v4l2_camera

A ROS 2 camera driver using Video4Linux2 For Canlab (V4L2).

System Requirements

Requirements:

• CANLAB CLEB-G-Series (GUIDE)
• CANLAB CLV-G-Series (GUIDE)
• CANLAB CLMU-G-Series (GUIDE)
• ROS 2 Foxy

Download Pacakage

If you need to modify the code or ensure you have the latest update you will need to clone this repo then build the package.

$ mkdir -p ~/ros_v4l2_camera/src
$ cd ~/ros_v4l2_camera/src
$ git clone --branch foxy https://github.com/canlab-co/ros_v4l2_camera.git
$ cd ~/ros_v4l2_camera
$ colcon build
$ source ~/ros_v4l2_camera/install/setup.bash

Usage

Publish camera images, using the default parameters:

    # launch the v4l2_camera executable
    CLEB-G-01A : ros2 launch v4l2_camera v4l2_camera_cleb_launch.py
    CLV-G-01A : ros2 launch v4l2_camera v4l2_camera_clv_launch.py
    CLMU-G-01A : ros2 launch v4l2_camera v4l2_camera_clmu_launch.py
    
    # run the executable with default settings:        
    1CH : ros2 run v4l2_camera v4l2_camera_node (default : /dev/video0)

Preview the image (open another terminal):

    ros2 run rqt_image_view rqt_image_view

DDS Configuration

For better image transport performance over DDS, we recommend using FastDDS with Shared Memory Transport enabled. First copy the the fastdds.xml config file to a suitable directory, eg. $HOME/fastdds.xml

cd ~/ros_v4l2_camera
cp fastdds.xml ~/

Next add these two lines to your ~/.bashrc

export RMW_IMPLEMENTATION=rmw_fastrtps_cpp
export FASTRTPS_DEFAULT_PROFILES_FILE=$HOME/fastdds.xml

Make sure to source ~/.bashrc first on all terminals before launching any ROS 2 nodes including the driver.

Nodes

v4l2_camera_node

The v4l2_camera_node interfaces with standard V4L2 devices and publishes images as sensor_msgs/Image messages.

Published Topics

• /image_raw - sensor_msgs/Image

  The image.

Parameters

• video_device - string, default: "/dev/video0"

  The device the camera is on.

• pixel_format - string, default: "UYVY"

  The pixel format to request from the camera. Must be a valid four character 'FOURCC' code supported by V4L2 and by your camera. The node outputs the available formats supported by your camera when started.
  Currently supported: "UYVY"

• output_encoding - string, default: "yuv422"

  The encoding to use for the output image.
  Currently supported: "rgb8", "rgba8", "bgr8", "bgra8", "mono16", "yuv422".
  Defaults to yuv422. Note that encodings other than yuv422 incurs conversion overhead.

• image_size - integer_array, default: [1920, 1080]

  Width and height of the image.

• Camera Control Parameters

  Not Support