2 * Copyright (c) 2001-2010 Krzysztof Foltman, Markus Schmidt, Thor Harald Johansen and others
3 * Copyright (c) 2015 Paul B Mahol
5 * This file is part of FFmpeg.
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.
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.
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
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"
31 #define FILTER_ORDER 4
40 typedef struct FoSection {
41 double a0, a1, a2, a3, a4;
42 double b0, b1, b2, b3, b4;
48 typedef struct EqualizatorFilter {
60 typedef struct AudioNEqualizerContext {
71 EqualizatorFilter *filters;
73 } AudioNEqualizerContext;
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
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 },
92 AVFILTER_DEFINE_CLASS(anequalizer);
94 static void draw_curves(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *out)
96 AudioNEqualizerContext *s = ctx->priv;
97 char *colors, *color, *saveptr = NULL;
100 colors = av_strdup(s->colors);
104 memset(out->data[0], 0, s->h * out->linesize[0]);
106 for (ch = 0; ch < inlink->channels; ch++) {
107 uint8_t fg[4] = { 0xff, 0xff, 0xff, 0xff };
111 color = av_strtok(ch == 0 ? colors : NULL, " |", &saveptr);
113 av_parse_color(fg, color, -1, ctx);
115 for (f = 0; f < s->w; f++) {
116 double zr, zi, zr2, zi2;
122 w = M_PI * (s->fscale ? pow(s->w - 1, f / s->w) : f) / (s->w - 1);
128 for (n = 0; n < s->nb_filters; n++) {
129 if (s->filters[n].channel != ch ||
130 s->filters[n].ignore)
133 for (i = 0; i < FILTER_ORDER / 2; i++) {
134 FoSection *S = &s->filters[n].section[i];
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)); */
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);
148 v = av_clip((1. + -20 * log10(Hmag) / s->mag) * s->h / 2, 0, s->h - 1);
153 for (y = v; y <= prev_v; y++)
154 AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
156 for (y = prev_v; y <= v; y++)
157 AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
167 static int config_video(AVFilterLink *outlink)
169 AVFilterContext *ctx = outlink->src;
170 AudioNEqualizerContext *s = ctx->priv;
171 AVFilterLink *inlink = ctx->inputs[0];
177 av_frame_free(&s->video);
178 s->video = out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
180 return AVERROR(ENOMEM);
181 outlink->sample_aspect_ratio = (AVRational){1,1};
183 draw_curves(ctx, inlink, out);
188 static av_cold int init(AVFilterContext *ctx)
190 AudioNEqualizerContext *s = ctx->priv;
191 AVFilterPad pad, vpad;
194 .name = av_strdup("out0"),
195 .type = AVMEDIA_TYPE_AUDIO,
199 return AVERROR(ENOMEM);
201 if (s->draw_curves) {
202 vpad = (AVFilterPad){
203 .name = av_strdup("out1"),
204 .type = AVMEDIA_TYPE_VIDEO,
205 .config_props = config_video,
208 return AVERROR(ENOMEM);
211 ff_insert_outpad(ctx, 0, &pad);
214 ff_insert_outpad(ctx, 1, &vpad);
219 static int query_formats(AVFilterContext *ctx)
221 AVFilterLink *inlink = ctx->inputs[0];
222 AVFilterLink *outlink = ctx->outputs[0];
223 AudioNEqualizerContext *s = ctx->priv;
224 AVFilterFormats *formats;
225 AVFilterChannelLayouts *layouts;
226 static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
227 static const enum AVSampleFormat sample_fmts[] = {
233 if (s->draw_curves) {
234 AVFilterLink *videolink = ctx->outputs[1];
235 formats = ff_make_format_list(pix_fmts);
236 if ((ret = ff_formats_ref(formats, &videolink->in_formats)) < 0)
240 formats = ff_make_format_list(sample_fmts);
241 if ((ret = ff_formats_ref(formats, &inlink->out_formats)) < 0 ||
242 (ret = ff_formats_ref(formats, &outlink->in_formats)) < 0)
245 layouts = ff_all_channel_counts();
246 if ((ret = ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts)) < 0 ||
247 (ret = ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts)) < 0)
