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/avassert.h"
66 #include "libavutil/opt.h"
92 typedef struct ChanCache {
100 enum FilterType filter_type;
114 void (*filter)(AVFilterContext *ctx, 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)
121 BiquadsContext *s = ctx->priv;
123 if (s->filter_type != biquad) {
124 if (s->frequency <= 0 || s->width <= 0) {
125 av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f and/or width %f <= 0\n",
126 s->frequency, s->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[] = {
147 layouts = ff_all_channel_counts();
149 return AVERROR(ENOMEM);
150 ret = ff_set_common_channel_layouts(ctx, layouts);
154 formats = ff_make_format_list(sample_fmts);
156 return AVERROR(ENOMEM);
157 ret = ff_set_common_formats(ctx, formats);
161 formats = ff_all_samplerates();
163 return AVERROR(ENOMEM);
164 return ff_set_common_samplerates(ctx, formats);
167 #define BIQUAD_FILTER(name, type, min, max, need_clipping) \
168 static void biquad_## name (AVFilterContext *ctx, \
169 const void *input, void *output, int len, \
170 double *in1, double *in2, \
171 double *out1, double *out2, \
172 double b0, double b1, double b2, \
173 double a1, double a2) \
175 const type *ibuf = input; \
176 type *obuf = output; \
185 for (i = 0; i+1 < len; i++) { \
186 o2 = i2 * b2 + i1 * b1 + ibuf[i] * b0 + o2 * a2 + o1 * a1; \
188 if (need_clipping && o2 < min) { \
189 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
191 } else if (need_clipping && o2 > max) { \
192 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
198 o1 = i1 * b2 + i2 * b1 + ibuf[i] * b0 + o1 * a2 + o2 * a1; \
200 if (need_clipping && o1 < min) { \
201 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
203 } else if (need_clipping && o1 > max) { \
204 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
211 double o0 = ibuf[i] * b0 + i1 * b1 + i2 * b2 + o1 * a1 + o2 * a2; \
216 if (need_clipping && o0 < min) { \
217 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
219 } else if (need_clipping && o0 > max) { \
220 av_log(ctx, AV_LOG_WARNING, "clipping\n"); \
232 BIQUAD_FILTER(s16, int16_t, INT16_MIN, INT16_MAX, 1)
233 BIQUAD_FILTER(s32, int32_t, INT32_MIN, INT32_MAX, 1)
234 BIQUAD_FILTER(flt, float, -1., 1., 0)
235 BIQUAD_FILTER(dbl, double, -1., 1., 0)
237 static int config_output(AVFilterLink *outlink)
239 AVFilterContext *ctx = outlink->src;
240 BiquadsContext *s = ctx->priv;
241 AVFilterLink *inlink = ctx->inputs[0];
242 double A = exp(s->gain / 40 * log(10.));
243 double w0 = 2 * M_PI * s->frequency / inlink->sample_rate;
247 av_log(ctx, AV_LOG_ERROR,
248 "Invalid frequency %f. Frequency must be less than half the sample-rate %d.\n",
249 s->frequency, inlink->sample_rate);
250 return AVERROR(EINVAL);
253 switch (s->width_type) {
258 alpha = sin(w0) / (2 * s->frequency / s->width);
261 alpha = sin(w0) * sinh(log(2.) / 2 * s->width * w0 / sin(w0));
264 alpha = sin(w0) / (2 * s->width);
267 alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / s->width - 1) + 2);
273 switch (s->filter_type) {
277 s->a0 = 1 + alpha / A;
278 s->a1 = -2 * cos(w0);
279 s->a2 = 1 - alpha / A;
280 s->b0 = 1 + alpha * A;
281 s->b1 = -2 * cos(w0);
282 s->b2 = 1 - alpha * A;
285 s->a0 = (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
286 s->a1 = -2 * ((A - 1) + (A + 1) * cos(w0));
287 s->a2 = (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
288 s->b0 = A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
289 s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0));
290 s->b2 = A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
293 s->a0 = (A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
294 s->a1 = 2 * ((A - 1) - (A + 1) * cos(w0));
295 s->a2 = (A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
296 s->b0 = A * ((A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
297 s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0));
298 s->b2 = A * ((A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
303 s->a1 = -2 * cos(w0);
307 s->b2 = -sin(w0) / 2;
310 s->a1 = -2 * cos(w0);
319 s->a1 = -2 * cos(w0);
322 s->b1 = -2 * cos(w0);
335 s->a1 = -2 * cos(w0);
337 s->b0 = (1 - cos(w0)) / 2;
339 s->b2 = (1 - cos(w0)) / 2;
347 s->b0 = (1 - s->a1) / 2;
352 s->a1 = -2 * cos(w0);
354 s->b0 = (1 + cos(w0)) / 2;
355 s->b1 = -(1 + cos(w0));
356 s->b2 = (1 + cos(w0)) / 2;
361 s->a1 = -2 * cos(w0);
364 s->b1 = -2 * cos(w0);
377 s->cache = av_realloc_f(s->cache, sizeof(ChanCache), inlink->channels);
379 return AVERROR(ENOMEM);
380 memset(s->cache, 0, sizeof(ChanCache) * inlink->channels);
382 switch (inlink->format) {
383 case AV_SAMPLE_FMT_S16P: s->filter = biquad_s16; break;
384 case AV_SAMPLE_FMT_S32P: s->filter = biquad_s32; break;
385 case AV_SAMPLE_FMT_FLTP: s->filter = biquad_flt; break;
386 case AV_SAMPLE_FMT_DBLP: s->filter = biquad_dbl; break;
387 default: av_assert0(0);
393 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
395 AVFilterContext *ctx = inlink->dst;
396 BiquadsContext *s = ctx->priv;
397 AVFilterLink *outlink = ctx->outputs[0];
399 int nb_samples = buf->nb_samples;
402 if (av_frame_is_writable(buf)) {
405 out_buf = ff_get_audio_buffer(inlink, nb_samples);
408 return AVERROR(ENOMEM);
410 av_frame_copy_props(out_buf, buf);
413 for (ch = 0; ch < av_frame_get_channels(buf); ch++)
414 s->filter(ctx, buf->extended_data[ch],
415 out_buf->extended_data[ch], nb_samples,
416 &s->cache[ch].i1, &s->cache[ch].i2,
417 &s->cache[ch].o1, &s->cache[ch].o2,
418 s->b0, s->b1, s->b2, s->a1, s->a2);
423 return ff_filter_frame(outlink, out_buf);
426 static av_cold void uninit(AVFilterContext *ctx)
428 BiquadsContext *s = ctx->priv;
433 static const AVFilterPad inputs[] = {
436 .type = AVMEDIA_TYPE_AUDIO,
437 .filter_frame = filter_frame,
442 static const AVFilterPad outputs[] = {
445 .type = AVMEDIA_TYPE_AUDIO,
446 .config_props = config_output,
451 #define OFFSET(x) offsetof(BiquadsContext, x)
452 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
454 #define DEFINE_BIQUAD_FILTER(name_, description_) \
455 AVFILTER_DEFINE_CLASS(name_); \
456 static av_cold int name_##_init(AVFilterContext *ctx) \
458 BiquadsContext *s = ctx->priv; \
459 s->class = &name_##_class; \
460 s->filter_type = name_; \
464 AVFilter ff_af_##name_ = { \
466 .description = NULL_IF_CONFIG_SMALL(description_), \
467 .priv_size = sizeof(BiquadsContext), \
468 .init = name_##_init, \
470 .query_formats = query_formats, \
472 .outputs = outputs, \
473 .priv_class = &name_##_class, \
476 #if CONFIG_EQUALIZER_FILTER
477 static const AVOption equalizer_options[] = {
478 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
479 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
480 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
481 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
482 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
