make camera and pixel format configurable in launch file

launch/camera.launch.py

@@ -1,4 +1,6 @@
+from launch.actions import DeclareLaunchArgument
 from launch.launch_description import LaunchDescription
+from launch.substitutions import LaunchConfiguration
 
 from launch_ros.actions import ComposableNodeContainer
 from launch_ros.descriptions import ComposableNode
@@ -13,6 +15,32 @@ def generate_launch_description() -> LaunchDescription:
         LaunchDescription: the launch description
 
     """
+    # parameters
+    camera_param_name = "camera"
+    camera_param_default = str(0)
+    camera_param = LaunchConfiguration(
+        camera_param_name,
+        default=camera_param_default,
+    )
+    camera_launch_arg = DeclareLaunchArgument(
+        camera_param_name,
+        default_value=camera_param_default,
+        description="camera ID or name"
+    )
+
+    format_param_name = "format"
+    format_param_default = str()
+    format_param = LaunchConfiguration(
+        format_param_name,
+        default=format_param_default,
+    )
+    format_launch_arg = DeclareLaunchArgument(
+        format_param_name,
+        default_value=format_param_default,
+        description="pixel format"
+    )
+
+    # composable nodes in single container
     container = ComposableNodeContainer(
         name='camera_container',
         namespace='',
@@ -23,9 +51,10 @@ def generate_launch_description() -> LaunchDescription:
                 package='camera_ros',
                 plugin='camera::CameraNode',
                 parameters=[{
-                    "camera": 0,
+                    "camera": camera_param,
                     "width": 640,
                     "height": 480,
+                    "format": format_param,
                 }],
                 extra_arguments=[{'use_intra_process_comms': True}],
             ),
@@ -38,4 +67,8 @@ def generate_launch_description() -> LaunchDescription:
         ],
     )
 
-    return LaunchDescription([container])
+    return LaunchDescription([
+        container,
+        camera_launch_arg,
+        format_launch_arg,
+    ])