250 formats = ff_all_samplerates();
251 if ((ret = ff_formats_ref(formats, &inlink->out_samplerates)) < 0 ||
252 (ret = ff_formats_ref(formats, &outlink->in_samplerates)) < 0)
258 static av_cold void uninit(AVFilterContext *ctx)
260 AudioNEqualizerContext *s = ctx->priv;
262 av_freep(&ctx->output_pads[0].name);
264 av_freep(&ctx->output_pads[1].name);
265 av_frame_free(&s->video);
266 av_freep(&s->filters);
271 static void butterworth_fo_section(FoSection *S, double beta,
272 double si, double g, double g0,
275 if (c0 == 1 || c0 == -1) {
276 S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
277 S->b1 = 2*c0*(g*g*beta*beta - g0*g0)/D;
278 S->b2 = (g*g*beta*beta - 2*g0*g*beta*si + g0*g0)/D;
283 S->a1 = 2*c0*(beta*beta - 1)/D;
284 S->a2 = (beta*beta - 2*beta*si + 1)/D;
288 S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
289 S->b1 = -4*c0*(g0*g0 + g*g0*si*beta)/D;
290 S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - g*g*beta*beta)/D;
291 S->b3 = -4*c0*(g0*g0 - g*g0*si*beta)/D;
292 S->b4 = (g*g*beta*beta - 2*g*g0*si*beta + g0*g0)/D;
295 S->a1 = -4*c0*(1 + si*beta)/D;
296 S->a2 = 2*(1 + 2*c0*c0 - beta*beta)/D;
297 S->a3 = -4*c0*(1 - si*beta)/D;
298 S->a4 = (beta*beta - 2*si*beta + 1)/D;
302 static void butterworth_bp_filter(EqualizatorFilter *f,
303 int N, double w0, double wb,
304 double G, double Gb, double G0)
306 double g, c0, g0, beta;
312 if (G == 0 && G0 == 0) {
313 f->section[0].a0 = 1;
314 f->section[0].b0 = 1;
315 f->section[1].a0 = 1;
316 f->section[1].b0 = 1;
321 Gb = ff_exp10(Gb/20);
322 G0 = ff_exp10(G0/20);
324 epsilon = sqrt((G * G - Gb * Gb) / (Gb * Gb - G0 * G0));
326 g0 = pow(G0, 1.0 / N);
327 beta = pow(epsilon, -1.0 / N) * tan(wb/2);
330 for (i = 1; i <= L; i++) {
331 double ui = (2.0 * i - 1) / N;
332 double si = sin(M_PI * ui / 2.0);
333 double Di = beta * beta + 2 * si * beta + 1;
335 butterworth_fo_section(&f->section[i - 1], beta, si, g, g0, Di, c0);
339 static void chebyshev1_fo_section(FoSection *S, double a,
340 double c, double tetta_b,
341 double g0, double si, double b,
344 if (c0 == 1 || c0 == -1) {
345 S->b0 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) + 2*g0*b*si*tetta_b*tetta_b + g0*g0)/D;
346 S->b1 = 2*c0*(tetta_b*tetta_b*(b*b+g0*g0*c*c) - g0*g0)/D;
347 S->b2 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) - 2*g0*b*si*tetta_b + g0*g0)/D;
352 S->a1 = 2*c0*(tetta_b*tetta_b*(a*a+c*c) - 1)/D;
353 S->a2 = (tetta_b*tetta_b*(a*a+c*c) - 2*a*si*tetta_b + 1)/D;
357 S->b0 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b + 2*g0*b*si*tetta_b + g0*g0)/D;
358 S->b1 = -4*c0*(g0*g0 + g0*b*si*tetta_b)/D;
359 S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - (b*b + g0*g0*c*c)*tetta_b*tetta_b)/D;
360 S->b3 = -4*c0*(g0*g0 - g0*b*si*tetta_b)/D;
361 S->b4 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b - 2*g0*b*si*tetta_b + g0*g0)/D;
364 S->a1 = -4*c0*(1 + a*si*tetta_b)/D;
365 S->a2 = 2*(1 + 2*c0*c0 - (a*a + c*c)*tetta_b*tetta_b)/D;
366 S->a3 = -4*c0*(1 - a*si*tetta_b)/D;
367 S->a4 = ((a*a + c*c)*tetta_b*tetta_b - 2*a*si*tetta_b + 1)/D;
371 static void chebyshev1_bp_filter(EqualizatorFilter *f,
372 int N, double w0, double wb,
373 double G, double Gb, double G0)
375 double a, b, c0, g0, alfa, beta, tetta_b;
381 if (G == 0 && G0 == 0) {
382 f->section[0].a0 = 1;
383 f->section[0].b0 = 1;
384 f->section[1].a0 = 1;
385 f->section[1].b0 = 1;
390 Gb = ff_exp10(Gb/20);
391 G0 = ff_exp10(G0/20);
393 epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
395 alfa = pow(1.0/epsilon + sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
396 beta = pow(G/epsilon + Gb * sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
397 a = 0.5 * (alfa - 1.0/alfa);
398 b = 0.5 * (beta - g0*g0*(1/beta));
402 for (i = 1; i <= L; i++) {
403 double ui = (2.0*i-1.0)/N;
