Read info about source from source/flow_def

CMakeLists.txt

@@ -77,7 +77,7 @@ FetchContent_MakeAvailable(json)
 find_package(PkgConfig REQUIRED)
 
 # Check for FFmpeg components
-pkg_check_modules(FFMPEG REQUIRED
+pkg_check_modules(FFMPEG REQUIRED IMPORTED_TARGET
     libavformat
     libavcodec
     libswscale
@@ -85,10 +85,9 @@ pkg_check_modules(FFMPEG REQUIRED
     libswresample
 )
 
-# Create an interface library for FFmpeg
+# Wrap in a named alias so nodes just link against "ffmpeg"
 add_library(ffmpeg INTERFACE)
-target_include_directories(ffmpeg INTERFACE ${FFMPEG_INCLUDE_DIRS})
-target_link_libraries(ffmpeg INTERFACE ${FFMPEG_LIBRARIES})
+target_link_libraries(ffmpeg INTERFACE PkgConfig::FFMPEG)
 
 # ── Shared utilities (Signal.hpp, NodeBase.hpp, FlowDef.hpp, V210.hpp) ───────
 add_library(dmf-shared INTERFACE)