| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * Copyright (c) 2022 Paul B Mahol | ||
| 3 | * | ||
| 4 | * This file is part of FFmpeg. | ||
| 5 | * | ||
| 6 | * FFmpeg is free software; you can redistribute it and/or | ||
| 7 | * modify it under the terms of the GNU Lesser General Public License | ||
| 8 | * as published by the Free Software Foundation; either | ||
| 9 | * version 2.1 of the License, or (at your option) any later version. | ||
| 10 | * | ||
| 11 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | ||
| 14 | * GNU Lesser General Public License for more details. | ||
| 15 | * | ||
| 16 | * You should have received a copy of the GNU Lesser General Public License | ||
| 17 | * along with FFmpeg; if not, write to the Free Software Foundation, Inc., | ||
| 18 | * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 19 | */ | ||
| 20 | |||
| 21 | #include "libavutil/channel_layout.h" | ||
| 22 | #include "libavutil/opt.h" | ||
| 23 | #include "audio.h" | ||
| 24 | #include "avfilter.h" | ||
| 25 | #include "filters.h" | ||
| 26 | #include "formats.h" | ||
| 27 | #include "internal.h" | ||
| 28 | |||
| 29 | #include <float.h> | ||
| 30 | |||
| 31 | typedef struct AudioVirtualBassContext { | ||
| 32 | const AVClass *class; | ||
| 33 | |||
| 34 | double cutoff; | ||
| 35 | double strength; | ||
| 36 | |||
| 37 | double a[3], m[3], cf[2]; | ||
| 38 | } AudioVirtualBassContext; | ||
| 39 | |||
| 40 | #define OFFSET(x) offsetof(AudioVirtualBassContext, x) | ||
| 41 | #define TFLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_RUNTIME_PARAM | ||
| 42 | #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM | ||
| 43 | |||
| 44 | static const AVOption virtualbass_options[] = { | ||
| 45 | { "cutoff", "set virtual bass cutoff", OFFSET(cutoff), AV_OPT_TYPE_DOUBLE, {.dbl=250},100,500, FLAGS }, | ||
| 46 | { "strength", "set virtual bass strength", OFFSET(strength), AV_OPT_TYPE_DOUBLE, {.dbl=3}, 0.5, 3, TFLAGS }, | ||
| 47 | {NULL} | ||
| 48 | }; | ||
| 49 | |||
| 50 | AVFILTER_DEFINE_CLASS(virtualbass); | ||
| 51 | |||
| 52 | ✗ | static int query_formats(AVFilterContext *ctx) | |
| 53 | { | ||
| 54 | ✗ | AVFilterChannelLayouts *in_layout = NULL, *out_layout = NULL; | |
| 55 | ✗ | AVFilterFormats *formats = NULL; | |
| 56 | int ret; | ||
| 57 | |||
| 58 | ✗ | if ((ret = ff_add_format (&formats, AV_SAMPLE_FMT_DBLP )) < 0 || | |
| 59 | ✗ | (ret = ff_set_common_formats (ctx, formats )) < 0 || | |
| 60 | ✗ | (ret = ff_add_channel_layout (&in_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO)) < 0 || | |
| 61 | ✗ | (ret = ff_channel_layouts_ref(in_layout, &ctx->inputs[0]->outcfg.channel_layouts)) < 0 || | |
| 62 | ✗ | (ret = ff_add_channel_layout (&out_layout, &(AVChannelLayout)AV_CHANNEL_LAYOUT_2POINT1)) < 0 || | |
| 63 | ✗ | (ret = ff_channel_layouts_ref(out_layout, &ctx->outputs[0]->incfg.channel_layouts)) < 0) | |
| 64 | ✗ | return ret; | |
| 65 | |||
| 66 | ✗ | return ff_set_common_all_samplerates(ctx); | |
| 67 | } | ||
| 68 | |||
| 69 | ✗ | static int config_input(AVFilterLink *inlink) | |
| 70 | { | ||
| 71 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 72 | ✗ | AudioVirtualBassContext *s = ctx->priv; | |
| 73 | ✗ | const double Q = 0.707; | |
| 74 | double g, k; | ||
| 75 | |||
| 76 | ✗ | g = tan(M_PI * s->cutoff / inlink->sample_rate); | |
| 77 | ✗ | k = 1. / Q; | |
| 78 | ✗ | s->a[0] = 1. / (1. + g * (g + k)); | |
| 79 | ✗ | s->a[1] = g * s->a[0]; | |
| 80 | ✗ | s->a[2] = g * s->a[1]; | |
| 81 | ✗ | s->m[0] = 0.; | |
| 82 | ✗ | s->m[1] = 0.; | |
| 83 | ✗ | s->m[2] = 1.; | |
