From 34773ee69fde4d2fe5dde653ad0aad4c0690a407 Mon Sep 17 00:00:00 2001 From: Paul B Mahol Date: Mon, 30 Nov 2020 09:49:03 +0100 Subject: avfilter: add asubcut filter --- libavfilter/af_asupercut.c | 89 ++++++++++++++++++++++++++++++++++++---------- 1 file changed, 70 insertions(+), 19 deletions(-) (limited to 'libavfilter/af_asupercut.c') diff --git a/libavfilter/af_asupercut.c b/libavfilter/af_asupercut.c index ef241405d8..6d0a2b79a9 100644 --- a/libavfilter/af_asupercut.c +++ b/libavfilter/af_asupercut.c @@ -32,6 +32,7 @@ typedef struct ASuperCutContext { const AVClass *class; double cutoff; + double level; int order; int filter_count; @@ -95,27 +96,52 @@ static int get_coeffs(AVFilterContext *ctx) s->filter_count = s->order / 2 + (s->order & 1); calc_q_factors(s->order, q); - if (s->order & 1) { - BiquadCoeffs *coeffs = &s->coeffs[0]; - double omega = 2. * tan(M_PI * w0); + if (!strcmp(ctx->filter->name, "asubcut")) { + if (s->order & 1) { + BiquadCoeffs *coeffs = &s->coeffs[0]; + double omega = 2. * tan(M_PI * w0); - coeffs->b0 = omega / (2. + omega); - coeffs->b1 = coeffs->b0; - coeffs->b2 = 0.; - coeffs->a1 = -(omega - 2.) / (2. + omega); - coeffs->a2 = 0.; - } + coeffs->b0 = 2. / (2. + omega); + coeffs->b1 = -coeffs->b0; + coeffs->b2 = 0.; + coeffs->a1 = -(omega - 2.) / (2. + omega); + coeffs->a2 = 0.; + } + + for (int b = (s->order & 1); b < s->filter_count; b++) { + BiquadCoeffs *coeffs = &s->coeffs[b]; + const int idx = b - (s->order & 1); + double norm = 1.0 / (1.0 + K / q[idx] + K * K); - for (int b = (s->order & 1); b < s->filter_count; b++) { - BiquadCoeffs *coeffs = &s->coeffs[b]; - const int idx = b - (s->order & 1); - double norm = 1.0 / (1.0 + K / q[idx] + K * K); + coeffs->b0 = norm; + coeffs->b1 = -2.0 * coeffs->b0; + coeffs->b2 = coeffs->b0; + coeffs->a1 = -2.0 * (K * K - 1.0) * norm; + coeffs->a2 = -(1.0 - K / q[idx] + K * K) * norm; + } + } else { + if (s->order & 1) { + BiquadCoeffs *coeffs = &s->coeffs[0]; + double omega = 2. * tan(M_PI * w0); + + coeffs->b0 = omega / (2. + omega); + coeffs->b1 = coeffs->b0; + coeffs->b2 = 0.; + coeffs->a1 = -(omega - 2.) / (2. + omega); + coeffs->a2 = 0.; + } - coeffs->b0 = K * K * norm; - coeffs->b1 = 2.0 * coeffs->b0; - coeffs->b2 = coeffs->b0; - coeffs->a1 = -2.0 * (K * K - 1.0) * norm; - coeffs->a2 = -(1.0 - K / q[idx] + K * K) * norm; + for (int b = (s->order & 1); b < s->filter_count; b++) { + BiquadCoeffs *coeffs = &s->coeffs[b]; + const int idx = b - (s->order & 1); + double norm = 1.0 / (1.0 + K / q[idx] + K * K); + + coeffs->b0 = K * K * norm; + coeffs->b1 = 2.0 * coeffs->b0; + coeffs->b2 = coeffs->b0; + coeffs->a1 = -2.0 * (K * K - 1.0) * norm; + coeffs->a2 = -(1.0 - K / q[idx] + K * K) * norm; + } } return 0; @@ -135,6 +161,7 @@ static int filter_channels_## name(AVFilterContext *ctx, void *arg, \ AVFrame *in = td->in; \ const int start = (in->channels * jobnr) / nb_jobs; \ const int end = (in->channels * (jobnr+1)) / nb_jobs; \ + const double level = s->level; \ \ for (int ch = start; ch < end; ch++) { \ const type *src = (const type *)in->extended_data[ch]; \ @@ -150,7 +177,7 @@ static int filter_channels_## name(AVFilterContext *ctx, void *arg, \ type *w = ((type *)s->w->extended_data[ch]) + b * 2; \ \ for (int n = 0; n < in->nb_samples; n++) { \ - type sin = b ? dst[n] : src[n]; \ + type sin = b ? dst[n] : src[n] * level; \ type sout = sin * b0 + w[0]; \ \ w[0] = b1 * sin + w[1] + a1 * sout; \ @@ -240,6 +267,7 @@ static av_cold void uninit(AVFilterContext *ctx) static const AVOption asupercut_options[] = { { "cutoff", "set cutoff frequency", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=20000}, 20000, 192000, FLAGS }, { "order", "set filter order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=10}, 3, 20, FLAGS }, + { "level", "set input level", OFFSET(level), AV_OPT_TYPE_DOUBLE, {.dbl=1.}, 0., 1., FLAGS }, { NULL } }; @@ -276,3 +304,26 @@ AVFilter ff_af_asupercut = { .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS, }; + +static const AVOption asubcut_options[] = { + { "cutoff", "set cutoff frequency", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=20}, 2, 200, FLAGS }, + { "order", "set filter order", OFFSET(order), AV_OPT_TYPE_INT, {.i64=10}, 3, 20, FLAGS }, + { "level", "set input level", OFFSET(level), AV_OPT_TYPE_DOUBLE, {.dbl=1.}, 0., 1., FLAGS }, + { NULL } +}; + +AVFILTER_DEFINE_CLASS(asubcut); + +AVFilter ff_af_asubcut = { + .name = "asubcut", + .description = NULL_IF_CONFIG_SMALL("Cut subwoofer frequencies."), + .query_formats = query_formats, + .priv_size = sizeof(ASuperCutContext), + .priv_class = &asubcut_class, + .uninit = uninit, + .inputs = inputs, + .outputs = outputs, + .process_command = process_command, + .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | + AVFILTER_FLAG_SLICE_THREADS, +}; -- cgit v1.2.3