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Diffstat (limited to 'gst/filter/gstwsinc.c')
-rw-r--r-- | gst/filter/gstwsinc.c | 311 |
1 files changed, 0 insertions, 311 deletions
diff --git a/gst/filter/gstwsinc.c b/gst/filter/gstwsinc.c deleted file mode 100644 index 19300456..00000000 --- a/gst/filter/gstwsinc.c +++ /dev/null @@ -1,311 +0,0 @@ -/* -*- c-basic-offset: 2 -*- - * GStreamer - * Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu> - * - * 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/ - */ - -/* FIXME: - * - this filter is totally unoptimized ! - * - we do not destroy the allocated memory for filters and residue - * - this might be improved upon with bytestream - */ - -#include <gst/gst.h> -#include "gstfilter.h" -#include <math.h> /* M_PI */ -#include <string.h> /* memmove */ - -GstElementDetails gst_wsinc_details = { - "WSinc", - "Filter/Audio/Effect", - "Windowed sinc filter", - VERSION, - "Thomas <thomas@apestaart.org>", - "(C) 2002 Steven W. Smith", -}; - -enum { - /* FILL ME */ - LAST_SIGNAL -}; - -enum { - ARG_0, - ARG_LENGTH, - ARG_FREQUENCY, -}; - -#define GST_TYPE_WSINC \ - (gst_wsinc_get_type()) -#define GST_WSINC(obj) \ - (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_WSINC,GstWSinc)) -#define GST_WSINC_CLASS(klass) \ - (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_ULAW,GstWSinc)) -#define GST_IS_WSINC(obj) \ - (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_WSINC)) -#define GST_IS_WSINC_CLASS(obj) \ - (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_WSINC)) - -typedef struct _GstWSinc GstWSinc; -typedef struct _GstWSincClass GstWSincClass; - -struct _GstWSinc -{ - GstElement element; - - GstPad *sinkpad, *srcpad; - - double frequency; - int wing_size; /* length of a "wing" of the filter; - actual length is 2 * wing_size + 1 */ - - gfloat *residue; /* buffer for left-over samples from previous buffer */ - double *kernel; -}; - -struct _GstWSincClass -{ - GstElementClass parent_class; -}; - -static void gst_wsinc_class_init (GstWSincClass * klass); -static void gst_wsinc_init (GstWSinc * filter); - -static void gst_wsinc_set_property (GObject * object, guint prop_id, - const GValue * value, - GParamSpec * pspec); -static void gst_wsinc_get_property (GObject * object, guint prop_id, - GValue * value, GParamSpec * pspec); - -static void gst_wsinc_chain (GstPad * pad, GstBuffer * buf); -static GstPadConnectReturn - gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps); - -static GstElementClass *parent_class = NULL; -/*static guint gst_wsinc_signals[LAST_SIGNAL] = { 0 }; */ - -GType gst_wsinc_get_type (void) -{ - static GType wsinc_type = 0; - - if (!wsinc_type) { - static const GTypeInfo wsinc_info = { - sizeof (GstWSincClass), NULL, NULL, - (GClassInitFunc) gst_wsinc_class_init, NULL, NULL, - sizeof (GstWSinc), 0, - (GInstanceInitFunc) gst_wsinc_init, - }; - - wsinc_type = g_type_register_static (GST_TYPE_ELEMENT, "GstWSinc", - &wsinc_info, 0); - } - return wsinc_type; -} - -static void -gst_wsinc_class_init (GstWSincClass * klass) -{ - GObjectClass *gobject_class; - GstElementClass *gstelement_class; - - gobject_class = (GObjectClass *) klass; - gstelement_class = (GstElementClass *) klass; - - parent_class = g_type_class_ref (GST_TYPE_ELEMENT); - - g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_FREQUENCY, - g_param_spec_double ("frequency", "Frequency", - "Cut-off Frequency relative to sample rate)", - 0.0, 0.5, - 0, G_PARAM_READWRITE)); - g_object_class_install_property (G_OBJECT_CLASS (klass), ARG_LENGTH, - g_param_spec_int ("length", "Length", - "N such that the filter length = 2N + 1", - 1, G_MAXINT, - 1, G_PARAM_READWRITE)); - - gobject_class->set_property = gst_wsinc_set_property; - gobject_class->get_property = gst_wsinc_get_property; -} - -static void -gst_wsinc_init (GstWSinc * filter) -{ - filter->sinkpad = gst_pad_new_from_template (gst_filter_sink_factory (), "sink"); - gst_pad_set_chain_function (filter->sinkpad, gst_wsinc_chain); - gst_pad_set_connect_function (filter->sinkpad, gst_wsinc_sink_connect); - gst_element_add_pad (GST_ELEMENT (filter), filter->sinkpad); - - filter->srcpad = gst_pad_new_from_template (gst_filter_src_factory (), "src"); - gst_element_add_pad (GST_ELEMENT (filter), filter->srcpad); - - filter->wing_size = 50; - filter->frequency = 0.25; - filter->kernel = NULL; -} - -static GstPadConnectReturn -gst_wsinc_sink_connect (GstPad * pad, GstCaps * caps) -{ - int i = 0; - double sum = 0.0; - int len = 0; - GstWSinc *filter = GST_WSINC (gst_pad_get_parent (pad)); - - g_assert (GST_IS_PAD (pad)); - g_assert (caps != NULL); - - if (!GST_CAPS_IS_FIXED (caps)) - return GST_PAD_CONNECT_DELAYED; - - if (gst_pad_try_set_caps (filter->srcpad, caps)) - { - /* connection works, so init the filter */ - /* FIXME: remember to free it */ - /* fill the kernel */ - g_print ("DEBUG: initing filter kernel\n"); - len = filter->wing_size; - GST_DEBUG (GST_CAT_PLUGIN_INFO, - "wsinc: initializing filter kernel of length %d", len * 2 + 1); - filter->kernel = (double *) g_malloc (sizeof (double) * (2 * len + 1)); - - for (i = 0; i <= len * 2; ++i) - { - if (i == len) - filter->kernel[i] = 2 * M_PI * filter->frequency; - else - filter->kernel[i] = sin (2 * M_PI * filter->frequency * (i - len)) - / (i - len); - /* windowing */ - filter->kernel[i] *= (0.54 - 0.46 * cos (M_PI * i / len)); - } - - /* normalize for unity gain at DC - * FIXME: sure this is not supposed to be quadratic ? */ - for (i = 0; i <= len * 2; ++i) sum += filter->kernel[i]; - for (i = 0; i <= len * 2; ++i) filter->kernel[i] /= sum; - - /* set up the residue memory space */ - filter->residue = (gfloat *) g_malloc (sizeof (gfloat) * (len * 2 + 1)); - for (i = 0; i <= len * 2; ++i) filter->residue[i] = 0.0; - - return GST_PAD_CONNECT_OK; - } - - return GST_PAD_CONNECT_REFUSED; -} - -static void -gst_wsinc_chain (GstPad * pad, GstBuffer * buf) -{ - GstWSinc *filter; - gfloat *src; - gfloat *input; - gint residue_samples; - gint input_samples; - gint total_samples; - int i, j; - - filter = GST_WSINC (gst_pad_get_parent (pad)); - - /* FIXME: out of laziness, we copy the left-over bit from last buffer - * together with the incoming buffer to a new buffer to make the loop - * easy; this could be a lot more optimized though - * to make amends we keep the incoming buffer around and write our - * output samples there */ - - src = (gfloat *) GST_BUFFER_DATA (buf); - residue_samples = filter->wing_size * 2 + 1; - input_samples = GST_BUFFER_SIZE (buf) / sizeof (gfloat); - total_samples = residue_samples + input_samples; - - input = (gfloat *) g_malloc (sizeof (gfloat) * total_samples); - - /* copy the left-over bit */ - memcpy (input, filter->residue, sizeof (gfloat) * residue_samples); - - /* copy the new buffer */ - memcpy (&input[residue_samples], src, sizeof (gfloat) * input_samples); - /* copy the tail of the current input buffer to the residue */ - memcpy (filter->residue, &src[input_samples - residue_samples], - sizeof (gfloat) * residue_samples); - - /* convolution */ - /* since we copied the previous set of samples we needed before the actual - * input data, we need to add the filter length to our indices for input */ - for (i = 0; i < input_samples; ++i) - { - src[i] = 0.0; - for (j = 0; j < residue_samples; ++j) - src[i] += input[i - j + residue_samples] * filter->kernel[j]; - } - - g_free (input); - gst_pad_push (filter->srcpad, buf); -} - -static void -gst_wsinc_set_property (GObject * object, guint prop_id, const GValue * value, GParamSpec * pspec) -{ - GstWSinc *filter; - - /* it's not null if we got it, but it might not be ours */ - g_return_if_fail (GST_IS_WSINC (object)); - - filter = GST_WSINC (object); - - switch (prop_id) { - case ARG_LENGTH: - filter->wing_size = g_value_get_int (value); - break; - case ARG_FREQUENCY: - filter->frequency = g_value_get_double (value); - break; - default: - break; - } -} - -static void -gst_wsinc_get_property (GObject * object, guint prop_id, GValue * value, GParamSpec * pspec) -{ - GstWSinc *filter; - - /* it's not null if we got it, but it might not be ours */ - g_return_if_fail (GST_IS_WSINC (object)); - - filter = GST_WSINC (object); - - switch (prop_id) { - case ARG_LENGTH: - g_value_set_int (value, filter->wing_size); - break; - case ARG_FREQUENCY: - g_value_set_double (value, filter->frequency); - break; - default: - G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec); - break; - } -} - |