mirror of
https://gitlab.freedesktop.org/gstreamer/gstreamer.git
synced 2024-12-22 00:06:36 +00:00
de3d1d62ab
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.
84 lines
2.6 KiB
C
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__ */
|