fake:

package/public/vlc/vlc.conf

@@ -20,7 +20,8 @@
 # 
 # --- ROCK-COPYRIGHT-NOTE-END ---
 
-confopt="$confopt --enable-dvdread" # --with-dvdcss=/usr
+pkginstalled libdvdread && var_append confopt ' ' '--enable-dvdread'
+pkginstalled wxwidgets || var_append confopt ' ' '--disable-wxwidgets'
 
 # set these so libsmbclient.h and libsmbclient.so are found
 if pkginstalled samba ; then