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/opt.h"
25 #include "libavutil/parseutils.h"
30 #define FILTER_ORDER 4
39 typedef struct FoSection {
40 double a0, a1, a2, a3, a4;
41 double b0, b1, b2, b3, b4;
47 typedef struct EqualizatorFilter {
59 typedef struct AudioNEqualizerContext {
70 EqualizatorFilter *filters;
72 } AudioNEqualizerContext;
74 #define OFFSET(x) offsetof(AudioNEqualizerContext, x)
75 #define A AV_OPT_FLAG_AUDIO_PARAM
76 #define V AV_OPT_FLAG_VIDEO_PARAM
77 #define F AV_OPT_FLAG_FILTERING_PARAM
79 static const AVOption anequalizer_options[] = {
80 { "params", NULL, OFFSET(args), AV_OPT_TYPE_STRING, {.str=""}, 0, 0, A|F },
81 { "curves", "draw frequency response curves", OFFSET(draw_curves), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, V|F },
82 { "size", "set video size", OFFSET(w), AV_OPT_TYPE_IMAGE_SIZE, {.str = "hd720"}, 0, 0, V|F },
83 { "mgain", "set max gain", OFFSET(mag), AV_OPT_TYPE_DOUBLE, {.dbl=60}, -900, 900, V|F },
84 { "fscale", "set frequency scale", OFFSET(fscale), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, V|F, "fscale" },
85 { "lin", "linear", 0, AV_OPT_TYPE_CONST, {.i64=0}, 0, 0, V|F, "fscale" },
86 { "log", "logarithmic", 0, AV_OPT_TYPE_CONST, {.i64=1}, 0, 0, V|F, "fscale" },
87 { "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 },
91 AVFILTER_DEFINE_CLASS(anequalizer);
93 static void draw_curves(AVFilterContext *ctx, AVFilterLink *inlink, AVFrame *out)
95 AudioNEqualizerContext *s = ctx->priv;
96 char *colors, *color, *saveptr = NULL;
99 colors = av_strdup(s->colors);
103 memset(out->data[0], 0, s->h * out->linesize[0]);
105 for (ch = 0; ch < inlink->channels; ch++) {
106 uint8_t fg[4] = { 0xff, 0xff, 0xff, 0xff };
110 color = av_strtok(ch == 0 ? colors : NULL, " |", &saveptr);
112 av_parse_color(fg, color, -1, ctx);
114 for (f = 0; f < s->w; f++) {
115 double zr, zi, zr2, zi2;
121 w = M_PI * (s->fscale ? pow(s->w - 1, f / s->w) : f) / (s->w - 1);
127 for (n = 0; n < s->nb_filters; n++) {
128 if (s->filters[n].channel != ch ||
129 s->filters[n].ignore)
132 for (i = 0; i < FILTER_ORDER / 2; i++) {
133 FoSection *S = &s->filters[n].section[i];
135 /* H *= (((((S->b4 * z + S->b3) * z + S->b2) * z + S->b1) * z + S->b0) /
136 ((((S->a4 * z + S->a3) * z + S->a2) * z + S->a1) * z + S->a0)); */
138 Hr = S->b4*(1-8*zr2*zi2) + S->b2*(zr2-zi2) + zr*(S->b1+S->b3*(zr2-3*zi2))+ S->b0;
139 Hi = zi*(S->b3*(3*zr2-zi2) + S->b1 + 2*zr*(2*S->b4*(zr2-zi2) + S->b2));
140 Hmag *= hypot(Hr, Hi);
141 Hr = S->a4*(1-8*zr2*zi2) + S->a2*(zr2-zi2) + zr*(S->a1+S->a3*(zr2-3*zi2))+ S->a0;
142 Hi = zi*(S->a3*(3*zr2-zi2) + S->a1 + 2*zr*(2*S->a4*(zr2-zi2) + S->a2));
143 Hmag /= hypot(Hr, Hi);
147 v = av_clip((1. + -20 * log10(Hmag) / s->mag) * s->h / 2, 0, s->h - 1);
152 for (y = v; y <= prev_v; y++)
153 AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
155 for (y = prev_v; y <= v; y++)
156 AV_WL32(out->data[0] + y * out->linesize[0] + x * 4, AV_RL32(fg));
166 static int config_video(AVFilterLink *outlink)
168 AVFilterContext *ctx = outlink->src;
169 AudioNEqualizerContext *s = ctx->priv;
170 AVFilterLink *inlink = ctx->inputs[0];
176 av_frame_free(&s->video);
177 s->video = out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
