FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
asrc_anoisesrc.c
Go to the documentation of this file.
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 "internal.h"
25 #include "libavutil/lfg.h"
26 #include "libavutil/random_seed.h"
27 
28 typedef struct {
29  const AVClass *class;
31  double amplitude;
32  int64_t duration;
33  int64_t color;
34  int64_t seed;
36 
37  int64_t pts;
38  int infinite;
39  double (*filter)(double white, double *buf);
40  double buf[7];
43 
44 #define OFFSET(x) offsetof(ANoiseSrcContext, x)
45 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
46 
47 static const AVOption anoisesrc_options[] = {
48  { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
49  { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64 = 48000}, 15, INT_MAX, FLAGS },
50  { "amplitude", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
51  { "a", "set amplitude", OFFSET(amplitude), AV_OPT_TYPE_DOUBLE, {.dbl = 1.}, 0., 1., FLAGS },
52  { "duration", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
53  { "d", "set duration", OFFSET(duration), AV_OPT_TYPE_DURATION, {.i64 = 0}, 0, INT64_MAX, FLAGS },
54  { "color", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 2, FLAGS, "color" },
55  { "colour", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 2, FLAGS, "color" },
56  { "c", "set noise color", OFFSET(color), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 2, FLAGS, "color" },
57  { "white", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, FLAGS, "color" },
58  { "pink", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, FLAGS, "color" },
59  { "brown", 0, 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 0, FLAGS, "color" },
60  { "seed", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
61  { "s", "set random seed", OFFSET(seed), AV_OPT_TYPE_INT64, {.i64 = -1}, -1, UINT_MAX, FLAGS },
62  { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
63  { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
64  {NULL}
65 };
66 
67 AVFILTER_DEFINE_CLASS(anoisesrc);
68 
70 {
71  ANoiseSrcContext *s = ctx->priv;
72  static const int64_t chlayouts[] = { AV_CH_LAYOUT_MONO, -1 };
73  int sample_rates[] = { s->sample_rate, -1 };
74  static const enum AVSampleFormat sample_fmts[] = {
77  };
78 
81  int ret;
82 
83  formats = ff_make_format_list(sample_fmts);
84  if (!formats)
85  return AVERROR(ENOMEM);
86  ret = ff_set_common_formats (ctx, formats);
87  if (ret < 0)
88  return ret;
89 
90  layouts = avfilter_make_format64_list(chlayouts);
91  if (!layouts)
92  return AVERROR(ENOMEM);
93  ret = ff_set_common_channel_layouts(ctx, layouts);
94  if (ret < 0)
95  return ret;
96 
97  formats = ff_make_format_list(sample_rates);
98  if (!formats)
99  return AVERROR(ENOMEM);
100  return ff_set_common_samplerates(ctx, formats);
101 }
102 
103 static double white_filter(double white, double *buf)
104 {
105  return white;
106 }
107 
108 static double pink_filter(double white, double *buf)
109 {
110  double pink;
111 
112  /* http://www.musicdsp.org/files/pink.txt */
113  buf[0] = 0.99886 * buf[0] + white * 0.0555179;
114  buf[1] = 0.99332 * buf[1] + white * 0.0750759;
115  buf[2] = 0.96900 * buf[2] + white * 0.1538520;
116  buf[3] = 0.86650 * buf[3] + white * 0.3104856;
117  buf[4] = 0.55000 * buf[4] + white * 0.5329522;
118  buf[5] = -0.7616 * buf[5] - white * 0.0168980;
119  pink = buf[0] + buf[1] + buf[2] + buf[3] + buf[4] + buf[5] + buf[6] + white * 0.5362;
120  buf[6] = white * 0.115926;
121  return pink * 0.11;
122 }
123 
124 static double brown_filter(double white, double *buf)
125 {
126  double brown;
127 
128  brown = ((0.02 * white) + buf[0]) / 1.02;
129  buf[0] = brown;
130  return brown * 3.5;
131 }
132 
133 static av_cold int config_props(AVFilterLink *outlink)
134 {
135  AVFilterContext *ctx = outlink->src;
136  ANoiseSrcContext *s = ctx->priv;
137 
138  if (s->seed == -1)
139  s->seed = av_get_random_seed();
140  av_lfg_init(&s->c, s->seed);
141 
142  if (s->duration == 0)
143  s->infinite = 1;
145 
146  switch (s->color) {
147  case 0: s->filter = white_filter; break;
148  case 1: s->filter = pink_filter; break;
149  case 2: s->filter = brown_filter; break;
150  }
151 
152  return 0;
153 }
154 
155 static int request_frame(AVFilterLink *outlink)
156 {
157  AVFilterContext *ctx = outlink->src;
158  ANoiseSrcContext *s = ctx->priv;
159  AVFrame *frame;
160  int nb_samples, i;
161  double *dst;
162 
163  if (!s->infinite && s->duration <= 0) {
164  return AVERROR_EOF;
165  } else if (!s->infinite && s->duration < s->nb_samples) {
166  nb_samples = s->duration;
