ROS start SVO recording

Software ROS1
1

Hello, I’m quite new to Stereolabs and ROS.
So I have a basic question, how do I start a SVO recording when I run roslaunch zed_wrapper zed2i.launch in the first terminal?
And is it possible to start two recordings at the same time, because I have two ZEDs running parallel using the multicam example?

2

Hi @gpodann
you can start the SVO recoding by calling the start_svo_recording service:
https://www.stereolabs.com/docs/ros/zed-node/#services
You can start it by command line or by using the Service Caller plugin of the rqt GUI tool.

3

Thanks for the link.
But what is the exact command line command to start it. I tried start_svo_recording and rosservice start_svo_recording but it didn’t work…

4

You can get the list of services with
$ rosservice list
then you can get the service info with
$ rosservice info /zed2i/zed_node/start_svo_recording
you can see that the only argument is the ROS filename, that must be an ABSOLUTE path name.

$ rosservice call /zed2i/zed_node/start_svo_recording "test.svo"

1 Like
5

Hello!

Is it possible to record to the svo file only particular topics while using a ROS wrapper?

Or the solution is to convert svo to bag and extract desirable topics?

6

The SVO does not know what’s ROS.
The SVO is a file containing the RAW data stream from a ZED camera and it is used to “simulate” a connected device by opening it with the ZED SDK.
The ZED SDK uses the data provided by the SVO file in the same way it uses the data provided by a real connected camera.
When you set the SVO as an input for the ZED Wrapper, you start a ROS node that performs the same elaboration performed with a live camera, so you can choose which topic will be published simply by subscribing to it, in the same way, you do with a connected ZED.