libvlc: add libvlc_media_player_add_slave

In order to add a slave when the media player is playing.

include/vlc/libvlc_media.h

@@ -786,9 +786,9 @@ libvlc_media_type_t libvlc_media_get_type( libvlc_media_t *p_md );
  * \version LibVLC 3.0.0 and later.
  *
  * \param p_md media descriptor object
- * \param psz_uri Uri of the slave (should contain a valid scheme).
  * \param i_type subtitle or audio
  * \param i_priority from 0 (low priority) to 4 (high priority)
+ * \param psz_uri Uri of the slave (should contain a valid scheme).
  *
  * \return 0 on success, -1 on error.
  */

include/vlc/libvlc_media_player.h

@@ -954,6 +954,27 @@ LIBVLC_API void libvlc_media_player_navigate( libvlc_media_player_t* p_mi,
  */
 LIBVLC_API void libvlc_media_player_set_video_title_display( libvlc_media_player_t *p_mi, libvlc_position_t position, unsigned int timeout );
 
+/**
+ * Add a slave to the current media player.
+ *
+ * \note If the player is playing, the slave will be added directly. This call
+ * will also update the slave list of the attached libvlc_media_t.
+ *
+ * \version LibVLC 3.0.0 and later.
+ *
+ * \see libvlc_media_slaves_add
+ *
+ * \param p_mi the media player
+ * \param i_type subtitle or audio
+ * \param psz_uri Uri of the slave (should contain a valid scheme).
+ *
+ * \return 0 on success, -1 on error.
+ */
+LIBVLC_API
+int libvlc_media_player_add_slave( libvlc_media_player_t *p_mi,
+                                   libvlc_media_slave_type_t i_type,
+                                   const char *psz_uri );
+
 /**
  * Release (free) libvlc_track_description_t
  *

lib/media_player.c

@@ -1891,6 +1891,31 @@ void libvlc_media_player_set_video_title_display( libvlc_media_player_t *p_mi, l
     }
 }
 
+int libvlc_media_player_add_slave( libvlc_media_player_t *p_mi,
+                                   libvlc_media_slave_type_t i_type,
+                                   const char *psz_uri )
+{
+    input_thread_t *p_input_thread = libvlc_get_input_thread ( p_mi );
+
+    if( p_input_thread == NULL )
+    {
+        libvlc_media_t *p_media = libvlc_media_player_get_media( p_mi );
+        if( p_media == NULL )
+            return -1;
+
+        int i_ret = libvlc_media_slaves_add( p_media, i_type, 4, psz_uri );
+        libvlc_media_release( p_media );
+        return i_ret;
+    }
+    else
+    {
+        int i_ret = input_AddSlave( p_input_thread, i_type, psz_uri );
+        vlc_object_release( p_input_thread );
+
+        return i_ret == VLC_SUCCESS ? 0 : -1;
+    }
+}
+
 /**
  * Maximum size of a formatted equalizer amplification band frequency value.
  *