2 * Copyright (c) 2013 Paul B Mahol
3 * Copyright (c) 2006-2008 Rob Sykes <robs@users.sourceforge.net>
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
23 * 2-pole filters designed by Robert Bristow-Johnson <rbj@audioimagination.com>
24 * see http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
26 * 1-pole filters based on code (c) 2000 Chris Bagwell <cbagwell@sprynet.com>
27 * Algorithms: Recursive single pole low/high pass filter
28 * Reference: The Scientist and Engineer's Guide to Digital Signal Processing
30 * low-pass: output[N] = input[N] * A + output[N-1] * B
31 * X = exp(-2.0 * pi * Fc)
34 * Fc = cutoff freq / sample rate
36 * Mimics an RC low-pass filter:
38 * ---/\/\/\/\----------->
46 * high-pass: output[N] = A0 * input[N] + A1 * input[N-1] + B1 * output[N-1]
47 * X = exp(-2.0 * pi * Fc)
51 * Fc = cutoff freq / sample rate
53 * Mimics an RC high-pass filter:
65 #include "libavutil/opt.h"
66 #include "libavutil/avassert.h"
92 typedef struct ChanCache {
100 enum FilterType filter_type;
101 enum WidthType width_type;
114 void (*filter)(const void *ibuf, void *obuf, int len,
115 double *i1, double *i2, double *o1, double *o2,
116 double b0, double b1, double b2, double a1, double a2);
119 static av_cold int init(AVFilterContext *ctx, const char *args)
121 BiquadsContext *p = ctx->priv;
123 if (p->filter_type != biquad) {
124 if (p->frequency <= 0 || p->width <= 0) {
125 av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f and/or width %f <= 0\n",
126 p->frequency, p->width);
127 return AVERROR(EINVAL);
134 static int query_formats(AVFilterContext *ctx)
136 AVFilterFormats *formats;
137 AVFilterChannelLayouts *layouts;
138 static const enum AVSampleFormat sample_fmts[] = {
146 layouts = ff_all_channel_layouts();
148 return AVERROR(ENOMEM);
149 ff_set_common_channel_layouts(ctx, layouts);
151 formats = ff_make_format_list(sample_fmts);
153 return AVERROR(ENOMEM);
154 ff_set_common_formats(ctx, formats);
156 formats = ff_all_samplerates();
158 return AVERROR(ENOMEM);
159 ff_set_common_samplerates(ctx, formats);