404 double ci = cos(M_PI*ui/2.0);
405 double si = sin(M_PI*ui/2.0);
406 double Di = (a*a + ci*ci)*tetta_b*tetta_b + 2.0*a*si*tetta_b + 1;
408 chebyshev1_fo_section(&f->section[i - 1], a, ci, tetta_b, g0, si, b, Di, c0);
412 static void chebyshev2_fo_section(FoSection *S, double a,
413 double c, double tetta_b,
414 double g, double si, double b,
417 if (c0 == 1 || c0 == -1) {
418 S->b0 = (g*g*tetta_b*tetta_b + 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
419 S->b1 = 2*c0*(g*g*tetta_b*tetta_b - b*b - g*g*c*c)/D;
420 S->b2 = (g*g*tetta_b*tetta_b - 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
425 S->a1 = 2*c0*(tetta_b*tetta_b - a*a - c*c)/D;
426 S->a2 = (tetta_b*tetta_b - 2*tetta_b*a*si + a*a + c*c)/D;
430 S->b0 = (g*g*tetta_b*tetta_b + 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
431 S->b1 = -4*c0*(b*b + g*g*c*c + g*b*si*tetta_b)/D;
432 S->b2 = 2*((b*b + g*g*c*c)*(1 + 2*c0*c0) - g*g*tetta_b*tetta_b)/D;
433 S->b3 = -4*c0*(b*b + g*g*c*c - g*b*si*tetta_b)/D;
434 S->b4 = (g*g*tetta_b*tetta_b - 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
437 S->a1 = -4*c0*(a*a + c*c + a*si*tetta_b)/D;
438 S->a2 = 2*((a*a + c*c)*(1 + 2*c0*c0) - tetta_b*tetta_b)/D;
439 S->a3 = -4*c0*(a*a + c*c - a*si*tetta_b)/D;
440 S->a4 = (tetta_b*tetta_b - 2*a*si*tetta_b + a*a + c*c)/D;
444 static void chebyshev2_bp_filter(EqualizatorFilter *f,
445 int N, double w0, double wb,
446 double G, double Gb, double G0)
448 double a, b, c0, tetta_b;
449 double epsilon, g, eu, ew;
454 if (G == 0 && G0 == 0) {
455 f->section[0].a0 = 1;
456 f->section[0].b0 = 1;
457 f->section[1].a0 = 1;
458 f->section[1].b0 = 1;
463 Gb = ff_exp10(Gb/20);
464 G0 = ff_exp10(G0/20);
466 epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
468 eu = pow(epsilon + sqrt(1 + epsilon*epsilon), 1.0/N);
469 ew = pow(G0*epsilon + Gb*sqrt(1 + epsilon*epsilon), 1.0/N);
470 a = (eu - 1.0/eu)/2.0;
471 b = (ew - g*g/ew)/2.0;
475 for (i = 1; i <= L; i++) {
476 double ui = (2.0 * i - 1.0)/N;
477 double ci = cos(M_PI * ui / 2.0);
478 double si = sin(M_PI * ui / 2.0);
479 double Di = tetta_b*tetta_b + 2*a*si*tetta_b + a*a + ci*ci;
481 chebyshev2_fo_section(&f->section[i - 1], a, ci, tetta_b, g, si, b, Di, c0);
485 static double butterworth_compute_bw_gain_db(double gain)
491 else if(gain > -6 && gain < 6)
492 bw_gain = gain * 0.5;
499 static double chebyshev1_compute_bw_gain_db(double gain)
505 else if(gain > -6 && gain < 6)
506 bw_gain = gain * 0.9;
513 static double chebyshev2_compute_bw_gain_db(double gain)
519 else if(gain > -6 && gain < 6)
520 bw_gain = gain * 0.3;
527 static inline double hz_2_rad(double x, double fs)
529 return 2 * M_PI * x / fs;
532 static void equalizer(EqualizatorFilter *f, double sample_rate)
534 double w0 = hz_2_rad(f->freq, sample_rate);
535 double wb = hz_2_rad(f->width, sample_rate);
540 bw_gain = butterworth_compute_bw_gain_db(f->gain);
541 butterworth_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
544 bw_gain = chebyshev1_compute_bw_gain_db(f->gain);
545 chebyshev1_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
548 bw_gain = chebyshev2_compute_bw_gain_db(f->gain);
549 chebyshev2_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
555 static int add_filter(AudioNEqualizerContext *s, AVFilterLink *inlink)
557 equalizer(&s->filters[s->nb_filters], inlink->sample_rate);
558 if (s->nb_filters >= s->nb_allocated) {
559 EqualizatorFilter *filters;
561 filters = av_calloc(s->nb_allocated, 2 * sizeof(*s->filters));
563 return AVERROR(ENOMEM);
564 memcpy(filters, s->filters, sizeof(*s->filters) * s->nb_allocated);
566 s->filters = filters;
567 s->nb_allocated *= 2;
574 static int config_input(AVFilterLink *inlink)
576 AVFilterContext *ctx = inlink->dst;
577 AudioNEqualizerContext *s = ctx->priv;
