves) {
204         vpad = (AVFilterPad){
205             .name         = "out1",
206             .type         = AVMEDIA_TYPE_VIDEO,
207             .config_props = config_video,
208         };
209         ret = ff_insert_outpad(ctx, 1, &vpad);
210         if (ret < 0)
211             return ret;
212     }
213 
214     return 0;
215 }
216 
query_formats(AVFilterContext * ctx)217 static int query_formats(AVFilterContext *ctx)
218 {
219     AVFilterLink *inlink = ctx->inputs[0];
220     AVFilterLink *outlink = ctx->outputs[0];
221     AudioNEqualizerContext *s = ctx->priv;
222     AVFilterFormats *formats;
223     AVFilterChannelLayouts *layouts;
224     static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
225     static const enum AVSampleFormat sample_fmts[] = {
226         AV_SAMPLE_FMT_DBLP,
227         AV_SAMPLE_FMT_NONE
228     };
229     int ret;
230 
231     if (s->draw_curves) {
232         AVFilterLink *videolink = ctx->outputs[1];
233         formats = ff_make_format_list(pix_fmts);
234         if ((ret = ff_formats_ref(formats, &videolink->incfg.formats)) < 0)
235             return ret;
236     }
237 
238     formats = ff_make_format_list(sample_fmts);
239     if ((ret = ff_formats_ref(formats, &inlink->outcfg.formats)) < 0 ||
240         (ret = ff_formats_ref(formats, &outlink->incfg.formats)) < 0)
241         return ret;
242 
243     layouts = ff_all_channel_counts();
244     if ((ret = ff_channel_layouts_ref(layouts, &inlink->outcfg.channel_layouts)) < 0 ||
245         (ret = ff_channel_layouts_ref(layouts, &outlink->incfg.channel_layouts)) < 0)
246         return ret;
247 
248     formats = ff_all_samplerates();
249     if ((ret = ff_formats_ref(formats, &inlink->outcfg.samplerates)) < 0 ||
250         (ret = ff_formats_ref(formats, &outlink->incfg.samplerates)) < 0)
251         return ret;
252 
253     return 0;
254 }
255 
uninit(AVFilterContext * ctx)256 static av_cold void uninit(AVFilterContext *ctx)
257 {
258     AudioNEqualizerContext *s = ctx->priv;
259 
260     av_frame_free(&s->video);
261     av_freep(&s->filters);
262     s->nb_filters = 0;
263     s->nb_allocated = 0;
264 }
265 
butterworth_fo_section(FoSection * S,double beta,double si,double g,double g0,double D,double c0)266 static void butterworth_fo_section(FoSection *S, double beta,
267                                    double si, double g, double g0,
268                                    double D, double c0)
269 {
270     if (c0 == 1 || c0 == -1) {
271         S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
272         S->b1 = 2*c0*(g*g*beta*beta - g0*g0)/D;
273         S->b2 = (g*g*beta*beta - 2*g0*g*beta*si + g0*g0)/D;
274         S->b3 = 0;
275         S->b4 = 0;
276 
277         S->a0 = 1;
278         S->a1 = 2*c0*(beta*beta - 1)/D;
279         S->a2 = (beta*beta - 2*beta*si + 1)/D;
280         S->a3 = 0;
281         S->a4 = 0;
282     } else {
283         S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
284         S->b1 = -4*c0*(g0*g0 + g*g0*si*beta)/D;
285         S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - g*g*beta*beta)/D;
286         S->b3 = -4*c0*(g0*g0 - g*g0*si*beta)/D;
287         S->b4 = (g*g*beta*beta - 2*g*g0*si*beta + g0*g0)/D;
288 
289         S->a0 = 1;
290         S->a1 = -4*c0*(1 + si*beta)/D;
291         S->a2 = 2*(1 + 2*c0*c0 - beta*beta)/D;
292         S->a3 = -4*c0*(1 - si*beta)/D;
293         S->a4 = (beta*beta - 2*si*beta + 1)/D;
294     }
295 }
296 
butterworth_bp_filter(EqualizatorFilter * f,int N,double w0,double wb,double G,double Gb,double G0)297 static void butterworth_bp_filter(EqualizatorFilter *f,
