mirror of https://github.com/FFmpeg/FFmpeg.git
Paul B Mahol
3 years ago
parent
557a1a8af2
commit
d39f9feddc
6 changed files with 207 additions and 1 deletions
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/*
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* Copyright (c) 2022 Paul B Mahol |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public License |
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* as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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* GNU Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public License |
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* along with FFmpeg; if not, write to the Free Software Foundation, Inc., |
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* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "libavutil/channel_layout.h" |
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#include "libavutil/opt.h" |
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#include "audio.h" |
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#include "avfilter.h" |
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#include "filters.h" |
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#include "internal.h" |
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#include <float.h> |
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typedef struct AudioVirtualBassContext { |
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const AVClass *class; |
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double cutoff; |
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double strength; |
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double a[3], m[3], cf[2]; |
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} AudioVirtualBassContext; |
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#define OFFSET(x) offsetof(AudioVirtualBassContext, x) |
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#define TFLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_RUNTIME_PARAM |
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#define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM |
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static const AVOption virtualbass_options[] = { |
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{ "cutoff", "set virtual bass cutoff", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=250},100,500, FLAGS }, |
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{ "strength", "set virtual bass strength", OFFSET(strength), AV_OPT_TYPE_DOUBLE, {.dbl=3}, 0.5, 3, TFLAGS }, |
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{NULL} |
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}; |
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AVFILTER_DEFINE_CLASS(virtualbass); |
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static int query_formats(AVFilterContext *ctx) |
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{ |
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AVFilterChannelLayouts *in_layout = NULL, *out_layout = NULL; |
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AVFilterFormats *formats = NULL; |
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int ret; |
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if ((ret = ff_add_format (&formats, AV_SAMPLE_FMT_DBLP )) < 0 || |
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(ret = ff_set_common_formats (ctx, formats )) < 0 || |
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(ret = ff_add_channel_layout (&in_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO)) < 0 || |
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(ret = ff_channel_layouts_ref(in_layout, &ctx->inputs[0]->outcfg.channel_layouts)) < 0 || |
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(ret = ff_add_channel_layout (&out_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_2POINT1)) < 0 || |
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(ret = ff_channel_layouts_ref(out_layout, &ctx->outputs[0]->incfg.channel_layouts)) < 0) |
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return ret; |
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return ff_set_common_all_samplerates(ctx); |
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} |
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static int config_input(AVFilterLink *inlink) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AudioVirtualBassContext *s = ctx->priv; |
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const double Q = 0.707; |
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double g, k; |
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g = tan(M_PI * s->cutoff / inlink->sample_rate); |
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k = 1. / Q; |
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s->a[0] = 1. / (1. + g * (g + k)); |
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s->a[1] = g * s->a[0]; |
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s->a[2] = g * s->a[1]; |
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s->m[0] = 0.; |
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s->m[1] = 0.; |
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s->m[2] = 1.; |
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return 0; |
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} |
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#define SQR(x) ((x) * (x)) |
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static double vb_fun(double x) |
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{ |
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double y = 2.5 * atan(0.9 * x) + 2.5 * sqrt(1. - SQR(0.9 * x)) - 2.5; |
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return y < 0. ? sin(y) : y; |
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} |
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static void vb_stereo(AVFilterContext *ctx, AVFrame *out, AVFrame *in) |
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{ |
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AudioVirtualBassContext *s = ctx->priv; |
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const double *lsrc = (const double *)in->extended_data[0]; |
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const double *rsrc = (const double *)in->extended_data[1]; |
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double *ldst = (double *)out->extended_data[0]; |
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double *rdst = (double *)out->extended_data[1]; |
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double *lfe = (double *)out->extended_data[2]; |
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const double st = M_PI / s->strength; |
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const double a0 = s->a[0]; |
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const double a1 = s->a[1]; |
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const double a2 = s->a[2]; |
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const double m0 = s->m[0]; |
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const double m1 = s->m[1]; |
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const double m2 = s->m[2]; |
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double b0 = s->cf[0]; |
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double b1 = s->cf[1]; |
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memcpy(ldst, lsrc, in->nb_samples * sizeof(double)); |
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memcpy(rdst, rsrc, in->nb_samples * sizeof(double)); |
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for (int n = 0; n < in->nb_samples; n++) { |
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const double center = (lsrc[n] + rsrc[n]) * 0.5; |
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const double v0 = center; |
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const double v3 = v0 - b1; |
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const double v1 = a0 * b0 + a1 * v3; |
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const double v2 = b1 + a1 * b0 + a2 * v3; |
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double b, vb; |
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b0 = 2. * v1 - b0; |
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b1 = 2. * v2 - b1; |
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b = m0 * v0 + m1 * v1 + m2 * v2; |
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vb = sin(vb_fun(b) * st); |
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lfe[n] = vb; |
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} |
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s->cf[0] = b0; |
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s->cf[1] = b1; |
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} |
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static int filter_frame(AVFilterLink *inlink, AVFrame *in) |
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{ |
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AVFilterContext *ctx = inlink->dst; |
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AVFilterLink *outlink = ctx->outputs[0]; |
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AVFrame *out; |
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out = ff_get_audio_buffer(outlink, in->nb_samples); |
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if (!out) { |
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av_frame_free(&in); |
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return AVERROR(ENOMEM); |
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} |
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vb_stereo(ctx, out, in); |
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out->pts = in->pts; |
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av_frame_free(&in); |
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return ff_filter_frame(outlink, out); |
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} |
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static const AVFilterPad inputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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.filter_frame = filter_frame, |
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.config_props = config_input, |
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}, |
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}; |
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static const AVFilterPad outputs[] = { |
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{ |
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.name = "default", |
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.type = AVMEDIA_TYPE_AUDIO, |
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}, |
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}; |
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const AVFilter ff_af_virtualbass = { |
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.name = "virtualbass", |
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.description = NULL_IF_CONFIG_SMALL("Audio Virtual Bass."), |
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.priv_size = sizeof(AudioVirtualBassContext), |
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.priv_class = &virtualbass_class, |
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FILTER_INPUTS(inputs), |
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FILTER_OUTPUTS(outputs), |
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FILTER_QUERY_FUNC(query_formats), |
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.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, |
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.process_command = ff_filter_process_command, |
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}; |
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