rosbag-loader

Loader for loading and parsing ROS Bag files using the rosbag package.

!> Note that only lz4 decompression is implemented when reading compressed Rosbags.

!> Note that for the moment RosbagLoader always uses the browser implementation of rosbag.js. See #439

Use

Functions

load

load( url : String, options : ReaderOptions | null = null ) : Map | Array | RosbagReader

Loads and parses the ROS bag file. The promise resolves with the returned data from the parse function.

parse

parse( data : Blob, options : ReaderOptions | null = null ) : Map | Array | RosbagReader

Takes a file handle blob to read and a set of options to read the messages with. If readAllData is false a RosbagReader instance is returned otherwise all frames are read and returned. See the #RosbagReader#read for a description of the returned data.

ReaderOptions

flattenState

flattenState : Boolean = false

If true the hierarchy of objects is flattened into a single object with the flattenDelimiter separating object children.

flattenDelimiter

flattenDelimiter : String = '_'

The character to use to separate nested object names when flattening the object state.

indexTransform

indexTransform : Boolean = true

If true the transform object in the "/tf" and "/tf_static" messages are converted from an array in to an object indexed by child_frame_id:

{
     transforms: [
         { child_frame_id: 'base_link', transform: { ... } },
         { child_frame_id: 'world', transform: { ... } }
     ]
}

// into

{
     transforms: {
         'base_link': { child_frame_id: 'base_link', transform: { ... } },
         'world': { child_frame_id: 'world', transform: { ... } }
     }
}

readAllData

readAllData : Boolean = true

If true the full list of Rosbag data will be returned from the reader in the callback. Otherwise a RosbagReader handle will be returned so data can be read as needed.

normalizeTopicNames

normalizeTopicNames : Boolean = true

If true all topic names are normalized to be prefixed with a / the way roslibjs registers them over websocket. If false some topic name may not be prefixed with slashes.

separateTopicArrays

separateTopicArrays : Boolean = false

If true all topics are broken out into separate arrays of data in a map. Otherwise a single array of data is returned.

RosbagReader

Class for reading data from the rosbag file.

start

start : Number

The start time in ms of the rosbag file.

end

end : Number

The end time in ms of the rosbag file.

messageTypes

messageTypes : Object

A map from topic name to ROS topic message type.

topics

topics : Array<String>

The list of topics available in the given Rosbag.

constructor

constructor( handle : RosbagHandle, options : ReaderOptions ) : void

Takes a handle to the Rosbag.js Bag Instance to read messages from an a set of options to use when reading messages.

read

read( from : Number, to : Number, options : ReaderOptions ) : Promise<Object | Array>

Takes a from time and and to time in milliseconds and returns the set of data between those times. A set of options can be provided to override the set of options originally passed into the reader. Options from rosbag.js cannot be overriden here.

The shape of the returned data depends on the separateTopicArrays. If true then a map of topic name to array of frames of data is returned:

{
     '/tf' : [ ... ],
     '/tf_static' : [ ... ],
     '/markers' : [ ... ],
}

Otherwise an array of frames is returned. A frame consists of a time field in ms and state field which contains the ros topic message contents:

{
     time: number,
     state: {
         //...
     }
}