483 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
484 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
485 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
486 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
487 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
488 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
492 DEFINE_BIQUAD_FILTER(equalizer, "Apply two-pole peaking equalization (EQ) filter.");
493 #endif /* CONFIG_EQUALIZER_FILTER */
494 #if CONFIG_BASS_FILTER
495 static const AVOption bass_options[] = {
496 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
497 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
498 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
499 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
500 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
501 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
502 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
503 {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
504 {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
505 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
506 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
510 DEFINE_BIQUAD_FILTER(bass, "Boost or cut lower frequencies.");
511 #endif /* CONFIG_BASS_FILTER */
512 #if CONFIG_TREBLE_FILTER
513 static const AVOption treble_options[] = {
514 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
515 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
516 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
517 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
518 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
519 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
520 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
521 {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
522 {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
523 {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
524 {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
528 DEFINE_BIQUAD_FILTER(treble, "Boost or cut upper frequencies.");
529 #endif /* CONFIG_TREBLE_FILTER */
530 #if CONFIG_BANDPASS_FILTER
531 static const AVOption bandpass_options[] = {
532 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
533 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
534 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
535 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
536 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
537 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
538 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
539 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
540 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
541 {"csg", "use constant skirt gain", OFFSET(csg), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},
545 DEFINE_BIQUAD_FILTER(bandpass, "Apply a two-pole Butterworth band-pass filter.");
546 #endif /* CONFIG_BANDPASS_FILTER */
547 #if CONFIG_BANDREJECT_FILTER
548 static const AVOption bandreject_options[] = {
549 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
550 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
551 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
552 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
553 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
554 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
555 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
556 {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
557 {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
561 DEFINE_BIQUAD_FILTER(bandreject, "Apply a two-pole Butterworth band-reject filter.");
562 #endif /* CONFIG_BANDREJECT_FILTER */
563 #if CONFIG_LOWPASS_FILTER
564 static const AVOption lowpass_options[] = {
565 {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
566 {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
567 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
568 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
569 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
570 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
571 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
572 {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
573 {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
574 {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
575 {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
579 DEFINE_BIQUAD_FILTER(lowpass, "Apply a low-pass filter with 3dB point frequency.");
580 #endif /* CONFIG_LOWPASS_FILTER */
581 #if CONFIG_HIGHPASS_FILTER
582 static const AVOption highpass_options[] = {
583 {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
584 {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
585 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
586 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
587 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
588 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
589 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
590 {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
591 {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
592 {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
593 {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
597 DEFINE_BIQUAD_FILTER(highpass, "Apply a high-pass filter with 3dB point frequency.");
598 #endif /* CONFIG_HIGHPASS_FILTER */
599 #if CONFIG_ALLPASS_FILTER
600 static const AVOption allpass_options[] = {
601 {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
602 {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
603 {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HERTZ}, HERTZ, SLOPE, FLAGS, "width_type"},
604 {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
605 {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
606 {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
607 {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
608 {"width", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
609 {"w", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
613 DEFINE_BIQUAD_FILTER(allpass, "Apply a two-pole all-pass filter.");
614 #endif /* CONFIG_ALLPASS_FILTER */
615 #if CONFIG_BIQUAD_FILTER
616 static const AVOption biquad_options[] = {
617 {"a0", NULL, OFFSET(a0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
618 {"a1", NULL, OFFSET(a1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
619 {"a2", NULL, OFFSET(a2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
620 {"b0", NULL, OFFSET(b0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
621 {"b1", NULL, OFFSET(b1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
622 {"b2", NULL, OFFSET(b2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
626 DEFINE_BIQUAD_FILTER(biquad, "Apply a biquad IIR filter with the given coefficients.");
627 #endif /* CONFIG_BIQUAD_FILTER */