mediacontrol: doxygen updates

include/vlc/mediacontrol_structures.h

@@ -20,6 +20,12 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  *****************************************************************************/
+/**
+ * \defgroup mediacontrol_structures MediaControl Structures
+ * Data structures used in the MediaControl API.
+ *
+ * @{
+ */
 
 #ifndef _VLC_CONTROL_STRUCTURES_H
 #define _VLC_CONTROL_STRUCTURES_H 1
@@ -28,18 +34,33 @@
 extern "C" {
 # endif
 
+/**
+ * A position may have different origins: 
+ *  - absolute counts from the movie start
+ *  - relative counts from the current position
+ *  - modulo counts from the current position and wraps at the end of the movie
+ */
 typedef enum  {
     mediacontrol_AbsolutePosition,
     mediacontrol_RelativePosition,
     mediacontrol_ModuloPosition
 } mediacontrol_PositionOrigin;
 
+/**
+ * Units available in mediacontrol Positions
+ *  - ByteCount number of bytes
+ *  - SampleCount number of frames
+ *  - MediaTime time in milliseconds
+ */
 typedef enum {
     mediacontrol_ByteCount,
     mediacontrol_SampleCount,
     mediacontrol_MediaTime
 } mediacontrol_PositionKey;
 
+/**
+ * MediaControl Position
+ */
 typedef struct {
     mediacontrol_PositionOrigin origin;
     mediacontrol_PositionKey key;
@@ -51,3 +72,5 @@ typedef struct {
 # endif
 
 #endif
+
+/** @} */