gstreamer/libs/gst/base/gstpushsrc.c

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/* GStreamer
* Copyright (C) 1999,2000 Erik Walthinsen <omega@cse.ogi.edu>
* 2000,2005 Wim Taymans <wim@fluendo.com>
*
* gstpushsrc.c:
*
* 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.
*/
/**
* SECTION:gstpushsrc
* @short_description: Base class for push based source elements
* @see_also: #GstBaseSrc
*
* This class is mostly useful for elements that cannot do
* random access, or at least very slowly. The source usually
* prefers to push out a fixed size buffer.
*
* Classes extending this base class will usually be scheduled
* in a push based mode. It the peer accepts to operate without
* offsets and withing the limits of the allowed block size, this
* class can operate in getrange based mode automatically.
*
* The subclass should extend the methods from the baseclass in
* addition to the create method.
*
* Seeking, flushing, scheduling and sync is all handled by this
* base class.
*/
#include <stdlib.h>
#include <string.h>
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include "gstpushsrc.h"
#include "gsttypefindhelper.h"
#include <gst/gstmarshal.h>
GST_DEBUG_CATEGORY_STATIC (gst_push_src_debug);
#define GST_CAT_DEFAULT gst_push_src_debug
/* PushSrc signals and args */
enum
{
/* FILL ME */
LAST_SIGNAL
};
enum
{
PROP_0,
};
static GstElementClass *parent_class = NULL;
static void gst_push_src_base_init (gpointer g_class);
static void gst_push_src_class_init (GstPushSrcClass * klass);
static void gst_push_src_init (GstPushSrc * src, gpointer g_class);
GType
gst_push_src_get_type (void)
{
static GType push_src_type = 0;
if (!push_src_type) {
static const GTypeInfo push_src_info = {
sizeof (GstPushSrcClass),
(GBaseInitFunc) gst_push_src_base_init,
NULL,
(GClassInitFunc) gst_push_src_class_init,
NULL,
NULL,
sizeof (GstPushSrc),
0,
(GInstanceInitFunc) gst_push_src_init,
};
push_src_type = g_type_register_static (GST_TYPE_BASE_SRC,
"GstPushSrc", &push_src_info, G_TYPE_FLAG_ABSTRACT);
}
return push_src_type;
}
#if 0
static const GstEventMask *gst_push_src_get_event_mask (GstPad * pad);
#endif
static GstFlowReturn gst_push_src_create (GstBaseSrc * bsrc, guint64 offset,
guint length, GstBuffer ** ret);
static void
gst_push_src_base_init (gpointer g_class)
{
GST_DEBUG_CATEGORY_INIT (gst_push_src_debug, "pushsrc", 0, "pushsrc element");
}
static void
gst_push_src_class_init (GstPushSrcClass * klass)
{
GObjectClass *gobject_class;
GstElementClass *gstelement_class;
GstBaseSrcClass *gstbasesrc_class;
gobject_class = (GObjectClass *) klass;
gstelement_class = (GstElementClass *) klass;
gstbasesrc_class = (GstBaseSrcClass *) klass;
parent_class = g_type_class_ref (GST_TYPE_BASE_SRC);
gstbasesrc_class->create = GST_DEBUG_FUNCPTR (gst_push_src_create);
}
static void
gst_push_src_init (GstPushSrc * pushsrc, gpointer g_class)
{
}
static GstFlowReturn
gst_push_src_create (GstBaseSrc * bsrc, guint64 offset, guint length,
GstBuffer ** ret)
{
GstFlowReturn fret;
GstPushSrc *src;
GstPushSrcClass *pclass;
src = GST_PUSH_SRC (bsrc);
pclass = GST_PUSH_SRC_GET_CLASS (src);
if (pclass->create)
fret = pclass->create (src, ret);
else
fret = GST_FLOW_ERROR;
return fret;
}