/* 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., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#ifndef __GST_TAG_DEMUX_H__

#define __GST_TAG_DEMUX_H__

#include <gst/gst.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.

 *

 * Since: 0.10.15

 */

typedef enum {

  GST_TAG_DEMUX_RESULT_BROKEN_TAG,

  GST_TAG_DEMUX_RESULT_AGAIN,

  GST_TAG_DEMUX_RESULT_OK

} GstTagDemuxResult;

/**

 * GstTagDemux:

 *

 * Opaque #GstTagDemux structure.

 *

 * Since: 0.10.15

 */

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.

 *

 * Since: 0.10.15

 */

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];

};

#ifdef __SYMBIAN32__

IMPORT_C

#endif

GType     gst_tag_demux_get_type (void);

G_END_DECLS

#endif /* __GST_TAG_DEMUX_H__ */