gst_plugins_base/gst-libs/gst/tag/gsttagdemux.h
changeset 0 0e761a78d257
child 8 4a7fac7dd34a
equal deleted inserted replaced
-1:000000000000 0:0e761a78d257
       
     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>
       
     4  *
       
     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.
       
     9  *
       
    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.
       
    14  *
       
    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., 59 Temple Place - Suite 330,
       
    18  * Boston, MA 02111-1307, USA.
       
    19  */
       
    20 
       
    21 #ifndef __GST_TAG_DEMUX_H__
       
    22 #define __GST_TAG_DEMUX_H__
       
    23 
       
    24 #include <gst/gst.h>
       
    25 
       
    26 G_BEGIN_DECLS
       
    27 
       
    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))
       
    33 
       
    34 typedef struct _GstTagDemux        GstTagDemux;
       
    35 typedef struct _GstTagDemuxClass   GstTagDemuxClass;
       
    36 typedef struct _GstTagDemuxPrivate GstTagDemuxPrivate;
       
    37 
       
    38 /**
       
    39  * GstTagDemuxResult:
       
    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
       
    43  *
       
    44  * Result values from the parse_tag virtual function.
       
    45  *
       
    46  * Since: 0.10.15
       
    47  */
       
    48 typedef enum {
       
    49   GST_TAG_DEMUX_RESULT_BROKEN_TAG,
       
    50   GST_TAG_DEMUX_RESULT_AGAIN,
       
    51   GST_TAG_DEMUX_RESULT_OK
       
    52 } GstTagDemuxResult;
       
    53 
       
    54 /**
       
    55  * GstTagDemux:
       
    56  *
       
    57  * Opaque #GstTagDemux structure.
       
    58  *
       
    59  * Since: 0.10.15
       
    60  */
       
    61 struct _GstTagDemux
       
    62 {
       
    63   GstElement element;
       
    64 
       
    65   /*< private >*/
       
    66   GstTagDemuxPrivate  *priv;
       
    67 
       
    68   gpointer             reserved[GST_PADDING];
       
    69 };
       
    70 
       
    71 /**
       
    72  * GstTagDemuxClass:
       
    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.
       
    93  *
       
    94  * The #GstTagDemuxClass structure.  See documentation at beginning of section
       
    95  * for details about what subclasses need to override and do.
       
    96  *
       
    97  * Since: 0.10.15
       
    98  */
       
    99 struct _GstTagDemuxClass
       
   100 {
       
   101   GstElementClass parent_class;
       
   102 
       
   103   /* minimum size required to identify a tag at the start and determine
       
   104    * its total size */
       
   105   guint                  min_start_size;
       
   106 
       
   107   /* minimum size required to identify a tag at the end and determine
       
   108    * its total size */
       
   109   guint                  min_end_size;
       
   110 
       
   111   /* vtable */
       
   112 
       
   113   /* identify tag and determine the size required to parse the tag */
       
   114   gboolean               (*identify_tag)  (GstTagDemux * demux,
       
   115                                            GstBuffer   * buffer,
       
   116                                            gboolean      start_tag,
       
   117                                            guint       * tag_size);
       
   118 
       
   119   /* parse the tag once it is identified and its size is known */
       
   120   GstTagDemuxResult      (*parse_tag)     (GstTagDemux * demux,
       
   121                                            GstBuffer   * buffer,
       
   122                                            gboolean      start_tag,
       
   123                                            guint       * tag_size,
       
   124                                            GstTagList ** tags);
       
   125 
       
   126   /* merge start and end tags (optional) */
       
   127   GstTagList *           (*merge_tags)    (GstTagDemux      * demux,
       
   128                                            const GstTagList * start_tags,
       
   129                                            const GstTagList * end_tags);
       
   130 
       
   131   /*< private >*/
       
   132   gpointer               reserved[GST_PADDING];
       
   133 };
       
   134 #ifdef __SYMBIAN32__
       
   135 IMPORT_C
       
   136 #endif
       
   137 
       
   138 
       
   139 GType     gst_tag_demux_get_type (void);
       
   140 
       
   141 G_END_DECLS
       
   142 
       
   143 #endif /* __GST_TAG_DEMUX_H__ */
       
   144