FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
af_biquads.c
Go to the documentation of this file.
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 {
82 };
83 
84 enum WidthType {
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;
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 
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);
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 
135 {
138  static const enum AVSampleFormat sample_fmts[] = {
144  };
145  int ret;
146 
147  layouts = ff_all_channel_layouts();
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_INT, {.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 */
float, planar
Definition: samplefmt.h:70
#define NULL
Definition: coverity.c:32
int ff_set_common_channel_layouts(AVFilterContext *ctx, AVFilterChannelLayouts *layouts)
A helper for query_formats() which sets all links to the same list of channel layouts/sample rates...
Definition: formats.c:523
const char * s
Definition: avisynth_c.h:631
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
#define av_realloc_f(p, o, n)
AVOption.
Definition: opt.h:255
ChanCache * cache
Definition: af_biquads.c:112
FilterType
Definition: af_biquads.c:71
Main libavfilter public API header.
double i2
Definition: af_biquads.c:93
#define a0
Definition: regdef.h:46
double, planar
Definition: samplefmt.h:71
#define a1
Definition: regdef.h:47
static const AVFilterPad inputs[]
Definition: af_biquads.c:429
static enum AVSampleFormat formats[]
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:69
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:641
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1158
#define OFFSET(x)
Definition: af_biquads.c:447
#define av_cold
Definition: attributes.h:74
AVOptions.
#define A(x)
Definition: vp56_arith.h:28
#define av_log(a,...)
static const AVFilterPad outputs[]
Definition: af_biquads.c:438
A filter pad used for either input or output.
Definition: internal.h:63
static av_cold int init(AVFilterContext *ctx)
Definition: af_biquads.c:119
static double alpha(void *priv, double x, double y)
Definition: vf_geq.c:99
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:542
#define FLAGS
Definition: af_biquads.c:448
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:74
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:148
void * priv
private data for use by the filter
Definition: avfilter.h:654
simple assert() macros that are a bit more flexible than ISO C assert().
double o1
Definition: af_biquads.c:94
signed 32 bits, planar
Definition: samplefmt.h:69
typedef void(APIENTRY *FF_PFNGLACTIVETEXTUREPROC)(GLenum texture)
int32_t
#define a2
Definition: regdef.h:48
AVFilterChannelLayouts * ff_all_channel_layouts(void)
Construct an empty AVFilterChannelLayouts/AVFilterFormats struct – representing any channel layout (w...
Definition: formats.c:385
A list of supported channel layouts.
Definition: formats.h:85
#define BIQUAD_FILTER(name, type, min, max, need_clipping)
Definition: af_biquads.c:167
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:59
int av_frame_is_writable(AVFrame *frame)
Check if the frame data is writable.
Definition: frame.c:493
static int config_output(AVFilterLink *outlink)
Definition: af_biquads.c:236
void * buf
Definition: avisynth_c.h:553
Describe the class of an AVClass context structure.
Definition: log.h:67
int av_frame_get_channels(const AVFrame *frame)
#define DEFINE_BIQUAD_FILTER(name_, description_)
Definition: af_biquads.c:450
static int query_formats(AVFilterContext *ctx)
Definition: af_biquads.c:134
double o2
Definition: af_biquads.c:94
AVFilterLink ** outputs
array of pointers to output links
Definition: avfilter.h:648
enum MovChannelLayoutTag * layouts
Definition: mov_chan.c:434
AVFilterFormats * ff_all_samplerates(void)
Definition: formats.c:379
static av_cold void uninit(AVFilterContext *ctx)
Definition: af_biquads.c:422
static void filter(MpegAudioContext *s, int ch, const short *samples, int incr)
WidthType
Definition: af_biquads.c:84
static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
Definition: af_biquads.c:392
int len
double i1
Definition: af_biquads.c:93
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:633
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
#define av_freep(p)
signed 16 bits, planar
Definition: samplefmt.h:68
double frequency
Definition: af_biquads.c:106
#define M_PI
Definition: mathematics.h:46
internal API functions
void(* filter)(const void *ibuf, void *obuf, int len, double *i1, double *i2, double *o1, double *o2, double b0, double b1, double b2, double a1, double a2)
Definition: af_biquads.c:114
uint8_t ** extended_data
pointers to the data planes/channels.
Definition: frame.h:215
enum FilterType filter_type
Definition: af_biquads.c:100
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:225
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:530
int av_frame_copy_props(AVFrame *dst, const AVFrame *src)
Copy only "metadata" fields from src to dst.
Definition: frame.c:553
static int width