FFmpeg coverage

Directory: ../../../ffmpeg/
File: src/libavfilter/asrc_anoisesrc.c
Date: 2026-04-30 23:37:26
Exec Total Coverage
Lines: 0 84 0.0%
Functions: 0 9 0.0%
Branches: 0 33 0.0%
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1 /*
2 * Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
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 "libavutil/lfg.h"
28 #include "libavutil/random_seed.h"
29
30 typedef struct ANoiseSrcContext {
31 const AVClass *class;
32 int sample_rate;
33 double amplitude;
34 double density;
35 int64_t duration;
36 int color;
37 int64_t seed;
38 int nb_samples;
39
40 int64_t pts;
41 int infinite;
42 double (*filter)(double white, double *buf);
43 double buf[7];
44 AVLFG c;
45 } ANoiseSrcContext;
46
47 enum NoiseMode {
48 NM_WHITE,
49 NM_PINK,
50 NM_BROWN,
51 NM_BLUE,
52 NM_VIOLET,
53 NM_VELVET,
54 NM_NB
55 };
56
57 #define OFFSET(x) offsetof(ANoiseSrcContext, x)
58 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
59
60 static const AVOption anoisesrc_options[] = {
61 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
62 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
63 { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
64 { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
65 { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
66 { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
67 { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" },
68 { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" },
69 { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, .unit = "color" },
70 { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, .unit = "color" },
71 { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, .unit = "color" },
72 { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, .unit = "color" },
73 { "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, .unit = "color" },
74 { "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, .unit = "color" },
75 { "velvet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VELVET}, 0, 0, FLAGS, .unit = "color" },
76 { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
77 { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
78 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
79 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
80 { "density", "set density", OFFSET(density), AV_OPT_TYPE_DOUBLE, {.dbl = 0.05}, 0., 1., FLAGS },
81 {NULL}
82 };
83
84 AVFILTER_DEFINE_CLASS(anoisesrc);
85
86 ✗ static av_cold int query_formats(const AVFilterContext *ctx,
87 AVFilterFormatsConfig **cfg_in,
88 AVFilterFormatsConfig **cfg_out)
89 {
90 ✗ const ANoiseSrcContext *s = ctx->priv;
91 static const AVChannelLayout chlayouts[] = { AV_CHANNEL_LAYOUT_MONO, { 0 } };
92 ✗ int sample_rates[] = { s->sample_rate, -1 };
93 static const enum AVSampleFormat sample_fmts[] = {
94 AV_SAMPLE_FMT_DBL,
95 AV_SAMPLE_FMT_NONE
96 };
97 ✗ int ret = ff_set_sample_formats_from_list2(ctx, cfg_in, cfg_out, sample_fmts);
98 ✗ if (ret < 0)
99 ✗ return ret;
100
101 ✗ ret = ff_set_common_channel_layouts_from_list2(ctx, cfg_in, cfg_out, chlayouts);
102 ✗ if (ret < 0)
103 ✗ return ret;
104
105 ✗ return ff_set_common_samplerates_from_list2(ctx, cfg_in, cfg_out, sample_rates);
106 }
107
108 ✗ static double white_filter(double white, double *buf)
109 {
110 ✗ return white;
111 }
112
113 ✗ static double pink_filter(double white, double *buf)
114 {
115 double pink;
116
117 /* http://www.musicdsp.org/files/pink.txt */
118 ✗ buf[0] = 0.99886 * buf[0] + white * 0.0555179;
119 ✗ buf[1] = 0.99332 * buf[1] + white * 0.0750759;
120 ✗ buf[2] = 0.96900 * buf[2] + white * 0.1538520;
121 ✗ buf[3] = 0.86650 * buf[3] + white * 0.3104856;
122 ✗ buf[4] = 0.55000 * buf[4] + white * 0.5329522;
