mcap_ros2.writer module

exception mcap_ros2.writer.McapROS2WriteError[source]

Bases: McapError

Raised if a ROS2 message cannot be encoded to CDR with a given schema.

class mcap_ros2.writer.Writer(output: str | IO[Any] | BufferedWriter, chunk_size: int = 1048576, compression: CompressionType = CompressionType.ZSTD, enable_crcs: bool = True)[source]

Bases: object

finish()[source]

Finishes writing to the MCAP stream. This must be called before the stream is closed.

register_msgdef(datatype: str, msgdef_text: str) → Schema[source]

Write a Schema record for a ROS2 message definition.

write_message(topic: str, schema: Schema, message: Any, log_time: int | None = None, publish_time: int | None = None, sequence: int = 0)[source]

Write a ROS2 Message record, automatically registering a channel as needed.

Parameters:

  • topic – The topic of the message.

  • message – The message to write.

  • log_time – The time at which the message was logged as a nanosecond UNIX timestamp. Will default to the current time if not specified.

  • publish_time – The time at which the message was published as a nanosecond UNIX timestamp. Will default to log_time if not specified.

  • sequence – An optional sequence number.