Motion data (.tsv)

The motion data file contains the data of the trajectories of the motion capture and it has two parts: file header and data. It can contain either 2D or 3D data depending on the settings on the TSV export page in the Project options dialog.

Header

The header is included when the Include TSV header option is checked in the TSV export settings.

In the file header, the variable names are written as one word (without any embedded spaces) followed by a tab character and the variable value as a second word. Each variable is on a new line. The following variables are available in the file header:

  • FILE_VERSION
    Version number of export format, currently 2.0.0.

    FILE_VERSION is not included for versions earlier than 2.0.0.

  • NO_OF_FRAMES
    Total number of frames in the exported file.

  • NO_OF_CAMERAS
    Number of cameras used in the motion capture.

  • NO_OF_MARKERS
    Total number of trajectories (markers) in the exported file.

    Only included in 3D data export.

  • FREQUENCY
    Measurement frequency used in the motion capture.

    When using external timebase the frequency is set to the actual frequency for the Multiplier/Divisor mode and to EXT for the Edge triggered mode.

  • DESCRIPTION
    At present not in use by QTM.

    Only included in 3D data export.

  • TIME_STAMP
    Date and time when the motion capture was made. The date and time is followed by a tab character and then the timestamp in seconds and ticks from when the computer was started.

    The time stamp is recalculated when trimming the file.

    The time stamps indicate the start of the capture according to the QTM software. The time stamps may not exactly correspond to the first frame of the capture and it is discouraged to use them for synchronization with data from other devices connected to the same or another synchronized computer.

  • DATA_INCLUDED
    Type of data included in the file, i.e. 2D or 3D.

  • EVENT
    Each event is added on a new row starting with word EVENT. Then followed by the name of the event, frame number and time, each separated by a tab character.

    The events are only added if Include events are active for the TSV export settings.

  • MARKER_NAMES
    List of trajectory labels (trajectories in the Labeled trajectories window) separated by tab characters. Unidentified trajectories have no names and are therefore only represented by a tab character. The number of names in the list corresponds to the value given by the NO_OF_MARKERS variable.

    Only included in 3D data export.

  • TRAJECTORY_TYPES
    List of trajectory type for each exported trajectory separated by tab characters. The list is sorted in the same order as the MARKER_NAMES. The available types are Measured, Mixed, Virtual, Gap-filled and - (empty label).

Data

In 3D export the data part follows on a new line after the last marker name. The trajectory data (in mm) is then stored in tab-separated columns, where every row represents one frame. Each trajectory has one column for each direction (X, Y and Z). The data for the first marker is therefore stored in the first three columns and data for the second marker is stored in column 4, 5 and 6 etc.

In 2D export the data part follows on a new line after the variable DATA_INCLUDED. The data part starts with a row with the number of the cameras. The marker data for each camera is then given below its corresponding heading, e.g. Camera: 1. Every marker has four columns with data, which is the same as that shown in the Data info window: x, y, xSize and ySize. Each row in the marker data represents one frame and it is just the markers that are visible in that frame that are included. The order of the markers can therefore not be used to identify the markers.

By default the 2D data in the TSV export is linearized in contrast to that in the Data info window. Therefore the 2D data will differ between the two. You can change to raw unlinearized data by disabling the Export linearized 2D data option.

There are three options in the TSV export which you can use to add more information to the file.

  • When the Export time data for every frame option is checked, two columns will be added containing time data. The first column contains the frame number and the second contains the time in seconds relative to the start of the capture. If the camera frames contain timestamps (SMPTE or IRIG), a third column with timestamp data is added. The format of the timestamp string depends on the type of timestamp used.

  • When the Write column header option is checked, a header is added above each column describing the contents of that column.

  • When the Include type information per frame option is checked, a column is added for each trajectory with the trajectory type per frame.