git.sesse.net Git - ffmpeg/blob - 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     uint64_t channels;
 109
 110     double a0, a1, a2;
 111     double b0, b1, b2;
 112
 113     ChanCache *cache;
 114     int clippings;
 115     int block_align;
 116
 117     void (*filter)(struct BiquadsContext *s, const void *ibuf, void *obuf, int len,
 118                    double *i1, double *i2, double *o1, double *o2,
 119                    double b0, double b1, double b2, double a1, double a2);
 120 } BiquadsContext;
 121
 122 static av_cold int init(AVFilterContext *ctx)
 123 {
 124     BiquadsContext *s = ctx->priv;
 125
 126     if (s->filter_type != biquad) {
 127         if (s->frequency <= 0 || s->width <= 0) {
 128             av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f and/or width %f <= 0\n",
 129                    s->frequency, s->width);
 130             return AVERROR(EINVAL);
 131         }
 132     }
 133
 134     return 0;
 135 }
 136
 137 static int query_formats(AVFilterContext *ctx)
 138 {
 139     AVFilterFormats *formats;
 140     AVFilterChannelLayouts *layouts;
 141     static const enum AVSampleFormat sample_fmts[] = {
 142         AV_SAMPLE_FMT_S16P,
 143         AV_SAMPLE_FMT_S32P,
 144         AV_SAMPLE_FMT_FLTP,
 145         AV_SAMPLE_FMT_DBLP,
 146         AV_SAMPLE_FMT_NONE
 147     };
 148     int ret;
 149
 150     layouts = ff_all_channel_counts();
 151     if (!layouts)
 152         return AVERROR(ENOMEM);
 153     ret = ff_set_common_channel_layouts(ctx, layouts);
 154     if (ret < 0)
 155         return ret;
 156
 157     formats = ff_make_format_list(sample_fmts);
 158     if (!formats)
 159         return AVERROR(ENOMEM);
 160     ret = ff_set_common_formats(ctx, formats);
 161     if (ret < 0)
 162         return ret;
 163
 164     formats = ff_all_samplerates();
 165     if (!formats)
 166         return AVERROR(ENOMEM);
 167     return ff_set_common_samplerates(ctx, formats);
 168 }
 169
 170 #define BIQUAD_FILTER(name, type, min, max, need_clipping)                    \
 171 static void biquad_## name (BiquadsContext *s,                                \
 172                             const void *input, void *output, int len,         \
 173                             double *in1, double *in2,                         \
 174                             double *out1, double *out2,                       \
 175                             double b0, double b1, double b2,                  \
 176                             double a1, double a2)                             \
 177 {                                                                             \
 178     const type *ibuf = input;                                                 \
 179     type *obuf = output;                                                      \
 180     double i1 = *in1;                                                         \
 181     double i2 = *in2;                                                         \
 182     double o1 = *out1;                                                        \
 183     double o2 = *out2;                                                        \
 184     int i;                                                                    \
 185     a1 = -a1;                                                                 \
 186     a2 = -a2;                                                                 \
 187                                                                               \
 188     for (i = 0; i+1 < len; i++) {                                             \
 189         o2 = i2 * b2 + i1 * b1 + ibuf[i] * b0 + o2 * a2 + o1 * a1;            \
 190         i2 = ibuf[i];                                                         \
 191         if (need_clipping && o2 < min) {                                      \
 192             s->clippings++;                                                   \
 193             obuf[i] = min;                                                    \
 194         } else if (need_clipping && o2 > max) {                               \
 195             s->clippings++;                                                   \
 196             obuf[i] = max;                                                    \
 197         } else {                                                              \
 198             obuf[i] = o2;                                                     \
 199         }                                                                     \
 200         i++;                                                                  \
 201         o1 = i1 * b2 + i2 * b1 + ibuf[i] * b0 + o1 * a2 + o2 * a1;            \
 202         i1 = ibuf[i];                                                         \
 203         if (need_clipping && o1 < min) {                                      \
 204             s->clippings++;                                                   \
 205             obuf[i] = min;                                                    \
 206         } else if (need_clipping && o1 > max) {                               \
 207             s->clippings++;                                                   \
 208             obuf[i] = max;                                                    \
