diff options
author | Paul B Mahol <onemda@gmail.com> | 2020-12-16 20:36:56 +0300 |
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committer | Paul B Mahol <onemda@gmail.com> | 2020-12-16 20:38:51 +0300 |
commit | 69be00aa611b6c489c56fb189a2a65b1b404337d (patch) | |
tree | 8eabd6883df2d8ce1615b83717f21b81d0cd3baa /libavfilter/af_biquads.c | |
parent | 1a8e719f36f09a4e85db4d3e37c546adecd31fee (diff) |
avfilter/af_biquads: add one-pole shelf filters by adding pole option
Diffstat (limited to 'libavfilter/af_biquads.c')
-rw-r--r-- | libavfilter/af_biquads.c | 64 |
1 files changed, 52 insertions, 12 deletions
diff --git a/libavfilter/af_biquads.c b/libavfilter/af_biquads.c index edefe15d05..6e1da52fb3 100644 --- a/libavfilter/af_biquads.c +++ b/libavfilter/af_biquads.c @@ -514,22 +514,54 @@ static int config_filter(AVFilterLink *outlink, int reset) case bass: beta = sqrt((A * A + 1) - (A - 1) * (A - 1)); case lowshelf: - s->a0 = (A + 1) + (A - 1) * cos(w0) + beta * alpha; - s->a1 = -2 * ((A - 1) + (A + 1) * cos(w0)); - s->a2 = (A + 1) + (A - 1) * cos(w0) - beta * alpha; - s->b0 = A * ((A + 1) - (A - 1) * cos(w0) + beta * alpha); - s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0)); - s->b2 = A * ((A + 1) - (A - 1) * cos(w0) - beta * alpha); + if (s->poles == 1) { + double A = ff_exp10(s->gain / 20); + double ro = -sin(w0 / 2. - M_PI_4 / (sin(w0 / 2. + M_PI_4))); + double n = (A + 1) / (A - 1); + double alpha1 = A == 1. ? 0. : n - FFSIGN(n) * sqrt(n * n - 1); + double beta0 = ((1 + A) + (1 - A) * alpha1) * 0.5; + double beta1 = ((1 - A) + (1 + A) * alpha1) * 0.5; + + s->a0 = 1 + ro * alpha1; + s->a1 = -ro - alpha1; + s->a2 = 0; + s->b0 = beta0 + ro * beta1; + s->b1 = -beta1 - ro * beta0; + s->b2 = 0; + } else { + s->a0 = (A + 1) + (A - 1) * cos(w0) + beta * alpha; + s->a1 = -2 * ((A - 1) + (A + 1) * cos(w0)); + s->a2 = (A + 1) + (A - 1) * cos(w0) - beta * alpha; + s->b0 = A * ((A + 1) - (A - 1) * cos(w0) + beta * alpha); + s->b1 = 2 * A * ((A - 1) - (A + 1) * cos(w0)); + s->b2 = A * ((A + 1) - (A - 1) * cos(w0) - beta * alpha); + } break; case treble: beta = sqrt((A * A + 1) - (A - 1) * (A - 1)); case highshelf: - s->a0 = (A + 1) - (A - 1) * cos(w0) + beta * alpha; - s->a1 = 2 * ((A - 1) - (A + 1) * cos(w0)); - s->a2 = (A + 1) - (A - 1) * cos(w0) - beta * alpha; - s->b0 = A * ((A + 1) + (A - 1) * cos(w0) + beta * alpha); - s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0)); - s->b2 = A * ((A + 1) + (A - 1) * cos(w0) - beta * alpha); + if (s->poles == 1) { + double A = ff_exp10(s->gain / 20); + double ro = sin(w0 / 2. - M_PI_4 / (sin(w0 / 2. + M_PI_4))); + double n = (A + 1) / (A - 1); + double alpha1 = A == 1. ? 0. : n - FFSIGN(n) * sqrt(n * n - 1); + double beta0 = ((1 + A) + (1 - A) * alpha1) * 0.5; + double beta1 = ((1 - A) + (1 + A) * alpha1) * 0.5; + + s->a0 = 1 + ro * alpha1; + s->a1 = ro + alpha1; + s->a2 = 0; + s->b0 = beta0 + ro * beta1; + s->b1 = beta1 + ro * beta0; + s->b2 = 0; + } else { + s->a0 = (A + 1) - (A - 1) * cos(w0) + beta * alpha; + s->a1 = 2 * ((A - 1) - (A + 1) * cos(w0)); + s->a2 = (A + 1) - (A - 1) * cos(w0) - beta * alpha; + s->b0 = A * ((A + 1) + (A - 1) * cos(w0) + beta * alpha); + s->b1 =-2 * A * ((A - 1) + (A + 1) * cos(w0)); + s->b2 = A * ((A + 1) + (A - 1) * cos(w0) - beta * alpha); + } break; case bandpass: if (s->csg) { @@ -914,6 +946,8 @@ static const AVOption bass_options[] = { {"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}, + {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, + {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, {"mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"m", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS}, @@ -953,6 +987,8 @@ static const AVOption treble_options[] = { {"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}, + {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, + {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, {"mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"m", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS}, @@ -1184,6 +1220,8 @@ static const AVOption lowshelf_options[] = { {"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}, + {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, + {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, {"mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"m", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS}, @@ -1223,6 +1261,8 @@ static const AVOption highshelf_options[] = { {"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}, + {"poles", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, + {"p", "set number of poles", OFFSET(poles), AV_OPT_TYPE_INT, {.i64=2}, 1, 2, AF}, {"mix", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"m", "set mix", OFFSET(mix), AV_OPT_TYPE_DOUBLE, {.dbl=1}, 0, 1, FLAGS}, {"channels", "set channels to filter", OFFSET(channels), AV_OPT_TYPE_CHANNEL_LAYOUT, {.i64=-1}, INT64_MIN, INT64_MAX, FLAGS}, |