| 84 | |||
| 85 | ✗ | return 0; | |
| 86 | } | ||
| 87 | |||
| 88 | #define SQR(x) ((x) * (x)) | ||
| 89 | |||
| 90 | ✗ | static double vb_fun(double x) | |
| 91 | { | ||
| 92 | ✗ | double y = 2.5 * atan(0.9 * x) + 2.5 * sqrt(1. - SQR(0.9 * x)) - 2.5; | |
| 93 | |||
| 94 | ✗ | return y < 0. ? sin(y) : y; | |
| 95 | } | ||
| 96 | |||
| 97 | ✗ | static void vb_stereo(AVFilterContext *ctx, AVFrame *out, AVFrame *in) | |
| 98 | { | ||
| 99 | ✗ | AudioVirtualBassContext *s = ctx->priv; | |
| 100 | ✗ | const double *lsrc = (const double *)in->extended_data[0]; | |
| 101 | ✗ | const double *rsrc = (const double *)in->extended_data[1]; | |
| 102 | ✗ | double *ldst = (double *)out->extended_data[0]; | |
| 103 | ✗ | double *rdst = (double *)out->extended_data[1]; | |
| 104 | ✗ | double *lfe = (double *)out->extended_data[2]; | |
| 105 | ✗ | const double st = M_PI / s->strength; | |
| 106 | ✗ | const double a0 = s->a[0]; | |
| 107 | ✗ | const double a1 = s->a[1]; | |
| 108 | ✗ | const double a2 = s->a[2]; | |
| 109 | ✗ | const double m0 = s->m[0]; | |
| 110 | ✗ | const double m1 = s->m[1]; | |
| 111 | ✗ | const double m2 = s->m[2]; | |
| 112 | ✗ | double b0 = s->cf[0]; | |
| 113 | ✗ | double b1 = s->cf[1]; | |
| 114 | |||
| 115 | ✗ | memcpy(ldst, lsrc, in->nb_samples * sizeof(double)); | |
| 116 | ✗ | memcpy(rdst, rsrc, in->nb_samples * sizeof(double)); | |
| 117 | |||
| 118 | ✗ | for (int n = 0; n < in->nb_samples; n++) { | |
| 119 | ✗ | const double center = (lsrc[n] + rsrc[n]) * 0.5; | |
| 120 | ✗ | const double v0 = center; | |
| 121 | ✗ | const double v3 = v0 - b1; | |
| 122 | ✗ | const double v1 = a0 * b0 + a1 * v3; | |
| 123 | ✗ | const double v2 = b1 + a1 * b0 + a2 * v3; | |
| 124 | double b, vb; | ||
| 125 | |||
| 126 | ✗ | b0 = 2. * v1 - b0; | |
| 127 | ✗ | b1 = 2. * v2 - b1; | |
| 128 | |||
| 129 | ✗ | b = m0 * v0 + m1 * v1 + m2 * v2; | |
| 130 | ✗ | vb = sin(vb_fun(b) * st); | |
| 131 | |||
| 132 | ✗ | lfe[n] = vb; | |
| 133 | } | ||
| 134 | |||
| 135 | ✗ | s->cf[0] = b0; | |
| 136 | ✗ | s->cf[1] = b1; | |
| 137 | ✗ | } | |
| 138 | |||
| 139 | ✗ | static int filter_frame(AVFilterLink *inlink, AVFrame *in) | |
| 140 | { | ||
| 141 | ✗ | AVFilterContext *ctx = inlink->dst; | |
| 142 | ✗ | AVFilterLink *outlink = ctx->outputs[0]; | |
| 143 | AVFrame *out; | ||
| 144 | |||
| 145 | ✗ | out = ff_get_audio_buffer(outlink, in->nb_samples); | |
| 146 | ✗ | if (!out) { | |
| 147 | ✗ | av_frame_free(&in); | |
| 148 | ✗ | return AVERROR(ENOMEM); | |
| 149 | } | ||
| 150 | ✗ | av_frame_copy_props(out, in); | |
| 151 | |||
| 152 | ✗ | vb_stereo(ctx, out, in); | |
| 153 | |||
| 154 | ✗ | av_frame_free(&in); | |
| 155 | ✗ | return ff_filter_frame(outlink, out); | |
| 156 | } | ||
| 157 | |||
| 158 | static const AVFilterPad inputs[] = { | ||
| 159 | { | ||
| 160 | .name = "default", | ||
| 161 | .type = AVMEDIA_TYPE_AUDIO, | ||
| 162 | .filter_frame = filter_frame, | ||
| 163 | .config_props = config_input, | ||
| 164 | }, | ||
| 165 | }; | ||
| 166 | |||
| 167 | const AVFilter ff_af_virtualbass = { | ||
| 168 | .name = "virtualbass", | ||
| 169 | .description = NULL_IF_CONFIG_SMALL("Audio Virtual Bass."), | ||
| 170 | .priv_size = sizeof(AudioVirtualBassContext), | ||
| 171 | .priv_class = &virtualbass_class, | ||
| 172 | FILTER_INPUTS(inputs), | ||
| 173 | FILTER_OUTPUTS(ff_audio_default_filterpad), | ||
| 174 | FILTER_QUERY_FUNC(query_formats), | ||
| 175 | .flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL, | ||
| 176 | .process_command = ff_filter_process_command, | ||
| 177 | }; | ||
| 178 |