lavfi/dynaudnorm: rename pow2 to pow_2
[ffmpeg.git] / libavfilter / af_biquads.c
1 /*
2  * Copyright (c) 2013 Paul B Mahol
3  * Copyright (c) 2006-2008 Rob Sykes <robs@users.sourceforge.net>
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 /*
23  * 2-pole filters designed by Robert Bristow-Johnson <rbj@audioimagination.com>
24  *   see http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt
25  *
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
29  *
30  *   low-pass: output[N] = input[N] * A + output[N-1] * B
31  *     X = exp(-2.0 * pi * Fc)
32  *     A = 1 - X
33  *     B = X
34  *     Fc = cutoff freq / sample rate
35  *
36  *     Mimics an RC low-pass filter:
37  *
38  *     ---/\/\/\/\----------->
39  *                   |
40  *                  --- C
41  *                  ---
42  *                   |
43  *                   |
44  *                   V
45  *
46  *   high-pass: output[N] = A0 * input[N] + A1 * input[N-1] + B1 * output[N-1]
47  *     X  = exp(-2.0 * pi * Fc)
48  *     A0 = (1 + X) / 2
49  *     A1 = -(1 + X) / 2
50  *     B1 = X
51  *     Fc = cutoff freq / sample rate
52  *
53  *     Mimics an RC high-pass filter:
54  *
55  *         || C
56  *     ----||--------->
57  *         ||    |
58  *               <
59  *               > R
60  *               <
61  *               |
62  *               V
63  */
64
65 #include "libavutil/avassert.h"
66 #include "libavutil/opt.h"
67 #include "audio.h"
68 #include "avfilter.h"
69 #include "internal.h"
70
71 enum FilterType {
72     biquad,
73     equalizer,
74     bass,
75     treble,
76     band,
77     bandpass,
78     bandreject,
79     allpass,
80     highpass,
81     lowpass,
82 };
83
84 enum WidthType {
85     NONE,
86     HERTZ,
87     OCTAVE,
88     QFACTOR,
89     SLOPE,
90 };
91
92 typedef struct ChanCache {
93     double i1, i2;
94     double o1, o2;
95 } ChanCache;
96
97 typedef struct BiquadsContext {
98     const AVClass *class;
99
100     enum FilterType filter_type;
101     int width_type;
102     int poles;
103     int csg;
104
105     double gain;
106     double frequency;
107     double width;
108
109     double a0, a1, a2;
110     double b0, b1, b2;
111
112     ChanCache *cache;
113     int clippings;
114
115     void (*filter)(struct BiquadsContext *s, const void *ibuf, void *obuf, int len,
116                    double *i1, double *i2, double *o1, double *o2,
117                    double b0, double b1, double b2, double a1, double a2);
118 } BiquadsContext;
119
120 static av_cold int init(AVFilterContext *ctx)
121 {
122     BiquadsContext *s = ctx->priv;
123
124     if (s->filter_type != biquad) {
125         if (s->frequency <= 0 || s->width <= 0) {
126             av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f and/or width %f <= 0\n",
127                    s->frequency, s->width);
128             return AVERROR(EINVAL);
129         }
130     }
131
132     return 0;
133 }
134
135 static int query_formats(AVFilterContext *ctx)
136 {
137     AVFilterFormats *formats;
138     AVFilterChannelLayouts *layouts;
139     static const enum AVSampleFormat sample_fmts[] = {
140         AV_SAMPLE_FMT_S16P,
141         AV_SAMPLE_FMT_S32P,
142         AV_SAMPLE_FMT_FLTP,
143         AV_SAMPLE_FMT_DBLP,
144         AV_SAMPLE_FMT_NONE
145     };
146     int ret;
147
148     layouts = ff_all_channel_counts();
149     if (!layouts)
150         return AVERROR(ENOMEM);
151     ret = ff_set_common_channel_layouts(ctx, layouts);
152     if (ret < 0)
153         return ret;
154
155     formats = ff_make_format_list(sample_fmts);
156     if (!formats)
157         return AVERROR(ENOMEM);
158     ret = ff_set_common_formats(ctx, formats);
159     if (ret < 0)
160         return ret;
161
162     formats = ff_all_samplerates();
163     if (!formats)
164         return AVERROR(ENOMEM);
165     return ff_set_common_samplerates(ctx, formats);
166 }
167
168 #define BIQUAD_FILTER(name, type, min, max, need_clipping)                    \
169 static void biquad_## name (BiquadsContext *s,                                \
170                             const void *input, void *output, int len,         \
171                             double *in1, double *in2,                         \
172                             double *out1, double *out2,                       \
173                             double b0, double b1, double b2,                  \
174                             double a1, double a2)                             \
175 {                                                                             \
176     const type *ibuf = input;                                                 \
177     type *obuf = output;                                                      \
178     double i1 = *in1;                                                         \
179     double i2 = *in2;                                                         \
180     double o1 = *out1;                                                        \
181     double o2 = *out2;                                                        \
182     int i;                                                                    \