164 #define BIQUAD_FILTER(name, type, min, max) \
165 static void biquad_## name (const void *input, void *output, int len, \
166 double *in1, double *in2, \
167 double *out1, double *out2, \
168 double b0, double b1, double b2, \
169 double a1, double a2) \
171 const type *ibuf = input; \
172 type *obuf = output; \
181 for (i = 0; i+1 < len; i++) { \
182 o2 = i2 * b2 + i1 * b1 + ibuf[i] * b0 + o2 * a2 + o1 * a1; \
185 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
187 } else if (o2 > max) { \
188 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
194 o1 = i1 * b2 + i2 * b1 + ibuf[i] * b0 + o1 * a2 + o2 * a1; \
197 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
199 } else if (o1 > max) { \
200 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
207 double o0 = ibuf[i] * b0 + i1 * b1 + i2 * b2 + o1 * a1 + o2 * a2; \
213 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
215 } else if (o0 > max) { \
216 av_log(NULL, AV_LOG_WARNING, "clipping\n"); \
228 BIQUAD_FILTER(s16, int16_t, INT16_MIN, INT16_MAX)
229 BIQUAD_FILTER(s32, int32_t, INT32_MIN, INT32_MAX)
230 BIQUAD_FILTER(flt, float, -1., 1.)
231 BIQUAD_FILTER(dbl, double, -1., 1.)
233 static int config_output(AVFilterLink *outlink)
235 AVFilterContext *ctx = outlink->src;
236 BiquadsContext *p = ctx->priv;
237 AVFilterLink *inlink = ctx->inputs[0];
238 double A = exp(p->gain / 40 * log(10.));
239 double w0 = 2 * M_PI * p->frequency / inlink->sample_rate;
243 av_log(ctx, AV_LOG_ERROR,
244 "Invalid frequency %f. Frequency must be less than half the sample-rate %d.\n",
245 p->frequency, inlink->sample_rate);
246 return AVERROR(EINVAL);
249 switch (p->width_type) {
254 alpha = sin(w0) / (2 * p->frequency / p->width);
257 alpha = sin(w0) * sinh(log(2.) / 2 * p->width * w0 / sin(w0));
260 alpha = sin(w0) / (2 * p->width);
263 alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / p->width - 1) + 2);
269 switch (p->filter_type) {
273 p->a0 = 1 + alpha / A;
274 p->a1 = -2 * cos(w0);
275 p->a2 = 1 - alpha / A;
276 p->b0 = 1 + alpha * A;
277 p->b1 = -2 * cos(w0);
278 p->b2 = 1 - alpha * A;
281 p->a0 = (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
282 p->a1 = -2 * ((A - 1) + (A + 1) * cos(w0));
283 p->a2 = (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
284 p->b0 = A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
285 p->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0));
286 p->b2 = A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
289 p->a0 = (A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
290 p->a1 = 2 * ((A - 1) - (A + 1) * cos(w0));
291 p->a2 = (A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
292 p->b0 = A * ((A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
293 p->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0));
294 p->b2 = A * ((A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
299 p->a1 = -2 * cos(w0);
303 p->b2 = -sin(w0) / 2;
306 p->a1 = -2 * cos(w0);
315 p->a1 = -2 * cos(w0);
318 p->b1 = -2 * cos(w0);
331 p->a1 = -2 * cos(w0);
333 p->b0 = (1 - cos(w0)) / 2;
335 p->b2 = (1 - cos(w0)) / 2;
343 p->b0 = (1 - p->a1) / 2;
348 p->a1 = -2 * cos(w0);
350 p->b0 = (1 + cos(w0)) / 2;
351 p->b1 = -(1 + cos(w0));
352 p->b2 = (1 + cos(w0)) / 2;
357 p->a1 = -2 * cos(w0);
360 p->b1 = -2 * cos(w0);
373 p->cache = av_realloc_f(p->cache, sizeof(ChanCache), inlink->channels);
375 return AVERROR(ENOMEM);
376 memset(p->cache, 0, sizeof(ChanCache) * inlink->channels);
378 switch (inlink->format) {
379 case AV_SAMPLE_FMT_S16P: p->filter = biquad_s16; break;
380 case AV_SAMPLE_FMT_S32P: p->filter = biquad_s32; break;
381 case AV_SAMPLE_FMT_FLTP: p->filter = biquad_flt; break;
382 case AV_SAMPLE_FMT_DBLP: p->filter = biquad_dbl; break;
383 default: av_assert0(0);
389 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
391 BiquadsContext *p = inlink->dst->priv;
392 AVFilterLink *outlink = inlink->dst->outputs[0];
394 int nb_samples = buf->nb_samples;
397 if (av_frame_is_writable(buf)) {
400 out_buf = ff_get_audio_buffer(inlink, nb_samples);
402 return AVERROR(ENOMEM);
403 av_frame_copy_props(out_buf, buf);
406 for (ch = 0; ch < av_frame_get_channels(buf); ch++)
407 p->filter(buf->extended_data[ch],
408 out_buf->extended_data[ch], nb_samples,
409 &p->cache[ch].i1, &p->cache[ch].i2,
410 &p->cache[ch].o1, &p->cache[ch].o2,
411 p->b0, p->b1, p->b2, p->a1, p->a2);
416 return ff_filter_frame(outlink, out_buf);
419 static av_cold void uninit(AVFilterContext *ctx)
421 BiquadsContext *p = ctx->priv;
426 static const AVFilterPad inputs[] = {
429 .type = AVMEDIA_TYPE_AUDIO,
430 .filter_frame = filter_frame,
435 static const AVFilterPad outputs[] = {
438 .type = AVMEDIA_TYPE_AUDIO,
439 .config_props = config_output,
444 #define OFFSET(x) offsetof(BiquadsContext, x)
445 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
447 #define DEFINE_BIQUAD_FILTER(name_, description_) \
448 AVFILTER_DEFINE_CLASS(name_); \
449 static av_cold int name_##_init(AVFilterContext *ctx, const char *args) \
451 BiquadsContext *p = ctx->priv; \
452 p->class = &name_##_class; \
453 p->filter_type = name_; \
454 return init(ctx, args); \
457 AVFilter avfilter_af_##name_ = { \
459 .description = NULL_IF_CONFIG_SMALL(description_), \
460 .priv_size = sizeof(BiquadsContext), \
461 .init = name_##_init, \
463 .query_formats = query_formats, \
465 .outputs = outputs, \
466 .priv_class = &name_##_class, \
469 #if CONFIG_EQUALIZER_FILTER
470 static const AVOption equalizer_options[] = {
471 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
472 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
473 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
474 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
475 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
476 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
477 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
478 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
479 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
480 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
481 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
485 DEFINE_BIQUAD_FILTER(equalizer, "Apply two-pole peaking equalization (EQ) filter.");
486 #endif /* CONFIG_EQUALIZER_FILTER */
487 #if CONFIG_BASS_FILTER
488 static const AVOption bass_options[] = {
