fix cmake detection of V4L2 + add -y to apt-get command

CMakeLists.txt

@@ -43,7 +43,7 @@ target_link_libraries (${PROJECT_NAME} ${CMAKE_THREAD_LIBS_INIT})
 find_path(LOG4CPP_INCLUDE_DIR log4cpp/Category.hh)
 if (NOT LOG4CPP_INCLUDE_DIR)
         message(STATUS "Could not find the liblog4cpp5-dev.")
-        EXEC_PROGRAM("sudo apt-get install liblog4cpp5-dev")
+        EXEC_PROGRAM("sudo apt-get install -y liblog4cpp5-dev")
         find_path(V4L2_INCLUDE_DIR log4cpp/Category.hh)
 endif (NOT LOG4CPP_INCLUDE_DIR)
 include_directories(${LOG4CPP_INCLUDE_DIR}) 
@@ -52,22 +52,22 @@ find_library(LOG4CPP_LIBRARY log4cpp)
 target_link_libraries(${PROJECT_NAME} "${LOG4CPP_LIBRARY}")
 
 # V4L2
-find_path(V4L2_INCLUDE_DIR libv4l2.h)
-if (NOT V4L2_INCLUDE_DIR)
-	message(STATUS "Could not find the libv4l-dev.")
-	EXEC_PROGRAM("sudo apt-get install libv4l-dev")
-	find_path(V4L2_INCLUDE_DIR libv4l2.h)
-endif (NOT V4L2_INCLUDE_DIR)
-include_directories(${V4L2_INCLUDE_DIR}) 
+find_path(LIBV4L2_INCLUDE_DIR libv4l2.h)
+if (NOT LIBV4L2_INCLUDE_DIR)
+	message(STATUS "Could not find package V4L2. Try to install it")
+	EXEC_PROGRAM("sudo apt-get install -y libv4l-dev")
+	find_path(LIBV4L2_INCLUDE_DIR libv4l2.h)
+endif (NOT LIBV4L2_INCLUDE_DIR)
+include_directories(${LIBV4L2_INCLUDE_DIR}) 
 
-find_library(V4L2_LIBRARY v4l2)
-target_link_libraries(${PROJECT_NAME} "${V4L2_LIBRARY}")
+find_library(LIBV4L2_LIBRARY v4l2)
+target_link_libraries(${PROJECT_NAME} "${LIBV4L2_LIBRARY}")
 
 # live555
 find_path(LIBLIVE555_INCLUDE_DIR liveMedia/liveMedia.hh)
 if (NOT LIBLIVE555_INCLUDE_DIR)
         message(STATUS "Could not find the liblivemedia-dev")
-        EXEC_PROGRAM("sudo apt-get install liblivemedia-dev")
+        EXEC_PROGRAM("sudo apt-get install -y liblivemedia-dev")
         find_path(LIBLIVE555_INCLUDE_DIR liveMedia/liveMedia.hh)
 endif (NOT LIBLIVE555_INCLUDE_DIR)
 foreach (LIBLIVE555_module groupsock liveMedia UsageEnvironment BasicUsageEnvironment)