* @title: audiotestsrc
*
* AudioTestSrc can be used to generate basic audio signals. It support several
- * different waveforms and allows to set the base frequency and volume.
+ * different waveforms and allows to set the base frequency and volume. Some
+ * waveforms might use additional properties.
+ *
+ * Waveform specific notes:
+ *
+ * <orderedlist>
+ * <listitem>
+ * <itemizedlist><title>Gaussian white noise</title>
+ *
+ * This waveform produces white (zero mean) Gaussian noise.
+ * Volume sets the standard deviation of the noise in units of the range
+ * of values of the sample type, e.g. volume=0.1 produces noise with a
+ * standard deviation of 0.1*32767=3277 with 16-bit integer samples,
+ * or 0.1*1.0=0.1 with floating-point samples.
+ *
+ * </itemizedlist>
+ * </listitem>
+ * <listitem>
+ * <itemizedlist><title>Ticks</title>
+ *
+ * This waveform is special in that it does not produce one continuous
+ * signal. Instead, it produces finite-length sine wave pulses (the "ticks").
+ * It is useful for detecting time shifts between audio signal, for example
+ * between RTSP audio clients that shall play synchronized. It is also useful
+ * for generating a signal that feeds the trigger of an oscilloscope.
+ *
+ * To further help with oscilloscope triggering and time offset detection,
+ * the waveform can apply a different volume to every Nth tick (this is then
+ * called the "marker tick"). For instance, one could generate a tick every
+ * 100ms, and make every 20th tick a marker tick (meaning that every 2 seconds
+ * there is a marker tick). This is useful for detecting large time offsets
+ * while still frequently triggering an oscilloscope.
+ *
+ * Also, a "ramp" can be applied to the begin & end of ticks. The sudden
+ * start of the sine tick is a discontinuity, even if the sine wave starts
+ * at 0. The* resulting artifacts can often make it more difficult to use the
+ * ticks for an oscilloscope's trigger. To that end, an initial "ramp" can
+ * be applied. The first few samples are modulated by a cubic function to
+ * reduce the impact of the discontinuity, resulting in smaller artifacts.
+ * The number of samples equals floor(samplerate / sine-wave-frequency).
+ * Example: with a sample rate of 48 kHz and a sine wave frequency of 10 kHz,
+ * the first 4 samples are modulated by the cubic function.
+ * </itemizedlist>
+ * </listitem>
+ * </orderedlist>
*
* ## Example launch line
* |[
* This pipeline produces a sine with default frequency, 440 Hz, and the
* default volume, 0.8 (relative to a maximum 1.0).
* |[
- * gst-launch-1.0 audiotestsrc wave=2 freq=200 ! tee name=t ! queue ! audioconvert ! autoaudiosink t. ! queue ! audioconvert ! libvisual_lv_scope ! videoconvert ! autovideosink
+ * gst-launch-1.0 audiotestsrc wave=2 freq=200 ! tee name=t ! queue ! audioconvert ! \
+ * autoaudiosink t. ! queue ! audioconvert ! libvisual_lv_scope ! videoconvert ! autovideosink
* ]|
* In this example a saw wave is generated. The wave is shown using a
* scope visualizer from libvisual, allowing you to visually verify that
* the saw wave is correct.
*
+ * |[
+ * gst-launch-1.0 audiotestsrc wave=ticks apply-tick-ramp=true tick-interval=100000000 \
+ * freq=10000 volume=0.4 marker-tick-period=10 sine-periods-per-tick=20 ! autoaudiosink
+ * ]| This pipeline produces a series of 10 kHz sine wave ticks. Each tick is
+ * 20 sine wave periods long, ticks occur every 100 ms and have a volume of
+ * 0.4. Every 10th tick is a marker tick and has the default marker tick volume
+ * of 1.0. The beginning and end of the ticks are modulated with the ramp.
