diff -r 71e347f905f2 -r 4a7fac7dd34a gst_plugins_good/gst/audiofx/audiowsinclimit.c --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/gst_plugins_good/gst/audiofx/audiowsinclimit.c Fri Apr 16 15:15:52 2010 +0300 @@ -0,0 +1,373 @@ +/* -*- c-basic-offset: 2 -*- + * + * GStreamer + * Copyright (C) 1999-2001 Erik Walthinsen + * 2006 Dreamlab Technologies Ltd. + * 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. + * + * + * this windowed sinc filter is taken from the freely downloadable DSP book, + * "The Scientist and Engineer's Guide to Digital Signal Processing", + * chapter 16 + * available at http://www.dspguide.com/ + * + */ + +/** + * SECTION:element-audiowsinclimit + * + * Attenuates all frequencies above the cutoff frequency (low-pass) or all frequencies below the + * cutoff frequency (high-pass). The length parameter controls the rolloff, the window parameter + * controls rolloff and stopband attenuation. The Hamming window provides a faster rolloff but a bit + * worse stopband attenuation, the other way around for the Blackman window. + * + * This element has the advantage over the Chebyshev lowpass and highpass filter that it has + * a much better rolloff when using a larger kernel size and almost linear phase. The only + * disadvantage is the much slower execution time with larger kernels. + * + * + * Example launch line + * |[ + * gst-launch audiotestsrc freq=1500 ! audioconvert ! audiowsinclimit mode=low-pass frequency=1000 length=501 ! audioconvert ! alsasink + * gst-launch filesrc location="melo1.ogg" ! oggdemux ! vorbisdec ! audioconvert ! audiowsinclimit mode=high-pass frequency=15000 length=501 ! audioconvert ! alsasink + * gst-launch audiotestsrc wave=white-noise ! audioconvert ! audiowsinclimit mode=low-pass frequency=1000 length=10001 window=blackman ! audioconvert ! alsasink + * ]| + * + */ + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include +#include +#include +#include +#include + +#include "audiowsinclimit.h" + +#define GST_CAT_DEFAULT gst_audio_wsinclimit_debug +GST_DEBUG_CATEGORY_STATIC (GST_CAT_DEFAULT); + +enum +{ + PROP_0, + PROP_LENGTH, + PROP_FREQUENCY, + PROP_MODE, + PROP_WINDOW +}; + +enum +{ + MODE_LOW_PASS = 0, + MODE_HIGH_PASS +}; + +#define GST_TYPE_AUDIO_WSINC_LIMIT_MODE (gst_audio_wsinclimit_mode_get_type ()) +static GType +gst_audio_wsinclimit_mode_get_type (void) +{ + static GType gtype = 0; + + if (gtype == 0) { + static const GEnumValue values[] = { + {MODE_LOW_PASS, "Low pass (default)", + "low-pass"}, + {MODE_HIGH_PASS, "High pass", + "high-pass"}, + {0, NULL, NULL} + }; + + gtype = g_enum_register_static ("GstAudioWSincLimitMode", values); + } + return gtype; +} + +enum +{ + WINDOW_HAMMING = 0, + WINDOW_BLACKMAN +}; + +#define GST_TYPE_AUDIO_WSINC_LIMIT_WINDOW (gst_audio_wsinclimit_window_get_type ()) +static GType +gst_audio_wsinclimit_window_get_type (void) +{ + static GType gtype = 0; + + if (gtype == 0) { + static const GEnumValue values[] = { + {WINDOW_HAMMING, "Hamming window (default)", + "hamming"}, + {WINDOW_BLACKMAN, "Blackman window", + "blackman"}, + {0, NULL, NULL} + }; + + gtype = g_enum_register_static ("GstAudioWSincLimitWindow", values); + } + return gtype; +} + +#define DEBUG_INIT(bla) \ + GST_DEBUG_CATEGORY_INIT (gst_audio_wsinclimit_debug, "audiowsinclimit", 0, \ + "Low-pass and High-pass Windowed sinc filter plugin"); + +GST_BOILERPLATE_FULL (GstAudioWSincLimit, gst_audio_wsinclimit, GstAudioFilter, + GST_TYPE_AUDIO_FX_BASE_FIR_FILTER, DEBUG_INIT); + +static void gst_audio_wsinclimit_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec); +static void gst_audio_wsinclimit_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec); +static void gst_audio_wsinclimit_finalize (GObject * object); + +static gboolean gst_audio_wsinclimit_setup (GstAudioFilter * base, + GstRingBufferSpec * format); + +/* Element class */ + +static void +gst_audio_wsinclimit_base_init (gpointer g_class) +{ + GstElementClass *element_class = GST_ELEMENT_CLASS (g_class); + + gst_element_class_set_details_simple (element_class, + "Low pass & high pass filter", "Filter/Effect/Audio", + "Low pass and high pass windowed sinc filter", + "Thomas Vander Stichele , " + "Steven W. Smith, " + "Dreamlab Technologies Ltd. , " + "Sebastian Dröge "); +} + +static void +gst_audio_wsinclimit_class_init (GstAudioWSincLimitClass * klass) +{ + GObjectClass *gobject_class = (GObjectClass *) klass; + GstAudioFilterClass *filter_class = (GstAudioFilterClass *) klass; + + gobject_class->set_property = gst_audio_wsinclimit_set_property; + gobject_class->get_property = gst_audio_wsinclimit_get_property; + gobject_class->finalize = gst_audio_wsinclimit_finalize; + + /* FIXME: Don't use the complete possible range but restrict the upper boundary + * so automatically generated UIs can use a slider */ + g_object_class_install_property (gobject_class, PROP_FREQUENCY, + g_param_spec_float ("cutoff", "Cutoff", + "Cut-off Frequency (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_LENGTH, + g_param_spec_int ("length", "Length", + "Filter kernel length, will be rounded to the next odd number", + 3, 50000, 101, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + + g_object_class_install_property (gobject_class, PROP_MODE, + g_param_spec_enum ("mode", "Mode", + "Low pass or high pass mode", GST_TYPE_AUDIO_WSINC_LIMIT_MODE, + MODE_LOW_PASS, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + + g_object_class_install_property (gobject_class, PROP_WINDOW, + g_param_spec_enum ("window", "Window", + "Window function to use", GST_TYPE_AUDIO_WSINC_LIMIT_WINDOW, + WINDOW_HAMMING, + G_PARAM_READWRITE | GST_PARAM_CONTROLLABLE | G_PARAM_STATIC_STRINGS)); + + filter_class->setup = GST_DEBUG_FUNCPTR (gst_audio_wsinclimit_setup); +} + +static void +gst_audio_wsinclimit_init (GstAudioWSincLimit * self, + GstAudioWSincLimitClass * g_class) +{ + self->mode = MODE_LOW_PASS; + self->window = WINDOW_HAMMING; + self->kernel_length = 101; + self->cutoff = 0.0; + + self->lock = g_mutex_new (); +} + +static void +gst_audio_wsinclimit_build_kernel (GstAudioWSincLimit * self) +{ + gint i = 0; + gdouble sum = 0.0; + gint len = 0; + gdouble w; + gdouble *kernel = NULL; + + len = self->kernel_length; + + if (GST_AUDIO_FILTER (self)->format.rate == 0) { + GST_DEBUG ("rate not set yet"); + return; + } + + if (GST_AUDIO_FILTER (self)->format.channels == 0) { + GST_DEBUG ("channels not set yet"); + return; + } + + /* Clamp cutoff frequency between 0 and the nyquist frequency */ + self->cutoff = + CLAMP (self->cutoff, 0.0, GST_AUDIO_FILTER (self)->format.rate / 2); + + GST_DEBUG ("gst_audio_wsinclimit_: initializing filter kernel of length %d " + "with cutoff %.2lf Hz " + "for mode %s", + len, self->cutoff, + (self->mode == MODE_LOW_PASS) ? "low-pass" : "high-pass"); + + /* fill the kernel */ + w = 2 * M_PI * (self->cutoff / GST_AUDIO_FILTER (self)->format.rate); + + kernel = g_new (gdouble, len); + + for (i = 0; i < len; ++i) { + if (i == len / 2) + kernel[i] = w; + else + kernel[i] = sin (w * (i - len / 2)) / (i - len / 2); + /* windowing */ + if (self->window == WINDOW_HAMMING) + kernel[i] *= (0.54 - 0.46 * cos (2 * M_PI * i / len)); + else + kernel[i] *= (0.42 - 0.5 * cos (2 * M_PI * i / len) + + 0.08 * cos (4 * M_PI * i / len)); + } + + /* normalize for unity gain at DC */ + for (i = 0; i < len; ++i) + sum += kernel[i]; + for (i = 0; i < len; ++i) + kernel[i] /= sum; + + /* convert to highpass if specified */ + if (self->mode == MODE_HIGH_PASS) { + for (i = 0; i < len; ++i) + kernel[i] = -kernel[i]; + kernel[len / 2] += 1.0; + } + + gst_audio_fx_base_fir_filter_set_kernel (GST_AUDIO_FX_BASE_FIR_FILTER (self), + kernel, self->kernel_length, (len - 1) / 2); +} + +/* GstAudioFilter vmethod implementations */ + +/* get notified of caps and plug in the correct process function */ +static gboolean +gst_audio_wsinclimit_setup (GstAudioFilter * base, GstRingBufferSpec * format) +{ + GstAudioWSincLimit *self = GST_AUDIO_WSINC_LIMIT (base); + + gst_audio_wsinclimit_build_kernel (self); + + return GST_AUDIO_FILTER_CLASS (parent_class)->setup (base, format); +} + +static void +gst_audio_wsinclimit_finalize (GObject * object) +{ + GstAudioWSincLimit *self = GST_AUDIO_WSINC_LIMIT (object); + + g_mutex_free (self->lock); + self->lock = NULL; + + G_OBJECT_CLASS (parent_class)->finalize (object); +} + +static void +gst_audio_wsinclimit_set_property (GObject * object, guint prop_id, + const GValue * value, GParamSpec * pspec) +{ + GstAudioWSincLimit *self = GST_AUDIO_WSINC_LIMIT (object); + + g_return_if_fail (GST_IS_AUDIO_WSINC_LIMIT (self)); + + switch (prop_id) { + case PROP_LENGTH:{ + gint val; + + g_mutex_lock (self->lock); + val = g_value_get_int (value); + if (val % 2 == 0) + val++; + + if (val != self->kernel_length) { + gst_audio_fx_base_fir_filter_push_residue (GST_AUDIO_FX_BASE_FIR_FILTER + (self)); + self->kernel_length = val; + gst_audio_wsinclimit_build_kernel (self); + } + g_mutex_unlock (self->lock); + break; + } + case PROP_FREQUENCY: + g_mutex_lock (self->lock); + self->cutoff = g_value_get_float (value); + gst_audio_wsinclimit_build_kernel (self); + g_mutex_unlock (self->lock); + break; + case PROP_MODE: + g_mutex_lock (self->lock); + self->mode = g_value_get_enum (value); + gst_audio_wsinclimit_build_kernel (self); + g_mutex_unlock (self->lock); + break; + case PROP_WINDOW: + g_mutex_lock (self->lock); + self->window = g_value_get_enum (value); + gst_audio_wsinclimit_build_kernel (self); + g_mutex_unlock (self->lock); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +} + +static void +gst_audio_wsinclimit_get_property (GObject * object, guint prop_id, + GValue * value, GParamSpec * pspec) +{ + GstAudioWSincLimit *self = GST_AUDIO_WSINC_LIMIT (object); + + switch (prop_id) { + case PROP_LENGTH: + g_value_set_int (value, self->kernel_length); + break; + case PROP_FREQUENCY: + g_value_set_float (value, self->cutoff); + break; + case PROP_MODE: + g_value_set_enum (value, self->mode); + break; + case PROP_WINDOW: + g_value_set_enum (value, self->window); + break; + default: + G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); + break; + } +}