298                                   int N, double w0, double wb,
299                                   double G, double Gb, double G0)
300 {
301     double g, c0, g0, beta;
302     double epsilon;
303     int r =  N % 2;
304     int L = (N - r) / 2;
305     int i;
306 
307     if (G == 0 && G0 == 0) {
308         f->section[0].a0 = 1;
309         f->section[0].b0 = 1;
310         f->section[1].a0 = 1;
311         f->section[1].b0 = 1;
312         return;
313     }
314 
315     G  = ff_exp10(G/20);
316     Gb = ff_exp10(Gb/20);
317     G0 = ff_exp10(G0/20);
318 
319     epsilon = sqrt((G * G - Gb * Gb) / (Gb * Gb - G0 * G0));
320     g  = pow(G,  1.0 / N);
321     g0 = pow(G0, 1.0 / N);
322     beta = pow(epsilon, -1.0 / N) * tan(wb/2);
323     c0 = cos(w0);
324 
325     for (i = 1; i <= L; i++) {
326         double ui = (2.0 * i - 1) / N;
327         double si = sin(M_PI * ui / 2.0);
328         double Di = beta * beta + 2 * si * beta + 1;
329 
330         butterworth_fo_section(&f->section[i - 1], beta, si, g, g0, Di, c0);
331     }
332 }
333 
chebyshev1_fo_section(FoSection * S,double a,double c,double tetta_b,double g0,double si,double b,double D,double c0)334 static void chebyshev1_fo_section(FoSection *S, double a,
335                                   double c, double tetta_b,
336                                   double g0, double si, double b,
337                                   double D, double c0)
338 {
339     if (c0 == 1 || c0 == -1) {
340         S->b0 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) + 2*g0*b*si*tetta_b*tetta_b + g0*g0)/D;
341         S->b1 = 2*c0*(tetta_b*tetta_b*(b*b+g0*g0*c*c) - g0*g0)/D;
342         S->b2 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) - 2*g0*b*si*tetta_b + g0*g0)/D;
343         S->b3 = 0;
344         S->b4 = 0;
345 
346         S->a0 = 1;
347         S->a1 = 2*c0*(tetta_b*tetta_b*(a*a+c*c) - 1)/D;
348         S->a2 = (tetta_b*tetta_b*(a*a+c*c) - 2*a*si*tetta_b + 1)/D;
349         S->a3 = 0;
350         S->a4 = 0;
351     } else {
352         S->b0 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b + 2*g0*b*si*tetta_b + g0*g0)/D;
353         S->b1 = -4*c0*(g0*g0 + g0*b*si*tetta_b)/D;
354         S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - (b*b + g0*g0*c*c)*tetta_b*tetta_b)/D;
355         S->b3 = -4*c0*(g0*g0 - g0*b*si*tetta_b)/D;
356         S->b4 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b - 2*g0*b*si*tetta_b + g0*g0)/D;
357 
358         S->a0 = 1;
359         S->a1 = -4*c0*(1 + a*si*tetta_b)/D;
360         S->a2 = 2*(1 + 2*c0*c0 - (a*a + c*c)*tetta_b*tetta_b)/D;
361         S->a3 = -4*c0*(1 - a*si*tetta_b)/D;
362         S->a4 = ((a*a + c*c)*tetta_b*tetta_b - 2*a*si*tetta_b + 1)/D;
363     }
364 }
365 
chebyshev1_bp_filter(EqualizatorFilter * f,int N,double w0,double wb,double G,double Gb,double G0)366 static void chebyshev1_bp_filter(EqualizatorFilter *f,
367                                  int N, double w0, double wb,
368                                  double G, double Gb, double G0)
369 {
370     double a, b, c0, g0, alfa, beta, tetta_b;
371     double epsilon;
372     int r =  N % 2;
373     int L = (N - r) / 2;
374     int i;
375 
376     if (G == 0 && G0 == 0) {
377         f->section[0].a0 = 1;
378         f->section[0].b0 = 1;
379         f->section[1].a0 = 1;
380         f->section[1].b0 = 1;
381         return;
382     }
383 
384     G  = ff_exp10(G/20);
385     Gb = ff_exp10(Gb/20);
386     G0 = ff_exp10(G0/20);
387 
