gst-analytics: add missing mtd segmentation API

- add gst_analytics_segmentation_mtd_get_mtd_type() which is required to
  retrieve the concrete type of a generic mtd (GstAnalyticsMtd).

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/8307>

girs/GstAnalytics-1.0.gir

@@ -877,6 +877,30 @@ Ids (@an_meta_first_id and @an_meta_second_id) must be from a call to
           </parameter>
         </parameters>
       </method>
+      <method name="get_segmentation_mtd" c:identifier="gst_analytics_relation_meta_get_segmentation_mtd" version="1.26">
+        <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c">Fill @rlt if a analytics-meta with id == @an_meta_id exist in @meta instance,
+otherwise this method return FALSE and @rlt is invalid.</doc>
+        <source-position filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.h"/>
+        <return-value transfer-ownership="none">
+          <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c">TRUE if successful.</doc>
+          <type name="gboolean" c:type="gboolean"/>
+        </return-value>
+        <parameters>
+          <instance-parameter name="meta" transfer-ownership="none">
+            <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c">Instance of #GstAnalyticsRelationMeta</doc>
+            <type name="RelationMeta" c:type="GstAnalyticsRelationMeta*"/>
+          </instance-parameter>
+          <parameter name="an_meta_id" transfer-ownership="none">
+            <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c">Id of #GstAnalyticsSegmentationMtd instance to retrieve</doc>
+            <type name="guint" c:type="guint"/>
+          </parameter>
+          <parameter name="rlt" direction="out" caller-allocates="1" transfer-ownership="none">
+            <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c">Will be filled with relatable
+   meta</doc>
+            <type name="SegmentationMtd" c:type="GstAnalyticsSegmentationMtd*"/>
+          </parameter>
+        </parameters>
+      </method>
       <method name="get_tracking_mtd" c:identifier="gst_analytics_relation_meta_get_tracking_mtd" version="1.24">
         <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticsobjecttrackingmtd.c">Fill @rlt if a analytics-meta with id == @an_meta_id exist in @meta instance,
 otherwise this method return FALSE and @rlt is invalid.</doc>
@@ -958,7 +982,7 @@ Ids must have been obtained a call to
           </parameter>
         </parameters>
       </method>
-      <function name="get_info" c:identifier="gst_analytics_relation_meta_get_info" version="1.24" introspectable="0">
+      <function name="get_info" c:identifier="gst_analytics_relation_meta_get_info" version="1.24">
         <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticsmeta.c">Get the meta info</doc>
         <source-position filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticsmeta.h"/>
         <return-value transfer-ownership="none">
@@ -1744,7 +1768,7 @@ information about the tracking, for example, it can be used alongside a
         <type name="GType" c:type="GType"/>
       </return-value>
     </function>
-    <function name="relation_meta_get_info" c:identifier="gst_analytics_relation_meta_get_info" moved-to="RelationMeta.get_info" version="1.24" introspectable="0">
+    <function name="relation_meta_get_info" c:identifier="gst_analytics_relation_meta_get_info" moved-to="RelationMeta.get_info" version="1.24">
       <doc xml:space="preserve" filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticsmeta.c">Get the meta info</doc>
       <source-position filename="../subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticsmeta.h"/>
       <return-value transfer-ownership="none">

subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.c

@@ -465,3 +465,26 @@ gst_analytics_segmentation_mtd_transform (GstBuffer * transbuf,
 
   return TRUE;
 }
+
+/**
+ * gst_analytics_relation_meta_get_segmentation_mtd:
+ * @meta: Instance of #GstAnalyticsRelationMeta
+ * @an_meta_id: Id of #GstAnalyticsSegmentationMtd instance to retrieve
+ * @rlt: (out caller-allocates)(not nullable): Will be filled with relatable
+ *    meta
+ *
+ * Fill @rlt if a analytics-meta with id == @an_meta_id exist in @meta instance,
+ * otherwise this method return FALSE and @rlt is invalid.
+ *
+ * Returns: TRUE if successful.
+ *
+ * Since: 1.26
+ */
+gboolean
+gst_analytics_relation_meta_get_segmentation_mtd (GstAnalyticsRelationMeta *
+    meta, guint an_meta_id, GstAnalyticsSegmentationMtd * rlt)
+{
+  return gst_analytics_relation_meta_get_mtd (meta, an_meta_id,
+      gst_analytics_segmentation_mtd_get_mtd_type (),
+      (GstAnalyticsSegmentationMtd *) rlt);
+}

subprojects/gst-plugins-bad/gst-libs/gst/analytics/gstanalyticssegmentationmtd.h

@@ -93,5 +93,10 @@ gst_analytics_relation_meta_add_segmentation_mtd (GstAnalyticsRelationMeta *
     guint masks_loc_w, guint masks_loc_h, GstAnalyticsSegmentationMtd *
     segmentation_mtd);
 
+GST_ANALYTICS_META_API
+gboolean
+gst_analytics_relation_meta_get_segmentation_mtd (GstAnalyticsRelationMeta *
+    meta, guint an_meta_id, GstAnalyticsSegmentationMtd * rlt);
+
 G_END_DECLS
 #endif // __GST_ANALYTICS_SEGMENTATION_META_H__