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/* GStreamer Base Class for Tag Demuxing
* Copyright (C) 2005 Jan Schmidt <thaytan@mad.scientist.com>
* Copyright (C) 2006 Tim-Philipp Müller <tim centricular 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., 51 Franklin St, Fifth Floor,
* Boston, MA 02110-1301, USA.
*/
#ifndef __GST_TAG_DEMUX_H__
#define __GST_TAG_DEMUX_H__
#include <gst/gst.h>
#include <gst/tag/tag-enumtypes.h>
G_BEGIN_DECLS
#define GST_TYPE_TAG_DEMUX (gst_tag_demux_get_type())
#define GST_TAG_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_CAST((obj),GST_TYPE_TAG_DEMUX,GstTagDemux))
#define GST_TAG_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST((klass),GST_TYPE_TAG_DEMUX,GstTagDemuxClass))
#define GST_IS_TAG_DEMUX(obj) (G_TYPE_CHECK_INSTANCE_TYPE((obj),GST_TYPE_TAG_DEMUX))
#define GST_IS_TAG_DEMUX_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE((klass),GST_TYPE_TAG_DEMUX))
typedef struct _GstTagDemux GstTagDemux;
typedef struct _GstTagDemuxClass GstTagDemuxClass;
typedef struct _GstTagDemuxPrivate GstTagDemuxPrivate;
/**
* GstTagDemuxResult:
* @GST_TAG_DEMUX_RESULT_BROKEN_TAG: cannot parse tag, just skip it
* @GST_TAG_DEMUX_RESULT_AGAIN : call again with less or more data
* @GST_TAG_DEMUX_RESULT_OK : parsed tag successfully
*
* Result values from the parse_tag virtual function.
*/
typedef enum {
GST_TAG_DEMUX_RESULT_BROKEN_TAG,
GST_TAG_DEMUX_RESULT_AGAIN,
GST_TAG_DEMUX_RESULT_OK
} GstTagDemuxResult;
/**
* GstTagDemux:
* @element: parent element
*
* Opaque #GstTagDemux structure.
*/
struct _GstTagDemux
{
GstElement element;
/*< private >*/
GstTagDemuxPrivate *priv;
gpointer reserved[GST_PADDING];
};
/**
* GstTagDemuxClass:
* @parent_class: the parent class.
* @min_start_size: minimum size required to identify a tag at the start and
* determine its total size. Set to 0 if not interested in start tags.
* Subclasses should set this in their class_init function.
* @min_end_size: minimum size required to identify a tag at the end and
* determine its total size. Set to 0 if not interested in end tags.
* Subclasses should set this in their class_init function.
* @identify_tag: identify tag and determine the size required to parse the
* tag. Buffer may be larger than the specified minimum size.
* Subclassed MUST override this vfunc in their class_init function.
* @parse_tag: parse the tag. Buffer will be exactly of the size determined by
* the identify_tag vfunc before. The parse_tag vfunc may change the size
* stored in *tag_size and return GST_TAG_DEMUX_RESULT_AGAIN to request a
* larger or smaller buffer. It is also permitted to adjust the tag_size to a
* smaller value and then return GST_TAG_DEMUX_RESULT_OK in one go.
* Subclassed MUST override the parse_tag vfunc in their class_init function.
* @merge_tags: merge start and end tags. Subclasses may want to override this
* vfunc to allow prioritising of start or end tag according to user
* preference. Note that both start_tags and end_tags may be NULL. By default
* start tags are prefered over end tags.
*
* The #GstTagDemuxClass structure. See documentation at beginning of section
* for details about what subclasses need to override and do.
*/
struct _GstTagDemuxClass
{
GstElementClass parent_class;
/* minimum size required to identify a tag at the start and determine
* its total size */
guint min_start_size;
/* minimum size required to identify a tag at the end and determine
* its total size */
guint min_end_size;
/* vtable */
/* identify tag and determine the size required to parse the tag */
gboolean (*identify_tag) (GstTagDemux * demux,
GstBuffer * buffer,
gboolean start_tag,
guint * tag_size);
/* parse the tag once it is identified and its size is known */
GstTagDemuxResult (*parse_tag) (GstTagDemux * demux,
GstBuffer * buffer,
gboolean start_tag,
guint * tag_size,
GstTagList ** tags);
/* merge start and end tags (optional) */
GstTagList * (*merge_tags) (GstTagDemux * demux,
const GstTagList * start_tags,
const GstTagList * end_tags);
/*< private >*/
gpointer reserved[GST_PADDING];
};
GST_TAG_API
GType gst_tag_demux_get_type (void);
#ifdef G_DEFINE_AUTOPTR_CLEANUP_FUNC
G_DEFINE_AUTOPTR_CLEANUP_FUNC(GstTagDemux, gst_object_unref)
#endif
G_END_DECLS
#endif /* __GST_TAG_DEMUX_H__ */