gst/: Update GstTagSetter and GstTagMergeMode documentation. Mention that tags can come from events and from applicat...

Original commit message from CVS:
* gst/gsttaglist.h:
* gst/gsttagsetter.c:
Update GstTagSetter and GstTagMergeMode documentation. Mention
that tags can come from events and from application. Fix example.

ChangeLog

@@ -1,3 +1,10 @@
+2008-12-15  Stefan Kost  <ensonic@users.sf.net>
+
+	* gst/gsttaglist.h:
+	* gst/gsttagsetter.c:
+	  Update GstTagSetter and GstTagMergeMode documentation. Mention
+	  that tags can come from events and from application. Fix example.
+
 2008-12-15  Wim Taymans  <wim.taymans@collabora.co.uk>
 
 	* docs/design/part-TODO.txt:

gst/gsttaglist.h

@@ -40,11 +40,12 @@ G_BEGIN_DECLS
  * @GST_TAG_MERGE_COUNT: the number of merge modes
  *
  * The different tag merging modes are basically replace, overwrite and append,
- * but they can be seen from two directions.  Given two taglists: (A) the tags
- * already in the element and (B) the ones that are supplied to
- * gst_tag_setter_merge_tags() or gst_tag_setter_add_tags(), how are these tags
- * merged? In the table below this is shown for the cases that a tag exists in
- * the list (A) or does not exists (!A) and combinations thereof.
+ * but they can be seen from two directions. Given two taglists: (A) the tags
+ * already in the element and (B) the ones that are supplied to the element (
+ * e.g. via gst_tag_setter_merge_tags() / gst_tag_setter_add_tags() or a
+ * %GST_EVENT_TAG), how are these tags merged?
+ * In the table below this is shown for the cases that a tag exists in the list
+ * (A) or does not exists (!A) and combinations thereof.
  *
  * <table frame="all" colsep="1" rowsep="1">
  *   <title>merge mode</title>

gst/gsttagsetter.c

@@ -24,30 +24,26 @@
  * @short_description: Element interface that allows setting and retrieval
  *                     of media metadata
  *
- * <refsect2>
- * <para>
  * Element interface that allows setting of media metadata.
- * </para>
- * <para>
+ *
  * Elements that support changing a stream's metadata will implement this
  * interface. Examples of such elements are 'vorbisenc', 'theoraenc' and
  * 'id3v2mux'.
- * </para>
- * <para>
+ * 
  * If you just want to retrieve metadata in your application then all you
  * need to do is watch for tag messages on your pipeline's bus. This
  * interface is only for setting metadata, not for extracting it. To set tags
  * from the application, find tagsetter elements and set tags using e.g.
- * gst_tag_setter_merge_tags() or gst_tag_setter_add_tags(). The application
- * should do that before the element goes to %GST_STATE_PAUSED.
- * </para>
- * <para>
+ * gst_tag_setter_merge_tags() or gst_tag_setter_add_tags(). Also consider
+ * setting the #GstTagMergeMode that is used for tag events that arrive at the
+ * tagsetter element (default mode is to keep existing tags).
+ * The application should do that before the element goes to %GST_STATE_PAUSED.
+ * 
  * Elements implementing the #GstTagSetter interface often have to merge
  * any tags received from upstream and the tags set by the application via
  * the interface. This can be done like this:
- * </para>
- * <para>
- * <programlisting>
+ *
+ * |[
  * GstTagMergeMode merge_mode;
  * const GstTagList *application_tags;
  * const GstTagList *event_tags;
@@ -57,7 +53,7 @@
  * tagsetter = GST_TAG_SETTER (element);
  *  
  * merge_mode = gst_tag_setter_get_tag_merge_mode (tagsetter);
- * tagsetter_tags = gst_tag_setter_get_tag_list (tagsetter);
+ * application_tags = gst_tag_setter_get_tag_list (tagsetter);
  * event_tags = (const GstTagList *) element->event_tags;
  *  
  * GST_LOG_OBJECT (tagsetter, "merging tags, merge mode = %d", merge_mode);
@@ -67,12 +63,9 @@
  * result = gst_tag_list_merge (application_tags, event_tags, merge_mode);
  *  
  * GST_LOG_OBJECT (tagsetter, "final tags: %" GST_PTR_FORMAT, result);
- * </programlisting>
- * </para>
- * <para>
+ * ]|
+ * 
  * Last reviewed on 2006-05-18 (0.10.6)
- * </para>
- * </refsect2>
  */
 
 #ifdef HAVE_CONFIG_H