 209         } else {                                                              \
 210             obuf[i] = o1;                                                     \
 211         }                                                                     \
 212     }                                                                         \
 213     if (i < len) {                                                            \
 214         double o0 = ibuf[i] * b0 + i1 * b1 + i2 * b2 + o1 * a1 + o2 * a2;     \
 215         i2 = i1;                                                              \
 216         i1 = ibuf[i];                                                         \
 217         o2 = o1;                                                              \
 218         o1 = o0;                                                              \
 219         if (need_clipping && o0 < min) {                                      \
 220             s->clippings++;                                                   \
 221             obuf[i] = min;                                                    \
 222         } else if (need_clipping && o0 > max) {                               \
 223             s->clippings++;                                                   \
 224             obuf[i] = max;                                                    \
 225         } else {                                                              \
 226             obuf[i] = o0;                                                     \
 227         }                                                                     \
 228     }                                                                         \
 229     *in1  = i1;                                                               \
 230     *in2  = i2;                                                               \
 231     *out1 = o1;                                                               \
 232     *out2 = o2;                                                               \
 233 }
 234
 235 BIQUAD_FILTER(s16, int16_t, INT16_MIN, INT16_MAX, 1)
 236 BIQUAD_FILTER(s32, int32_t, INT32_MIN, INT32_MAX, 1)
 237 BIQUAD_FILTER(flt, float,   -1., 1., 0)
 238 BIQUAD_FILTER(dbl, double,  -1., 1., 0)
 239
 240 static int config_output(AVFilterLink *outlink)
 241 {
 242     AVFilterContext *ctx    = outlink->src;
 243     BiquadsContext *s       = ctx->priv;
 244     AVFilterLink *inlink    = ctx->inputs[0];
 245     double A = exp(s->gain / 40 * log(10.));
 246     double w0 = 2 * M_PI * s->frequency / inlink->sample_rate;
 247     double alpha;
 248
 249     if (w0 > M_PI) {
 250         av_log(ctx, AV_LOG_ERROR,
 251                "Invalid frequency %f. Frequency must be less than half the sample-rate %d.\n",
 252                s->frequency, inlink->sample_rate);
 253         return AVERROR(EINVAL);
 254     }
 255
 256     switch (s->width_type) {
 257     case NONE:
 258         alpha = 0.0;
 259         break;
 260     case HERTZ:
 261         alpha = sin(w0) / (2 * s->frequency / s->width);
 262         break;
 263     case OCTAVE:
 264         alpha = sin(w0) * sinh(log(2.) / 2 * s->width * w0 / sin(w0));
 265         break;
 266     case QFACTOR:
 267         alpha = sin(w0) / (2 * s->width);
 268         break;
 269     case SLOPE:
 270         alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / s->width - 1) + 2);
 271         break;
 272     default:
 273         av_assert0(0);
 274     }
 275
 276     switch (s->filter_type) {
 277     case biquad:
 278         break;
 279     case equalizer:
 280         s->a0 =   1 + alpha / A;
 281         s->a1 =  -2 * cos(w0);
 282         s->a2 =   1 - alpha / A;
 283         s->b0 =   1 + alpha * A;
 284         s->b1 =  -2 * cos(w0);
 285         s->b2 =   1 - alpha * A;
 286         break;
 287     case bass:
 288         s->a0 =          (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
 289         s->a1 =    -2 * ((A - 1) + (A + 1) * cos(w0));
 290         s->a2 =          (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
 291         s->b0 =     A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
 292         s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0));
 293         s->b2 =     A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
 294         break;
 295     case treble:
 296         s->a0 =          (A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha;
 297         s->a1 =     2 * ((A - 1) - (A + 1) * cos(w0));
 298         s->a2 =          (A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha;
 299         s->b0 =     A * ((A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha);
 300         s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0));
 301         s->b2 =     A * ((A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha);
 302         break;
 303     case bandpass:
 304         if (s->csg) {
 305             s->a0 =  1 + alpha;
 306             s->a1 = -2 * cos(w0);
 307             s->a2 =  1 - alpha;
 308             s->b0 =  sin(w0) / 2;
 309             s->b1 =  0;
 310             s->b2 = -sin(w0) / 2;
 311         } else {
 312             s->a0 =  1 + alpha;
 313             s->a1 = -2 * cos(w0);
 314             s->a2 =  1 - alpha;
 315             s->b0 =  alpha;
 316             s->b1 =  0;