*/
#ifdef HAVE_CONFIG_H
GST_DEBUG_CATEGORY_STATIC (audio_test_src_debug);
#define GST_CAT_DEFAULT audio_test_src_debug
-#define DEFAULT_SAMPLES_PER_BUFFER 1024
-#define DEFAULT_WAVE GST_AUDIO_TEST_SRC_WAVE_SINE
-#define DEFAULT_FREQ 440.0
-#define DEFAULT_VOLUME 0.8
-#define DEFAULT_IS_LIVE FALSE
-#define DEFAULT_TIMESTAMP_OFFSET G_GINT64_CONSTANT (0)
-#define DEFAULT_CAN_ACTIVATE_PUSH TRUE
-#define DEFAULT_CAN_ACTIVATE_PULL FALSE
+#define DEFAULT_SAMPLES_PER_BUFFER 1024
+#define DEFAULT_WAVE GST_AUDIO_TEST_SRC_WAVE_SINE
+#define DEFAULT_FREQ 440.0
+#define DEFAULT_VOLUME 0.8
+#define DEFAULT_IS_LIVE FALSE
+#define DEFAULT_TIMESTAMP_OFFSET G_GINT64_CONSTANT (0)
+#define DEFAULT_SINE_PERIODS_PER_TICK 10
+#define DEFAULT_TIME_BETWEEN_TICKS GST_SECOND
+#define DEFAULT_MARKER_TICK_PERIOD 0
+#define DEFAULT_MARKER_TICK_VOLUME 1.0
+#define DEFAULT_APPLY_TICK_RAMP FALSE
+#define DEFAULT_CAN_ACTIVATE_PUSH TRUE
+#define DEFAULT_CAN_ACTIVATE_PULL FALSE
enum
{
PROP_VOLUME,
PROP_IS_LIVE,
PROP_TIMESTAMP_OFFSET,
+ PROP_SINE_PERIODS_PER_TICK,
+ PROP_TICK_INTERVAL,
+ PROP_MARKER_TICK_PERIOD,
+ PROP_MARKER_TICK_VOLUME,
+ PROP_APPLY_TICK_RAMP,
PROP_CAN_ACTIVATE_PUSH,
PROP_CAN_ACTIVATE_PULL
};
"An offset added to timestamps set on buffers (in ns)", G_MININT64,
G_MAXINT64, DEFAULT_TIMESTAMP_OFFSET,
G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_SINE_PERIODS_PER_TICK,
+ g_param_spec_uint ("sine-periods-per-tick", "Sine periods per tick",
+ "Number of sine wave periods in one tick. Only used if wave = ticks.",
+ 1, G_MAXUINT, DEFAULT_SINE_PERIODS_PER_TICK,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_TICK_INTERVAL,
+ g_param_spec_uint64 ("tick-interval", "Time between ticks",
+ "Distance between start of current and start of next tick, in nanoseconds.",
+ 1, G_MAXUINT64, DEFAULT_TIME_BETWEEN_TICKS,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_MARKER_TICK_PERIOD,
+ g_param_spec_uint ("marker-tick-period", "Marker tick period",
+ "Make every Nth tick a marker tick (= a tick with different volume). "
+ "Only used if wave = ticks. 0 = no marker ticks.",
+ 0, G_MAXUINT, DEFAULT_MARKER_TICK_PERIOD,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_MARKER_TICK_VOLUME,
+ g_param_spec_double ("marker-tick-volume", "Marker tick volume",
+ "Volume of marker ticks. Only used if wave = ticks and"
+ "marker-tick-period is set to a nonzero value.",
+ 0.0, 1.0, DEFAULT_MARKER_TICK_VOLUME,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
+ g_object_class_install_property (gobject_class, PROP_APPLY_TICK_RAMP,
+ g_param_spec_boolean ("apply-tick-ramp", "Apply tick ramp",
+ "Apply ramp to tick samples", DEFAULT_APPLY_TICK_RAMP,
+ G_PARAM_READWRITE | G_PARAM_STATIC_STRINGS));
g_object_class_install_property (gobject_class, PROP_CAN_ACTIVATE_PUSH,
g_param_spec_boolean ("can-activate-push", "Can activate push",
"Can activate in push mode", DEFAULT_CAN_ACTIVATE_PUSH,
src->timestamp_offset = DEFAULT_TIMESTAMP_OFFSET;
src->can_activate_pull = DEFAULT_CAN_ACTIVATE_PULL;
+ src->sine_periods_per_tick = DEFAULT_SINE_PERIODS_PER_TICK;
+ src->tick_interval = DEFAULT_TIME_BETWEEN_TICKS;
+ src->marker_tick_period = DEFAULT_MARKER_TICK_PERIOD;
+ src->marker_tick_volume = DEFAULT_MARKER_TICK_VOLUME;
+ src->apply_tick_ramp = DEFAULT_APPLY_TICK_RAMP;
+
src->gen = NULL;
src->wave = DEFAULT_WAVE;
};
static void
-gst_audio_test_src_init_sine_table (GstAudioTestSrc * src)
+gst_audio_test_src_init_sine_table (GstAudioTestSrc * src, gboolean use_volume)
{
gint i;
gdouble ang = 0.0;
gdouble step = M_PI_M2 / 1024.0;
- gdouble amp = src->volume;
+ gdouble amp = use_volume ? src->volume : 1.0;
for (i = 0; i < 1024; i++) {
src->wave_table[i] = sin (ang) * amp;
(ProcessFunc) gst_audio_test_src_create_sine_table_double
};
+static inline gdouble
+calc_scaled_tick_volume (GstAudioTestSrc * src, gdouble scale)
+{
+ gdouble vol;
+ vol = ((src->marker_tick_period > 0)
+ && ((src->tick_counter % src->marker_tick_period) == 0))
+ ? src->marker_tick_volume : src->volume;
+ return vol * scale;
+}
+
+
#define DEFINE_TICKS(type,scale) \
static void \
