LogPlayer
[Utilities, C++, Linux]

Replays logged data. More...

Replays logged data.

Provides

• orca_interface_camera [LogPlayer.Provides.CameraX]
• orca_interface_gps [LogPlayer.Provides.GpsX]
• orca_interface_home
• orca_interface_laserscanner2d [LogPlayer.Provides.LaserX]
• orca_interface_odometry2d [Logger.Provides.Odometry2dX]
• orca_interface_odometry3d [Logger.Provides.Odometry3dX]
• orca_interface_status
• orca_interface_tracer

Requires

• none

Operation

This component plays back logged data: either recorded by the Orca LogRecorder or other non-Orca loggers (see Logfile format for an explanation). It sets up provided interfaces to which components can hook up to. Data can be accessed by remote calls (such as getData(), getConfig()). Data is also "pushed" to IceStorm, so components can directly subscribe to the interfaces.

Note that no provided interfaces need to be specified in the .cfg file, because all interface information is contained in the master file.

The LogPLayer can be extended by adding dynamically-loaded plug-in replayers. See LogPlayer.Config.FactoryLibNames.

Logfile format

The standard way to replay data is to use data logged by the Orca LogRecorder. It generates a human-readable master file containing a header that specifies subfiles with the actual data. The master file body contains timestamps and references to the subfiles. See LogRecorder for a detailed description of the logfile format.

The subfiles can be encoded in different formats using the Orca LogRecorder (eg. {'ice','ascii','asciigenerated'}). Not all interfaces support replaying in all possible formats. To distinguish between the different encoding types, the master file header contains a field called encoding type.

Configuration

• LogPlayer.Config.FactoryLibNames (string)
  • A space-separated list of libraries containing logreader factories.
  • This list is ordered. Putting a custom library earlier in the list means that it will be used to instantiate logreaders before later factories.
  • default: libOrcaLogFactory.so

• LogPlayer.Config.AutoStart (bool)
  • Start replaying automatically. If AutoStart=0, replay will not commence until the LogPlayer is instructed by the user.
  • Default: 0

• LogPlayer.Config.LogFilename (string)
  • The name of the master file
  • Default: 'master.log'

• LogPlayer.Config.ReplayController (string)
  • The user's interface. Valid values are:
    • "interactive" (default)
      • The user can interactively pause/rewind/etc replay with a text-based menu
    • "continuous"
      • Once replay is started it runs till completion, at which time the component quits.

• LogPlayer.Config.BeginTime (Time)
  • When the component starts the log will be fast-forwarded by BeginTime.
  • Format: DD:HH:MM:SS.uuu
  • Note that none of the values have to be normalized (e.g.<60) and minutes, hours, and days are optional. The following statements are valid and equivalent:
    • 121.250
    • 1:61.250
    • 2:1.250
    • 0:0:2:1.250
  • Default: 0.0 (i.e. start from the begining)

• LogPlayer.Config.ReplayRate (double)
  • Adjusts the playback speed.
  • Valid values: >=0.0
    • 0.0 : waits for user to type ENTER for every data object
    • <1.0 : the logs are replayed slower than real time.
    • 1.0 : real time
    • >1.0 : faster than real time.
  • Default: 1.0

• LogPlayer.Config.RequireAll (bool)
  • If set to 1, will not replay anything unless all interface/format pairs are supported. If set to 0, will replay whatever is possible.
  • Default: 1

An example configuration file is installed into [ORCA-INSTALL-DIR]/share/orca/cfg/ directory.

Authors

• Tobias Kaupp, Alex Brooks, Alexei Makarenko