179 return AVERROR(ENOMEM);
180 outlink->sample_aspect_ratio = (AVRational){1,1};
182 draw_curves(ctx, inlink, out);
187 static av_cold int init(AVFilterContext *ctx)
189 AudioNEqualizerContext *s = ctx->priv;
190 AVFilterPad pad, vpad;
193 .name = av_strdup("out0"),
194 .type = AVMEDIA_TYPE_AUDIO,
198 return AVERROR(ENOMEM);
200 if (s->draw_curves) {
201 vpad = (AVFilterPad){
202 .name = av_strdup("out1"),
203 .type = AVMEDIA_TYPE_VIDEO,
204 .config_props = config_video,
207 return AVERROR(ENOMEM);
210 ff_insert_outpad(ctx, 0, &pad);
213 ff_insert_outpad(ctx, 1, &vpad);
218 static int query_formats(AVFilterContext *ctx)
220 AVFilterLink *inlink = ctx->inputs[0];
221 AVFilterLink *outlink = ctx->outputs[0];
222 AudioNEqualizerContext *s = ctx->priv;
223 AVFilterFormats *formats;
224 AVFilterChannelLayouts *layouts;
225 static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_RGBA, AV_PIX_FMT_NONE };
226 static const enum AVSampleFormat sample_fmts[] = {
232 if (s->draw_curves) {
233 AVFilterLink *videolink = ctx->outputs[1];
234 formats = ff_make_format_list(pix_fmts);
235 if ((ret = ff_formats_ref(formats, &videolink->in_formats)) < 0)
239 formats = ff_make_format_list(sample_fmts);
240 if ((ret = ff_formats_ref(formats, &inlink->out_formats)) < 0 ||
241 (ret = ff_formats_ref(formats, &outlink->in_formats)) < 0)
244 layouts = ff_all_channel_counts();
245 if ((ret = ff_channel_layouts_ref(layouts, &inlink->out_channel_layouts)) < 0 ||
246 (ret = ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts)) < 0)
249 formats = ff_all_samplerates();
250 if ((ret = ff_formats_ref(formats, &inlink->out_samplerates)) < 0 ||
251 (ret = ff_formats_ref(formats, &outlink->in_samplerates)) < 0)
257 static av_cold void uninit(AVFilterContext *ctx)
259 AudioNEqualizerContext *s = ctx->priv;
261 av_freep(&ctx->output_pads[0].name);
263 av_freep(&ctx->output_pads[1].name);
264 av_frame_free(&s->video);
265 av_freep(&s->filters);
270 static void butterworth_fo_section(FoSection *S, double beta,
271 double si, double g, double g0,
274 if (c0 == 1 || c0 == -1) {
275 S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
276 S->b1 = 2*c0*(g*g*beta*beta - g0*g0)/D;
277 S->b2 = (g*g*beta*beta - 2*g0*g*beta*si + g0*g0)/D;
282 S->a1 = 2*c0*(beta*beta - 1)/D;
283 S->a2 = (beta*beta - 2*beta*si + 1)/D;
287 S->b0 = (g*g*beta*beta + 2*g*g0*si*beta + g0*g0)/D;
288 S->b1 = -4*c0*(g0*g0 + g*g0*si*beta)/D;
289 S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - g*g*beta*beta)/D;
290 S->b3 = -4*c0*(g0*g0 - g*g0*si*beta)/D;
291 S->b4 = (g*g*beta*beta - 2*g*g0*si*beta + g0*g0)/D;
294 S->a1 = -4*c0*(1 + si*beta)/D;
295 S->a2 = 2*(1 + 2*c0*c0 - beta*beta)/D;
296 S->a3 = -4*c0*(1 - si*beta)/D;
297 S->a4 = (beta*beta - 2*si*beta + 1)/D;
301 static void butterworth_bp_filter(EqualizatorFilter *f,
302 int N, double w0, double wb,
303 double G, double Gb, double G0)
305 double g, c0, g0, beta;
311 if (G == 0 && G0 == 0) {
312 f->section[0].a0 = 1;
313 f->section[0].b0 = 1;
314 f->section[1].a0 = 1;
315 f->section[1].b0 = 1;
320 Gb = ff_exp10(Gb/20);
321 G0 = ff_exp10(G0/20);
323 epsilon = sqrt((G * G - Gb * Gb) / (Gb * Gb - G0 * G0));
325 g0 = pow(G0, 1.0 / N);
