mcap_ros1.reader module provides high-level ROS1 message reading
capability. For more low-level control, consider using the underlying
mcap.reader.McapReader objects directly.
- class mcap_ros1.reader.McapROS1Message(ros_msg: Any, message: Message, channel: Channel, schema: Schema)[source]¶
Contains a single ROS message and associated metadata.
ros_msg – the decoded ROS1 message.
sequence_count – the message sequence count if included in the MCAP, or 0 otherwise.
topic – the topic that the message was published on.
channel_metadata – the metadata associated with this ROS1 topic, if any.
log_time_ns – the time this message was logged by the recorder, as a POSIX nanosecond timestamp.
log_time_ns – the time this message was published, as a POSIX nanosecond timestamp.
- channel_metadata: Dict[str, str]¶
- property log_time: datetime¶
The timestamp representing when this message was logged by the recorder.
- log_time_ns: int¶
- property publish_time: datetime¶
The timestamp representing when this message was published.
- publish_time_ns: int¶
- ros_msg: Any¶
- sequence_count: int¶
- topic: str¶
- mcap_ros1.reader.read_ros1_messages(source: str | bytes | PathLike[str] | McapReader | IO[bytes], topics: Iterable[str] | None = None, start_time: int | datetime | None = None, end_time: int | datetime | None = None, log_time_order: bool = True, reverse: bool = False) Iterator[McapROS1Message] [source]¶
High-level generator that reads ROS1 messages from an MCAP file.
source – some source of MCAP file data. Supply a stream of bytes, an McapReader instance, or the path to a valid MCAP file in the filesystem.
topics – an optional list of topics to read from the MCAP file.
start_time – if not None, messages logged before this time will not be included.
end_time – if not None, messages logged at this timestamp or after will not be included.
log_time_order – if True, messages will be yielded in ascending log time order. If False, messages will be yielded in the order they appear in the MCAP file.
reverse – if both
reverseare True, messages will be yielded in descending log time order.
an McapROS1Message instance for each ROS1 message in the MCAP file.
this generator assumes the source MCAP conforms to the ros1 MCAP profile. If you need to decode ROS1 messages from a file containing other encodings, use the
mcap.reader.McapReader.iter_messages()function to iterate through Message records in your MCAP, and decode the ROS1 messages with the