ROS Node Parameters set is success even if there was an error in the value

[edgarcamilocamacho]

Required Info
Camera Model	D435 / D435i
Firmware Version	5.16.0.1
Operating System & Version	Ubuntu 20.04.6 LTS
Kernel Version (Linux Only)	5.10.104-tegra
Platform	NVIDIA Jetson AGX
Librealsense SDK Version	2.56.1
ROS Distro	Humble
RealSense ROS Wrapper Version	4.56.1

Issue Description

I wanted to change the format of the RGB camera and did a typo like:

$ ros2 param set /gary/cameras/nav_bottom rgb_camera.color_format "BRG8"
Set parameter successful

As you can see the node responds that the setting of the parameter was success, but the logs of the camera's node says:

[nav_bottom-5] [ERROR] [1731349854.170183534] [gary.cameras.nav_bottom]: color stream doesn't support BRG8 format. Run 'ros2 param describe <your_node_name> rgb_camera.color_format' to get the list of supported formats. Setting the ROS param 'rgb_camera.color_format' back to: BGR8

If the parameter is not ok and the node itselfs has knowledge about it, it should return FAILED when trying to set the parameter, no?

[MartyG-RealSense]

Hi @edgarcamilocamacho Technically, RealSense cameras (and the librealsense SDK) support the BGR8 color format. However, the RealSense ROS wrapper - which runs on top of librealsense - only provides the streams in one format. For the color stream, that default format is RGB8.

In 2021 a RealSense ROS user at #1670 edited the source code of the ROS wrapper's base_realsense_node.cpp file to change the supported default format for a particular stream type.

[edgarcamilocamacho]

But what I mean is that I made a typo and I didin't write "BGR" but "BRG", that's the point.

[MartyG-RealSense]

Thanks for the clarification. It seems like a problem with ROS2 rather than the RealSense ROS wrapper, as ROS2 allows it to register as successful but the wrapper catches the error.