1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
|
/* 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"
#include <gst/gstmarshal.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_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->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, FALSE, FALSE, TRUE, 1, -1, 1);
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_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;
}
|