183     a1 = -a1;                                                                 \
184     a2 = -a2;                                                                 \
185                                                                               \
186     for (i = 0; i+1 < len; i++) {                                             \
187         o2 = i2 * b2 + i1 * b1 + ibuf[i] * b0 + o2 * a2 + o1 * a1;            \
188         i2 = ibuf[i];                                                         \
189         if (need_clipping && o2 < min) {                                      \
190             s->clippings++;                                                   \
191             obuf[i] = min;                                                    \
192         } else if (need_clipping && o2 > max) {                               \
193             s->clippings++;                                                   \
194             obuf[i] = max;                                                    \
195         } else {                                                              \
196             obuf[i] = o2;                                                     \
197         }                                                                     \
198         i++;                                                                  \
199         o1 = i1 * b2 + i2 * b1 + ibuf[i] * b0 + o1 * a2 + o2 * a1;            \
200         i1 = ibuf[i];                                                         \
201         if (need_clipping && o1 < min) {                                      \
202             s->clippings++;                                                   \
203             obuf[i] = min;                                                    \
204         } else if (need_clipping && o1 > max) {                               \
205             s->clippings++;                                                   \
206             obuf[i] = max;                                                    \
207         } else {                                                              \
208             obuf[i] = o1;                                                     \
209         }                                                                     \
210     }                                                                         \
211     if (i < len) {                                                            \
212         double o0 = ibuf[i] * b0 + i1 * b1 + i2 * b2 + o1 * a1 + o2 * a2;     \
213         i2 = i1;                                                              \
214         i1 = ibuf[i];                                                         \
215         o2 = o1;                                                              \
216         o1 = o0;                                                              \
217         if (need_clipping && o0 < min) {                                      \
218             s->clippings++;                                                   \
219             obuf[i] = min;                                                    \
220         } else if (need_clipping && o0 > max) {                               \
221             s->clippings++;                                                   \
222             obuf[i] = max;                                                    \
223         } else {                                                              \
224             obuf[i] = o0;                                                     \
225         }                                                                     \
226     }                                                                         \
227     *in1  = i1;                                                               \
228     *in2  = i2;                                                               \
229     *out1 = o1;                                                               \
230     *out2 = o2;                                                               \
231 }
232
233 BIQUAD_FILTER(s16, int16_t, INT16_MIN, INT16_MAX, 1)
234 BIQUAD_FILTER(s32, int32_t, INT32_MIN, INT32_MAX, 1)
235 BIQUAD_FILTER(flt, float,   -1., 1., 0)
236 BIQUAD_FILTER(dbl, double,  -1., 1., 0)
237
238 static int config_output(AVFilterLink *outlink)
239 {
240     AVFilterContext *ctx    = outlink->src;
241     BiquadsContext *s       = ctx->priv;
242     AVFilterLink *inlink    = ctx->inputs[0];
243     double A = exp(s->gain / 40 * log(10.));
244     double w0 = 2 * M_PI * s->frequency / inlink->sample_rate;
245     double alpha;
246
247     if (w0 > M_PI) {
248         av_log(ctx, AV_LOG_ERROR,
249                "Invalid frequency %f. Frequency must be less than half the sample-rate %d.\n",
250                s->frequency, inlink->sample_rate);
251         return AVERROR(EINVAL);
252     }
253
254     switch (s->width_type) {
255     case NONE:
256         alpha = 0.0;
257         break;
258     case HERTZ:
259         alpha = sin(w0) / (2 * s->frequency / s->width);
260         break;
261     case OCTAVE:
262         alpha = sin(w0) * sinh(log(2.) / 2 * s->width * w0 / sin(w0));
263         break;
264     case QFACTOR:
265         alpha = sin(w0) / (2 * s->width);
