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path: root/libavfilter/asrc_anoisesrc.c (plain)
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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/opt.h"
22#include "audio.h"
23#include "avfilter.h"
24#include "internal.h"
25#include "libavutil/lfg.h"
26#include "libavutil/random_seed.h"
27
28typedef struct {
29 const AVClass *class;
30 int sample_rate;
31 double amplitude;
32 int64_t duration;
33 int64_t color;
34 int64_t seed;
35 int nb_samples;
36
37 int64_t pts;
38 int infinite;
39 double (*filter)(double white, double *buf);
40 double buf[7];
41 AVLFG c;
42} ANoiseSrcContext;
43
44#define OFFSET(x) offsetof(ANoiseSrcContext, x)
45#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
46
47static const AVOption anoisesrc_options[] = {
48 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
49 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
50 { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
51 { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
52 { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
53 { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
54 { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 2, FLAGS, "color" },
55 { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 2, FLAGS, "color" },
56 { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 2, FLAGS, "color" },
57 { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, FLAGS, "color" },
58 { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, FLAGS, "color" },
59 { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, FLAGS, "color" },
60 { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
61 { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
62 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
63 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
64 {NULL}
65};
66
67AVFILTER_DEFINE_CLASS(anoisesrc);
68
69static av_cold int query_formats(AVFilterContext *ctx)
70{
71 ANoiseSrcContext *s = ctx->priv;
72 static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
73 int sample_rates[] = { s->sample_rate, -1 };
74 static const enum AVSampleFormat sample_fmts[] = {
75 AV_SAMPLE_FMT_DBL,
76 AV_SAMPLE_FMT_NONE
77 };
78
79 AVFilterFormats *formats;
80 AVFilterChannelLayouts *layouts;
81 int ret;
82
83 formats = ff_make_format_list(sample_fmts);
84 if (!formats)
85 return AVERROR(ENOMEM);
86 ret = ff_set_common_formats (ctx, formats);
87 if (ret < 0)
88 return ret;
89
90 layouts = avfilter_make_format64_list(chlayouts);
91 if (!layouts)
92 return AVERROR(ENOMEM);
93 ret = ff_set_common_channel_layouts(ctx, layouts);
94 if (ret < 0)
95 return ret;
96
97 formats = ff_make_format_list(sample_rates);
98 if (!formats)
99 return AVERROR(ENOMEM);
100 return ff_set_common_samplerates(ctx, formats);
101}
102
103static double white_filter(double white, double *buf)
104{
105 return white;
106}
107
108static double pink_filter(double white, double *buf)
109{
110 double pink;
111
112 /* http://www.musicdsp.org/files/pink.txt */
113 buf[0] = 0.99886 * buf[0] + white * 0.0555179;
114 buf[1] = 0.99332 * buf[1] + white * 0.0750759;
115 buf[2] = 0.96900 * buf[2] + white * 0.1538520;
116 buf[3] = 0.86650 * buf[3] + white * 0.3104856;
117 buf[4] = 0.55000 * buf[4] + white * 0.5329522;
118 buf[5] = -0.7616 * buf[5] - white * 0.0168980;
119 pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
120 buf[6] = white * 0.115926;
121 return pink * 0.11;
122}
123
124static double brown_filter(double white, double *buf)
125{
126 double brown;
127
128 brown = ((0.02 * white) + buf[0]) / 1.02;
129 buf[0] = brown;
130 return brown * 3.5;
131}
132
133static av_cold int config_props(AVFilterLink *outlink)
134{
135 AVFilterContext *ctx = outlink->src;
136 ANoiseSrcContext *s = ctx->priv;
137
138 if (s->seed == -1)
139 s->seed = av_get_random_seed();
140 av_lfg_init(&s->c, s->seed);
141
142 if (s->duration == 0)
143 s->infinite = 1;
144 s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
145
146 switch (s->color) {
147 case 0: s->filter = white_filter; break;
148 case 1: s->filter = pink_filter; break;
149 case 2: s->filter = brown_filter; break;
150 }
151
152 return 0;
153}
154
155static int request_frame(AVFilterLink *outlink)
156{
157 AVFilterContext *ctx = outlink->src;
158 ANoiseSrcContext *s = ctx->priv;
159 AVFrame *frame;
160 int nb_samples, i;
161 double *dst;
162
163 if (!s->infinite && s->duration <= 0) {
164 return AVERROR_EOF;
165 } else if (!s->infinite && s->duration < s->nb_samples) {
166 nb_samples = s->duration;
167 } else {
168 nb_samples = s->nb_samples;
169 }
170
171 if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
172 return AVERROR(ENOMEM);
173
174 dst = (double *)frame->data[0];
175 for (i = 0; i < nb_samples; i++) {
176 double white;
177 white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
178 dst[i] = s->filter(white, s->buf);
179 }
180
181 if (!s->infinite)
182 s->duration -= nb_samples;
183
184 frame->pts = s->pts;
185 s->pts += nb_samples;
186 return ff_filter_frame(outlink, frame);
187}
188
189static const AVFilterPad anoisesrc_outputs[] = {
190 {
191 .name = "default",
192 .type = AVMEDIA_TYPE_AUDIO,
193 .request_frame = request_frame,
194 .config_props = config_props,
195 },
196 { NULL }
197};
198
199AVFilter ff_asrc_anoisesrc = {
200 .name = "anoisesrc",
201 .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
202 .query_formats = query_formats,
203 .priv_size = sizeof(ANoiseSrcContext),
204 .inputs = NULL,
205 .outputs = anoisesrc_outputs,
206 .priv_class = &anoisesrc_class,
207};
208
generated by cgit at 2024-05-17 08:26:16 (GMT)