diff -r 71e347f905f2 -r 4a7fac7dd34a gst_plugins_good/gst/audiofx/audiochebband.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gst_plugins_good/gst/audiofx/audiochebband.c Fri Apr 16 15:15:52 2010 +0300 @@ -0,0 +1,666 @@ +/* + * GStreamer + * Copyright (C) 2007-2009 Sebastian Dröge + * + * 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., 59 Temple Place - Suite 330, + * Boston, MA 02111-1307, USA. + */ + +/* + * Chebyshev type 1 filter design based on + * "The Scientist and Engineer's Guide to DSP", Chapter 20. + * http://www.dspguide.com/ + * + * For type 2 and Chebyshev filters in general read + * http://en.wikipedia.org/wiki/Chebyshev_filter + * + * Transformation from lowpass to bandpass/bandreject: + * http://docs.dewresearch.com/DspHelp/html/IDH_LinearSystems_LowpassToBandPassZ.htm + * http://docs.dewresearch.com/DspHelp/html/IDH_LinearSystems_LowpassToBandStopZ.htm + * + */ + +/** + * SECTION:element-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 audiotestsrc freq=1500 ! audioconvert ! audiochebband mode=band-pass lower-frequency=1000 upper-frequenc=6000 poles=4 ! audioconvert ! alsasink + * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audiochebband mode=band-reject lower-frequency=1000 upper-frequency=4000 ripple=0.2 ! audioconvert ! alsasink + * gst-launch audiotestsrc wave=white-noise ! audioconvert ! audiochebband mode=band-pass lower-frequency=1000 upper-frequency=4000 type=2 ! audioconvert ! alsasink + * ]| + * + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include +#include +#include +#include +#include + +#include + +#include "math_compat.h" + +#include "audiochebband.h" + +#define GST_CAT_DEFAULT gst_audio_cheb_band_debug +GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); + +enum +{ + PROP_0, + PROP_MODE, + PROP_TYPE, + PROP_LOWER_FREQUENCY, + PROP_UPPER_FREQUENCY, + PROP_RIPPLE, + PROP_POLES +}; + +#define DEBUG_INIT(bla) \ + GST_DEBUG_CATEGORY_INIT (gst_audio_cheb_band_debug, "audiochebband", 0, "audiochebband element"); + +GST_BOILERPLATE_FULL (GstAudioChebBand, gst_audio_cheb_band, + GstAudioFXBaseIIRFilter, GST_TYPE_AUDIO_FX_BASE_IIR_FILTER, DEBUG_INIT); + +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, + GstRingBufferSpec * format); + +enum +{ + MODE_BAND_PASS = 0, + MODE_BAND_REJECT +}; + +#define GST_TYPE_AUDIO_CHEBYSHEV_FREQ_BAND_MODE (gst_audio_cheb_band_mode_get_type ()) +static GType +gst_audio_cheb_band_mode_get_type (void) +{ + static GType gtype = 0; + + if (gtype == 0) { + static const GEnumValue values[] = { + {MODE_BAND_PASS, "Band pass (default)", + "band-pass"}, + {MODE_BAND_REJECT, "Band reject", + "band-reject"}, + {0, NULL, NULL} + }; + + gtype = g_enum_register_static ("GstAudioChebBandMode", values); + } + return gtype; +} + +/* GObject vmethod implementations */ + +static void +gst_audio_cheb_band_base_init (gpointer klass) +{ + GstElementClass *element_class = GST_ELEMENT_CLASS (klass); + + gst_element_class_set_details_simple (element_class, + "Band pass & band reject filter", "Filter/Effect/Audio", + "Chebyshev band pass and band reject filter", + "Sebastian Dröge "); +} + +static void +gst_audio_cheb_band_class_init (GstAudioChebBandClass * klass) +{ + GObjectClass *gobject_class = (GObjectClass *) klass; + GstAudioFilterClass *filter_class = (GstAudioFilterClass *) klass; + + gobject_class->set_property = gst_audio_cheb_band_set_property; + gobject_class->get_property = gst_audio_cheb_band_get_property; + gobject_class->finalize = gst_audio_cheb_band_finalize; + + g_object_class_install_property (gobject_class, PROP_MODE, + g_param_spec_enum ("mode", "Mode", + "Low pass or high pass mode", GST_TYPE_AUDIO_CHEBYSHEV_FREQ_BAND_MODE, + MODE_BAND_PASS, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + g_object_class_install_property (gobject_class, PROP_TYPE, + g_param_spec_int ("type", "Type", "Type of the chebychev filter", 1, 2, 1, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + + /* FIXME: Don't use the complete possible range but restrict the upper boundary + * so automatically generated UIs can use a slider without */ + g_object_class_install_property (gobject_class, PROP_LOWER_FREQUENCY, + g_param_spec_float ("lower-frequency", "Lower frequency", + "Start frequency of the band (Hz)", 0.0, 100000.0, + 0.0, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + g_object_class_install_property (gobject_class, PROP_UPPER_FREQUENCY, + g_param_spec_float ("upper-frequency", "Upper frequency", + "Stop frequency of the band (Hz)", 0.0, 100000.0, 0.0, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + g_object_class_install_property (gobject_class, PROP_RIPPLE, + g_param_spec_float ("ripple", "Ripple", "Amount of ripple (dB)", 0.0, + 200.0, 0.25, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + /* FIXME: What to do about this upper boundary? With a frequencies near + * rate/4 32 poles are completely possible, with frequencies very low + * or very high 16 poles already produces only noise */ + g_object_class_install_property (gobject_class, PROP_POLES, + g_param_spec_int ("poles", "Poles", + "Number of poles to use, will be rounded up to the next multiply of four", + 4, 32, 4, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + + filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_cheb_band_setup); +} + +static void +gst_audio_cheb_band_init (GstAudioChebBand * filter, + GstAudioChebBandClass * klass) +{ + filter->lower_frequency = filter->upper_frequency = 0.0; + filter->mode = MODE_BAND_PASS; + filter->type = 1; + filter->poles = 4; + filter->ripple = 0.25; + + filter->lock = g_mutex_new (); +} + +static void +generate_biquad_coefficients (GstAudioChebBand * filter, + gint p, gdouble * a0, gdouble * a1, gdouble * a2, gdouble * a3, + gdouble * a4, gdouble * b1, gdouble * b2, gdouble * b3, gdouble * b4) +{ + gint np = filter->poles / 2; + gdouble ripple = filter->ripple; + + /* pole location in s-plane */ + gdouble rp, ip; + + /* zero location in s-plane */ + gdouble iz = 0.0; + + /* transfer function coefficients for the z-plane */ + gdouble x0, x1, x2, y1, y2; + gint type = filter->type; + + /* Calculate pole location for lowpass at frequency 1 */ + { + gdouble angle = (M_PI / 2.0) * (2.0 * p - 1) / np; + + rp = -sin (angle); + ip = cos (angle); + } + + /* If we allow ripple, move the pole from the unit + * circle to an ellipse and keep cutoff at frequency 1 */ + if (ripple > 0 && type == 1) { + gdouble es, vx; + + es = sqrt (pow (10.0, ripple / 10.0) - 1.0); + + vx = (1.0 / np) * asinh (1.0 / es); + rp = rp * sinh (vx); + ip = ip * cosh (vx); + } else if (type == 2) { + gdouble es, vx; + + es = sqrt (pow (10.0, ripple / 10.0) - 1.0); + vx = (1.0 / np) * asinh (es); + rp = rp * sinh (vx); + ip = ip * cosh (vx); + } + + /* Calculate inverse of the pole location to move from + * type I to type II */ + if (type == 2) { + gdouble mag2 = rp * rp + ip * ip; + + rp /= mag2; + ip /= mag2; + } + + /* Calculate zero location for frequency 1 on the + * unit circle for type 2 */ + if (type == 2) { + gdouble angle = M_PI / (np * 2.0) + ((p - 1) * M_PI) / (np); + gdouble mag2; + + iz = cos (angle); + mag2 = iz * iz; + iz /= mag2; + } + + /* Convert from s-domain