 317             s->b2 = -alpha;
 318         }
 319         break;
 320     case bandreject:
 321         s->a0 =  1 + alpha;
 322         s->a1 = -2 * cos(w0);
 323         s->a2 =  1 - alpha;
 324         s->b0 =  1;
 325         s->b1 = -2 * cos(w0);
 326         s->b2 =  1;
 327         break;
 328     case lowpass:
 329         if (s->poles == 1) {
 330             s->a0 = 1;
 331             s->a1 = -exp(-w0);
 332             s->a2 = 0;
 333             s->b0 = 1 + s->a1;
 334             s->b1 = 0;
 335             s->b2 = 0;
 336         } else {
 337             s->a0 =  1 + alpha;
 338             s->a1 = -2 * cos(w0);
 339             s->a2 =  1 - alpha;
 340             s->b0 = (1 - cos(w0)) / 2;
 341             s->b1 =  1 - cos(w0);
 342             s->b2 = (1 - cos(w0)) / 2;
 343         }
 344         break;
 345     case highpass:
 346         if (s->poles == 1) {
 347             s->a0 = 1;
 348             s->a1 = -exp(-w0);
 349             s->a2 = 0;
 350             s->b0 = (1 - s->a1) / 2;
 351             s->b1 = -s->b0;
 352             s->b2 = 0;
 353         } else {
 354             s->a0 =   1 + alpha;
 355             s->a1 =  -2 * cos(w0);
 356             s->a2 =   1 - alpha;
 357             s->b0 =  (1 + cos(w0)) / 2;
 358             s->b1 = -(1 + cos(w0));
 359             s->b2 =  (1 + cos(w0)) / 2;
 360         }
 361         break;
 362     case allpass:
 363         s->a0 =  1 + alpha;
 364         s->a1 = -2 * cos(w0);
 365         s->a2 =  1 - alpha;
 366         s->b0 =  1 - alpha;
 367         s->b1 = -2 * cos(w0);
 368         s->b2 =  1 + alpha;
 369         break;
 370     default:
 371         av_assert0(0);
 372     }
 373
 374     s->a1 /= s->a0;
 375     s->a2 /= s->a0;
 376     s->b0 /= s->a0;
 377     s->b1 /= s->a0;
 378     s->b2 /= s->a0;
 379
 380     s->cache = av_realloc_f(s->cache, sizeof(ChanCache), inlink->channels);
 381     if (!s->cache)
 382         return AVERROR(ENOMEM);
 383     memset(s->cache, 0, sizeof(ChanCache) * inlink->channels);
 384
 385     switch (inlink->format) {
 386     case AV_SAMPLE_FMT_S16P: s->filter = biquad_s16; break;
 387     case AV_SAMPLE_FMT_S32P: s->filter = biquad_s32; break;
 388     case AV_SAMPLE_FMT_FLTP: s->filter = biquad_flt; break;
 389     case AV_SAMPLE_FMT_DBLP: s->filter = biquad_dbl; break;
 390     default: av_assert0(0);
 391     }
 392
 393     s->block_align = av_get_bytes_per_sample(inlink->format);
 394
 395     return 0;
 396 }
 397
 398 static int filter_frame(AVFilterLink *inlink, AVFrame *buf)
 399 {
 400     AVFilterContext  *ctx = inlink->dst;
 401     BiquadsContext *s     = ctx->priv;
 402     AVFilterLink *outlink = ctx->outputs[0];
 403     AVFrame *out_buf;
 404     int nb_samples = buf->nb_samples;
 405     int ch;
 406
 407     if (av_frame_is_writable(buf)) {
 408         out_buf = buf;
 409     } else {
 410         out_buf = ff_get_audio_buffer(inlink, nb_samples);
 411         if (!out_buf) {
 412             av_frame_free(&buf);
 413             return AVERROR(ENOMEM);
 414         }
 415         av_frame_copy_props(out_buf, buf);
 416     }
 417
 418     for (ch = 0; ch < buf->channels; ch++) {
 419         if (!((av_channel_layout_extract_channel(inlink->channel_layout, ch) & s->channels))) {
 420             if (buf != out_buf)
 421                 memcpy(out_buf->extended_data[ch], buf->extended_data[ch], nb_samples * s->block_align);
 422             continue;
 423         }
 424         s->filter(s, buf->extended_data[ch],
 425                   out_buf->extended_data[ch], nb_samples,
 426                   &s->cache[ch].i1, &s->cache[ch].i2,
 427                   &s->cache[ch].o1, &s->cache[ch].o2,
 428                   s->b0, s->b1, s->b2, s->a1, s->a2);
 429     }
 430
 431     if (s->clippings > 0)
 432         av_log(ctx, AV_LOG_WARNING, "clipping %d times. Please reduce gain.\n", s->clippings);
 433     s->clippings = 0;
 434
 435     if (buf != out_buf)
 436         av_frame_free(&buf);
 437
 438     return ff_filter_frame(outlink, out_buf);
 439 }
 440
 441 static av_cold void uninit(AVFilterContext *ctx)
 442 {
 443     BiquadsContext *s = ctx->priv;
 444
 445     av_freep(&s->cache);
 446 }
 447
 448 static const AVFilterPad inputs[] = {
 449     {
 450         .name         = "default",
 451         .type         = AVMEDIA_TYPE_AUDIO,
 452         .filter_frame = filter_frame,
 453     },
 454     { NULL }
 455 };
 456
 457 static const AVFilterPad outputs[] = {
 458     {
 459         .name         = "default",
 460         .type         = AVMEDIA_TYPE_AUDIO,
 461         .config_props = config_output,
 462     },
 463     { NULL }
 464 };
 465
 466 #define OFFSET(x) offsetof(BiquadsContext, x)
 467 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
 468
 469 #define DEFINE_BIQUAD_FILTER(name_, description_)                       \
 470 AVFILTER_DEFINE_CLASS(name_);                                           \
 471 static av_cold int name_##_init(AVFilterContext *ctx) \
 472 {                                                                       \
 473     BiquadsContext *s = ctx->priv;                                      \
 474     s->class = &name_##_class;                                          \
 475     s->filter_type = name_;                                             \
