#include <string.h>
#include <gst/gst.h>
#include <gst/base/gstbasetransform.h>
#include <gst/audio/audio.h>
#include <gst/audio/gstaudiofilter.h>
#include <math.h>
#include "math_compat.h"
#include "audiochebband.h"
#include "gst/glib-compat-private.h"

Include dependency graph for audiochebband.c:

Macros
#define	GST_CAT_DEFAULT gst_audio_cheb_band_debug

#define	gst_audio_cheb_band_parent_class parent_class

#define	GST_TYPE_AUDIO_CHEBYSHEV_FREQ_BAND_MODE (gst_audio_cheb_band_mode_get_type ())

Enumerations
enum	{ PROP_0 , PROP_MODE , PROP_TYPE , PROP_LOWER_FREQUENCY , PROP_UPPER_FREQUENCY , PROP_RIPPLE , PROP_POLES }

enum	{ MODE_BAND_PASS = 0 , MODE_BAND_REJECT }

Functions
	GST_DEBUG_CATEGORY_STATIC (gst_audio_cheb_band_debug)

	G_DEFINE_TYPE (GstAudioChebBand, gst_audio_cheb_band,(gst_audio_fx_base_iir_filter_get_type()))

	GST_ELEMENT_REGISTER_DEFINE (audiochebband, "audiochebband", GST_RANK_NONE,(gst_audio_cheb_band_get_type()))

static void	gst_audio_cheb_band_set_property (GObject object, guint prop_id, const GValue value, GParamSpec *pspec)

static void	gst_audio_cheb_band_get_property (GObject object, guint prop_id, GValue value, GParamSpec *pspec)

static void	gst_audio_cheb_band_finalize (GObject *object)

static gboolean	gst_audio_cheb_band_setup (GstAudioFilter filter, const GstAudioInfo info)

static GType	gst_audio_cheb_band_mode_get_type (void)

static void	gst_audio_cheb_band_class_init (GstAudioChebBandClass *klass)

static void	gst_audio_cheb_band_init (GstAudioChebBand *filter)

static void	generate_biquad_coefficients (GstAudioChebBand filter, gint p, gint rate, gdouble b0, gdouble b1, gdouble b2, gdouble b3, gdouble b4, gdouble a1, gdouble a2, gdouble a3, gdouble a4)

static void	generate_coefficients (GstAudioChebBand filter, const GstAudioInfo info)

Macro Definition Documentation

◆ gst_audio_cheb_band_parent_class

#define gst_audio_cheb_band_parent_class parent_class

Definition at line 100 of file audiochebband.c.

◆ GST_CAT_DEFAULT

#define GST_CAT_DEFAULT gst_audio_cheb_band_debug

SECTION:element-audiochebband @title: audiochebband

Attenuates all frequencies outside (bandpass) or inside (bandreject) of a frequency band. The number of poles and the ripple parameter control the rolloff.

This element has the advantage over the windowed sinc bandpass and bandreject filter that it is much faster and produces almost as good results. It's only disadvantages are the highly non-linear phase and the slower rolloff compared to a windowed sinc filter with a large kernel.

For type 1 the ripple parameter specifies how much ripple in dB is allowed in the passband, i.e. some frequencies in the passband will be amplified by that value. A higher ripple value will allow a faster rolloff.

For type 2 the ripple parameter specifies the stopband attenuation. In the stopband the gain will be at most this value. A lower ripple value will allow a faster rolloff.

As a special case, a Chebyshev type 1 filter with no ripple is a Butterworth filter.

‍Be warned that a too large number of poles can produce noise. The most poles are possible with a cutoff frequency at a quarter of the sampling rate.

Example launch line

|[ gst-launch-1.0 audiotestsrc freq=1500 ! audioconvert ! audiochebband mode=band-pass lower-frequency=1000 upper-frequency=6000 poles=4 ! audioconvert ! alsasink gst-launch-1.0 filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audiochebband mode=band-reject lower-frequency=1000 upper-frequency=4000 ripple=0.2 ! audioconvert ! alsasink gst-launch-1.0 audiotestsrc wave=white-noise ! audioconvert ! audiochebband mode=band-pass lower-frequency=1000 upper-frequency=4000 type=2 ! audioconvert ! alsasink ]|

Definition at line 86 of file audiochebband.c.

◆ GST_TYPE_AUDIO_CHEBYSHEV_FREQ_BAND_MODE

#define GST_TYPE_AUDIO_CHEBYSHEV_FREQ_BAND_MODE (gst_audio_cheb_band_mode_get_type ())

Definition at line 121 of file audiochebband.c.

Enumeration Type Documentation

◆ anonymous enum

anonymous enum

Enumerator
PROP_0
PROP_MODE
PROP_TYPE
PROP_LOWER_FREQUENCY
PROP_UPPER_FREQUENCY
PROP_RIPPLE
PROP_POLES

Definition at line 89 of file audiochebband.c.

◆ anonymous enum

anonymous enum

Enumerator
MODE_BAND_PASS
MODE_BAND_REJECT

Definition at line 115 of file audiochebband.c.

Function Documentation

◆ G_DEFINE_TYPE()

G_DEFINE_TYPE	(	GstAudioChebBand	,
		gst_audio_cheb_band	,
		(gst_audio_fx_base_iir_filter_get_type())
	)

◆ generate_biquad_coefficients()

static void generate_biquad_coefficients	(	GstAudioChebBand *	filter,
		gint	p,
		gint	rate,
		gdouble *	b0,
		gdouble *	b1,
		gdouble *	b2,
		gdouble *	b3,
		gdouble *	b4,
		gdouble *	a1,
		gdouble *	a2,
		gdouble *	a3,
		gdouble *	a4
	)