388     epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
389     g0 = pow(G0,1.0/N);
390     alfa = pow(1.0/epsilon    + sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
391     beta = pow(G/epsilon + Gb * sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
392     a = 0.5 * (alfa - 1.0/alfa);
393     b = 0.5 * (beta - g0*g0*(1/beta));
394     tetta_b = tan(wb/2);
395     c0 = cos(w0);
396 
397     for (i = 1; i <= L; i++) {
398         double ui = (2.0*i-1.0)/N;
399         double ci = cos(M_PI*ui/2.0);
400         double si = sin(M_PI*ui/2.0);
401         double Di = (a*a + ci*ci)*tetta_b*tetta_b + 2.0*a*si*tetta_b + 1;
402 
403         chebyshev1_fo_section(&f->section[i - 1], a, ci, tetta_b, g0, si, b, Di, c0);
404     }
405 }
406 
chebyshev2_fo_section(FoSection * S,double a,double c,double tetta_b,double g,double si,double b,double D,double c0)407 static void chebyshev2_fo_section(FoSection *S, double a,
408                                   double c, double tetta_b,
409                                   double g, double si, double b,
410                                   double D, double c0)
411 {
412     if (c0 == 1 || c0 == -1) {
413         S->b0 = (g*g*tetta_b*tetta_b + 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
414         S->b1 = 2*c0*(g*g*tetta_b*tetta_b - b*b - g*g*c*c)/D;
415         S->b2 = (g*g*tetta_b*tetta_b - 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
416         S->b3 = 0;
417         S->b4 = 0;
418 
419         S->a0 = 1;
420         S->a1 = 2*c0*(tetta_b*tetta_b - a*a - c*c)/D;
421         S->a2 = (tetta_b*tetta_b - 2*tetta_b*a*si + a*a + c*c)/D;
422         S->a3 = 0;
423         S->a4 = 0;
424     } else {
425         S->b0 = (g*g*tetta_b*tetta_b + 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
426         S->b1 = -4*c0*(b*b + g*g*c*c + g*b*si*tetta_b)/D;
427         S->b2 = 2*((b*b + g*g*c*c)*(1 + 2*c0*c0) - g*g*tetta_b*tetta_b)/D;
428         S->b3 = -4*c0*(b*b + g*g*c*c - g*b*si*tetta_b)/D;
429         S->b4 = (g*g*tetta_b*tetta_b - 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
430 
431         S->a0 = 1;
432         S->a1 = -4*c0*(a*a + c*c + a*si*tetta_b)/D;
433         S->a2 = 2*((a*a + c*c)*(1 + 2*c0*c0) - tetta_b*tetta_b)/D;
434         S->a3 = -4*c0*(a*a + c*c - a*si*tetta_b)/D;
435         S->a4 = (tetta_b*tetta_b - 2*a*si*tetta_b + a*a + c*c)/D;
436     }
437 }
438 
chebyshev2_bp_filter(EqualizatorFilter * f,int N,double w0,double wb,double G,double Gb,double G0)439 static void chebyshev2_bp_filter(EqualizatorFilter *f,
440                                  int N, double w0, double wb,
441                                  double G, double Gb, double G0)
442 {
443     double a, b, c0, tetta_b;
444     double epsilon, g, eu, ew;
445     int r =  N % 2;
446     int L = (N - r) / 2;
447     int i;
448 
449     if (G == 0 && G0 == 0) {
450         f->section[0].a0 = 1;
451         f->section[0].b0 = 1;
452         f->section[1].a0 = 1;
453         f->section[1].b0 = 1;
454         return;
455     }
456 
457     G  = ff_exp10(G/20);
458     Gb = ff_exp10(Gb/20);
459     G0 = ff_exp10(G0/20);
460 
461     epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
462     g  = pow(G, 1.0 / N);
463     eu = pow(epsilon + sqrt(1 + epsilon*epsilon), 1.0/N);
464     ew = pow(G0*epsilon + Gb*sqrt(1 + epsilon*epsilon), 1.0/N);
465     a = (eu - 1.0/eu)/2.0;
466     b = (ew - g*g/ew)/2.0;
467     tetta_b = tan(wb/2);
468     c0 = cos(w0);
469 
470     for (i = 1; i <= L; i++) {
471         double ui = (2.0 * i - 1.0)/N;
