1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
|
/*
* Copyright (c) 2015 Kyle Swanson <k@ylo.ph>.
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public License
* as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libavutil/channel_layout.h"
#include "libavutil/opt.h"
#include "audio.h"
#include "avfilter.h"
#include "filters.h"
#include "internal.h"
#include "libavutil/lfg.h"
#include "libavutil/random_seed.h"
typedef struct ANoiseSrcContext {
const AVClass *class;
int sample_rate;
double amplitude;
int64_t duration;
int color;
int64_t seed;
int nb_samples;
int64_t pts;
int infinite;
double (*filter)(double white, double *buf, double half_amplitude);
double buf[7];
AVLFG c;
} ANoiseSrcContext;
enum NoiseMode {
NM_WHITE,
NM_PINK,
NM_BROWN,
NM_BLUE,
NM_VIOLET,
NM_VELVET,
NM_NB
};
#define OFFSET(x) offsetof(ANoiseSrcContext, x)
#define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
static const AVOption anoisesrc_options[] = {
{ "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
{ "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
{ "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
{ "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
{ "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
{ "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
{ "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
{ "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
{ "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, NM_NB - 1, FLAGS, "color" },
{ "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_WHITE}, 0, 0, FLAGS, "color" },
{ "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_PINK}, 0, 0, FLAGS, "color" },
{ "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BROWN}, 0, 0, FLAGS, "color" },
{ "blue", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_BLUE}, 0, 0, FLAGS, "color" },
{ "violet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VIOLET}, 0, 0, FLAGS, "color" },
{ "velvet", 0, 0, AV_OPT_TYPE_CONST, {.i64 = NM_VELVET}, 0, 0, FLAGS, "color" },
{ "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
{ "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
{ "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
{ "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
{NULL}
};
AVFILTER_DEFINE_CLASS(anoisesrc);
static av_cold int query_formats(AVFilterContext *ctx)
{
ANoiseSrcContext *s = ctx->priv;
static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
int sample_rates[] = { s->sample_rate, -1 };
static const enum AVSampleFormat sample_fmts[] = {
AV_SAMPLE_FMT_DBL,
AV_SAMPLE_FMT_NONE
};
AVFilterFormats *formats;
AVFilterChannelLayouts *layouts;
int ret;
formats = ff_make_format_list(sample_fmts);
if (!formats)
return AVERROR(ENOMEM);
ret = ff_set_common_formats (ctx, formats);
if (ret < 0)
return ret;
layouts = ff_make_format64_list(chlayouts);
if (!layouts)
return AVERROR(ENOMEM);
ret = ff_set_common_channel_layouts(ctx, layouts);
if (ret < 0)
return ret;
formats = ff_make_format_list(sample_rates);
if (!formats)
return AVERROR(ENOMEM);
return ff_set_common_samplerates(ctx, formats);
}
static double white_filter(double white, double *buf, double ha)
{
return white;
}
static double pink_filter(double white, double *buf, double ha)
{
double pink;
/* http://www.musicdsp.org/files/pink.txt */
buf[0] = 0.99886 * buf[0] + white * 0.0555179;
buf[1] = 0.99332 * buf[1] + white * 0.0750759;
buf[2] = 0.96900 * buf[2] + white * 0.1538520;
buf[3] = 0.86650 * buf[3] + white * 0.3104856;
buf[4] = 0.55000 * buf[4] + white * 0.5329522;
buf[5] = -0.7616 * buf[5] - white * 0.0168980;
pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
buf[6] = white * 0.115926;
return pink * 0.11;
}
static double blue_filter(double white, double *buf, double ha)
{
double blue;
/* Same as pink_filter but subtract the offsets rather than add */
buf[0] = 0.0555179 * white - 0.99886 * buf[0];
buf[1] = 0.0750759 * white - 0.99332 * buf[1];
buf[2] = 0.1538520 * white - 0.96900 * buf[2];
buf[3] = 0.3104856 * white - 0.86650 * buf[3];
buf[4] = 0.5329522 * white - 0.55000 * buf[4];
buf[5] = -0.016898 * white + 0.76160 * buf[5];
blue = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
buf[6] = white * 0.115926;
return blue * 0.11;
}
static double brown_filter(double white, double *buf, double ha)
{
double brown;
brown = ((0.02 * white) + buf[0]) / 1.02;
buf[0] = brown;
return brown * 3.5;
}
static double violet_filter(double white, double *buf, double ha)
{
double violet;
violet = ((0.02 * white) - buf[0]) / 1.02;
buf[0] = violet;
return violet * 3.5;
}
static double velvet_filter(double white, double *buf, double ha)
{
return 2. * ha * ((white > ha) - (white < -ha));
}
static av_cold int config_props(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
ANoiseSrcContext *s = ctx->priv;
if (s->seed == -1)
s->seed = av_get_random_seed();
av_lfg_init(&s->c, s->seed);
if (s->duration == 0)
s->infinite = 1;
s->duration = av_rescale(s->duration, s->sample_rate, AV_TIME_BASE);
switch (s->color) {
case NM_WHITE: s->filter = white_filter; break;
case NM_PINK: s->filter = pink_filter; break;
case NM_BROWN: s->filter = brown_filter; break;
case NM_BLUE: s->filter = blue_filter; break;
case NM_VIOLET: s->filter = violet_filter; break;
case NM_VELVET: s->filter = velvet_filter; break;
}
return 0;
}
static int activate(AVFilterContext *ctx)
{
AVFilterLink *outlink = ctx->outputs[0];
ANoiseSrcContext *s = ctx->priv;
AVFrame *frame;
int nb_samples, i;
double *dst;
if (!ff_outlink_frame_wanted(outlink))
return FFERROR_NOT_READY;
if (!s->infinite && s->duration <= 0) {
ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
return 0;
} else if (!s->infinite && s->duration < s->nb_samples) {
nb_samples = s->duration;
} else {
nb_samples = s->nb_samples;
}
if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
return AVERROR(ENOMEM);
dst = (double *)frame->data[0];
for (i = 0; i < nb_samples; i++) {
double white;
white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
dst[i] = s->filter(white, s->buf, s->amplitude * 0.5);
}
if (!s->infinite)
s->duration -= nb_samples;
frame->pts = s->pts;
s->pts += nb_samples;
return ff_filter_frame(outlink, frame);
}
static const AVFilterPad anoisesrc_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_AUDIO,
.config_props = config_props,
},
{ NULL }
};
const AVFilter ff_asrc_anoisesrc = {
.name = "anoisesrc",
.description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
.query_formats = query_formats,
.priv_size = sizeof(ANoiseSrcContext),
.inputs = NULL,
.activate = activate,
.outputs = anoisesrc_outputs,
.priv_class = &anoisesrc_class,
};
|
