[ AC_MSG_ERROR([Could not find libmad on your system: you may get it from http://www.underbit.com/products/mad/. Alternatively you can use --disable-mad to disable the mad plugin.]) ])
AC_MSG_ERROR([Your libmpeg2 is too old (you need the cvs version): you may get a more recent one from http://libmpeg2.sf.net/. Alternatively you can use --disable-libmpeg2 to disable the libmpeg2 plugin.])])],