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 /* * Copyright (c) 2013 Paul B Mahol * Copyright (c) 2006-2008 Rob Sykes * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /* * 2-pole filters designed by Robert Bristow-Johnson * see http://www.musicdsp.org/files/Audio-EQ-Cookbook.txt * * 1-pole filters based on code (c) 2000 Chris Bagwell * Algorithms: Recursive single pole low/high pass filter * Reference: The Scientist and Engineer's Guide to Digital Signal Processing * * low-pass: output[N] = input[N] * A + output[N-1] * B * X = exp(-2.0 * pi * Fc) * A = 1 - X * B = X * Fc = cutoff freq / sample rate * * Mimics an RC low-pass filter: * * ---/\/\/\/\-----------> * | * --- C * --- * | * | * V * * high-pass: output[N] = A0 * input[N] + A1 * input[N-1] + B1 * output[N-1] * X = exp(-2.0 * pi * Fc) * A0 = (1 + X) / 2 * A1 = -(1 + X) / 2 * B1 = X * Fc = cutoff freq / sample rate * * Mimics an RC high-pass filter: * * || C * ----||---------> * || | * < * > R * < * | * V */ #include "libavutil/avassert.h" #include "libavutil/opt.h" #include "audio.h" #include "avfilter.h" #include "internal.h" enum FilterType { biquad, equalizer, bass, treble, band, bandpass, bandreject, allpass, highpass, lowpass, }; enum WidthType { NONE, HERTZ, OCTAVE, QFACTOR, SLOPE, }; typedef struct ChanCache { double i1, i2; double o1, o2; } ChanCache; typedef struct BiquadsContext { const AVClass *class; enum FilterType filter_type; int width_type; int poles; int csg; double gain; double frequency; double width; double a0, a1, a2; double b0, b1, b2; ChanCache *cache; int clippings; void (*filter)(struct BiquadsContext *s, 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); } BiquadsContext; static av_cold int init(AVFilterContext *ctx) { BiquadsContext *s = ctx->priv; if (s->filter_type != biquad) { if (s->frequency <= 0 || s->width <= 0) { av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f and/or width %f <= 0\n", s->frequency, s->width); return AVERROR(EINVAL); } } return 0; } static int query_formats(AVFilterContext *ctx) { AVFilterFormats *formats; AVFilterChannelLayouts *layouts; static const enum AVSampleFormat sample_fmts[] = { AV_SAMPLE_FMT_S16P, AV_SAMPLE_FMT_S32P, AV_SAMPLE_FMT_FLTP, AV_SAMPLE_FMT_DBLP, AV_SAMPLE_FMT_NONE }; int ret; layouts = ff_all_channel_counts(); if (!layouts) return AVERROR(ENOMEM); ret = ff_set_common_channel_layouts(ctx, layouts); if (ret < 0) return ret; formats = ff_make_format_list(sample_fmts); if (!formats) return AVERROR(ENOMEM); ret = ff_set_common_formats(ctx, formats); if (ret < 0) return ret; formats = ff_all_samplerates(); if (!formats) return AVERROR(ENOMEM); return ff_set_common_samplerates(ctx, formats); } #define BIQUAD_FILTER(name, type, min, max, need_clipping) \ static void biquad_## name (BiquadsContext *s, \ const void *input, void *output, int len, \ double *in1, double *in2, \ double *out1, double *out2, \ double b0, double b1, double b2, \ double a1, double a2) \ { \ const type *ibuf = input; \ type *obuf = output; \ double i1 = *in1; \ double i2 = *in2; \ double o1 = *out1; \ double o2 = *out2; \ int i; \ a1 = -a1; \ a2 = -a2; \ \ for (i = 0; i+1 < len; i++) { \ o2 = i2 * b2 + i1 * b1 + ibuf[i] * b0 + o2 * a2 + o1 * a1; \ i2 = ibuf[i]; \ if (need_clipping && o2 < min) { \ s->clippings++; \ obuf[i] = min; \ } else if (need_clipping && o2 > max) { \ s->clippings++; \ obuf[i] = max; \ } else { \ obuf[i] = o2; \ } \ i++; \ o1 = i1 * b2 + i2 * b1 + ibuf[i] * b0 + o1 * a2 + o2 * a1; \ i1 = ibuf[i]; \ if (need_clipping && o1 < min) { \ s->clippings++; \ obuf[i] = min; \ } else if (need_clipping && o1 > max) { \ s->clippings++; \ obuf[i] = max; \ } else { \ obuf[i] = o1; \ } \ } \ if (i < len) { \ double o0 = ibuf[i] * b0 + i1 * b1 + i2 * b2 + o1 * a1 + o2 * a2; \ i2 = i1; \ i1 = ibuf[i]; \ o2 = o1; \ o1 = o0; \ if (need_clipping && o0 < min) { \ s->clippings++; \ obuf[i] = min; \ } else if (need_clipping && o0 > max) { \ s->clippings++; \ obuf[i] = max; \ } else { \ obuf[i] = o0; \ } \ } \ *in1 = i1; \ *in2 = i2; \ *out1 = o1; \ *out2 = o2; \ } BIQUAD_FILTER(s16, int16_t, INT16_MIN, INT16_MAX, 1) BIQUAD_FILTER(s32, int32_t, INT32_MIN, INT32_MAX, 1) BIQUAD_FILTER(flt, float, -1., 1., 0) BIQUAD_FILTER(dbl, double, -1., 1., 0) static int config_output(AVFilterLink *outlink) { AVFilterContext *ctx = outlink->src; BiquadsContext *s = ctx->priv; AVFilterLink *inlink = ctx->inputs[0]; double A = exp(s->gain / 40 * log(10.)); double w0 = 2 * M_PI * s->frequency / inlink->sample_rate; double alpha; if (w0 > M_PI) { av_log(ctx, AV_LOG_ERROR, "Invalid frequency %f. Frequency must be less than half the sample-rate %d.\n", s->frequency, inlink->sample_rate); return AVERROR(EINVAL); } switch (s->width_type) { case NONE: alpha = 0.0; break; case HERTZ: alpha = sin(w0) / (2 * s->frequency / s->width); break; case OCTAVE: alpha = sin(w0) * sinh(log(2.) / 2 * s->width * w0 / sin(w0)); break; case QFACTOR: alpha = sin(w0) / (2 * s->width); break; case SLOPE: alpha = sin(w0) / 2 * sqrt((A + 1 / A) * (1 / s->width - 1) + 2); break; default: av_assert0(0); } switch (s->filter_type) { case biquad: break; case equalizer: s->a0 = 1 + alpha / A; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha / A; s->b0 = 1 + alpha * A; s->b1 = -2 * cos(w0); s->b2 = 1 - alpha * A; break; case bass: s->a0 = (A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha; s->a1 = -2 * ((A - 1) + (A + 1) * cos(w0)); s->a2 = (A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha; s->b0 = A * ((A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha); s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0)); s->b2 = A * ((A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha); break; case treble: s->a0 = (A + 1) - (A - 1) * cos(w0) + 2 * sqrt(A) * alpha; s->a1 = 2 * ((A - 1) - (A + 1) * cos(w0)); s->a2 = (A + 1) - (A - 1) * cos(w0) - 2 * sqrt(A) * alpha; s->b0 = A * ((A + 1) + (A - 1) * cos(w0) + 2 * sqrt(A) * alpha); s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0)); s->b2 = A * ((A + 1) + (A - 1) * cos(w0) - 2 * sqrt(A) * alpha); break; case bandpass: if (s->csg) { s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = sin(w0) / 2; s->b1 = 0; s->b2 = -sin(w0) / 2; } else { s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = alpha; s->b1 = 0; s->b2 = -alpha; } break; case bandreject: s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = 1; s->b1 = -2 * cos(w0); s->b2 = 1; break; case lowpass: if (s->poles == 1) { s->a0 = 1; s->a1 = -exp(-w0); s->a2 = 0; s->b0 = 1 + s->a1; s->b1 = 0; s->b2 = 0; } else { s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = (1 - cos(w0)) / 2; s->b1 = 1 - cos(w0); s->b2 = (1 - cos(w0)) / 2; } break; case highpass: if (s->poles == 1) { s->a0 = 1; s->a1 = -exp(-w0); s->a2 = 0; s->b0 = (1 - s->a1) / 2; s->b1 = -s->b0; s->b2 = 0; } else { s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = (1 + cos(w0)) / 2; s->b1 = -(1 + cos(w0)); s->b2 = (1 + cos(w0)) / 2; } break; case allpass: s->a0 = 1 + alpha; s->a1 = -2 * cos(w0); s->a2 = 1 - alpha; s->b0 = 1 - alpha; s->b1 = -2 * cos(w0); s->b2 = 1 + alpha; break; default: av_assert0(0); } s->a1 /= s->a0; s->a2 /= s->a0; s->b0 /= s->a0; s->b1 /= s->a0; s->b2 /= s->a0; s->cache = av_realloc_f(s->cache, sizeof(ChanCache), inlink->channels); if (!s->cache) return AVERROR(ENOMEM); memset(s->cache, 0, sizeof(ChanCache) * inlink->channels); switch (inlink->format) { case AV_SAMPLE_FMT_S16P: s->filter = biquad_s16; break; case AV_SAMPLE_FMT_S32P: s->filter = biquad_s32; break; case AV_SAMPLE_FMT_FLTP: s->filter = biquad_flt; break; case AV_SAMPLE_FMT_DBLP: s->filter = biquad_dbl; break; default: av_assert0(0); } return 0; } static int filter_frame(AVFilterLink *inlink, AVFrame *buf) { AVFilterContext *ctx = inlink->dst; BiquadsContext *s = ctx->priv; AVFilterLink *outlink = ctx->outputs[0]; AVFrame *out_buf; int nb_samples = buf->nb_samples; int ch; if (av_frame_is_writable(buf)) { out_buf = buf; } else { out_buf = ff_get_audio_buffer(inlink, nb_samples); if (!out_buf) { av_frame_free(&buf); return AVERROR(ENOMEM); } av_frame_copy_props(out_buf, buf); } for (ch = 0; ch < av_frame_get_channels(buf); ch++) s->filter(s, buf->extended_data[ch], out_buf->extended_data[ch], nb_samples, &s->cache[ch].i1, &s->cache[ch].i2, &s->cache[ch].o1, &s->cache[ch].o2, s->b0, s->b1, s->b2, s->a1, s->a2); if (s->clippings > 0) av_log(ctx, AV_LOG_WARNING, "clipping %d times. Please reduce gain.\n", s->clippings); if (buf != out_buf) av_frame_free(&buf); return ff_filter_frame(outlink, out_buf); } static av_cold void uninit(AVFilterContext *ctx) { BiquadsContext *s = ctx->priv; av_freep(&s->cache); } static const AVFilterPad inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .filter_frame = filter_frame, }, { NULL } }; static const AVFilterPad outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .config_props = config_output, }, { NULL } }; #define OFFSET(x) offsetof(BiquadsContext, x) #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM #define DEFINE_BIQUAD_FILTER(name_, description_) \ AVFILTER_DEFINE_CLASS(name_); \ static av_cold int name_##_init(AVFilterContext *ctx) \ { \ BiquadsContext *s = ctx->priv; \ s->class = &name_##_class; \ s->filter_type = name_; \ return init(ctx); \ } \ \ AVFilter ff_af_##name_ = { \ .name = #name_, \ .description = NULL_IF_CONFIG_SMALL(description_), \ .priv_size = sizeof(BiquadsContext), \ .init = name_##_init, \ .uninit = uninit, \ .query_formats = query_formats, \ .inputs = inputs, \ .outputs = outputs, \ .priv_class = &name_##_class, \ } #if CONFIG_EQUALIZER_FILTER static const AVOption equalizer_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=0}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS}, {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 999, FLAGS}, {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(equalizer, "Apply two-pole peaking equalization (EQ) filter."); #endif /* CONFIG_EQUALIZER_FILTER */ #if CONFIG_BASS_FILTER static const AVOption bass_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=100}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS}, {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS}, {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(bass, "Boost or cut lower frequencies."); #endif /* CONFIG_BASS_FILTER */ #if CONFIG_TREBLE_FILTER static const AVOption treble_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS}, {"w", "set shelf transition steep", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 99999, FLAGS}, {"gain", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {"g", "set gain", OFFSET(gain), AV_OPT_TYPE_DOUBLE, {.dbl=0}, -900, 900, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(treble, "Boost