ROS2-Camera-Streamer

A camera streaming system for ROS 2

Tested using ROS 2 Humble, Ubuntu 22.04, amd64 laptop.
Tested using ROS 2 Humble, Jetson Linux DP 6.0, Jetson AGX Orin.

Prerequisites:

1. Install ROS 2 Compressed Image Transport: sudo apt install ros-humble-compressed-image-transport
2. Make sure Compressed Image Transport is listed: ros2 run image_transport list_transports
3. OpenCV 4.x
4. libsystemd-dev: sudo apt install libsystemd-dev

Usage:

1. Find the serial ID for the USB camera devices using the find_devpath.bash file within the utils/ folder.
2. Set the proper host machine architecture using HOST_MACHINE within encoder.launch.py.
3. Add CameraEncoder objects to the encoder.launch.py file, and give each a camera name and serial ID.
4. Add CameraDecoder objects to the decoder.launch.py file, and specify the camera name.
5. Build the package using colcon build
6. Run ros2 launch camera_streamer encoder.launch.py to start the encoder.
7. Run ros2 launch camera_streamer decoder.launch.py to start the decoder.

Publishers

• Topic: <camera_name>/out, Type: Image, QoS: SensorData; Video feed output.

Services

• Service: <camera_name>/toggle_camera, Type: std_srvs/SetBool; Toggle the camera feed on or off. (Will also release the USB device).
• Service: <camera_name>/set_encoder_config, Type: SetEncoderConfig; Set encoder parameters such as resolution and frame rate.

Extra Features:

• To use the built-in camera viewer, enable ENABLE_WINDOW_VIEW within decoder.launch.py.
• JPEG image compression can be set using the JPEG_COMPRESSION variable within encoder.launch.py.
• Set cameras to auto enable on encoder startup using AUTO_ENABLE_CAMERAS within encoder.launch.py.
• Test encoder services using ros2 launch camera_streamer config_test.launch.py. Make sure the camera name is specified.

Notes:

• Seem to only be able to use two cameras per physical USB controller. May need to update GStreamer API configuration to allocate less memory to the device?
• Other ROS 2 image transports can potentially be used. Would need to change IMAGE_TRANSPORT within decoder.launch.py to the name within ros2 run image_transport list_transports list, and then add the proper ROS 2 parameters for the transport into encoder.launch.py:

// Example from encoder.launch.py for compressed image transport:
{self.camera_name + '.transport.format': 'jpeg'},
{self.camera_name + '.transport.jpeg_quality': self.jpeg_quality}