Option to write custom time series data in mcap files

[konsgken]

Hi,

I would like to ask you if there is an option to write custom time series data, except from the ones that you provide in nuscenes2mcap repo (e.g. distance from a target vehicle through time) in MCAP files. Is there any defined message for writing custom time series data?

[jtbandes]

You can use any encoding for your custom data (see details of Channel and Schema records in the spec: https://mcap.dev/specification/index.html#channel-op0x04). Common encodings are listed here: https://mcap.dev/specification/appendix.html

[jtbandes]

Maybe one of these? https://docs.ros2.org/galactic/api/std_msgs/index-msg.html

[amacneil]

To be clear, you can create your own ROS 2 message for custom time series data, and you can write any message into an MCAP file.

[konsgken]

Thanks @jtbandes for the information. @amacneil is there a way to visualise (in foxglove studio) and read custom ros2 message definitions from mcap files? If yes, how can I create such a message definition;

[jtbandes]

Would recommend checking out this tutorial: https://docs.ros.org/en/humble/Tutorials/Beginner-Client-Libraries/Custom-ROS2-Interfaces.html

[amacneil]

@konsgken yes they will work in Foxglove Studio. Some panels will work with any message, other panels require a specific message.

https://foxglove.dev/docs/studio/messages/introduction