2 * Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
4 * This file is part of FFmpeg.
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.
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.
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
21 #include "libavutil/opt.h"
25 #include "libavutil/lfg.h"
26 #include "libavutil/random_seed.h"
28 typedef struct ANoiseSrcContext {
39 double (*filter)(double white, double *buf, double half_amplitude);
54 #define OFFSET(x) offsetof(ANoiseSrcContext, x)
55 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
57 static const AVOption anoisesrc_options[] = {
58 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
59 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
60 { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
61 { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
62 { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
63 { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
64 { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
65 { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
66 { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
67 { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, "color" },
68 { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, "color" },
69 { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, "color" },
70 { "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, "color" },
71 { "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, "color" },
72 { "velvet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VELVET}, 0, 0, FLAGS, "color" },
73 { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
74 { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
75 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
76 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
80 AVFILTER_DEFINE_CLASS(anoisesrc);
82 static av_cold int query_formats(AVFilterContext *ctx)
84 ANoiseSrcContext *s = ctx->priv;
85 static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
86 int sample_rates[] = { s->sample_rate, -1 };
87 static const enum AVSampleFormat sample_fmts[] = {
92 AVFilterFormats *formats;
93 AVFilterChannelLayouts *layouts;
96 formats = ff_make_format_list(sample_fmts);
98 return AVERROR(ENOMEM);
99 ret = ff_set_common_formats (ctx, formats);
103 layouts = avfilter_make_format64_list(chlayouts);
105 return AVERROR(ENOMEM);
106 ret = ff_set_common_channel_layouts(ctx, layouts);
110 formats = ff_make_format_list(sample_rates);
112 return AVERROR(ENOMEM);
113 return ff_set_common_samplerates(ctx, formats);
116 static double white_filter(double white, double *buf, double ha)
121 static double pink_filter(double white, double *buf, double ha)
125 /* http://www.musicdsp.org/files/pink.txt */
126 buf[0] = 0.99886 * buf[0] + white * 0.0555179;
127 buf[1] = 0.99332 * buf[1] + white * 0.0750759;
128 buf[2] = 0.96900 * buf[2] + white * 0.1538520;
129 buf[3] = 0.86650 * buf[3] + white * 0.3104856;
130 buf[4] = 0.55000 * buf[4] + white * 0.5329522;
131 buf[5] = -0.7616 * buf[5] - white * 0.0168980;
132 pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
133 buf[6] = white * 0.115926;
137 static double blue_filter(double white, double *buf, double ha)
141 /* Same as pink_filter but subtract the offsets rather than add */
142 buf[0] = 0.0555179 * white - 0.99886 * buf[0];
143 buf[1] = 0.0750759 * white - 0.99332 * buf[1];
144 buf[2] = 0.1538520 * white - 0.96900 * buf[2];
145 buf[3] = 0.3104856 * white - 0.86650 * buf[3];
146 buf[4] = 0.5329522 * white - 0.55000 * buf[4];
147 buf[5] = -0.016898 * white + 0.76160 * buf[5];
148 blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
149 buf[6] = white * 0.115926;
153 static double brown_filter(double white, double *buf, double ha)
157 brown = ((0.02 * white) + buf[0]) / 1.02;
162 static double violet_filter(double white, double *buf, double ha)
166 violet = ((0.02 * white) - buf[0]) / 1.02;
171 static double velvet_filter(double white, double *buf, double ha)
173 return 2. * ha * ((white > ha) - (white < -ha));
176 static av_cold int config_props(AVFilterLink *outlink)
178 AVFilterContext *ctx = outlink->src;
179 ANoiseSrcContext *s = ctx->priv;
182 s->seed = av_get_random_seed();
183 av_lfg_init(&s->c, s->seed);
185 if (s->duration == 0)
187 s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
190 case NM_WHITE: s->filter = white_filter; break;
191 case NM_PINK: s->filter = pink_filter; break;
192 case NM_BROWN: s->filter = brown_filter; break;
193 case NM_BLUE: s->filter = blue_filter; break;
194 case NM_VIOLET: s->filter = violet_filter; break;
195 case NM_VELVET: s->filter = velvet_filter; break;
201 static int request_frame(AVFilterLink *outlink)
203 AVFilterContext *ctx = outlink->src;
204 ANoiseSrcContext *s = ctx->priv;
209 if (!s->infinite && s->duration <= 0) {
211 } else if (!s->infinite && s->duration < s->nb_samples) {
212 nb_samples = s->duration;
214 nb_samples = s->nb_samples;
217 if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
218 return AVERROR(ENOMEM);
220 dst = (double *)frame->data[0];
221 for (i = 0; i < nb_samples; i++) {
223 white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
224 dst[i] = s->filter(white, s->buf, s->amplitude * 0.5);
228 s->duration -= nb_samples;
231 s->pts += nb_samples;
232 return ff_filter_frame(outlink, frame);
235 static const AVFilterPad anoisesrc_outputs[] = {
238 .type = AVMEDIA_TYPE_AUDIO,
239 .request_frame = request_frame,
240 .config_props = config_props,
245 AVFilter ff_asrc_anoisesrc = {
247 .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
248 .query_formats = query_formats,
249 .priv_size = sizeof(ANoiseSrcContext),
251 .outputs = anoisesrc_outputs,
252 .priv_class = &anoisesrc_class,