split

split

split a long rosbag into several section

Use case

Say you have a long rosbag that contains several runs of your robot. You may want to separate the rosbag into several files and process each of them individually.

Usage

split can be used both as a command line application and in Python code.

Command line

A basic use of split is to simply call it from the command line.

rosbag-tools split path/to/rosbag -o /path/to/clip -t "[timestamp1, timestamp2]"

Here are all the CLI options of rosbag-tools split:

$ rosbag-tools split -h
Usage: rosbag-tools split [OPTIONS] INBAG

  Split out an INBAG

  INBAG is the path to a rosbag file Can be a bag in ROS 1 or in ROS 2

Options:
  -o, --output, --outbag TEXT  Basename of the split bag files. Defaults to
                               INBAG_COUNT
  -t, --timestamps TEXT        List of timestamps in the format '[S., S.]', in
                               elapsed seconds since the start of the rosbag
  --timestamps-file PATH       Path to a file containing timestamps
                               representing elapsed seconds since the start of
                               the rosbag. Each timestamp is on an individual
                               line.
  -f, --force-overwriting      Force output file overwriting
  --msg, --msg-path PATH       Custom messages path. Can be a path to a ROS
                               workspace.
  -h, --help                   Show this message and exit.

Python Code API

You can also call rosbag-tools split directly into your Python code :

from rosbag_tools.split import BagSplitter

data_path = "path/to/a/rosbag.bag"  # ROS 1
data_path = "path/to/a/rosbag"  # ROS 2
splitter = BagSplitter(data_path)

# Change the input bag
splitter.inbag = "path/to/another/rosbag"

# Split the bagfile at 42 seconds
splitter.split_rosbag(timestamps=[42.0], outbag_path="path/to/clip")

# Save 3 bagfiles
splitter.split_rosbag(timestamps=[10.0, 42.0], outbag_path="/clip/out/first/25/seconds")