* ./configure.ac.in: libmad and liba52 need to be explicitely disabled,

    otherwise we fail with an error when they are not found.

configure.ac.in

@@ -1389,7 +1389,7 @@ dnl  mad plugin
 dnl
 AC_ARG_ENABLE(mad,
   [  --enable-mad            libmad module (default disabled)])
-if test "x${enable_mad}" = "xyes"
+if test "x${enable_mad}" != "xno"
 then
   AC_ARG_WITH(mad,
     [    --with-mad=PATH       path to libmad],[],[])
@@ -1696,10 +1696,7 @@ then
         LDFLAGS_a52tofloat32="${LDFLAGS_test} -la52 ${LDFLAGS_a52tofloat32}"
         CPPFLAGS_a52tofloat32="${CPPFLAGS_a52tofloat32} ${CPPFLAGS_test}"
       ],[
-        if test "x${enable_dvbpsi}" != "x"
-        then
-          AC_MSG_ERROR([Could not find a52 on your system: you may get it from http://liba52.sf.net])
-        fi
+        AC_MSG_ERROR([Could not find a52 on your system: you may get it from http://liba52.sf.net/. Alternatively you can use --disable-a52 to disable the a52 plugin.])
       ])
     ])
     CPPFLAGS="${CPPFLAGS_save}"