123 ✗ buf[5] = -0.7616 * buf[5] - white * 0.0168980;
124 ✗ pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
125 ✗ buf[6] = white * 0.115926;
126 ✗ return pink * 0.11;
127 }
128
129 ✗ static double blue_filter(double white, double *buf)
130 {
131 double blue;
132
133 /* Same as pink_filter but subtract the offsets rather than add */
134 ✗ buf[0] = 0.0555179 * white - 0.99886 * buf[0];
135 ✗ buf[1] = 0.0750759 * white - 0.99332 * buf[1];
136 ✗ buf[2] = 0.1538520 * white - 0.96900 * buf[2];
137 ✗ buf[3] = 0.3104856 * white - 0.86650 * buf[3];
138 ✗ buf[4] = 0.5329522 * white - 0.55000 * buf[4];
139 ✗ buf[5] = -0.016898 * white + 0.76160 * buf[5];
140 ✗ blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
141 ✗ buf[6] = white * 0.115926;
142 ✗ return blue * 0.11;
143 }
144
145 ✗ static double brown_filter(double white, double *buf)
146 {
147 double brown;
148
149 ✗ brown = ((0.02 * white) + buf[0]) / 1.02;
150 ✗ buf[0] = brown;
151 ✗ return brown * 3.5;
152 }
153
154 ✗ static double violet_filter(double white, double *buf)
155 {
156 double violet;
157
158 ✗ violet = ((0.02 * white) - buf[0]) / 1.02;
159 ✗ buf[0] = violet;
160 ✗ return violet * 3.5;
161 }
162
163 ✗ static double velvet_filter(double white, double *buf)
164 {
165 ✗ double awhite = fabs(white);
166 ✗ return FFDIFFSIGN(white, 0.0) * buf[1] * (awhite < buf[0]);
167 }
168
169 ✗ static av_cold int config_props(AVFilterLink *outlink)
170 {
171 ✗ AVFilterContext *ctx = outlink->src;
172 ✗ ANoiseSrcContext *s = ctx->priv;
173
174 ✗ if (s->seed == -1)
175 ✗ s->seed = av_get_random_seed();
176 ✗ av_lfg_init(&s->c, s->seed);
177
178 ✗ if (s->duration == 0)
179 ✗ s->infinite = 1;
180 ✗ s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
181
182 ✗ switch (s->color) {
183 ✗ case NM_WHITE: s->filter = white_filter; break;
184 ✗ case NM_PINK: s->filter = pink_filter; break;
185 ✗ case NM_BROWN: s->filter = brown_filter; break;
186 ✗ case NM_BLUE: s->filter = blue_filter; break;
187 ✗ case NM_VIOLET: s->filter = violet_filter; break;
188 ✗ case NM_VELVET: s->buf[0] = s->amplitude * s->density;
189 ✗ s->buf[1] = s->amplitude;
190 ✗ s->filter = velvet_filter; break;
191 }
192
193 ✗ return 0;
194 }
195
196 ✗ static int activate(AVFilterContext *ctx)
197 {
198 ✗ AVFilterLink *outlink = ctx->outputs[0];
199 ✗ ANoiseSrcContext *s = ctx->priv;
200 AVFrame *frame;
201 int nb_samples, i;
202 double *dst;
203
204 ✗ if (!ff_outlink_frame_wanted(outlink))
205 ✗ return FFERROR_NOT_READY;
206
207 ✗ if (!s->infinite && s->duration <= 0) {
208 ✗ ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
209 ✗ return 0;
210 ✗ } else if (!s->infinite && s->duration < s->nb_samples) {
211 ✗ nb_samples = s->duration;
212 } else {
213 ✗ nb_samples = s->nb_samples;
214 }
215
216 ✗ if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
217 ✗ return AVERROR(ENOMEM);
218
219 ✗ dst = (double *)frame->data[0];
220 ✗ for (i = 0; i < nb_samples; i++) {
221 double white;
222 ✗ white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
223 ✗ dst[i] = s->filter(white, s->buf);
224 }
225
226 ✗ if (!s->infinite)
227 ✗ s->duration -= nb_samples;
228
229 ✗ frame->pts = s->pts;
230 ✗ s->pts += nb_samples;
231 ✗ return ff_filter_frame(outlink, frame);
232 }
233
234 static const AVFilterPad anoisesrc_outputs[] = {
235 {
236 .name = "default",
237 .type = AVMEDIA_TYPE_AUDIO,
238 .config_props = config_props,
239 },
240 };
241
242 const FFFilter ff_asrc_anoisesrc = {
243 .p.name = "anoisesrc",
244 .p.description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
245 .p.priv_class = &anoisesrc_class,
246 .priv_size = sizeof(ANoiseSrcContext),
247 .activate = activate,
248 FILTER_OUTPUTS(anoisesrc_outputs),
249 FILTER_QUERY_FUNC2(query_formats),
250 };
251