How to Convert ROS 2 Bag to ROS 1 Bag (for Foxglove Compatibility)

Overview

Foxglove does not currently support direct playback of ROS 2 .db3 bag files. To visualize ROS 2 data in Foxglove, you need to convert the ROS 2 bag to a ROS 1 .bag format.

This guide walks through the process of converting a ROS 2 bag file into a ROS 1 compatible format using the rosbags tool, so that it can be played in Foxglove or other ROS 1-based tools.

Prerequisites

Python 3.8+
rosbags Python package
- Install via pip
- pip3 install rosbags

Instructons

Step 1: Prepare the ROS 2 Bag Directory

Create a directory that includes both the ROS 2 .db3 file and the corresponding metadata.yaml file.

Sample `metadata.yaml` Structure

rosbag2_bagfile_information:
  version: 5
  storage_identifier: sqlite3
  duration:
    nanoseconds: 96723832439
  starting_time:
    nanoseconds_since_epoch: 1751276554917484117
  message_count: 4845
  topics_with_message_count:
    - topic_metadata:
        name: /ouster_sensor_center/signal_image
        type: sensor_msgs/msg/Image
        serialization_format: cdr
      message_count: 969
    - topic_metadata:
        name: /ouster_sensor_center/reflec_image
        type: sensor_msgs/msg/Image
        serialization_format: cdr
      message_count: 969
    - topic_metadata:
        name: /ouster_sensor_center/range_image
        type: sensor_msgs/msg/Image
        serialization_format: cdr
      message_count: 969
    - topic_metadata:
        name: /ouster_sensor_center/points
        type: sensor_msgs/msg/PointCloud2
        serialization_format: cdr
      message_count: 969
    - topic_metadata:
        name: /ouster_sensor_center/nearir_image
        type: sensor_msgs/msg/Image
        serialization_format: cdr
      message_count: 969
  compression_format: ""
  compression_mode: ""
  relative_file_paths:
    - rosbag2_2025_06_30-11_42_32_0.db3
  files:
    - path: rosbag2_2025_06_30-11_42_32_0.db3
      starting_time:
        nanoseconds_since_epoch: 1751276554917484117
      duration:
        nanoseconds: 96723832439
      message_count: 484

Step 2: Run rosbag-convert

Use the following command to convert:

rosbag-convert /path/to/directory-containing-db3-and-metadata

This will generate a ROS 1-compatible .bag file that can be used in tools like Foxglove Studio.

Example as below:

Now you can directly use the rosbag in Foxglove to see all the related topics for visualization.