167  } else {
168  nb_samples = s->nb_samples;
169  }
170 
171  if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
172  return AVERROR(ENOMEM);
173 
174  dst = (double *)frame->data[0];
175  for (i = 0; i < nb_samples; i++) {
176  double white;
177  white = s->amplitude * ((2 * ((double) av_lfg_get(&s->c) / 0xffffffff)) - 1);
178  dst[i] = s->filter(white, s->buf);
179  }
180 
181  if (!s->infinite)
182  s->duration -= nb_samples;
183 
184  frame->pts = s->pts;
185  s->pts += nb_samples;
186  return ff_filter_frame(outlink, frame);
187 }
188 
189 static const AVFilterPad anoisesrc_outputs[] = {
190  {
191  .name = "default",
192  .type = AVMEDIA_TYPE_AUDIO,
193  .request_frame = request_frame,
194  .config_props = config_props,
195  },
196  { NULL }
197 };
198 
200  .name = "anoisesrc",
201  .description = NULL_IF_CONFIG_SMALL("Generate a noise audio signal."),
202  .query_formats = query_formats,
203  .priv_size = sizeof(ANoiseSrcContext),
204  .inputs = NULL,
205  .outputs = anoisesrc_outputs,
206  .priv_class = &anoisesrc_class,
207 };
Definition: lfg.h:27
#define NULL
Definition: coverity.c:32
int ff_set_common_channel_layouts(AVFilterContext *ctx, AVFilterChannelLayouts *layouts)
A helper for query_formats() which sets all links to the same list of channel layouts/sample rates...
Definition: formats.c:549
const char * s
Definition: avisynth_c.h:768
This structure describes decoded (raw) audio or video data.
Definition: frame.h:187
AVOption.
Definition: opt.h:246
Main libavfilter public API header.
static const AVOption anoisesrc_options[]
double(* filter)(double white, double *buf)
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:283
const char * name
Pad name.
Definition: internal.h:60
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1125
#define av_cold
Definition: attributes.h:82
static av_cold int query_formats(AVFilterContext *ctx)
AVOptions.
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:271
static void filter(int16_t *output, ptrdiff_t out_stride, int16_t *low, ptrdiff_t low_stride, int16_t *high, ptrdiff_t high_stride, int len, uint8_t clip)
Definition: cfhd.c:80
int64_t duration
Definition: movenc.c:63
static AVFrame * frame
AVFilter ff_asrc_anoisesrc
#define OFFSET(x)
#define AVERROR_EOF
End of file.
Definition: error.h:55
static int request_frame(AVFilterLink *outlink)
AVFILTER_DEFINE_CLASS(anoisesrc)
A filter pad used for either input or output.
Definition: internal.h:54
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:568
#define FLAGS
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:86
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:179
void * priv
private data for use by the filter
Definition: avfilter.h:338
int64_t av_rescale(int64_t a, int64_t b, int64_t c)
Rescale a 64-bit integer with rounding to nearest.
Definition: mathematics.c:129
#define AV_TIME_BASE
Internal time base represented as integer.
Definition: avutil.h:254
AVFormatContext * ctx
Definition: movenc.c:48
static const AVFilterPad outputs[]
Definition: af_afftfilt.c:386
A list of supported channel layouts.
Definition: formats.h:85
sample_rate
static av_cold int config_props(AVFilterLink *outlink)
static const AVFilterPad inputs[]
Definition: af_afftfilt.c:376
AVFilterChannelLayouts * avfilter_make_format64_list(const int64_t *fmts)
Definition: formats.c:303
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
static double white_filter(double white, double *buf)
static unsigned int seed
Definition: videogen.c:78
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:47
void * buf
Definition: avisynth_c.h:690
Describe the class of an AVClass context structure.
Definition: log.h:67
static double brown_filter(double white, double *buf)
Filter definition.
Definition: avfilter.h:144
const char * name
Filter name.
Definition: avfilter.h:148
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
enum MovChannelLayoutTag * layouts
Definition: mov_chan.c:434
static double pink_filter(double white, double *buf)
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:201
static const AVFilterPad anoisesrc_outputs[]
sample_rates
A list of supported formats for one end of a filter link.
Definition: formats.h:64
An instance of a filter.
Definition: avfilter.h:323
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
uint32_t av_get_random_seed(void)
Get a seed to use in conjunction with random functions.
Definition: random_seed.c:120
formats
Definition: signature.h:48
internal API functions
#define AV_CH_LAYOUT_MONO
for(j=16;j >0;--j)
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:556