to z-domain by + * using the bilinear Z-transform, i.e. + * substitute s by (2/t)*((z-1)/(z+1)) + * with t = 2 * tan(0.5). + */ + if (type == 1) { + gdouble t, m, d; + + t = 2.0 * tan (0.5); + m = rp * rp + ip * ip; + d = 4.0 - 4.0 * rp * t + m * t * t; + + x0 = (t * t) / d; + x1 = 2.0 * x0; + x2 = x0; + y1 = (8.0 - 2.0 * m * t * t) / d; + y2 = (-4.0 - 4.0 * rp * t - m * t * t) / d; + } else { + gdouble t, m, d; + + t = 2.0 * tan (0.5); + m = rp * rp + ip * ip; + d = 4.0 - 4.0 * rp * t + m * t * t; + + x0 = (t * t * iz * iz + 4.0) / d; + x1 = (-8.0 + 2.0 * iz * iz * t * t) / d; + x2 = x0; + y1 = (8.0 - 2.0 * m * t * t) / d; + y2 = (-4.0 - 4.0 * rp * t - m * t * t) / d; + } + + /* Convert from lowpass at frequency 1 to either bandpass + * or band reject. + * + * For bandpass substitute z^(-1) with: + * + * -2 -1 + * -z + alpha * z - beta + * ---------------------------- + * -2 -1 + * beta * z - alpha * z + 1 + * + * alpha = (2*a*b)/(1+b) + * beta = (b-1)/(b+1) + * a = cos((w1 + w0)/2) / cos((w1 - w0)/2) + * b = tan(1/2) * cot((w1 - w0)/2) + * + * For bandreject substitute z^(-1) with: + * + * -2 -1 + * z - alpha * z + beta + * ---------------------------- + * -2 -1 + * beta * z - alpha * z + 1 + * + * alpha = (2*a)/(1+b) + * beta = (1-b)/(1+b) + * a = cos((w1 + w0)/2) / cos((w1 - w0)/2) + * b = tan(1/2) * tan((w1 - w0)/2) + * + */ + { + gdouble a, b, d; + gdouble alpha, beta; + gdouble w0 = + 2.0 * M_PI * (filter->lower_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + gdouble w1 = + 2.0 * M_PI * (filter->upper_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + + if (filter->mode == MODE_BAND_PASS) { + a = cos ((w1 + w0) / 2.0) / cos ((w1 - w0) / 2.0); + b = tan (1.0 / 2.0) / tan ((w1 - w0) / 2.0); + + alpha = (2.0 * a * b) / (1.0 + b); + beta = (b - 1.0) / (b + 1.0); + + d = 1.0 + beta * (y1 - beta * y2); + + *a0 = (x0 + beta * (-x1 + beta * x2)) / d; + *a1 = (alpha * (-2.0 * x0 + x1 + beta * x1 - 2.0 * beta * x2)) / d; + *a2 = + (-x1 - beta * beta * x1 + 2.0 * beta * (x0 + x2) + + alpha * alpha * (x0 - x1 + x2)) / d; + *a3 = (alpha * (x1 + beta * (-2.0 * x0 + x1) - 2.0 * x2)) / d; + *a4 = (beta * (beta * x0 - x1) + x2) / d; + *b1 = (alpha * (2.0 + y1 + beta * y1 - 2.0 * beta * y2)) / d; + *b2 = + (-y1 - beta * beta * y1 - alpha * alpha * (1.0 + y1 - y2) + + 2.0 * beta * (-1.0 + y2)) / d; + *b3 = (alpha * (y1 + beta * (2.0 + y1) - 2.0 * y2)) / d; + *b4 = (-beta * beta - beta * y1 + y2) / d; + } else { + a = cos ((w1 + w0) / 2.0) / cos ((w1 - w0) / 2.0); + b = tan (1.0 / 2.0) * tan ((w1 - w0) / 2.0); + + alpha = (2.0 * a) / (1.0 + b); + beta = (1.0 - b) / (1.0 + b); + + d = -1.0 + beta * (beta * y2 + y1); + + *a0 = (-x0 - beta * x1 - beta * beta * x2) / d; + *a1 = (alpha * (2.0 * x0 + x1 + beta * x1 + 2.0 * beta * x2)) / d; + *a2 = + (-x1 - beta * beta * x1 - 2.0 * beta * (x0 + x2) - + alpha * alpha * (x0 + x1 + x2)) / d; + *a3 = (alpha * (x1 + beta * (2.0 * x0 + x1) + 2.0 * x2)) / d; + *a4 = (-beta * beta * x0 - beta * x1 - x2) / d; + *b1 = (alpha * (-2.0 + y1 + beta * y1 + 2.0 * beta * y2)) / d; + *b2 = + -(y1 + beta * beta * y1 + 2.0 * beta * (-1.0 + y2) + + alpha * alpha * (-1.0 + y1 + y2)) / d; + *b3 = (alpha * (beta * (-2.0 + y1) + y1 + 2.0 * y2)) / d; + *b4 = -(-beta * beta + beta * y1 + y2) / d; + } + } +} + +static void +generate_coefficients (GstAudioChebBand * filter) +{ + if (GST_AUDIO_FILTER (filter)->format.rate == 0) { + gdouble *a = g_new0 (gdouble, 1); + + a[0] = 1.0; + gst_audio_fx_base_iir_filter_set_coefficients (GST_AUDIO_FX_BASE_IIR_FILTER + (filter), a, 1, NULL, 0); + GST_LOG_OBJECT (filter, "rate was not set yet"); + return; + } + + if (filter->upper_frequency <= filter->lower_frequency) { + gdouble *a = g_new0 (gdouble, 1); + + a[0] = (filter->mode == MODE_BAND_PASS) ? 