266         break;
267     case SLOPE:
268         alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / s->width - 1) + 2);
269         break;
270     default:
271         av_assert0(0);
272     }
273
274     switch (s->filter_type) {
275     case biquad:
276         break;
277     case equalizer:
278         s->a0 =   1 + alpha / A;
279         s->a1 =  -2 * cos(w0);
280         s->a2 =   1 - alpha / A;
281         s->b0 =   1 + alpha * A;
282         s->b1 =  -2 * cos(w0);
283         s->b2 =   1 - alpha * A;
284         break;
285     case bass:
286         s->a0 =          (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
287         s->a1 =    -2 * ((A - 1) + (A + 1) * cos(w0));
288         s->a2 =          (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
289         s->b0 =     A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
290         s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0));
291         s->b2 =     A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
292         break;
293     case treble:
294         s->a0 =          (A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
295         s->a1 =     2 * ((A - 1) - (A + 1) * cos(w0));
296         s->a2 =          (A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
297         s->b0 =     A * ((A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
298         s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0));
299         s->b2 =     A * ((A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
300         break;
301     case bandpass:
302         if (s->csg) {
303             s->a0 =  1 + alpha;
304             s->a1 = -2 * cos(w0);
305             s->a2 =  1 - alpha;
306             s->b0 =  sin(w0) / 2;
307             s->b1 =  0;
308             s->b2 = -sin(w0) / 2;
309         } else {
310             s->a0 =  1 + alpha;
311             s->a1 = -2 * cos(w0);
312             s->a2 =  1 - alpha;
313             s->b0 =  alpha;
314             s->b1 =  0;
315             s->b2 = -alpha;
316         }
317         break;
318     case bandreject:
319         s->a0 =  1 + alpha;
320         s->a1 = -2 * cos(w0);
321         s->a2 =  1 - alpha;
322         s->b0 =  1;
323         s->b1 = -2 * cos(w0);
324         s->b2 =  1;
325         break;
326     case lowpass:
327         if (s->poles == 1) {
328             s->a0 = 1;
329             s->a1 = -exp(-w0);
330             s->a2 = 0;
331             s->b0 = 1 + s->a1;
332             s->b1 = 0;
333             s->b2 = 0;
334         } else {
335             s->a0 =  1 + alpha;
336             s->a1 = -2 * cos(w0);
337             s->a2 =  1 - alpha;
338             s->b0 = (1 - cos(w0)) / 2;
339             s->b1 =  1 - cos(w0);
340             s->b2 = (1 - cos(w0)) / 2;
341         }
342         break;
343     case highpass:
344         if (s->poles == 1) {
345             s->a0 = 1;
346             s->a1 = -exp(-w0);
347             s->a2 = 0;
348             s->b0 = (1 - s->a1) / 2;
349             s->b1 = -s->b0;
350             s->b2 = 0;
351         } else {
352             s->a0 =   1 + alpha;
353             s->a1 =  -2 * cos(w0);
354             s->a2 =   1 - alpha;
355             s->b0 =  (1 + cos(w0)) / 2;
356             s->b1 = -(1 + cos(w0));
357             s->b2 =  (1 + cos(w0)) / 2;
358         }
359         break;
360     case allpass:
361         s->a0 =  1 + alpha;
362         s->a1 = -2 * cos(w0);
363         s->a2 =  1 - alpha;
364         s->b0 =  1 - alpha;
365         s->b1 = -2 * cos(w0);
366         s->b2 =  1 + alpha;
367         break;
368     default:
369         av_assert0(0);
370     }
371
372     s->a1 /= s->a0;
373     s->a2 /= s->a0;
374     s->b0 /= s->a0;
375     s->b1 /= s->a0;
376     s->b2 /= s->a0;
377
378     s->cache = av_realloc_f(s->cache, sizeof(ChanCache), inlink->channels);
379     if (!s->cache)
380         return AVERROR(ENOMEM);
381     memset(s->cache, 0, sizeof(ChanCache) * inlink->channels);
382
383     switch (inlink->format) {
384     case AV_SAMPLE_FMT_S16P: s->filter = biquad_s16; break;
385     case AV_SAMPLE_FMT_S32P: s->filter = biquad_s32; break;
386     case AV_SAMPLE_FMT_FLTP: s->filter = biquad_flt; break;
387     case AV_SAMPLE_FMT_DBLP: s->filter = biquad_dbl; break;
388     default: av_assert0(0);
389     }
390
391     return 0;
392 }
393
394 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
395 {
396     AVFilterContext  *ctx = inlink->dst;
397     BiquadsContext *s     = ctx->priv;
398     AVFilterLink *outlink = ctx->outputs[0];
399     AVFrame *out_buf;
400     int nb_samples = buf->nb_samples;
401     int ch;
402
403     if (av_frame_is_writable(buf)) {
404         out_buf = buf;
405     } else {
406         out_buf = ff_get_audio_buffer(inlink, nb_samples);
407         if (!out_buf) {
408             av_frame_free(&buf);
409             return AVERROR(ENOMEM);
410         }
411         av_frame_copy_props(out_buf, buf);
412     }
413
414     for (ch = 0; ch < av_frame_get_channels(buf); ch++)
415         s->filter(s, buf->extended_data[ch],
416                   out_buf->extended_data[ch], nb_samples,
417                   &s->cache[ch].i1, &s->cache[ch].i2,
