cmake/FindFFmpeg.cmake: Add sub library's CFLAGS to FFmpeg_CFLAGS.

extras/buildsystem/cmake/include/FindFFmpeg.cmake

@@ -19,6 +19,8 @@ if (NOT FFmpeg_SEARCHED)
         foreach (library ffmpeg avcodec avformat avutil postproc swscale)
             find_library( ${library}_LIBRARY ${library} )
             if (${library}_LIBRARY)
+              pkg_check_modules(${library}_LIBRARY lib${library})
+              set(FFmpeg_CFLAGS "${FFmpeg_CFLAGS} ${${library}_LIBRARY_CFLAGS}")
               set(FFmpeg_LIBRARIES "${library};${FFmpeg_LIBRARIES}")
               set(FFmpeg_FOUND TRUE CACHE INTERNAL "")
             endif (${library}_LIBRARY)
@@ -26,6 +28,8 @@ if (NOT FFmpeg_SEARCHED)
         foreach (library a52 faac lame z png mp3lame twolame)
             find_library( ${library}_LIBRARY ${library} )
             if (${library}_LIBRARY)
+              pkg_check_modules(${library}_LIBRARY lib${library})
+              set(FFmpeg_CFLAGS "${FFmpeg_CFLAGS} ${${library}_LIBRARY_CFLAGS}")
               set(FFmpeg_LIBRARIES "${library};${FFmpeg_LIBRARIES}")
             endif (${library}_LIBRARY)
         endforeach (library)