0.0 : 1.0; + gst_audio_fx_base_iir_filter_set_coefficients (GST_AUDIO_FX_BASE_IIR_FILTER + (filter), a, 1, NULL, 0); + + GST_LOG_OBJECT (filter, "frequency band had no or negative dimension"); + return; + } + + if (filter->upper_frequency > GST_AUDIO_FILTER (filter)->format.rate / 2) { + filter->upper_frequency = GST_AUDIO_FILTER (filter)->format.rate / 2; + GST_LOG_OBJECT (filter, "clipped upper frequency to nyquist frequency"); + } + + if (filter->lower_frequency < 0.0) { + filter->lower_frequency = 0.0; + GST_LOG_OBJECT (filter, "clipped lower frequency to 0.0"); + } + + /* Calculate coefficients for the chebyshev filter */ + { + gint np = filter->poles; + gdouble *a, *b; + gint i, p; + + a = g_new0 (gdouble, np + 5); + b = g_new0 (gdouble, np + 5); + + /* Calculate transfer function coefficients */ + a[4] = 1.0; + b[4] = 1.0; + + for (p = 1; p <= np / 4; p++) { + gdouble a0, a1, a2, a3, a4, b1, b2, b3, b4; + gdouble *ta = g_new0 (gdouble, np + 5); + gdouble *tb = g_new0 (gdouble, np + 5); + + generate_biquad_coefficients (filter, p, &a0, &a1, &a2, &a3, &a4, &b1, + &b2, &b3, &b4); + + memcpy (ta, a, sizeof (gdouble) * (np + 5)); + memcpy (tb, b, sizeof (gdouble) * (np + 5)); + + /* add the new coefficients for the new two poles + * to the cascade by multiplication of the transfer + * functions */ + for (i = 4; i < np + 5; i++) { + a[i] = + a0 * ta[i] + a1 * ta[i - 1] + a2 * ta[i - 2] + a3 * ta[i - 3] + + a4 * ta[i - 4]; + b[i] = + tb[i] - b1 * tb[i - 1] - b2 * tb[i - 2] - b3 * tb[i - 3] - + b4 * tb[i - 4]; + } + g_free (ta); + g_free (tb); + } + + /* Move coefficients to the beginning of the array + * and multiply the b coefficients with -1 to move from + * the transfer function's coefficients to the difference + * equation's coefficients */ + b[4] = 0.0; + for (i = 0; i <= np; i++) { + a[i] = a[i + 4]; + b[i] = -b[i + 4]; + } + + /* Normalize to unity gain at frequency 0 and frequency + * 0.5 for bandreject and unity gain at band center frequency + * for bandpass */ + if (filter->mode == MODE_BAND_REJECT) { + /* gain is sqrt(H(0)*H(0.5)) */ + + gdouble gain1 = + gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, b, np + 1, + 1.0, 0.0); + gdouble gain2 = + gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, b, np + 1, + -1.0, 0.0); + + gain1 = sqrt (gain1 * gain2); + + for (i = 0; i <= np; i++) { + a[i] /= gain1; + } + } else { + /* gain is H(wc), wc = center frequency */ + + gdouble w1 = + 2.0 * M_PI * (filter->lower_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + gdouble w2 = + 2.0 * M_PI * (filter->upper_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + gdouble w0 = (w2 + w1) / 2.0; + gdouble zr = cos (w0), zi = sin (w0); + gdouble gain = + gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, b, np + 1, zr, + zi); + + for (i = 0; i <= np; i++) { + a[i] /= gain; + } + } + + gst_audio_fx_base_iir_filter_set_coefficients (GST_AUDIO_FX_BASE_IIR_FILTER + (filter), a, np + 1, b, np + 1); + + GST_LOG_OBJECT (filter, + "Generated IIR coefficients for the Chebyshev filter"); + GST_LOG_OBJECT (filter, + "mode: %s, type: %d, poles: %d, lower-frequency: %.2f Hz, upper-frequency: %.2f Hz, ripple: %.2f dB", + (filter->mode == MODE_BAND_PASS) ? "band-pass" : "band-reject", + filter->type, filter->poles, filter->lower_frequency, + filter->upper_frequency, filter->ripple); + + GST_LOG_OBJECT (filter, "%.2f dB gain @ 0Hz", + 20.0 * log10 (gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, b, + np + 1, 1.0, 0.0))); + { + gdouble w1 = + 2.0 * M_PI * (filter->lower_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + gdouble w2 = + 2.0 * M_PI * (filter->upper_frequency / + GST_AUDIO_FILTER (filter)->format.rate); + gdouble w0 = (w2 + w1) / 2.0; + gdouble zr, zi; + + zr = cos (w1); + zi = sin (w1); + GST_LOG_OBJECT (filter, "%.2f dB gain @ %dHz", + 20.0 * log10 (gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, + b, np + 1, zr, zi)), (int) filter->lower_frequency); + zr = cos (w0); + zi = sin (w0); + GST_LOG_OBJECT (filter, "%.2f dB gain @ %dHz", + 20.0 * log10 (gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, + b, np + 1, zr, zi)), + (int) ((filter->lower_frequency + filter->upper_frequency) / 2.0)); + zr = cos (w2); + zi = sin (w2); + GST_LOG_OBJECT (filter, "%.2f dB gain @ %dHz", + 20.0 * log10 (gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, + b, np + 1, zr, zi)), (int) filter->upper_frequency); + } + GST_LOG_OBJECT (filter, "%.2f dB gain @ %dHz", + 20.0 * log10 (gst_audio_fx_base_iir_filter_calculate_gain (a, np + 1, b, + np + 1, -1.0, 0.0)), + GST_AUDIO_FILTER (filter)->format.rate / 2); + } +} + +static void +gst_audio_cheb_band_finalize (GObject * object) +{ + GstAudioChebBand *filter = GST_AUDIO_CHEB_BAND (object); + + g_mutex_free (filter->lock); + filter->lock = NULL; + + G_OBJECT_CLASS (parent_class)->finalize (object); +} + +static void +gst_audio_cheb_band_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec) +{ + GstAudioChebBand *filter = GST_AUDIO_CHEB_BAND (object); + + switch (prop_id) { + case PROP_MODE: + g_mutex_lock (filter->lock); + filter->mode = g_value_get_enum (value); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + case PROP_TYPE: + g_mutex_lock (filter->lock); + filter->type = g_value_get_int (value); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + case PROP_LOWER_FREQUENCY: + g_mutex_lock (filter->lock); + filter->lower_frequency = g_value_get_float (value); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + case PROP_UPPER_FREQUENCY: + g_mutex_lock (filter->lock); + filter->upper_frequency = g_value_get_float (value); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + case PROP_RIPPLE: + g_mutex_lock (filter->lock); + filter->ripple = g_value_get_float (value); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + case PROP_POLES: + g_mutex_lock (filter->lock); + filter->poles = GST_ROUND_UP_4 (g_value_get_int (value)); + generate_coefficients (filter); + g_mutex_unlock (filter->lock); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_audio_cheb_band_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec) +{ + GstAudioChebBand *filter = GST_AUDIO_CHEB_BAND (object); + + switch (prop_id) { + case PROP_MODE: + g_value_set_enum (value, filter->mode); + break; + case PROP_TYPE: + g_value_set_int (value, filter->type); + break; + case PROP_LOWER_FREQUENCY: + g_value_set_float (value, filter->lower_frequency); + break; + case PROP_UPPER_FREQUENCY: + g_value_set_float (value, filter->upper_frequency); + break; + case PROP_RIPPLE: + g_value_set_float (value, filter->ripple); + break; + case PROP_POLES: + g_value_set_int (value, filter->poles); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +/* GstAudioFilter vmethod implementations */ + +static gboolean +gst_audio_cheb_band_setup (GstAudioFilter * base, GstRingBufferSpec * format) +{ + GstAudioChebBand *filter = GST_AUDIO_CHEB_BAND (base); + + generate_coefficients (filter); + + return GST_AUDIO_FILTER_CLASS (parent_class)->setup (base, format); +}