Seyond Decoder Library

A C++ library for converting Seyond LiDAR SeyondScan messages to sensor_msgs/PointCloud2 format.

Overview

This library provides functionality to decode Seyond LiDAR data from the proprietary SeyondScan message format into standard ROS2 PointCloud2 messages. It is designed to be used as a library in other ROS2 packages, particularly for bag file processing and manipulation.

Features

• Converts seyond_lidar_ros::msg::SeyondScan to sensor_msgs::msg::PointCloud2
• Supports both spherical and XYZ point cloud data formats
• Configurable range filtering (min/max range)
• Configurable coordinate system transformation
• Support for intensity/reflectance selection
• Integration with Seyond SDK for hardware-specific optimizations

Dependencies

• ROS2 (Humble or later)
• PCL (Point Cloud Library)
• Eigen3
• seyond_lidar_ros package
• Seyond SDK (included in seyond_lidar_ros)

Building

# In your ROS2 workspace
cd ~/ros2_ws/src
# Clone or copy the seyond_decoder package
colcon build --packages-select seyond_decoder

Usage

As a Library

Include the library in your CMakeLists.txt:

find_package(seyond_decoder REQUIRED)
target_link_libraries(your_target seyond_decoder)

In your C++ code:

#include "seyond_decoder/seyond_decoder.hpp"

// Create decoder with configuration
seyond::DecoderConfig config;
config.max_range = 200.0;
config.min_range = 0.3;
config.frame_id = "lidar";

seyond::SeyondDecoder decoder(config);

// Convert SeyondScan to PointCloud2
auto pointcloud = decoder.convert(seyond_scan_msg);

Example Node

Run the example node that subscribes to SeyondScan and publishes PointCloud2:

ros2 run seyond_decoder seyond_decoder_example \
  --ros-args \
  -p input_topic:=/seyond_scan \
  -p output_topic:=/pointcloud \
  -p max_range:=100.0 \
  -p min_range:=0.5

Bag File Conversion

Use the bag_manipulate_integration example to convert bag files:

ros2 run seyond_decoder bag_manipulate_integration \
  input.mcap output.mcap /seyond_scan /pointcloud

Configuration

The DecoderConfig structure supports the following parameters:

• max_range: Maximum range for points (meters)
• min_range: Minimum range for points (meters)
• coordinate_mode: Coordinate system mode (0=default, 1=flipped-Y, 2=swapped-XY)
• use_reflectance: Use reflectance values for intensity (true/false)
• frame_id: Frame ID for the output point cloud

Integration with bag_manipulate

This library is designed to work seamlessly with the bag_manipulate package. You can extend the BagManipulator class to use this decoder:

#include "seyond_decoder/seyond_decoder.hpp"

class SeyondBagManipulator : public BagManipulator {
  // Use SeyondDecoder to convert messages during bag processing
  seyond::SeyondDecoder decoder_;
  // ... implementation
};

License

Apache License 2.0