 476     return init(ctx);                                             \
 477 }                                                                       \
 478                                                          \
 479 AVFilter ff_af_##name_ = {                         \
 480     .name          = #name_,                             \
 481     .description   = NULL_IF_CONFIG_SMALL(description_), \
 482     .priv_size     = sizeof(BiquadsContext),             \
 483     .init          = name_##_init,                       \
 484     .uninit        = uninit,                             \
 485     .query_formats = query_formats,                      \
 486     .inputs        = inputs,                             \
 487     .outputs       = outputs,                            \
 488     .priv_class    = &name_##_class,                     \
 489 }
 490
 491 #if CONFIG_EQUALIZER_FILTER
 492 static const AVOption equalizer_options[] = {
 493     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
 494     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS},
 495     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 496     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 497     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 498     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 499     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 500     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 501     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
 502     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS},
 503     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 504     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 505     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 506     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 507     {NULL}
 508 };
 509
 510 DEFINE_BIQUAD_FILTER(equalizer, "Apply two-pole peaking equalization (EQ) filter.");
 511 #endif  /* CONFIG_EQUALIZER_FILTER */
 512 #if CONFIG_BASS_FILTER
 513 static const AVOption bass_options[] = {
 514     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS},
 515     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 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     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 518     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 519     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 520     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 521     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 522     {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
 523     {"w",     "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
 524     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 525     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 526     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 527     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 528     {NULL}
 529 };
 530
 531 DEFINE_BIQUAD_FILTER(bass, "Boost or cut lower frequencies.");
 532 #endif  /* CONFIG_BASS_FILTER */
 533 #if CONFIG_TREBLE_FILTER
 534 static const AVOption treble_options[] = {
 535     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 536     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 537     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 538     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 539     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 540     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 541     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 542     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 543     {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
 544     {"w",     "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS},
 545     {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 546     {"g",    "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS},
 547     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 548     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 549     {NULL}
 550 };
 551
 552 DEFINE_BIQUAD_FILTER(treble, "Boost or cut upper frequencies.");
 553 #endif  /* CONFIG_TREBLE_FILTER */
 554 #if CONFIG_BANDPASS_FILTER
 555 static const AVOption bandpass_options[] = {
 556     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 557     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 558     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 559     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 560     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 561     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 562     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 563     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 564     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
 565     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
 566     {"csg",   "use constant skirt gain", OFFSET(csg), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS},
 567     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 568     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 569     {NULL}
 570 };
 571
 572 DEFINE_BIQUAD_FILTER(bandpass, "Apply a two-pole Butterworth band-pass filter.");
 573 #endif  /* CONFIG_BANDPASS_FILTER */
 574 #if CONFIG_BANDREJECT_FILTER
