MCAP Logger
SUMMARY
MCAPLogger captures every message published on a Zenoh (BabyROS) network into a single .mcap file — with no per-topic configuration. Use it to record robot runs, replay them for debugging, and convert them into training datasets.
Live Feed
rgb
→
imu
→
jts
→
dep
→
MCAP
Logger
Logger
→
Output
run.mcap00:00
rgb
imu
jts
dep
216.0 MB · 18000 msgs
MCAP is an open container format for robotics data — timestamped, multi-channel, seekable, and self-describing. MCAPLogger records the entire network in one call. Reading back is a single generator.
Install
bash
pip install telekinesis-dataengineImport
python
from telekinesis.dataengine import MCAPLoggerCapabilities
| Feature | Description |
|---|---|
| Universal capture | Subscribes to "**" by default — every topic on the Zenoh session, at any rate. |
| No configuration | No per-topic schema registration, no format negotiation. Open it and record. |
| Self-describing output | MCAP embeds channel schemas alongside data — files are readable without the original code. |
| Seekable playback | Read back messages in recording order with a single generator call. |
| Multi-rate support | Handles heterogeneous publish rates — cameras at 30 Hz, IMU at 100 Hz, joints at 5 Hz — in one file. |
Quick Start
python
import babyros
from telekinesis.dataengine import MCAPLogger
# ------------------------------------------------
# 1. Start publishers on the Zenoh network
# ------------------------------------------------
camera_pub = babyros.node.Publisher(topic="camera/rgb")
joint_pub = babyros.node.Publisher(topic="robot/joint_states")
# ------------------------------------------------
# 2. Record everything to an MCAP file
# ------------------------------------------------
with MCAPLogger("results/run.mcap") as logger:
for step in range(100):
camera_pub.publish(frame)
joint_pub.publish(joint_states)
# ------------------------------------------------
# 3. Read back in recording order
# ------------------------------------------------
for topic, obj in MCAPLogger.read("results/run.mcap"):
print(topic, obj)