326 beta = pow(epsilon, -1.0 / N) * tan(wb/2);
329 for (i = 1; i <= L; i++) {
330 double ui = (2.0 * i - 1) / N;
331 double si = sin(M_PI * ui / 2.0);
332 double Di = beta * beta + 2 * si * beta + 1;
334 butterworth_fo_section(&f->section[i - 1], beta, si, g, g0, Di, c0);
338 static void chebyshev1_fo_section(FoSection *S, double a,
339 double c, double tetta_b,
340 double g0, double si, double b,
343 if (c0 == 1 || c0 == -1) {
344 S->b0 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) + 2*g0*b*si*tetta_b*tetta_b + g0*g0)/D;
345 S->b1 = 2*c0*(tetta_b*tetta_b*(b*b+g0*g0*c*c) - g0*g0)/D;
346 S->b2 = (tetta_b*tetta_b*(b*b+g0*g0*c*c) - 2*g0*b*si*tetta_b + g0*g0)/D;
351 S->a1 = 2*c0*(tetta_b*tetta_b*(a*a+c*c) - 1)/D;
352 S->a2 = (tetta_b*tetta_b*(a*a+c*c) - 2*a*si*tetta_b + 1)/D;
356 S->b0 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b + 2*g0*b*si*tetta_b + g0*g0)/D;
357 S->b1 = -4*c0*(g0*g0 + g0*b*si*tetta_b)/D;
358 S->b2 = 2*(g0*g0*(1 + 2*c0*c0) - (b*b + g0*g0*c*c)*tetta_b*tetta_b)/D;
359 S->b3 = -4*c0*(g0*g0 - g0*b*si*tetta_b)/D;
360 S->b4 = ((b*b + g0*g0*c*c)*tetta_b*tetta_b - 2*g0*b*si*tetta_b + g0*g0)/D;
363 S->a1 = -4*c0*(1 + a*si*tetta_b)/D;
364 S->a2 = 2*(1 + 2*c0*c0 - (a*a + c*c)*tetta_b*tetta_b)/D;
365 S->a3 = -4*c0*(1 - a*si*tetta_b)/D;
366 S->a4 = ((a*a + c*c)*tetta_b*tetta_b - 2*a*si*tetta_b + 1)/D;
370 static void chebyshev1_bp_filter(EqualizatorFilter *f,
371 int N, double w0, double wb,
372 double G, double Gb, double G0)
374 double a, b, c0, g0, alfa, beta, tetta_b;
380 if (G == 0 && G0 == 0) {
381 f->section[0].a0 = 1;
382 f->section[0].b0 = 1;
383 f->section[1].a0 = 1;
384 f->section[1].b0 = 1;
389 Gb = ff_exp10(Gb/20);
390 G0 = ff_exp10(G0/20);
392 epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
394 alfa = pow(1.0/epsilon + sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
395 beta = pow(G/epsilon + Gb * sqrt(1 + 1/(epsilon*epsilon)), 1.0/N);
396 a = 0.5 * (alfa - 1.0/alfa);
397 b = 0.5 * (beta - g0*g0*(1/beta));
401 for (i = 1; i <= L; i++) {
402 double ui = (2.0*i-1.0)/N;
403 double ci = cos(M_PI*ui/2.0);
404 double si = sin(M_PI*ui/2.0);
405 double Di = (a*a + ci*ci)*tetta_b*tetta_b + 2.0*a*si*tetta_b + 1;
407 chebyshev1_fo_section(&f->section[i - 1], a, ci, tetta_b, g0, si, b, Di, c0);
411 static void chebyshev2_fo_section(FoSection *S, double a,
412 double c, double tetta_b,
413 double g, double si, double b,
416 if (c0 == 1 || c0 == -1) {
417 S->b0 = (g*g*tetta_b*tetta_b + 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
418 S->b1 = 2*c0*(g*g*tetta_b*tetta_b - b*b - g*g*c*c)/D;
419 S->b2 = (g*g*tetta_b*tetta_b - 2*tetta_b*g*b*si + b*b + g*g*c*c)/D;
424 S->a1 = 2*c0*(tetta_b*tetta_b - a*a - c*c)/D;
425 S->a2 = (tetta_b*tetta_b - 2*tetta_b*a*si + a*a + c*c)/D;
429 S->b0 = (g*g*tetta_b*tetta_b + 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
430 S->b1 = -4*c0*(b*b + g*g*c*c + g*b*si*tetta_b)/D;
431 S->b2 = 2*((b*b + g*g*c*c)*(1 + 2*c0*c0) - g*g*tetta_b*tetta_b)/D;
432 S->b3 = -4*c0*(b*b + g*g*c*c - g*b*si*tetta_b)/D;
433 S->b4 = (g*g*tetta_b*tetta_b - 2*g*b*si*tetta_b + b*b + g*g*c*c)/D;
436 S->a1 = -4*c0*(a*a + c*c + a*si*tetta_b)/D;
437 S->a2 = 2*((a*a + c*c)*(1 + 2*c0*c0) - tetta_b*tetta_b)/D;