578 char *args = av_strdup(s->args);
579 char *saveptr = NULL;
583 return AVERROR(ENOMEM);
585 s->nb_allocated = 32 * inlink->channels;
586 s->filters = av_calloc(inlink->channels, 32 * sizeof(*s->filters));
590 return AVERROR(ENOMEM);
594 char *arg = av_strtok(s->nb_filters == 0 ? args : NULL, "|", &saveptr);
599 s->filters[s->nb_filters].type = 0;
600 if (sscanf(arg, "c%d f=%lf w=%lf g=%lf t=%d", &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,
604 &s->filters[s->nb_filters].type) != 5 &&
605 sscanf(arg, "c%d f=%lf w=%lf g=%lf", &s->filters[s->nb_filters].channel,
606 &s->filters[s->nb_filters].freq,
607 &s->filters[s->nb_filters].width,
608 &s->filters[s->nb_filters].gain) != 4 ) {
610 return AVERROR(EINVAL);
613 if (s->filters[s->nb_filters].freq < 0 ||
614 s->filters[s->nb_filters].freq > inlink->sample_rate / 2.0)
615 s->filters[s->nb_filters].ignore = 1;
617 if (s->filters[s->nb_filters].channel < 0 ||
618 s->filters[s->nb_filters].channel >= inlink->channels)
619 s->filters[s->nb_filters].ignore = 1;
621 s->filters[s->nb_filters].type = av_clip(s->filters[s->nb_filters].type, 0, NB_TYPES - 1);
622 ret = add_filter(s, inlink);
632 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
633 char *res, int res_len, int flags)
635 AudioNEqualizerContext *s = ctx->priv;
636 AVFilterLink *inlink = ctx->inputs[0];
637 int ret = AVERROR(ENOSYS);
639 if (!strcmp(cmd, "change")) {
640 double freq, width, gain;
643 if (sscanf(args, "%d|f=%lf|w=%lf|g=%lf", &filter, &freq, &width, &gain) != 4)
644 return AVERROR(EINVAL);
646 if (filter < 0 || filter >= s->nb_filters)
647 return AVERROR(EINVAL);
649 if (freq < 0 || freq > inlink->sample_rate / 2.0)
650 return AVERROR(EINVAL);
652 s->filters[filter].freq = freq;
653 s->filters[filter].width = width;
654 s->filters[filter].gain = gain;
655 equalizer(&s->filters[filter], inlink->sample_rate);
657 draw_curves(ctx, inlink, s->video);
665 static inline double section_process(FoSection *S, double in)
670 out+= S->b1 * S->num[0] - S->denum[0] * S->a1;
671 out+= S->b2 * S->num[1] - S->denum[1] * S->a2;
672 out+= S->b3 * S->num[2] - S->denum[2] * S->a3;
673 out+= S->b4 * S->num[3] - S->denum[3] * S->a4;
675 S->num[3] = S->num[2];
676 S->num[2] = S->num[1];
677 S->num[1] = S->num[0];
680 S->denum[3] = S->denum[2];
681 S->denum[2] = S->denum[1];
682 S->denum[1] = S->denum[0];
688 static double process_sample(FoSection *s1, double in)
693 for (i = 0; i < FILTER_ORDER / 2; i++) {
694 p1 = section_process(&s1[i], p0);
701 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
703 AVFilterContext *ctx = inlink->dst;
704 AudioNEqualizerContext *s = ctx->priv;
705 AVFilterLink *outlink = ctx->outputs[0];
709 for (i = 0; i < s->nb_filters; i++) {
710 EqualizatorFilter *f = &s->filters[i];
712 if (f->gain == 0. || f->ignore)
715 bptr = (double *)buf->extended_data[f->channel];
716 for (n = 0; n < buf->nb_samples; n++) {
717 double sample = bptr[n];
719 sample = process_sample(f->section, sample);
724 if (s->draw_curves) {
725 const int64_t pts = buf->pts +
726 av_rescale_q(buf->nb_samples, (AVRational){ 1, inlink->sample_rate },
731 ret = ff_filter_frame(ctx->outputs[1], av_frame_clone(s->video));
736 return ff_filter_frame(outlink, buf);
739 static const AVFilterPad inputs[] = {
742 .type = AVMEDIA_TYPE_AUDIO,
743 .config_props = config_input,
744 .filter_frame = filter_frame,
750 AVFilter ff_af_anequalizer = {
751 .name = "anequalizer",
752 .description = NULL_IF_CONFIG_SMALL("Apply high-order audio parametric multi band equalizer."),
753 .priv_size = sizeof(AudioNEqualizerContext),
754 .priv_class = &anequalizer_class,
757 .query_formats = query_formats,
760 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
761 .process_command = process_command,