GStreamer Camera Feed with ROS 2 (Humble)

This repository provides a high-performance ROS 2 package for streaming USB camera feeds using GStreamer and OpenCV. It features hardware-aware pipelines for both x86 (amd64) and NVIDIA Jetson platforms, along with dynamic configuration services.

Key Features

• Hardware-Optimized Pipelines: Specific GStreamer strings for Jetson (v4l2src with jpegdec) and amd64 (decodebin) architectures.
• Dynamic Control: Change resolution and framerate at runtime via ROS 2 services without restarting nodes.
• Persistant Mapping: Includes utilities to map USB serial IDs to device paths, ensuring the correct camera is used even if /dev/videoX indices change.
• Built-in Filtering: Includes a "daylight" filter to enhance image warmth.
• Transport Support: Fully compatible with image_transport for compressed image streams.

Dependencies

Ensure you have the following installed on your system:

• ROS 2 Compressed Image Transport:

  sudo apt install ros-humble-compressed-image-transport

• System Libraries:

  sudo apt install libsystemd-dev

• OpenCV 4.x (typically included with ROS 2 Humble desktop installations).

Installation

1. Clone this repository into your ROS 2 workspace:

   cd ~/ros2_ws/src
   git clone <repository_url>

2. Build the workspace (ensure custom_interfaces is built first):

   cd ~/ros2_ws
   colcon build --packages-select custom_interfaces camera_streamer
   source install/setup.bash

Usage

1. Identify Your Camera Run the utility script to find the serial ID for your USB camera:

bash utils/find_devpath.bash

2. Configure the Encoder Edit camera_streamer/launch/encoder.launch.py:

• Set HOST_MACHINE to "amd64" or "jetson".
• Update the CameraEncoder object with your camera's name and the Serial ID found in the previous step. 3. Launch the Nodes On the Host (Camera Side):

ros2 launch camera_streamer encoder.launch.py

On the Target (Viewer Side):

ros2 launch camera_streamer decoder.launch.py

ROS 2 Interfaces

Services

• Toggle Camera (/<camera_name>/toggle_camera): Starts or stops the video capture.
• Set Encoder Config (/<camera_name>/set_encoder_config): Dynamically updates image_width, image_height, and frame_rate. Parameters
• camera_cap_width / camera_cap_height: The raw resolution captured from the hardware.
• image_send_width / image_send_height: The resolution after resizing, sent over the network.
• jpeg_quality: Compression level (1-100) for the compressed transport.

Package Structure

• camera_streamer: Contains the core encoder, decoder, and viewer nodes.
• custom_interfaces: Defines the SetEncoderConfig service.
• utils: Helper scripts for hardware identification.