Commit 5cd0e0f6 authored by Stefan Kost's avatar Stefan Kost
Browse files

audiotestsrc: add blue and violet noise by using spectral inversion

Add blue and violet noise by spectral inversion of pink and red noise.
Fixes #649969
parent 1cf831e7
......@@ -131,6 +131,8 @@ gst_audiostestsrc_wave_get_type (void)
{GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE, "White Gaussian noise",
"gaussian-noise"},
{GST_AUDIO_TEST_SRC_WAVE_RED_NOISE, "Red (brownian) noise", "red-noise"},
{GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE, "Blue noise", "blue-noise"},
{GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE, "Violet noise", "violet-noise"},
{0, NULL, NULL},
};
......@@ -879,6 +881,66 @@ static const ProcessFunc red_noise_funcs[] = {
(ProcessFunc) gst_audio_test_src_create_red_noise_double
};
/* Blue Noise: apply spectral inversion to pink noise */
#define DEFINE_BLUE_NOISE(type) \
static void \
gst_audio_test_src_create_blue_noise_##type (GstAudioTestSrc * src, g##type * samples) \
{ \
gint i, c; \
static gdouble flip=1.0; \
\
gst_audio_test_src_create_pink_noise_##type (src, samples); \
for (i = 0; i < src->generate_samples_per_buffer * src->channels; ) { \
for (c = 0; c < src->channels; ++c) { \
samples[i++] *= flip; \
} \
flip *= -1.0; \
} \
}
DEFINE_BLUE_NOISE (int16);
DEFINE_BLUE_NOISE (int32);
DEFINE_BLUE_NOISE (float);
DEFINE_BLUE_NOISE (double);
static const ProcessFunc blue_noise_funcs[] = {
(ProcessFunc) gst_audio_test_src_create_blue_noise_int16,
(ProcessFunc) gst_audio_test_src_create_blue_noise_int32,
(ProcessFunc) gst_audio_test_src_create_blue_noise_float,
(ProcessFunc) gst_audio_test_src_create_blue_noise_double
};
/* Violet Noise: apply spectral inversion to red noise */
#define DEFINE_VIOLET_NOISE(type) \
static void \
gst_audio_test_src_create_violet_noise_##type (GstAudioTestSrc * src, g##type * samples) \
{ \
gint i, c; \
static gdouble flip=1.0; \
\
gst_audio_test_src_create_red_noise_##type (src, samples); \
for (i = 0; i < src->generate_samples_per_buffer * src->channels; ) { \
for (c = 0; c < src->channels; ++c) { \
samples[i++] *= flip; \
} \
flip *= -1.0; \
} \
}
DEFINE_VIOLET_NOISE (int16);
DEFINE_VIOLET_NOISE (int32);
DEFINE_VIOLET_NOISE (float);
DEFINE_VIOLET_NOISE (double);
static const ProcessFunc violet_noise_funcs[] = {
(ProcessFunc) gst_audio_test_src_create_violet_noise_int16,
(ProcessFunc) gst_audio_test_src_create_violet_noise_int32,
(ProcessFunc) gst_audio_test_src_create_violet_noise_float,
(ProcessFunc) gst_audio_test_src_create_violet_noise_double
};
/*
......@@ -939,6 +1001,17 @@ gst_audio_test_src_change_wave (GstAudioTestSrc * src)
src->red.state = 0.0;
src->process = red_noise_funcs[src->format];
break;
case GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE:
if (!(src->gen))
src->gen = g_rand_new ();
gst_audio_test_src_init_pink_noise (src);
src->process = blue_noise_funcs[src->format];
break;
case GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE:
if (!(src->gen))
src->gen = g_rand_new ();
src->red.state = 0.0;
src->process = violet_noise_funcs[src->format];
default:
GST_ERROR ("invalid wave-form");
break;
......
......@@ -65,7 +65,9 @@ typedef enum {
GST_AUDIO_TEST_SRC_WAVE_SINE_TAB,
GST_AUDIO_TEST_SRC_WAVE_TICKS,
GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE,
GST_AUDIO_TEST_SRC_WAVE_RED_NOISE
GST_AUDIO_TEST_SRC_WAVE_RED_NOISE,
GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE,
GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE
} GstAudioTestSrcWave;
#define PINK_MAX_RANDOM_ROWS (30)
......
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