418                   &s->cache[ch].o1, &s->cache[ch].o2,
419                   s->b0, s->b1, s->b2, s->a1, s->a2);
420
421     if (s->clippings > 0)
422         av_log(ctx, AV_LOG_WARNING, "clipping %d times. Please reduce gain.\n", s->clippings);
423     s->clippings = 0;
424
425     if (buf != out_buf)
426         av_frame_free(&buf);
427
428     return ff_filter_frame(outlink, out_buf);
429 }
430
431 static av_cold void uninit(AVFilterContext *ctx)
432 {
433     BiquadsContext *s = ctx->priv;
434
435     av_freep(&s->cache);
436 }
437
438 static const AVFilterPad inputs[] = {
439     {
440         .name         = "default",
441         .type         = AVMEDIA_TYPE_AUDIO,
442         .filter_frame = filter_frame,
443     },
444     { NULL }
445 };
446
447 static const AVFilterPad outputs[] = {
448     {
449         .name         = "default",
450         .type         = AVMEDIA_TYPE_AUDIO,
451         .config_props = config_output,
452     },
453     { NULL }
454 };
455
456 #define OFFSET(x) offsetof(BiquadsContext, x)
457 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
458
459 #define DEFINE_BIQUAD_FILTER(name_, description_)                       \
460 AVFILTER_DEFINE_CLASS(name_);                                           \
461 static av_cold int name_##_init(AVFilterContext *ctx) \
462 {                                                                       \
463     BiquadsContext *s = ctx->priv;                                      \
464     s->class = &name_##_class;                                          \
465     s->filter_type = name_;                                             \
466     return init(ctx);                                             \
467 }                                                                       \
468                                                          \
469 AVFilter ff_af_##name_ = {                         \
470     .name          = #name_,                             \
471     .description   = NULL_IF_CONFIG_SMALL(description_), \
472     .priv_size     = sizeof(BiquadsContext),             \
473     .init          = name_##_init,                       \
474     .uninit        = uninit,                             \
475     .query_formats = query_formats,                      \
476     .inputs        = inputs,                             \
477     .outputs       = outputs,                            \
478     .priv_class    = &name_##_class,                     \
479 }
480
481 #if CONFIG_EQUALIZER_FILTER
482 static const AVOption equalizer_options[] = {
483     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
484     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
485     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
486     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
487     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
488     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
489     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
490     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
491     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
492     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
493     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
494     {NULL}
495 };
496
497 DEFINE_BIQUAD_FILTER(equalizer, "Apply two-pole peaking equalization (EQ) filter.");
498 #endif  /* CONFIG_EQUALIZER_FILTER */
499 #if CONFIG_BASS_FILTER
500 static const AVOption bass_options[] = {
501     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
502     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
503     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
504     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
505     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
506     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
507     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
508     {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
509     {"w",     "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
510     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
511     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
512     {NULL}
513 };
514
515 DEFINE_BIQUAD_FILTER(bass, "Boost or cut lower frequencies.");
516 #endif  /* CONFIG_BASS_FILTER */
517 #if CONFIG_TREBLE_FILTER
518 static const AVOption treble_options[] = {
519     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
520     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
521     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
522     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
523     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
524     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
525     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
526     {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
527     {"w",     "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
528     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
529     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
530     {NULL}
531 };
532
533 DEFINE_BIQUAD_FILTER(treble, "Boost or cut upper frequencies.");
534 #endif  /* CONFIG_TREBLE_FILTER */
