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 "filters.h"
25 #include "internal.h"
26 #include "libavutil/lfg.h"
27 #include "libavutil/random_seed.h"
28
29 typedef struct ANoiseSrcContext {
30 const AVClass *class;
31 int sample_rate;
32 double amplitude;
33 int64_t duration;
34 int color;
35 int64_t seed;
36 int nb_samples;
37
38 int64_t pts;
39 int infinite;
40 double (*filter)(double white, double *buf, double half_amplitude);
41 double buf[7];
42 AVLFG c;
43 } ANoiseSrcContext;
44
45 enum NoiseMode {
46 NM_WHITE,
47 NM_PINK,
48 NM_BROWN,
49 NM_BLUE,
50 NM_VIOLET,
51 NM_VELVET,
52 NM_NB
53 };
54
55 #define OFFSET(x) offsetof(ANoiseSrcContext, x)
56 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
57
58 static const AVOption anoisesrc_options[] = {
59 { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
60 { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
61 { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
62 { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
63 { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
64 { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
65 { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
66 { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
67 { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
68 { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, "color" },
69 { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, "color" },
70 { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, "color" },
71 { "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, "color" },
72 { "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, "color" },
73 { "velvet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VELVET}, 0, 0, FLAGS, "color" },
74 { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
75 { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
76 { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
77 { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
78 {NULL}
79 };
80
81 AVFILTER_DEFINE_CLASS(anoisesrc);
82
query_formats(AVFilterContext * ctx)83 static av_cold int query_formats(AVFilterContext *ctx)
84 {
85 ANoiseSrcContext *s = ctx->priv;
86 static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
87 int sample_rates[] = { s->sample_rate, -1 };
88 static const enum AVSampleFormat sample_fmts[] = {
89 AV_SAMPLE_FMT_DBL,
90 AV_SAMPLE_FMT_NONE
91 };
92
93 AVFilterFormats *formats;
94 AVFilterChannelLayouts *layouts;
95 int ret;
96
97 formats = ff_make_format_list(sample_fmts);
98 if (!formats)
99 return AVERROR(ENOMEM);
100 ret = ff_set_common_formats (ctx, formats);
101 if (ret < 0)
102 return ret;
103
104 layouts = ff_make_format64_list(chlayouts);
105 if (!layouts)
106 return AVERROR(ENOMEM);
107 ret = ff_set_common_channel_layouts(ctx, layouts);
108 if (ret < 0)
109 return ret;
110
111 formats = ff_make_format_list(sample_rates);
112 if (!formats)
113 return AVERROR(ENOMEM);
114 return ff_set_common_samplerates(ctx, formats);
115 }
116
white_filter(double white,double * buf,double ha)117 static double white_filter(double white, double *buf, double ha)
118 {
119 return white;
120 }
121
pink_filter(double white,double * buf,double ha)122 static double pink_filter(double white, double *buf, double ha)
123 {
124 double pink;
125
126 /* http://www.musicdsp.org/files/pink.txt */
127 buf[0] = 0.99886 * buf[0] + white * 0.0555179;
128 buf[1] = 0.99332 * buf[1] + white * 0.0750759;
129 buf[2] = 0.96900 * buf[2] + white * 0.1538520;
130 buf[3] = 0.86650 * buf[3] + white * 0.3104856;
131 buf[4] = 0.55000 * buf[4] + white * 0.5329522;
132 buf[5] = -0.7616 * buf[5] - white * 0.0168980;
133 pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
