-VLC_EXPORT( int, picture_Setup, ( picture_t *, vlc_fourcc_t i_chroma, int i_width, int i_height, int i_sar_num, int i_sar_den ) );
+VLC_API int picture_Setup( picture_t *, vlc_fourcc_t i_chroma, int i_width, int i_height, int i_sar_num, int i_sar_den );
+
+
+/**
+ * This function will blend a given subpicture onto a picture.
+ *
+ * The subpicture and all its region must:
+ * - be absolute.
+ * - not be ephemere.
+ * - not have the fade flag.
+ * - contains only picture (no text rendering).
+ */
+VLC_API void picture_BlendSubpicture( picture_t *, filter_t *p_blend, subpicture_t * );
+