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rosbag playback speed [closed]

asked 2012-11-13 22:00:33 -0500

ChickenSoup gravatar image

updated 2016-05-17 02:40:15 -0500

Hi all,

We have some sensor data that are saved as .csv files (data+timestamp) from a robot, which does not run ROS. To run some algorithms, I converted once such file into a ROS bag file using a python script.

After setting the /use_sim_time parameter and when playback this bag file with rosbag play --clock abc.bag, all the data seems to be flushed at once.

I need to know what determines the natural play speed of a bag file. I thought it is done using the header.stamp

Thank you in advance

CS

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Closed for the following reason the question is answered, right answer was accepted by Martin Günther
close date 2016-05-17 03:26:40.305996

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answered 2012-11-13 22:10:26 -0500

Lorenz gravatar image

In your Python script, I guess you were using Bag.write. Did you specify the t parameter and set it to the correct time stamp? As far as I know, that's the parameter that controls playback speed.

The system cannot use header.stamp for a simple reason: not every message has a stamp but rosbag needs time information. Also, the C++ rosbag library uses the raw (serialized) message data blobs to store them in the file. There is just no way to access the header without knowing the exact message definition.

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Thank you very much. Yeah it was the 't' paramater.

ChickenSoup gravatar image ChickenSoup  ( 2012-11-13 22:31:25 -0500 )edit

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Asked: 2012-11-13 22:00:33 -0500

Seen: 801 times

Last updated: May 17 '16