live555: add pkg-config support (fixes #7915)

configure.ac

@@ -1598,6 +1598,13 @@ AC_ARG_ENABLE(live555,
     [enable RTSP input through live555 (default enabled)])])
 
 AS_IF([test "${enable_live555}" != "no" -a -n "${CXX}"], [
+  PKG_CHECK_MODULES(LIVE555, live555, [
+    VLC_ADD_PLUGIN([live555])
+    VLC_ADD_CXXFLAGS([live555], [$LIVE555_CFLAGS])
+    VLC_ADD_LIBS([live555],[$LIVE555_LIBS])
+  ], [
+    AC_MSG_WARN([${LIVE555_PKG_ERRORS}.])
+
     AC_LANG_PUSH(C++)
     VLC_SAVE_FLAGS
 
@@ -1605,7 +1612,7 @@ AS_IF([test "${enable_live555}" != "no" -a -n "${CXX}"], [
     AS_IF([test -f "${CONTRIB_DIR}/include/UsageEnvironment.hh"], [
       CPPFLAGS_live555="-I${CONTRIB_DIR}/include/liveMedia -I${CONTRIB_DIR}/include/groupsock -I${CONTRIB_DIR}/include/BasicUsageEnvironment -I${CONTRIB_DIR}/include/UsageEnvironment"
     ], [
-    AS_IF([test ${SYS} != "os2"], [
+      AS_IF([test "${SYS}" != "os2"], [
         LIVE555_PREFIX=${LIVE555_PREFIX-"/usr"}
         CPPFLAGS_live555="-I${LIVE555_PREFIX}/include/liveMedia -I${LIVE555_PREFIX}/include/groupsock -I${LIVE555_PREFIX}/include/BasicUsageEnvironment -I${LIVE555_PREFIX}/include/UsageEnvironment"
       ], [
@@ -1637,7 +1644,7 @@ AS_IF([test "${enable_live555}" != "no" -a -n "${CXX}"], [
     ])
 
     AS_IF([test "$ac_cv_live555" = "no"], [
-    AC_MSG_WARN([liveMedia is missing or its installed version is too old:
+      AC_MSG_WARN([live555 is missing or its installed version is too old:
 Version 2011.12.23 or later is required to proceed.
 You can get an updated one from http://www.live555.com/liveMedia .])
       AS_IF([test -n "${enable_live555}"], [
@@ -1662,10 +1669,12 @@ You can get an updated one from http://www.live555.com/liveMedia .])
         AC_CHECK_LIB(liveMedia, main, [
           VLC_ADD_PLUGIN([live555])
           VLC_ADD_LIBS([live555], [-lliveMedia ${other_libs}])
-      ],[],[${other_libs}])],[${other_libs_pic}])
+        ],[],[${other_libs}])
+      ],[${other_libs_pic}])
     ])
     VLC_RESTORE_FLAGS
     AC_LANG_POP(C++)
+  ])
 ])
 
 dnl