472         double ci = cos(M_PI * ui / 2.0);
473         double si = sin(M_PI * ui / 2.0);
474         double Di = tetta_b*tetta_b + 2*a*si*tetta_b + a*a + ci*ci;
475 
476         chebyshev2_fo_section(&f->section[i - 1], a, ci, tetta_b, g, si, b, Di, c0);
477     }
478 }
479 
butterworth_compute_bw_gain_db(double gain)480 static double butterworth_compute_bw_gain_db(double gain)
481 {
482     double bw_gain = 0;
483 
484     if (gain <= -6)
485         bw_gain = gain + 3;
486     else if(gain > -6 && gain < 6)
487         bw_gain = gain * 0.5;
488     else if(gain >= 6)
489         bw_gain = gain - 3;
490 
491     return bw_gain;
492 }
493 
chebyshev1_compute_bw_gain_db(double gain)494 static double chebyshev1_compute_bw_gain_db(double gain)
495 {
496     double bw_gain = 0;
497 
498     if (gain <= -6)
499         bw_gain = gain + 1;
500     else if(gain > -6 && gain < 6)
501         bw_gain = gain * 0.9;
502     else if(gain >= 6)
503         bw_gain = gain - 1;
504 
505     return bw_gain;
506 }
507 
chebyshev2_compute_bw_gain_db(double gain)508 static double chebyshev2_compute_bw_gain_db(double gain)
509 {
510     double bw_gain = 0;
511 
512     if (gain <= -6)
513         bw_gain = -3;
514     else if(gain > -6 && gain < 6)
515         bw_gain = gain * 0.3;
516     else if(gain >= 6)
517         bw_gain = 3;
518 
519     return bw_gain;
520 }
521 
hz_2_rad(double x,double fs)522 static inline double hz_2_rad(double x, double fs)
523 {
524     return 2 * M_PI * x / fs;
525 }
526 
equalizer(EqualizatorFilter * f,double sample_rate)527 static void equalizer(EqualizatorFilter *f, double sample_rate)
528 {
529     double w0 = hz_2_rad(f->freq,  sample_rate);
530     double wb = hz_2_rad(f->width, sample_rate);
531     double bw_gain;
532 
533     switch (f->type) {
534     case BUTTERWORTH:
535         bw_gain = butterworth_compute_bw_gain_db(f->gain);
536         butterworth_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
537         break;
538     case CHEBYSHEV1:
539         bw_gain = chebyshev1_compute_bw_gain_db(f->gain);
540         chebyshev1_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
541         break;
542     case CHEBYSHEV2:
543         bw_gain = chebyshev2_compute_bw_gain_db(f->gain);
544         chebyshev2_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
545         break;
546     }
547 
548 }
549 
add_filter(AudioNEqualizerContext * s,AVFilterLink * inlink)550 static int add_filter(AudioNEqualizerContext *s, AVFilterLink *inlink)
551 {
552     equalizer(&s->filters[s->nb_filters], inlink->sample_rate);
553     if (s->nb_filters >= s->nb_allocated - 1) {
554         EqualizatorFilter *filters;
555 
556         filters = av_calloc(s->nb_allocated, 2 * sizeof(*s->filters));
557         if (!filters)
558             return AVERROR(ENOMEM);
559         memcpy(filters, s->filters, sizeof(*s->filters) * s->nb_allocated);
560         av_free(s->filters);
561         s->filters = filters;
562         s->nb_allocated *= 2;
563     }
564     s->nb_filters++;
565 
566     return 0;
567 }
568 
config_input(AVFilterLink * inlink)569 static int config_input(AVFilterLink *inlink)
570 {
571     AVFilterContext *ctx = inlink->dst;
572     AudioNEqualizerContext *s = ctx->priv;
573     char *args = av_strdup(s->args);
574     char *saveptr = NULL;
575     int ret = 0;
576 
577     if (!args)
578         return AVERROR(ENOMEM);
579 
580     s->nb_allocated = 32 * inlink->channels;
581     s->filters = av_calloc(inlink->channels, 32 * sizeof(*s->filters));
582     if (!s->filters) {
