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);
53 #define OFFSET(x) offsetof(ANoiseSrcContext, x)
54 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
56 static const AVOption anoisesrc_options[] = {
57 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
58 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
59 { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
60 { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
61 { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
62 { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
63 { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
64 { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
65 { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
66 { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, "color" },
67 { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, "color" },
68 { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, "color" },
69 { "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, "color" },
70 { "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, "color" },
71 { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
72 { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
73 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
74 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
78 AVFILTER_DEFINE_CLASS(anoisesrc);
80 static av_cold int query_formats(AVFilterContext *ctx)
82 ANoiseSrcContext *s = ctx->priv;
83 static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
84 int sample_rates[] = { s->sample_rate, -1 };
85 static const enum AVSampleFormat sample_fmts[] = {
90 AVFilterFormats *formats;
91 AVFilterChannelLayouts *layouts;
94 formats = ff_make_format_list(sample_fmts);
96 return AVERROR(ENOMEM);
97 ret = ff_set_common_formats (ctx, formats);
101 layouts = avfilter_make_format64_list(chlayouts);
103 return AVERROR(ENOMEM);
104 ret = ff_set_common_channel_layouts(ctx, layouts);
108 formats = ff_make_format_list(sample_rates);
110 return AVERROR(ENOMEM);
111 return ff_set_common_samplerates(ctx, formats);
114 static double white_filter(double white, double *buf)
119 static double pink_filter(double white, double *buf)
123 /* http://www.musicdsp.org/files/pink.txt */
124 buf[0] = 0.99886 * buf[0] + white * 0.0555179;
125 buf[1] = 0.99332 * buf[1] + white * 0.0750759;
126 buf[2] = 0.96900 * buf[2] + white * 0.1538520;
127 buf[3] = 0.86650 * buf[3] + white * 0.3104856;
128 buf[4] = 0.55000 * buf[4] + white * 0.5329522;
129 buf[5] = -0.7616 * buf[5] - white * 0.0168980;
130 pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
131 buf[6] = white * 0.115926;
135 static double blue_filter(double white, double *buf)
139 /* Same as pink_filter but subtract the offsets rather than add */
140 buf[0] = 0.0555179 * white - 0.99886 * buf[0];
141 buf[1] = 0.0750759 * white - 0.99332 * buf[1];
142 buf[2] = 0.1538520 * white - 0.96900 * buf[2];
143 buf[3] = 0.3104856 * white - 0.86650 * buf[3];
144 buf[4] = 0.5329522 * white - 0.55000 * buf[4];
145 buf[5] = -0.016898 * white + 0.76160 * buf[5];
146 blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
147 buf[6] = white * 0.115926;
151 static double brown_filter(double white, double *buf)
155 brown = ((0.02 * white) + buf[0]) / 1.02;
160 static double violet_filter(double white, double *buf)
164 violet = ((0.02 * white) - buf[0]) / 1.02;
169 static av_cold int config_props(AVFilterLink *outlink)
171 AVFilterContext *ctx = outlink->src;
172 ANoiseSrcContext *s = ctx->priv;
175 s->seed = av_get_random_seed();
176 av_lfg_init(&s->c, s->seed);
178 if (s->duration == 0)
180 s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
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;
193 static int request_frame(AVFilterLink *outlink)
195 AVFilterContext *ctx = outlink->src;
196 ANoiseSrcContext *s = ctx->priv;
201 if (!s->infinite && s->duration <= 0) {
203 } else if (!s->infinite && s->duration < s->nb_samples) {
204 nb_samples = s->duration;
206 nb_samples = s->nb_samples;
209 if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
210 return AVERROR(ENOMEM);
212 dst = (double *)frame->data[0];
213 for (i = 0; i < nb_samples; i++) {
215 white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
216 dst[i] = s->filter(white, s->buf);
220 s->duration -= nb_samples;
223 s->pts += nb_samples;
224 return ff_filter_frame(outlink, frame);
227 static const AVFilterPad anoisesrc_outputs[] = {
230 .type = AVMEDIA_TYPE_AUDIO,
231 .request_frame = request_frame,
232 .config_props = config_props,
237 AVFilter ff_asrc_anoisesrc = {
239 .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
240 .query_formats = query_formats,
241 .priv_size = sizeof(ANoiseSrcContext),
243 .outputs = anoisesrc_outputs,
244 .priv_class = &anoisesrc_class,