GSCam (support for ROS 2 Eloquent Elusor)

This ROS2 package based on GSCam supports the Jetbot Pro robot with ROS 2 Eloquent Elusor, the last possible version for Ubuntu 18.04, officially supported by NVIDIA Jetson Nano 4GB.

GStreamer Library Support

GSCam supports the following versions of ROS2 and GStreamer:

ROS2 version	Ubuntu version	GStreamer version
Eloquent	18.04	1.00

Dependencies

These dependencies will be picked up by rosdep and are required to compile:

• libgstreamer1.0-dev
• libgstreamer-plugins-base1.0-dev

These additional packages are often useful:

• gstreamer1.0-tools
• libgstreamer-plugins-good1.0-dev

Ubuntu install:

sudo apt-get install gstreamer1.0-tools libgstreamer1.0-dev libgstreamer-plugins-base1.0-dev libgstreamer-plugins-good1.0-dev

License

GSCam for ROS2 is licensed under the Apache 2 license.

Note that GStreamer is licensed under the LGPL, and GStreamer plugins have their own license requirements.

API

Nodes

• gscam

Topics

• camera/image_raw
• camera/camera_info

Services

• camera/set_camera_info

Parameters

• camera_name: The name of the camera (corrsponding to the camera info)
• camera_info_url: A url (file://path/to/file, package://pkg_name/path/to/file) to the camera calibration file
• gscam_config: The GStreamer configuration string
• frame_id: The tf2 frame ID
• reopen_on_eof: Re-open the stream if it ends (EOF)
• sync_sink: Synchronize the app sink (sometimes setting this to false can resolve problems with sub-par framerates)
• use_gst_timestamps: Use the GStreamer buffer timestamps for the image message header timestamps (setting this to false results in header timestamps being the time that the image buffer transfer is completed)
• image_encoding: image encoding ("rgb8", "mono8", "yuv422", "jpeg")
• use_sensor_data_qos: The flag to use sensor data qos for camera topic(image, camera_info)

Examples

See example launch files and configs in the examples directory.

These examples have been tested and work well:

• v4l.launch.xml: Standard video4linux cameras like USB webcams
• v4ljpeg.launch.xml: Same as above, but publishes compressed images
• videofile.launch.xml: Opens any videofile readable by GStreamer
• component_pipeline_launch.py: Launch an image pipeline using ROS2 composition