gstreamer/gst/audiofx/audiowsinclimit.h
Sebastian Dröge de3d1d62ab gst/filter/gstlpwsinc.*: Add double support, replace "this" with "self" as the former is a C++ keyword.
Original commit message from CVS:
* gst/filter/gstlpwsinc.c: (gst_lpwsinc_dispose),
(gst_lpwsinc_class_init), (gst_lpwsinc_init), (process_32),
(process_64), (lpwsinc_build_kernel), (lpwsinc_setup),
(lpwsinc_get_unit_size), (lpwsinc_transform),
(lpwsinc_set_property), (lpwsinc_get_property):
* gst/filter/gstlpwsinc.h:
Add double support, replace "this" with "self" as the former
is a C++ keyword.
Implement the frequency property in Hz instead of fraction
of sampling frequency.
Remove some unecessary FIXMEs and add some TODOs, add some
required locking and refactor the kernel generation into a
separate function that is also called when the properties
change now.
And use BaseTransform::transform instead of transform_ip
as the convolution is done out of place anyway. Should
be done in place later.
2007-08-09 18:08:05 +00:00

84 lines
2.6 KiB
C

/* -*- c-basic-offset: 2 -*-
*
* GStreamer
* Copyright (C) 1999-2001 Erik Walthinsen <omega@cse.ogi.edu>
* 2006 Dreamlab Technologies Ltd. <mathis.hofer@dreamlab.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., 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
*/
#ifndef __GST_LPWSINC_H__
#define __GST_LPWSINC_H__
#include "gstfilter.h"
#include <gst/gst.h>
#include <gst/audio/gstaudiofilter.h>
G_BEGIN_DECLS
#define GST_TYPE_LPWSINC \
(gst_lpwsinc_get_type())
#define GST_LPWSINC(obj) \
(G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_LPWSINC,GstLPWSinc))
#define GST_LPWSINC_CLASS(klass) \
(G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_LPWSINC,GstLPWSincClass))
#define GST_IS_LPWSINC(obj) \
(G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_LPWSINC))
#define GST_IS_LPWSINC_CLASS(klass) \
(G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_LPWSINC))
typedef struct _GstLPWSinc GstLPWSinc;
typedef struct _GstLPWSincClass GstLPWSincClass;
typedef void (*GstLPWSincProcessFunc) (GstLPWSinc *, guint8 *, guint8 *, guint);
/**
* GstLPWSinc:
*
* Opaque data structure.
*/
struct _GstLPWSinc {
GstAudioFilter element;
GstLPWSincProcessFunc process;
gdouble frequency;
gint wing_size; /* length of a "wing" of the filter;
actual length is 2 * wing_size + 1 */
gdouble *residue; /* buffer for left-over samples from previous buffer */
gdouble *kernel; /* filter kernel */
gboolean have_kernel;
};
struct _GstLPWSincClass {
GstAudioFilterClass parent_class;
};
G_END_DECLS
#endif /* __GST_LPWSINC_H__ */