gst_audio_test_src_create_tick_##type (GstAudioTestSrc * src, g##type * samples) \
{ \
gint i, c, channels, samplerate, samplemod, channel_step, sample_step; \
+ gint num_nonzero_samples, num_ramp_samples, end_ramp_offset; \
gdouble step, scl; \
+ gdouble volscale; \
g##type *ptr; \
\
+ volscale = calc_scaled_tick_volume (src, scale); \
channels = GST_AUDIO_INFO_CHANNELS (&src->info); \
if (GST_AUDIO_INFO_LAYOUT (&src->info) == GST_AUDIO_LAYOUT_INTERLEAVED) { \
channel_step = 1; \
} \
samplerate = GST_AUDIO_INFO_RATE (&src->info); \
step = M_PI_M2 * src->freq / samplerate; \
+ num_nonzero_samples = samplerate * src->sine_periods_per_tick / src->freq; \
scl = 1024.0 / M_PI_M2; \
+ num_ramp_samples = src->apply_tick_ramp ? (samplerate / src->freq) : 0; \
+ end_ramp_offset = num_nonzero_samples - num_ramp_samples; \
\
for (i = 0; i < src->generate_samples_per_buffer; i++) { \
- samplemod = (src->next_sample + i) % samplerate; \
+ samplemod = (src->next_sample + i)%src->samples_between_ticks; \
\
ptr = samples; \
if (samplemod == 0) { \
src->accumulator = 0; \
- } else if (samplemod < 1600) { \
+ src->tick_counter++; \
+ volscale = calc_scaled_tick_volume (src, scale); \
+ } else if (samplemod < num_nonzero_samples) { \
+ gdouble ramp; \
+ if (num_ramp_samples > 0) { \
+ ramp = \
+ (samplemod < num_ramp_samples) ? (((gdouble)samplemod) / num_ramp_samples) : \
+ (samplemod >= end_ramp_offset) ? (((gdouble)(num_nonzero_samples - samplemod)) / num_ramp_samples) \
+ : 1.0; \
+ if (ramp > 1.0) \
+ ramp = 1.0; \
+ ramp *= ramp * ramp; \
+ } else \
+ ramp = 1.0; \
+ \
for (c = 0; c < channels; ++c) { \
*ptr = \
- (g##type) scale * src->wave_table[(gint) (src->accumulator * scl)]; \
+ (g##type) volscale * ramp * src->wave_table[(gint) (src->accumulator * scl)]; \
ptr += channel_step; \
} \
} else { \
src->process = pink_noise_funcs[idx];
break;
case GST_AUDIO_TEST_SRC_WAVE_SINE_TAB:
- gst_audio_test_src_init_sine_table (src);
+ gst_audio_test_src_init_sine_table (src, TRUE);
src->process = sine_table_funcs[idx];
break;
case GST_AUDIO_TEST_SRC_WAVE_TICKS:
- gst_audio_test_src_init_sine_table (src);
+ gst_audio_test_src_init_sine_table (src, FALSE);
src->process = tick_funcs[idx];
+ src->samples_between_ticks =
+ gst_util_uint64_scale_int (src->tick_interval,
+ GST_AUDIO_INFO_RATE (&(src->info)), GST_SECOND);
break;
case GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE:
if (!(src->gen))
{
switch (src->wave) {
case GST_AUDIO_TEST_SRC_WAVE_SINE_TAB:
- gst_audio_test_src_init_sine_table (src);
+ gst_audio_test_src_init_sine_table (src, TRUE);
break;
default:
break;
src->eos_reached = FALSE;
src->tags_pushed = FALSE;
src->accumulator = 0;
+ src->tick_counter = 0;
return TRUE;
}
case PROP_TIMESTAMP_OFFSET:
src->timestamp_offset = g_value_get_int64 (value);
break;
+ case PROP_SINE_PERIODS_PER_TICK:
+ src->sine_periods_per_tick = g_value_get_uint (value);
+ break;
+ case PROP_TICK_INTERVAL:
+ src->tick_interval = g_value_get_uint64 (value);
+ break;
+ case PROP_MARKER_TICK_PERIOD:
+ src->marker_tick_period = g_value_get_uint (value);
+ break;
+ case PROP_MARKER_TICK_VOLUME:
+ src->marker_tick_volume = g_value_get_double (value);
+ break;
+ case PROP_APPLY_TICK_RAMP:
+ src->apply_tick_ramp = g_value_get_boolean (value);
+ break;
case PROP_CAN_ACTIVATE_PUSH:
GST_BASE_SRC (src)->can_activate_push = g_value_get_boolean (value);
break;
case PROP_TIMESTAMP_OFFSET:
g_value_set_int64 (value, src->timestamp_offset);
break;
+ case PROP_SINE_PERIODS_PER_TICK:
+ g_value_set_uint (value, src->sine_periods_per_tick);
+ break;
+ case PROP_TICK_INTERVAL:
+ g_value_set_uint64 (value, src->tick_interval);
+ break;
+ case PROP_MARKER_TICK_PERIOD:
+ g_value_set_uint (value, src->marker_tick_period);
+ break;
+ case PROP_MARKER_TICK_VOLUME:
+ g_value_set_double (value, src->marker_tick_volume);
+ break;
+ case PROP_APPLY_TICK_RAMP:
+ g_value_set_boolean (value, src->apply_tick_ramp);
+ break;
case PROP_CAN_ACTIVATE_PUSH:
g_value_set_boolean (value, GST_BASE_SRC (src)->can_activate_push);
break;
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