 575 static const AVOption bandreject_options[] = {
 576     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 577     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 578     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 579     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 580     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 581     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 582     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 583     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 584     {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
 585     {"w",     "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS},
 586     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 587     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 588     {NULL}
 589 };
 590
 591 DEFINE_BIQUAD_FILTER(bandreject, "Apply a two-pole Butterworth band-reject filter.");
 592 #endif  /* CONFIG_BANDREJECT_FILTER */
 593 #if CONFIG_LOWPASS_FILTER
 594 static const AVOption lowpass_options[] = {
 595     {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
 596     {"f",         "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS},
 597     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 598     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 599     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 600     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 601     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 602     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 603     {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
 604     {"w",     "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
 605     {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
 606     {"p",     "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
 607     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 608     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 609     {NULL}
 610 };
 611
 612 DEFINE_BIQUAD_FILTER(lowpass, "Apply a low-pass filter with 3dB point frequency.");
 613 #endif  /* CONFIG_LOWPASS_FILTER */
 614 #if CONFIG_HIGHPASS_FILTER
 615 static const AVOption highpass_options[] = {
 616     {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 617     {"f",         "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 618     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 619     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"},
 620     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 621     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 622     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 623     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 624     {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
 625     {"w",     "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS},
 626     {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
 627     {"p",     "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS},
 628     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 629     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 630     {NULL}
 631 };
 632
 633 DEFINE_BIQUAD_FILTER(highpass, "Apply a high-pass filter with 3dB point frequency.");
 634 #endif  /* CONFIG_HIGHPASS_FILTER */
 635 #if CONFIG_ALLPASS_FILTER
 636 static const AVOption allpass_options[] = {
 637     {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 638     {"f",         "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS},
 639     {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HERTZ}, HERTZ, SLOPE, FLAGS, "width_type"},
 640     {"t",          "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HERTZ}, HERTZ, SLOPE, FLAGS, "width_type"},
 641     {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"},
 642     {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"},
 643     {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"},
 644     {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"},
 645     {"width", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
 646     {"w",     "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS},
 647     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 648     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 649     {NULL}
 650 };
 651
 652 DEFINE_BIQUAD_FILTER(allpass, "Apply a two-pole all-pass filter.");
 653 #endif  /* CONFIG_ALLPASS_FILTER */
 654 #if CONFIG_BIQUAD_FILTER
 655 static const AVOption biquad_options[] = {
 656     {"a0", NULL, OFFSET(a0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 657     {"a1", NULL, OFFSET(a1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 658     {"a2", NULL, OFFSET(a2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 659     {"b0", NULL, OFFSET(b0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 660     {"b1", NULL, OFFSET(b1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 661     {"b2", NULL, OFFSET(b2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS},
 662     {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 663     {"c",        "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS},
 664     {NULL}
 665 };
 666
 667 DEFINE_BIQUAD_FILTER(biquad, "Apply a biquad IIR filter with the given coefficients.");
 668 #endif  /* CONFIG_BIQUAD_FILTER */