438 S->a3 = -4*c0*(a*a + c*c - a*si*tetta_b)/D;
439 S->a4 = (tetta_b*tetta_b - 2*a*si*tetta_b + a*a + c*c)/D;
443 static void chebyshev2_bp_filter(EqualizatorFilter *f,
444 int N, double w0, double wb,
445 double G, double Gb, double G0)
447 double a, b, c0, tetta_b;
448 double epsilon, g, eu, ew;
453 if (G == 0 && G0 == 0) {
454 f->section[0].a0 = 1;
455 f->section[0].b0 = 1;
456 f->section[1].a0 = 1;
457 f->section[1].b0 = 1;
462 Gb = ff_exp10(Gb/20);
463 G0 = ff_exp10(G0/20);
465 epsilon = sqrt((G*G - Gb*Gb) / (Gb*Gb - G0*G0));
467 eu = pow(epsilon + sqrt(1 + epsilon*epsilon), 1.0/N);
468 ew = pow(G0*epsilon + Gb*sqrt(1 + epsilon*epsilon), 1.0/N);
469 a = (eu - 1.0/eu)/2.0;
470 b = (ew - g*g/ew)/2.0;
474 for (i = 1; i <= L; i++) {
475 double ui = (2.0 * i - 1.0)/N;
476 double ci = cos(M_PI * ui / 2.0);
477 double si = sin(M_PI * ui / 2.0);
478 double Di = tetta_b*tetta_b + 2*a*si*tetta_b + a*a + ci*ci;
480 chebyshev2_fo_section(&f->section[i - 1], a, ci, tetta_b, g, si, b, Di, c0);
484 static double butterworth_compute_bw_gain_db(double gain)
490 else if(gain > -6 && gain < 6)
491 bw_gain = gain * 0.5;
498 static double chebyshev1_compute_bw_gain_db(double gain)
504 else if(gain > -6 && gain < 6)
505 bw_gain = gain * 0.9;
512 static double chebyshev2_compute_bw_gain_db(double gain)
518 else if(gain > -6 && gain < 6)
519 bw_gain = gain * 0.3;
526 static inline double hz_2_rad(double x, double fs)
528 return 2 * M_PI * x / fs;
531 static void equalizer(EqualizatorFilter *f, double sample_rate)
533 double w0 = hz_2_rad(f->freq, sample_rate);
534 double wb = hz_2_rad(f->width, sample_rate);
539 bw_gain = butterworth_compute_bw_gain_db(f->gain);
540 butterworth_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
543 bw_gain = chebyshev1_compute_bw_gain_db(f->gain);
544 chebyshev1_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
547 bw_gain = chebyshev2_compute_bw_gain_db(f->gain);
548 chebyshev2_bp_filter(f, FILTER_ORDER, w0, wb, f->gain, bw_gain, 0);
554 static int add_filter(AudioNEqualizerContext *s, AVFilterLink *inlink)
556 equalizer(&s->filters[s->nb_filters], inlink->sample_rate);
557 if (s->nb_filters >= s->nb_allocated) {
558 EqualizatorFilter *filters;
560 filters = av_calloc(s->nb_allocated, 2 * sizeof(*s->filters));
562 return AVERROR(ENOMEM);
563 memcpy(filters, s->filters, sizeof(*s->filters) * s->nb_allocated);
565 s->filters = filters;
566 s->nb_allocated *= 2;
573 static int config_input(AVFilterLink *inlink)
575 AVFilterContext *ctx = inlink->dst;
576 AudioNEqualizerContext *s = ctx->priv;
577 char *args = av_strdup(s->args);
578 char *saveptr = NULL;
582 return AVERROR(ENOMEM);
584 s->nb_allocated = 32 * inlink->channels;
585 s->filters = av_calloc(inlink->channels, 32 * sizeof(*s->filters));
589 return AVERROR(ENOMEM);
593 char *arg = av_strtok(s->nb_filters == 0 ? args : NULL, "|", &saveptr);
598 s->filters[s->nb_filters].type = 0;
599 if (sscanf(arg, "c%d f=%lf w=%lf g=%lf t=%d", &s->filters[s->nb_filters].channel,
600 &s->filters[s->nb_filters].freq,
601 &s->filters[s->nb_filters].width,
602 &s->filters[s->nb_filters].gain,
603 &s->filters[s->nb_filters].type) != 5 &&
604 sscanf(arg, "c%d f=%lf w=%lf g=%lf", &s->filters[s->nb_filters].channel,
