Converting from ROS2 bag file to ROS1 bag file

Good tool for this is the rosags-convert utility.

1. install rosbags package

pip install rosbags

2. Now you can convert the bag. Example:

rosbags-convert /rosbag2_2025_11_05-14_01_53/

This directory should contain metadata,yaml file. For this concrete example, the output should be in the file rosbag2_2025_11_05-14_01_53.bag.

If you are getting error like this:

ERROR: Reading source bag: Rosbag2 version 9 not supported; please report issue.

simply open the /rosbag2_<timestamp>/metadata.yaml file and lower the version number at the beginning of the file.

rosbag2_bagfile_information:
  version: 9

In our case, just lowering it from 9 to 8 helped. This does not feel very correct, but if it works...