489 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
490 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
491 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
492 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
493 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
494 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
495 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
496 {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
497 {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
498 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
499 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
503 DEFINE_BIQUAD_FILTER(bass, "Boost or cut lower frequencies.");
504 #endif /* CONFIG_BASS_FILTER */
505 #if CONFIG_TREBLE_FILTER
506 static const AVOption treble_options[] = {
507 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
508 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
509 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
510 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
511 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
512 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
513 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
514 {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
515 {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
516 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
517 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
521 DEFINE_BIQUAD_FILTER(treble, "Boost or cut upper frequencies.");
522 #endif /* CONFIG_TREBLE_FILTER */
523 #if CONFIG_BANDPASS_FILTER
524 static const AVOption bandpass_options[] = {
525 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
526 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
527 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
528 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
529 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
530 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
531 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
532 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
533 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
534 {"csg", "use constant skirt gain", OFFSET(csg), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS},
538 DEFINE_BIQUAD_FILTER(bandpass, "Apply a two-pole Butterworth band-pass filter.");
539 #endif /* CONFIG_BANDPASS_FILTER */
540 #if CONFIG_BANDREJECT_FILTER
541 static const AVOption bandreject_options[] = {
542 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
543 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
544 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
545 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
546 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
547 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
548 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
549 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
550 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
554 DEFINE_BIQUAD_FILTER(bandreject, "Apply a two-pole Butterworth band-reject filter.");
555 #endif /* CONFIG_BANDREJECT_FILTER */
556 #if CONFIG_LOWPASS_FILTER
557 static const AVOption lowpass_options[] = {
558 {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
559 {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
560 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
561 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
562 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
563 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
564 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
565 {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
566 {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
567 {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
568 {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
572 DEFINE_BIQUAD_FILTER(lowpass, "Apply a low-pass filter with 3dB point frequency.");
573 #endif /* CONFIG_LOWPASS_FILTER */
574 #if CONFIG_HIGHPASS_FILTER
575 static const AVOption highpass_options[] = {
576 {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
577 {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
578 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HZ, SLOPE, FLAGS, "width_type"},
579 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
580 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
581 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
582 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
583 {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
584 {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
585 {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
586 {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
590 DEFINE_BIQUAD_FILTER(highpass, "Apply a high-pass filter with 3dB point frequency.");
591 #endif /* CONFIG_HIGHPASS_FILTER */
592 #if CONFIG_ALLPASS_FILTER
593 static const AVOption allpass_options[] = {
594 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
595 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
596 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HZ}, HZ, SLOPE, FLAGS, "width_type"},
597 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HZ}, 0, 0, FLAGS, "width_type"},
598 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
599 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
600 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
601 {"width", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
602 {"w", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
606 DEFINE_BIQUAD_FILTER(allpass, "Apply a two-pole all-pass filter.");
607 #endif /* CONFIG_ALLPASS_FILTER */
608 #if CONFIG_BIQUAD_FILTER
609 static const AVOption biquad_options[] = {
610 {"a0", NULL, OFFSET(a0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
611 {"a1", NULL, OFFSET(a1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
612 {"a2", NULL, OFFSET(a2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
613 {"b0", NULL, OFFSET(b0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
614 {"b1", NULL, OFFSET(b1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
615 {"b2", NULL, OFFSET(b2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
619 DEFINE_BIQUAD_FILTER(biquad, "Apply a biquad IIR filter with the given coefficients.");
620 #endif /* CONFIG_BIQUAD_FILTER */