583         s->nb_allocated = 0;
584         av_free(args);
585         return AVERROR(ENOMEM);
586     }
587 
588     while (1) {
589         char *arg = av_strtok(s->nb_filters == 0 ? args : NULL, "|", &saveptr);
590 
591         if (!arg)
592             break;
593 
594         s->filters[s->nb_filters].type = 0;
595         if (sscanf(arg, "c%d f=%lf w=%lf g=%lf t=%d", &s->filters[s->nb_filters].channel,
596                                                      &s->filters[s->nb_filters].freq,
597                                                      &s->filters[s->nb_filters].width,
598                                                      &s->filters[s->nb_filters].gain,
599                                                      &s->filters[s->nb_filters].type) != 5 &&
600             sscanf(arg, "c%d f=%lf w=%lf g=%lf", &s->filters[s->nb_filters].channel,
601                                                 &s->filters[s->nb_filters].freq,
602                                                 &s->filters[s->nb_filters].width,
603                                                 &s->filters[s->nb_filters].gain) != 4 ) {
604             av_free(args);
605             return AVERROR(EINVAL);
606         }
607 
608         if (s->filters[s->nb_filters].freq < 0 ||
609             s->filters[s->nb_filters].freq > inlink->sample_rate / 2.0)
610             s->filters[s->nb_filters].ignore = 1;
611 
612         if (s->filters[s->nb_filters].channel < 0 ||
613             s->filters[s->nb_filters].channel >= inlink->channels)
614             s->filters[s->nb_filters].ignore = 1;
615 
616         s->filters[s->nb_filters].type = av_clip(s->filters[s->nb_filters].type, 0, NB_TYPES - 1);
617         ret = add_filter(s, inlink);
618         if (ret < 0)
619             break;
620     }
621 
622     av_free(args);
623 
624     return ret;
625 }
626 
process_command(AVFilterContext * ctx,const char * cmd,const char * args,char * res,int res_len,int flags)627 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
628                            char *res, int res_len, int flags)
629 {
630     AudioNEqualizerContext *s = ctx->priv;
631     AVFilterLink *inlink = ctx->inputs[0];
632     int ret = AVERROR(ENOSYS);
633 
634     if (!strcmp(cmd, "change")) {
635         double freq, width, gain;
636         int filter;
637 
638         if (sscanf(args, "%d|f=%lf|w=%lf|g=%lf", &filter, &freq, &width, &gain) != 4)
639             return AVERROR(EINVAL);
640 
641         if (filter < 0 || filter >= s->nb_filters)
642             return AVERROR(EINVAL);
643 
644         if (freq < 0 || freq > inlink->sample_rate / 2.0)
645             return AVERROR(EINVAL);
646 
647         s->filters[filter].freq  = freq;
648         s->filters[filter].width = width;
649         s->filters[filter].gain  = gain;
650         equalizer(&s->filters[filter], inlink->sample_rate);
651         if (s->draw_curves)
652             draw_curves(ctx, inlink, s->video);
653 
654         ret = 0;
655     }
656 
657     return ret;
658 }
659 
section_process(FoSection * S,double in)660 static inline double section_process(FoSection *S, double in)
661 {
662     double out;
663 
664     out = S->b0 * in;
665     out+= S->b1 * S->num[0] - S->denum[0] * S->a1;
666     out+= S->b2 * S->num[1] - S->denum[1] * S->a2;
667     out+= S->b3 * S->num[2] - S->denum[2] * S->a3;
668     out+= S->b4 * S->num[3] - S->denum[3] * S->a4;
669 
670     S->num[3] = S->num[2];
671     S->num[2] = S->num[1];
672     S->num[1] = S->num[0];
673     S->num[0] = in;
674 
675     S->denum[3] = S->denum[2];
