gstreamer/gst/audiotestsrc/gstaudiotestsrc.h

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/* GStreamer
* Copyright (C) 2005 Stefan Kost <ensonic@users.sf.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library 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
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_AUDIO_TEST_SRC_H__
#define __GST_AUDIO_TEST_SRC_H__
#include <gst/gst.h>
#include <gst/base/gstbasesrc.h>
#include <gst/audio/audio.h>
G_BEGIN_DECLS
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#define GST_TYPE_AUDIO_TEST_SRC (gst_audio_test_src_get_type())
G_DECLARE_FINAL_TYPE (GstAudioTestSrc, gst_audio_test_src, GST, AUDIO_TEST_SRC,
GstBaseSrc)
/**
* GstAudioTestSrcWave:
* @GST_AUDIO_TEST_SRC_WAVE_SINE: a sine wave
* @GST_AUDIO_TEST_SRC_WAVE_SQUARE: a square wave
* @GST_AUDIO_TEST_SRC_WAVE_SAW: a saw wave
* @GST_AUDIO_TEST_SRC_WAVE_TRIANGLE: a tringle wave
* @GST_AUDIO_TEST_SRC_WAVE_SILENCE: silence
* @GST_AUDIO_TEST_SRC_WAVE_WHITE_NOISE: white uniform noise
* @GST_AUDIO_TEST_SRC_WAVE_PINK_NOISE: pink noise
* @GST_AUDIO_TEST_SRC_WAVE_SINE_TAB: sine wave using a table
* @GST_AUDIO_TEST_SRC_WAVE_TICKS: periodic ticks
audiotestsrc: Improvements to the "ticks" wave (Initially discussed in https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/issues/305) The ticks waveform can be useful for audio synchronization diagnostics and other cases where the time offset between waveforms is important. However, in its current form, it is too limited, and has problems with discontinuities, which result in severe artifacts when this waveform is output by a DAC. This patch fixes some discontinuities and considerably expand the ticks waveform's flexibility. They also introduce the notion of a "marker tick"; every Nth tick can have a different amplitude (usually one that is larger than the others). This is useful for combining frequent oscilloscope triggering with large time offset detection. For example, without marker ticks, the tick intervals must not be too small, otherwise the maximum time offset that can be unambiguously detected is quite small (for example, if the interval is 50ms, then no time offset larger than 25ms can be unambiguously recognized). If the tick intervals are too far apart, then no sudden changes can be clearly observed, since the oscilloscope is not updated quickly enough. But with marker ticks, this is not an issue: If there's for example a tick every 100 ms, then the oscilloscope can be triggered every 100 ms. And, if every 20th tick is a marker tick, then time offsets of up to 1 second can be discovered, even though the time between ticks is 100 ms. The patch also applies some minor cleanup to the audiotestsrc documentation.
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* @GST_AUDIO_TEST_SRC_WAVE_GAUSSIAN_WHITE_NOISE: white (zero mean) Gaussian noise
* @GST_AUDIO_TEST_SRC_WAVE_RED_NOISE: red (brownian) noise
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* @GST_AUDIO_TEST_SRC_WAVE_BLUE_NOISE: spectraly inverted pink noise
* @GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE: spectraly inverted red (brownian) noise
*
* Different types of supported sound waves.
*/
typedef enum {
GST_AUDIO_TEST_SRC_WAVE_SINE,
GST_AUDIO_TEST_SRC_WAVE_SQUARE,
GST_AUDIO_TEST_SRC_WAVE_SAW,
GST_AUDIO_TEST_SRC_WAVE_TRIANGLE,
GST_AUDIO_TEST_SRC_WAVE_SILENCE,
GST_AUDIO_TEST_SRC_WAVE_WHITE_NOISE,
GST_AUDIO_TEST_SRC_WAVE_PINK_NOISE,
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_BLUE_NOISE,
GST_AUDIO_TEST_SRC_WAVE_VIOLET_NOISE
} GstAudioTestSrcWave;
#define PINK_MAX_RANDOM_ROWS (30)
#define PINK_RANDOM_BITS (16)
#define PINK_RANDOM_SHIFT ((sizeof(long)*8)-PINK_RANDOM_BITS)
typedef struct {
glong rows[PINK_MAX_RANDOM_ROWS];
glong running_sum; /* Used to optimize summing of generators. */
gint index; /* Incremented each sample. */
gint index_mask; /* Index wrapped by ANDing with this mask. */
gdouble scalar; /* Used to scale within range of -1.0 to +1.0 */
} GstPinkNoise;
typedef struct {
gdouble state; /* noise state */
} GstRedNoise;
typedef void (*ProcessFunc) (GstAudioTestSrc*, guint8 *);
/**
* GstAudioTestSrc:
*
* audiotestsrc object structure.
*/
struct _GstAudioTestSrc {
GstBaseSrc parent;
ProcessFunc process;
GstAudioFormatPack pack_func;
gint pack_size;
gpointer tmp;
gsize tmpsize;
/* parameters */
GstAudioTestSrcWave wave;
gdouble volume;
gdouble freq;
/* audio parameters */
GstAudioInfo info;
gint samples_per_buffer;
/*< private >*/
gboolean tags_pushed; /* send tags just once ? */
GstClockTimeDiff timestamp_offset; /* base offset */
GstClockTime next_time; /* next timestamp */
gint64 next_sample; /* next sample to send */
gint64 next_byte; /* next byte to send */
gint64 sample_stop;
gboolean check_seek_stop;
gboolean eos_reached;
gint generate_samples_per_buffer; /* used to generate a partial buffer */
gboolean can_activate_pull;
gboolean reverse; /* play backwards */
/* waveform specific context data */
GRand *gen; /* random number generator */
gdouble accumulator; /* phase angle */
GstPinkNoise pink;
GstRedNoise red;
gdouble wave_table[1024];
audiotestsrc: Improvements to the "ticks" wave (Initially discussed in https://gitlab.freedesktop.org/gstreamer/gst-plugins-base/issues/305) The ticks waveform can be useful for audio synchronization diagnostics and other cases where the time offset between waveforms is important. However, in its current form, it is too limited, and has problems with discontinuities, which result in severe artifacts when this waveform is output by a DAC. This patch fixes some discontinuities and considerably expand the ticks waveform's flexibility. They also introduce the notion of a "marker tick"; every Nth tick can have a different amplitude (usually one that is larger than the others). This is useful for combining frequent oscilloscope triggering with large time offset detection. For example, without marker ticks, the tick intervals must not be too small, otherwise the maximum time offset that can be unambiguously detected is quite small (for example, if the interval is 50ms, then no time offset larger than 25ms can be unambiguously recognized). If the tick intervals are too far apart, then no sudden changes can be clearly observed, since the oscilloscope is not updated quickly enough. But with marker ticks, this is not an issue: If there's for example a tick every 100 ms, then the oscilloscope can be triggered every 100 ms. And, if every 20th tick is a marker tick, then time offsets of up to 1 second can be discovered, even though the time between ticks is 100 ms. The patch also applies some minor cleanup to the audiotestsrc documentation.
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guint sine_periods_per_tick;
guint64 tick_interval;
guint marker_tick_period;
gdouble marker_tick_volume;
gboolean apply_tick_ramp;
guint samples_between_ticks;
guint tick_counter;
};
G_END_DECLS
#endif /* __GST_AUDIO_TEST_SRC_H__ */