mcap cat giving error

[MMarcus95]

In GitLab by @ynistico on Aug 30, 2024, 17:15

mcap cat ../mcap_muse/vicon/vicon.mcap --topics name_of_the_topic --json | head -n 10 gives the error:

Error: failed to print messages: JSON output only supported for ros1msg, protobuf, and jsonschema schemas. Found: omgidl

I think this is the same reason why plutjuggler and matlab can't directly convert the mcap.
PlotJuggler is showing the error: There is no parser available for encoding [cdr] nor [omigdl]

[MMarcus95]

In GitLab by @mmarchitto on Sep 6, 2024, 11:35

we could investigate this python library for reading data directly from mcap file
https://mcap.dev/docs/python/

but maybe the encoding format we are using (omgidl) is not supported by this library.

We might need to change the encoding format...

[MMarcus95]

@ylenianistico , is this useful to replay mcap directly in plotjuggler and matlab?

[ylenianistico]

In plotjuggler we can visualize the data but not export it.
This will probably fix it. And the same for MATLAB @MMarcus95

[MMarcus95]

Just to remember. Is the need of using pltjuggler to export the mcap is because it can convert automatically an mcap to a rosbag?

[ylenianistico]

I don't know if Plotjuggler can convert to rosbag, but once we solve the problem of encoding compatibility we will have

• exporting using plotjuggler working
• mcap cat working
• mcap2ros conversion working
• mcaps readable with matlab

[MMarcus95]

Currently asking help here

[Ryan-Red]

See solution here: eProsima/DDS-Record-Replay#171

[Ryan-Red]

Tried to switch to ros2 messages, but unfortunately it bugged out and would only record the topic names and not the actual messages, so the bag was "empty"

[MMarcus95]

closing: migrating to ros2 record tool