ROS2 bag mcap Topic Extractor / db3 to mcap converter

Description

This repository contains 2 scripts, an db3_to_mcap converter and mcap_topic_extractor.

Usage

Navigate to the directory where the script is located and run the following command in the terminal. To use the mcap_topic_extractor:

python3 mcap_topic_extractor.py /path/to/input_bag/

To use the db3_to_mcap, run:

python3 db3_to_mcap.py /input/bag/bag.db3 /output/path/ 

Parameters For mcap_topic_extractor

The script uses two parameters you can change in main.py:

• TOPICS_TO_EXTRACT: Desired topics to extract from the bag.
• OUTPUT_PATH: Output path for the new bag.

Dependencies

The script requires the following dependencies:

• argparse
• rclpy
• rosidl_runtime_py
• rosbag2_py

Execution

When executed, the script will read all the messages in the input bag file and create a new bag file with only the desired topics.

Note

This script assumes that the input bag has messages in the CDR serialization format. If the input bag has messages in a different serialization format, please modify the input_serialization_format and output_serialization_format options in the ConverterOptions class.

Sources

https://github.com/foxglove/mcap/blob/main/python/examples/ros2/py_mcap_demo/py_mcap_demo/writer.py https://github.com/foxglove/mcap/blob/main/python/examples/ros2/py_mcap_demo/py_mcap_demo/reader.py