or cut upper frequencies."); #endif /* CONFIG_TREBLE_FILTER */ #if CONFIG_BANDPASS_FILTER static const AVOption bandpass_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS}, {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS}, {"csg", "use constant skirt gain", OFFSET(csg), AV_OPT_TYPE_BOOL, {.i64=0}, 0, 1, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(bandpass, "Apply a two-pole Butterworth band-pass filter."); #endif /* CONFIG_BANDPASS_FILTER */ #if CONFIG_BANDREJECT_FILTER static const AVOption bandreject_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS}, {"w", "set band-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.5}, 0, 999, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(bandreject, "Apply a two-pole Butterworth band-reject filter."); #endif /* CONFIG_BANDREJECT_FILTER */ #if CONFIG_LOWPASS_FILTER static const AVOption lowpass_options[] = { {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS}, {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=500}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS}, {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS}, {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS}, {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(lowpass, "Apply a low-pass filter with 3dB point frequency."); #endif /* CONFIG_LOWPASS_FILTER */ #if CONFIG_HIGHPASS_FILTER static const AVOption highpass_options[] = { {"frequency", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"f", "set frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=QFACTOR}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS}, {"w", "set width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=0.707}, 0, 99999, FLAGS}, {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS}, {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(highpass, "Apply a high-pass filter with 3dB point frequency."); #endif /* CONFIG_HIGHPASS_FILTER */ #if CONFIG_ALLPASS_FILTER static const AVOption allpass_options[] = { {"frequency", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"f", "set central frequency", OFFSET(frequency), AV_OPT_TYPE_DOUBLE, {.dbl=3000}, 0, 999999, FLAGS}, {"width_type", "set filter-width type", OFFSET(width_type), AV_OPT_TYPE_INT, {.i64=HERTZ}, HERTZ, SLOPE, FLAGS, "width_type"}, {"h", "Hz", 0, AV_OPT_TYPE_CONST, {.i64=HERTZ}, 0, 0, FLAGS, "width_type"}, {"q", "Q-Factor", 0, AV_OPT_TYPE_CONST, {.i64=QFACTOR}, 0, 0, FLAGS, "width_type"}, {"o", "octave", 0, AV_OPT_TYPE_CONST, {.i64=OCTAVE}, 0, 0, FLAGS, "width_type"}, {"s", "slope", 0, AV_OPT_TYPE_CONST, {.i64=SLOPE}, 0, 0, FLAGS, "width_type"}, {"width", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS}, {"w", "set filter-width", OFFSET(width), AV_OPT_TYPE_DOUBLE, {.dbl=707.1}, 0, 99999, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(allpass, "Apply a two-pole all-pass filter."); #endif /* CONFIG_ALLPASS_FILTER */ #if CONFIG_BIQUAD_FILTER static const AVOption biquad_options[] = { {"a0", NULL, OFFSET(a0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {"a1", NULL, OFFSET(a1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {"a2", NULL, OFFSET(a2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {"b0", NULL, OFFSET(b0), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {"b1", NULL, OFFSET(b1), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {"b2", NULL, OFFSET(b2), AV_OPT_TYPE_DOUBLE, {.dbl=1}, INT16_MIN, INT16_MAX, FLAGS}, {NULL} }; DEFINE_BIQUAD_FILTER(biquad, "Apply a biquad IIR filter with the given coefficients."); #endif /* CONFIG_BIQUAD_FILTER */