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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.
*
* Subclasses usually operate in a format that is different from the
* default GST_FORMAT_BYTES format of #GstBaseSrc.
*
* Classes extending this base class will usually be scheduled
* in a push based mode. If the peer accepts to operate without
* offsets and within the limits of the allowed block size, this
* class can operate in getrange based mode automatically. To make
* this possible, the subclass should implement and override the
* SCHEDULING query.
*
* 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.
*
* Last reviewed on 2006-07-04 (0.10.9)
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdlib.h>
#include <string.h>
#include "gstpushsrc.h"
#include "gsttypefindhelper.h"
GST_DEBUG_CATEGORY_STATIC (gst_push_src_debug);
#define GST_CAT_DEFAULT gst_push_src_debug
#define _do_init \
GST_DEBUG_CATEGORY_INIT (gst_push_src_debug, "pushsrc", 0, \
"pushsrc element");
#define gst_push_src_parent_class parent_class
G_DEFINE_TYPE_WITH_CODE (GstPushSrc, gst_push_src, GST_TYPE_BASE_SRC, _do_init);
static gboolean gst_push_src_query (GstBaseSrc * src, GstQuery * query);
static GstFlowReturn gst_push_src_create (GstBaseSrc * bsrc, guint64 offset,
guint length, GstBuffer ** ret);
static GstFlowReturn gst_push_src_alloc (GstBaseSrc * bsrc, guint64 offset,
guint length, GstBuffer ** ret);
static GstFlowReturn gst_push_src_fill (GstBaseSrc * bsrc, guint64 offset,
guint length, GstBuffer * ret);
static void
gst_push_src_class_init (GstPushSrcClass * klass)
{
GstBaseSrcClass *gstbasesrc_class = (GstBaseSrcClass *) klass;
gstbasesrc_class->create = GST_DEBUG_FUNCPTR (gst_push_src_create);
gstbasesrc_class->alloc = GST_DEBUG_FUNCPTR (gst_push_src_alloc);
gstbasesrc_class->fill = GST_DEBUG_FUNCPTR (gst_push_src_fill);
gstbasesrc_class->query = GST_DEBUG_FUNCPTR (gst_push_src_query);
}
static void
gst_push_src_init (GstPushSrc * pushsrc)
{
/* nop */
}
static gboolean
gst_push_src_query (GstBaseSrc * src, GstQuery * query)
{
gboolean ret;
switch (GST_QUERY_TYPE (query)) {
case GST_QUERY_SCHEDULING:
{
/* a pushsrc can by default never operate in pull mode override
* if you want something different. */
gst_query_set_scheduling (query, GST_SCHEDULING_FLAG_SEQUENTIAL, 1, -1,
0);
gst_query_add_scheduling_mode (query, GST_PAD_MODE_PUSH);
ret = TRUE;
break;
}
default:
ret = GST_BASE_SRC_CLASS (parent_class)->query (src, query);
break;
}
return ret;
}
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_BASE_SRC_CLASS (parent_class)->create (bsrc, offset, length, ret);
return fret;
}
static GstFlowReturn
gst_push_src_alloc (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->alloc)
fret = pclass->alloc (src, ret);
else
fret = GST_BASE_SRC_CLASS (parent_class)->alloc (bsrc, offset, length, ret);
return fret;
}
static GstFlowReturn
gst_push_src_fill (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->fill)
fret = pclass->fill (src, ret);
else
fret = GST_BASE_SRC_CLASS (parent_class)->fill (bsrc, offset, length, ret);
return fret;
}
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