676     S->denum[2] = S->denum[1];
677     S->denum[1] = S->denum[0];
678     S->denum[0] = out;
679 
680     return out;
681 }
682 
process_sample(FoSection * s1,double in)683 static double process_sample(FoSection *s1, double in)
684 {
685     double p0 = in, p1;
686     int i;
687 
688     for (i = 0; i < FILTER_ORDER / 2; i++) {
689         p1 = section_process(&s1[i], p0);
690         p0 = p1;
691     }
692 
693     return p1;
694 }
695 
filter_channels(AVFilterContext * ctx,void * arg,int jobnr,int nb_jobs)696 static int filter_channels(AVFilterContext *ctx, void *arg,
697                            int jobnr, int nb_jobs)
698 {
699     AudioNEqualizerContext *s = ctx->priv;
700     AVFrame *buf = arg;
701     const int start = (buf->channels * jobnr) / nb_jobs;
702     const int end = (buf->channels * (jobnr+1)) / nb_jobs;
703 
704     for (int i = 0; i < s->nb_filters; i++) {
705         EqualizatorFilter *f = &s->filters[i];
706         double *bptr;
707 
708         if (f->gain == 0. || f->ignore)
709             continue;
710         if (f->channel < start ||
711             f->channel >= end)
712             continue;
713 
714         bptr = (double *)buf->extended_data[f->channel];
715         for (int n = 0; n < buf->nb_samples; n++) {
716             double sample = bptr[n];
717 
718             sample  = process_sample(f->section, sample);
719             bptr[n] = sample;
720         }
721     }
722 
723     return 0;
724 }
725 
filter_frame(AVFilterLink * inlink,AVFrame * buf)726 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
727 {
728     AVFilterContext *ctx = inlink->dst;
729     AudioNEqualizerContext *s = ctx->priv;
730     AVFilterLink *outlink = ctx->outputs[0];
731 
732     if (!ctx->is_disabled)
733         ctx->internal->execute(ctx, filter_channels, buf, NULL, FFMIN(inlink->channels,
734                                                                 ff_filter_get_nb_threads(ctx)));
735 
736     if (s->draw_curves) {
737         AVFrame *clone;
738 
739         const int64_t pts = buf->pts +
740             av_rescale_q(buf->nb_samples, (AVRational){ 1, inlink->sample_rate },
741                          outlink->time_base);
742         int ret;
743 
744         s->video->pts = pts;
745         clone = av_frame_clone(s->video);
746         if (!clone)
747             return AVERROR(ENOMEM);
748         ret = ff_filter_frame(ctx->outputs[1], clone);
749         if (ret < 0)
750             return ret;
751     }
752 
753     return ff_filter_frame(outlink, buf);
754 }
755 
756 static const AVFilterPad inputs[] = {
757     {
758         .name           = "default",
759         .type           = AVMEDIA_TYPE_AUDIO,
760         .config_props   = config_input,
761         .filter_frame   = filter_frame,
762         .needs_writable = 1,
763     },
764     { NULL }
765 };
766 
767 AVFilter ff_af_anequalizer = {
768     .name          = "anequalizer",
769     .description   = NULL_IF_CONFIG_SMALL("Apply high-order audio parametric multi band equalizer."),
770     .priv_size     = sizeof(AudioNEqualizerContext),
771     .priv_class    = &anequalizer_class,
772     .init          = init,
773     .uninit        = uninit,
774     .query_formats = query_formats,
775     .inputs        = inputs,
776     .outputs       = NULL,
777     .process_command = process_command,
778     .flags         = AVFILTER_FLAG_DYNAMIC_OUTPUTS |
779                      AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
780                      AVFILTER_FLAG_SLICE_THREADS,
781 };
782