605 &s->filters[s->nb_filters].freq,
606 &s->filters[s->nb_filters].width,
607 &s->filters[s->nb_filters].gain) != 4 ) {
609 return AVERROR(EINVAL);
612 if (s->filters[s->nb_filters].freq < 0 ||
613 s->filters[s->nb_filters].freq > inlink->sample_rate / 2.0)
614 s->filters[s->nb_filters].ignore = 1;
616 if (s->filters[s->nb_filters].channel < 0 ||
617 s->filters[s->nb_filters].channel >= inlink->channels)
618 s->filters[s->nb_filters].ignore = 1;
620 s->filters[s->nb_filters].type = av_clip(s->filters[s->nb_filters].type, 0, NB_TYPES - 1);
621 ret = add_filter(s, inlink);
631 static int process_command(AVFilterContext *ctx, const char *cmd, const char *args,
632 char *res, int res_len, int flags)
634 AudioNEqualizerContext *s = ctx->priv;
635 AVFilterLink *inlink = ctx->inputs[0];
636 int ret = AVERROR(ENOSYS);
638 if (!strcmp(cmd, "change")) {
639 double freq, width, gain;
642 if (sscanf(args, "%d|f=%lf|w=%lf|g=%lf", &filter, &freq, &width, &gain) != 4)
643 return AVERROR(EINVAL);
645 if (filter < 0 || filter >= s->nb_filters)
646 return AVERROR(EINVAL);
648 if (freq < 0 || freq > inlink->sample_rate / 2.0)
649 return AVERROR(EINVAL);
651 s->filters[filter].freq = freq;
652 s->filters[filter].width = width;
653 s->filters[filter].gain = gain;
654 equalizer(&s->filters[filter], inlink->sample_rate);
656 draw_curves(ctx, inlink, s->video);
664 static inline double section_process(FoSection *S, double in)
669 out+= S->b1 * S->num[0] - S->denum[0] * S->a1;
670 out+= S->b2 * S->num[1] - S->denum[1] * S->a2;
671 out+= S->b3 * S->num[2] - S->denum[2] * S->a3;
672 out+= S->b4 * S->num[3] - S->denum[3] * S->a4;
674 S->num[3] = S->num[2];
675 S->num[2] = S->num[1];
676 S->num[1] = S->num[0];
679 S->denum[3] = S->denum[2];
680 S->denum[2] = S->denum[1];
681 S->denum[1] = S->denum[0];
687 static double process_sample(FoSection *s1, double in)
692 for (i = 0; i < FILTER_ORDER / 2; i++) {
693 p1 = section_process(&s1[i], p0);
700 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
702 AVFilterContext *ctx = inlink->dst;
703 AudioNEqualizerContext *s = ctx->priv;
704 AVFilterLink *outlink = ctx->outputs[0];
708 for (i = 0; i < s->nb_filters; i++) {
709 EqualizatorFilter *f = &s->filters[i];
711 if (f->gain == 0. || f->ignore)
714 bptr = (double *)buf->extended_data[f->channel];
715 for (n = 0; n < buf->nb_samples; n++) {
716 double sample = bptr[n];
718 sample = process_sample(f->section, sample);
723 if (s->draw_curves) {
724 const int64_t pts = buf->pts +
725 av_rescale_q(buf->nb_samples, (AVRational){ 1, inlink->sample_rate },
730 ret = ff_filter_frame(ctx->outputs[1], av_frame_clone(s->video));
735 return ff_filter_frame(outlink, buf);
738 static const AVFilterPad inputs[] = {
741 .type = AVMEDIA_TYPE_AUDIO,
742 .config_props = config_input,
743 .filter_frame = filter_frame,
749 AVFilter ff_af_anequalizer = {
750 .name = "anequalizer",
751 .description = NULL_IF_CONFIG_SMALL("Apply high-order audio parametric multi band equalizer."),
752 .priv_size = sizeof(AudioNEqualizerContext),
753 .priv_class = &anequalizer_class,
756 .query_formats = query_formats,
759 .flags = AVFILTER_FLAG_DYNAMIC_OUTPUTS,
760 .process_command = process_command,