Fix autoconf nuances with AM_CONDITIONAL

configure.ac

@@ -462,20 +462,23 @@ fi
 dnl Ogg Opus handling
 dnl -----------------
 dnl    We want Opus tracks supported by default, and we also want the user
-dnl    to be aware if there's a problem finding the Opus dependencies.
-dnl    If there's a problem, we want the user to either a) install the opus
-dnl    library or b) explicitly disable Opus.
+dnl    to be aware if there's a problem finding the Opus dependencies so
+dnl    they can either a) install the opusfile library or b) explicitly
+dnl    disable Opus.
 
 dnl    To achieve this, we provide a --disable-opus-cdda configure option
 dnl    but by default we look for Opus and fail if we can't find it.
 dnl    We only skip supporting Opus if the user explicitly passes the
 dnl    --disable-opus-cdda argument.
-
-AC_ARG_ENABLE([opus-cdda], AS_HELP_STRING([--disable-opus-cdda],
-            [Disable support for Opus-compressed CD-Audio tracks]))
-AS_IF([test "x$enable_opus_cdda" != "xno"],
-      [PKG_CHECK_MODULES([OPUSFILE], [opusfile], [HAVE_OPUSFILE=1])])
-AM_CONDITIONAL([USE_OPUS], [test "$HAVE_OPUSFILE" == "1"])
+AC_ARG_ENABLE(opus-cdda,
+              AS_HELP_STRING([--disable-opus-cdda],
+                             [Disable Opus CD audio track support]))
+AS_IF([test "x${enable_opus_cdda}" != "xno"],
+      [PKG_CHECK_MODULES([OPUSFILE],
+                         [opusfile],
+                         [LIBS+=" $OPUSFILE_LIBS"])])
+AM_CONDITIONAL([USE_OPUS],
+               [test "x${OPUSFILE_LIBS}" != "x"])
 
 AH_TEMPLATE(C_OPENGL,[Define to 1 to use opengl display output support])
 AC_CHECK_LIB(GL, main, have_gl_lib=yes, have_gl_lib=no , )

src/libs/decoders/Makefile.am

@@ -20,12 +20,6 @@ libdecoders_a_SOURCES = \
 	xxhash.c             \
 	xxhash.h
 
-if USE_OPUS
-	libdecoders_a_SOURCES += opus.c
-	AM_CFLAGS += -DUSE_OPUS $(OPUSFILE_CFLAGS)
-	LDADD += $(OPUSFILE_LIBS)
-endif
-
 libdecoders_a_CXXFLAGS = \
 	$(AM_CXXFLAGS) \
 	$(CXXFLAGS) \
@@ -37,3 +31,8 @@ libdecoders_a_CFLAGS = \
 	$(CFLAGS) \
 	-Wpedantic \
 	-Wall
+
+if USE_OPUS
+libdecoders_a_SOURCES += opus.c
+libdecoders_a_CFLAGS += -DUSE_OPUS $(OPUSFILE_CFLAGS)
+endif