535 #if CONFIG_BANDPASS_FILTER
536 static const AVOption bandpass_options[] = {
537     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
538     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
539     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
540     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
541     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
542     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
543     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
544     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
545     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
546     {"csg",   "use constant skirt gain", OFFSET(csg), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},
547     {NULL}
548 };
549
550 DEFINE_BIQUAD_FILTER(bandpass, "Apply a two-pole Butterworth band-pass filter.");
551 #endif  /* CONFIG_BANDPASS_FILTER */
552 #if CONFIG_BANDREJECT_FILTER
553 static const AVOption bandreject_options[] = {
554     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
555     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
556     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
557     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
558     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
559     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
560     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
561     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
562     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
563     {NULL}
564 };
565
566 DEFINE_BIQUAD_FILTER(bandreject, "Apply a two-pole Butterworth band-reject filter.");
567 #endif  /* CONFIG_BANDREJECT_FILTER */
568 #if CONFIG_LOWPASS_FILTER
569 static const AVOption lowpass_options[] = {
570     {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
571     {"f",         "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
572     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
573     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
574     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
575     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
576     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
577     {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
578     {"w",     "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
579     {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
580     {"p",     "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
581     {NULL}
582 };
583
584 DEFINE_BIQUAD_FILTER(lowpass, "Apply a low-pass filter with 3dB point frequency.");
585 #endif  /* CONFIG_LOWPASS_FILTER */
586 #if CONFIG_HIGHPASS_FILTER
587 static const AVOption highpass_options[] = {
588     {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
589     {"f",         "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
590     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
591     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
592     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
593     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
594     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
595     {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
596     {"w",     "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
597     {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
598     {"p",     "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
599     {NULL}
600 };
601
602 DEFINE_BIQUAD_FILTER(highpass, "Apply a high-pass filter with 3dB point frequency.");
603 #endif  /* CONFIG_HIGHPASS_FILTER */
604 #if CONFIG_ALLPASS_FILTER
605 static const AVOption allpass_options[] = {
606     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
607     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
608     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HERTZ}, HERTZ, SLOPE, FLAGS, "width_type"},
609     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
610     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
611     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
612     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
613     {"width", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
614     {"w",     "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
615     {NULL}
616 };
617
618 DEFINE_BIQUAD_FILTER(allpass, "Apply a two-pole all-pass filter.");
619 #endif  /* CONFIG_ALLPASS_FILTER */
620 #if CONFIG_BIQUAD_FILTER
621 static const AVOption biquad_options[] = {
622     {"a0", NULL, OFFSET(a0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
623     {"a1", NULL, OFFSET(a1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
624     {"a2", NULL, OFFSET(a2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
625     {"b0", NULL, OFFSET(b0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
626     {"b1", NULL, OFFSET(b1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
627     {"b2", NULL, OFFSET(b2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
628     {NULL}
629 };
630
631 DEFINE_BIQUAD_FILTER(biquad, "Apply a biquad IIR filter with the given coefficients.");
632 #endif  /* CONFIG_BIQUAD_FILTER */