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avfilter/asrc_anoisesrc: add velvet noise

This commit is contained in:
Paul B Mahol 2020-01-13 17:56:19 +01:00
parent fdddc0d678
commit 273886fa60
2 changed files with 16 additions and 8 deletions
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2
doc/filters.texi
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@ -5985,7 +5985,7 @@ results in noise with an infinite length.
@item color, colour, c
Specify the color of noise. Available noise colors are white, pink, brown,
blue and violet. Default color is white.
blue, violet and velvet. Default color is white.
@item seed, s
Specify a value used to seed the PRNG.

22
libavfilter/asrc_anoisesrc.c
View File

@ -36,7 +36,7 @@ typedef struct ANoiseSrcContext {
int64_t pts;
int infinite;
double (*filter)(double white, double *buf);
double (*filter)(double white, double *buf, double half_amplitude);
double buf[7];
AVLFG c;
} ANoiseSrcContext;
@ -47,6 +47,7 @@ enum NoiseMode {
NM_BROWN,
NM_BLUE,
NM_VIOLET,
NM_VELVET,
NM_NB
};
@ -68,6 +69,7 @@ static const AVOption anoisesrc_options[] = {
{ "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 },
@ -111,12 +113,12 @@ static av_cold int query_formats(AVFilterContext *ctx)
return ff_set_common_samplerates(ctx, formats);
}
static double white_filter(double white, double *buf)
static double white_filter(double white, double *buf, double ha)
{
return white;
}
static double pink_filter(double white, double *buf)
static double pink_filter(double white, double *buf, double ha)
{
double pink;
@ -132,7 +134,7 @@ static double pink_filter(double white, double *buf)
return pink * 0.11;
}
static double blue_filter(double white, double *buf)
static double blue_filter(double white, double *buf, double ha)
{
double blue;
@ -148,7 +150,7 @@ static double blue_filter(double white, double *buf)
return blue * 0.11;
}
static double brown_filter(double white, double *buf)
static double brown_filter(double white, double *buf, double ha)
{
double brown;
@ -157,7 +159,7 @@ static double brown_filter(double white, double *buf)
return brown * 3.5;
}
static double violet_filter(double white, double *buf)
static double violet_filter(double white, double *buf, double ha)
{
double violet;
@ -166,6 +168,11 @@ static double violet_filter(double white, double *buf)
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;
@ -185,6 +192,7 @@ static av_cold int config_props(AVFilterLink *outlink)
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;
@ -213,7 +221,7 @@ static int request_frame(AVFilterLink *outlink)
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);
dst[i] = s->filter(white, s->buf, s->amplitude * 0.5);
}
if (!s->infinite)