1 /* GStreamer Base Class for Tag Demuxing
2 * Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
3 * Copyright (C) 2006 Tim-Philipp Müller <tim centricular net>
5 * This library is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Library General Public
7 * License as published by the Free Software Foundation; either
8 * version 2 of the License, or (at your option) any later version.
10 * This library is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Library General Public License for more details.
15 * You should have received a copy of the GNU Library General Public
16 * License along with this library; if not, write to the
17 * Free Software Foundation, Inc., 51 Franklin St, Fifth Floor,
18 * Boston, MA 02110-1301, USA.
21 #ifndef __GST_TAG_DEMUX_H__
22 #define __GST_TAG_DEMUX_H__
28 #define GST_TYPE_TAG_DEMUX (gst_tag_demux_get_type())
29 #define GST_TAG_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_TAG_DEMUX,GstTagDemux))
30 #define GST_TAG_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_TAG_DEMUX,GstTagDemuxClass))
31 #define GST_IS_TAG_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_TAG_DEMUX))
32 #define GST_IS_TAG_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_TAG_DEMUX))
34 typedef struct _GstTagDemux GstTagDemux;
35 typedef struct _GstTagDemuxClass GstTagDemuxClass;
36 typedef struct _GstTagDemuxPrivate GstTagDemuxPrivate;
40 * @GST_TAG_DEMUX_RESULT_BROKEN_TAG: cannot parse tag, just skip it
41 * @GST_TAG_DEMUX_RESULT_AGAIN : call again with less or more data
42 * @GST_TAG_DEMUX_RESULT_OK : parsed tag successfully
44 * Result values from the parse_tag virtual function.
47 GST_TAG_DEMUX_RESULT_BROKEN_TAG,
48 GST_TAG_DEMUX_RESULT_AGAIN,
49 GST_TAG_DEMUX_RESULT_OK
52 GType gst_tag_demux_result_get_type (void);
53 #define GST_TYPE_TAG_DEMUX_RESULT (gst_tag_demux_result_get_type())
57 * @element: parent element
59 * Opaque #GstTagDemux structure.
66 GstTagDemuxPrivate *priv;
68 gpointer reserved[GST_PADDING];
73 * @parent_class: the parent class.
74 * @min_start_size: minimum size required to identify a tag at the start and
75 * determine its total size. Set to 0 if not interested in start tags.
76 * Subclasses should set this in their class_init function.
77 * @min_end_size: minimum size required to identify a tag at the end and
78 * determine its total size. Set to 0 if not interested in end tags.
79 * Subclasses should set this in their class_init function.
80 * @identify_tag: identify tag and determine the size required to parse the
81 * tag. Buffer may be larger than the specified minimum size.
82 * Subclassed MUST override this vfunc in their class_init function.
83 * @parse_tag: parse the tag. Buffer will be exactly of the size determined by
84 * the identify_tag vfunc before. The parse_tag vfunc may change the size
85 * stored in *tag_size and return GST_TAG_DEMUX_RESULT_AGAIN to request a
86 * larger or smaller buffer. It is also permitted to adjust the tag_size to a
87 * smaller value and then return GST_TAG_DEMUX_RESULT_OK in one go.
88 * Subclassed MUST override the parse_tag vfunc in their class_init function.
89 * @merge_tags: merge start and end tags. Subclasses may want to override this
90 * vfunc to allow prioritising of start or end tag according to user
91 * preference. Note that both start_tags and end_tags may be NULL. By default
92 * start tags are prefered over end tags.
94 * The #GstTagDemuxClass structure. See documentation at beginning of section
95 * for details about what subclasses need to override and do.
97 struct _GstTagDemuxClass
99 GstElementClass parent_class;
101 /* minimum size required to identify a tag at the start and determine
103 guint min_start_size;
105 /* minimum size required to identify a tag at the end and determine
111 /* identify tag and determine the size required to parse the tag */
112 gboolean (*identify_tag) (GstTagDemux * demux,
117 /* parse the tag once it is identified and its size is known */
118 GstTagDemuxResult (*parse_tag) (GstTagDemux * demux,
124 /* merge start and end tags (optional) */
125 GstTagList * (*merge_tags) (GstTagDemux * demux,
126 const GstTagList * start_tags,
127 const GstTagList * end_tags);
130 gpointer reserved[GST_PADDING];
133 GType gst_tag_demux_get_type (void);
137 #endif /* __GST_TAG_DEMUX_H__ */