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