rosbag_timing_inspector

A GUI tool to visualize and analyze message timing from ROS 2 bags (.mcap or .db3).

Built with Dear ImGui + ImPlot. No message deserialization is performed – only timestamps and topic names are read, so it opens even bags with custom or unavailable message types.

Features

• Timeline tab: zoomable 2D scatter plot – X = time, Y = topic lane. Each dot is one message. Pan/zoom with mouse. Toggle per-topic visibility and color. Measure mode: click twice to place two vertical markers and read the delta-T.
• Histograms / Stats tab: per-topic inter-message interval histogram and a statistics table (count, mean, std, min, max in ms).

Dependencies

System packages (Ubuntu / ROS 2 Jazzy):

sudo apt install libglfw3-dev

ROS 2 packages resolved automatically by rosdep:

• rosbag2_cpp
• rosbag2_storage

Storage backend plugins (installed with a typical ROS 2 desktop install):

• rosbag2_storage_mcap — for .mcap bags
• rosbag2_storage_sqlite3 — for .db3 bags

Third-party libraries (imgui, implot, tinyfiledialogs) are fetched automatically by CMake via FetchContent at build time – no manual installation needed.

Build

cd ~/ros2_ws

# Install ROS 2 dependencies
rosdep install --from-paths src/rosbag_timing_inspector --ignore-src -r -y

# Build (release build recommended for large bags)
colcon build --packages-select rosbag_timing_inspector \
             --cmake-args -DCMAKE_BUILD_TYPE=Release

Launch

source ~/ros2_ws/install/setup.bash

# Pass a bag path directly:
rosbag_timing_inspector /path/to/recording.mcap
rosbag_timing_inspector /path/to/recording.db3

# Or open without arguments and use File > Open bag...:
rosbag_timing_inspector

Usage tips

ROS build farm status

Distro	Develop branch	Releases	Stable release
ROS 2 Humble @ u22.04		amd64 arm64
ROS 2 Jazzy @ u24.04		amd64 arm64
ROS 2 Kilted @ u24.04		amd64 arm64
ROS 2 Lyrical @ u26.04		amd64 arm64
ROS 2 Rolling (u26.04)		amd64 arm64

License

MIT – Copyright (C) 2026 Jose Luis Blanco Claraco

Changelog for package rosbag_timing_inspector

1.0.0 (2026-06-10)

• fix: add opengl and libglfw3-dev as build dependencies Required by the ImGui/ImPlot renderer but missing from package.xml, causing ROS build farm failures (CMake could not find OpenGL/GLFW).
• fix: remove storage plugins from package.xml dependencies rosbag2_storage_mcap and rosbag2_storage_sqlite3 are auto-discovered runtime plugins and are not valid rosdep keys, causing build farm failures. They ship with a standard ROS 2 desktop install.
• fix: declare storage plugins as exec_depend, not depend rosbag2_storage_mcap and rosbag2_storage_sqlite3 are runtime-loaded plugins; the code only includes headers from rosbag2_cpp/rosbag2_storage. Using <depend> caused build farm rosdep resolution failures.
• docs: add Humble row to ROS build farm status table
• docs: add ROS build farm status badge table (Jazzy, Kilted, Lyrical, Rolling)
• Replace image in README with updated version Updated image in README with a new source and dimensions.
• Update README with image and features details Added an image to the README and expanded the features section.
• add more visual features
• install exe in bin
• Initial commit
• Contributors: Jose Luis Blanco-Claraco