FreeDV modulator: compilation conditional to codec2 library found

cmake/Modules/FindCodec2.cmake

@@ -0,0 +1,36 @@
+INCLUDE(FindPkgConfig)
+PKG_CHECK_MODULES(PC_CODEC2 "libcodec2")
+
+FIND_PATH(CODEC2_INCLUDE_DIR
+    NAMES codec2/codec2.h
+    HINTS ${PC_CODEC2_INCLUDE_DIR}
+          ${CMAKE_INSTALL_PREFIX}/include
+    PATHS ${CODEC2_DIR}/include
+          /usr/local/include
+          /usr/include
+)
+
+FIND_LIBRARY(CODEC2_LIBRARIES
+    NAMES codec2 libcodec2
+    HINTS ${PC_CODEC2_LIBDIR}
+          ${CMAKE_INSTALL_PREFIX}/lib
+          ${CMAKE_INSTALL_PREFIX}/lib64
+    PATHS ${CODEC2_DIR}/lib
+          ${CODEC2_DIR}/lib64
+          /usr/local/lib
+          /usr/local/lib64
+          /usr/lib
+          /usr/lib64
+)
+
+if(CODEC2_INCLUDE_DIR AND CODEC2_LIBRARIES)
+    set(CODEC2_FOUND TRUE CACHE INTERNAL "CODEC2 found")
+    message(STATUS "Found Codec2: ${CODEC2_INCLUDE_DIR}, ${CODEC2_LIBRARIES}")
+else()
+    set(CODEC2_FOUND FALSE CACHE INTERNAL "CODEC2 found")
+    message(STATUS "Codec2 not found")
+endif()
+
+INCLUDE(FindPackageHandleStandardArgs)
+FIND_PACKAGE_HANDLE_STANDARD_ARGS(CODEC2 DEFAULT_MSG CODEC2_LIBRARIES CODEC2_INCLUDE_DIR)
+MARK_AS_ADVANCED(CODEC2_LIBRARIES CODEC2_INCLUDE_DIR)

plugins/channeltx/CMakeLists.txt

@@ -20,5 +20,7 @@ if (BUILD_DEBIAN)
     add_subdirectory(remotesource)
 endif (BUILD_DEBIAN)
 
-# TODO: add FreeDV stuff only if codec2 library is present
-add_subdirectory(modfreedv)
+find_package(Codec2)
+if (CODEC2_FOUND)
+    add_subdirectory(modfreedv)
+endif(CODEC2_FOUND)