libcamera: Add MediaObject class hierarchy

Add a class hierarcy to represent all media objects a media graph represents.
Add a base MediaObject class, which retains the global unique object id,
and define the derived MediaEntity, MediaLink and MediaPad classes.

This hierarchy will be used by the MediaDevice objects which represents and
handles the media graph.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Jacopo Mondi <jacopo@jmondi.org>

src/libcamera/meson.build

@@ -4,12 +4,14 @@ libcamera_sources = files([
     'device_enumerator.cpp',
     'log.cpp',
     'main.cpp',
+    'media_object.cpp',
     'pipeline_handler.cpp',
 ])
 
 libcamera_headers = files([
     'include/device_enumerator.h',
     'include/log.h',
+    'include/media_object.h',
     'include/pipeline_handler.h',
     'include/utils.h',
 ])