134 buf[6] = white * 0.115926;
135 return pink * 0.11;
136 }
137
blue_filter(double white,double * buf,double ha)138 static double blue_filter(double white, double *buf, double ha)
139 {
140 double blue;
141
142 /* Same as pink_filter but subtract the offsets rather than add */
143 buf[0] = 0.0555179 * white - 0.99886 * buf[0];
144 buf[1] = 0.0750759 * white - 0.99332 * buf[1];
145 buf[2] = 0.1538520 * white - 0.96900 * buf[2];
146 buf[3] = 0.3104856 * white - 0.86650 * buf[3];
147 buf[4] = 0.5329522 * white - 0.55000 * buf[4];
148 buf[5] = -0.016898 * white + 0.76160 * buf[5];
149 blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
150 buf[6] = white * 0.115926;
151 return blue * 0.11;
152 }
153
brown_filter(double white,double * buf,double ha)154 static double brown_filter(double white, double *buf, double ha)
155 {
156 double brown;
157
158 brown = ((0.02 * white) + buf[0]) / 1.02;
159 buf[0] = brown;
160 return brown * 3.5;
161 }
162
violet_filter(double white,double * buf,double ha)163 static double violet_filter(double white, double *buf, double ha)
164 {
165 double violet;
166
167 violet = ((0.02 * white) - buf[0]) / 1.02;
168 buf[0] = violet;
169 return violet * 3.5;
170 }
171
velvet_filter(double white,double * buf,double ha)172 static double velvet_filter(double white, double *buf, double ha)
173 {
174 return 2. * ha * ((white > ha) - (white < -ha));
175 }
176
config_props(AVFilterLink * outlink)177 static av_cold int config_props(AVFilterLink *outlink)
178 {
179 AVFilterContext *ctx = outlink->src;
180 ANoiseSrcContext *s = ctx->priv;
181
182 if (s->seed == -1)
183 s->seed = av_get_random_seed();
184 av_lfg_init(&s->c, s->seed);
185
186 if (s->duration == 0)
187 s->infinite = 1;
188 s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
189
190 switch (s->color) {
191 case NM_WHITE: s->filter = white_filter; break;
192 case NM_PINK: s->filter = pink_filter; break;
193 case NM_BROWN: s->filter = brown_filter; break;
194 case NM_BLUE: s->filter = blue_filter; break;
195 case NM_VIOLET: s->filter = violet_filter; break;
196 case NM_VELVET: s->filter = velvet_filter; break;
197 }
198
199 return 0;
200 }
201
activate(AVFilterContext * ctx)202 static int activate(AVFilterContext *ctx)
203 {
204 AVFilterLink *outlink = ctx->outputs[0];
205 ANoiseSrcContext *s = ctx->priv;
206 AVFrame *frame;
207 int nb_samples, i;
208 double *dst;
209
210 if (!ff_outlink_frame_wanted(outlink))
211 return FFERROR_NOT_READY;
212
213 if (!s->infinite && s->duration <= 0) {
214 ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
215 return 0;
216 } else if (!s->infinite && s->duration < s->nb_samples) {
217 nb_samples = s->duration;
218 } else {
219 nb_samples = s->nb_samples;
220 }
221
222 if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
223 return AVERROR(ENOMEM);
224
225 dst = (double *)frame->data[0];
226 for (i = 0; i < nb_samples; i++) {
227 double white;
228 white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
229 dst[i] = s->filter(white, s->buf, s->amplitude * 0.5);
230 }
231
232 if (!s->infinite)
233 s->duration -= nb_samples;
234
235 frame->pts = s->pts;
236 s->pts += nb_samples;
237 return ff_filter_frame(outlink, frame);
238 }
239
240 static const AVFilterPad anoisesrc_outputs[] = {
241 {
242 .name = "default",
243 .type = AVMEDIA_TYPE_AUDIO,
244 .config_props = config_props,
245 },
246 { NULL }
247 };
248
249 AVFilter ff_asrc_anoisesrc = {
250 .name = "anoisesrc",
251 .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
252 .query_formats = query_formats,
253 .priv_size = sizeof(ANoiseSrcContext),
254 .inputs = NULL,
255 .activate = activate,
256 .outputs = anoisesrc_outputs,
257 .priv_class = &anoisesrc_class,
258 };
259