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