15 - LabSat 2 Video Syncronisation
A unique feature of LabSat is the ability to synchronise RF data recording with video from the optional Racelogic Video VBOX GPS data logger. To record video, the Racelogic Video VBOX is simply placed in the test vehicle at the same time as LabSat. The Video VBOX contains its own high performance GPS engine for time stamping the video so that the RF data can be synchronised with the video when replayed on the bench. Not only is the video perfectly synchronised, but GPS data can be graphically superimposed on the image during recording.
Synchronous replay is made possible because LabSat contains an internal GPS engine which is connected to its RF output channel. Therefore, during a replay, this GPS engine tracks satellites contained in the original recording, with the time-stamp from this GPS engine sent over the mini usb connection to a PC. The PC automatically synchronises the video with the UTC time embedded in the Video data. A range of Video VBOX products is available from Racelogic, all of which will enable the recording of GPS time stamped video.
|RLVD10P2P||Video VBOX Pro 10Hz with 2 cameras|
|RLVD10P4P||Video VBOX Pro 10Hz with 4 cameras|
|RLVBVD10LT1||Video VBOX Lite – 1 camera option|
|RLVBVD10LT2||Video VBOX Lite – 2 camera option|
Recording video using a Racelogic Video VBOX
To use the video synchronization feature, put the Video VBOX and the LabSat into the test vehicle at the same time. The Video VBOX should be set to ‘Log all of the time’ by pressing the front panel button after it has booted. Please refer to the Video VBOX manual, for full details on how to set up your Racelogic Video VBOX. To record GPS data on the LabSat, please refer to the earlier section: Recording GPS Data with LabSat. The Video VBOX is now recording the video, and the LabSat is recording the GPS data.
A new video (AVI) and data (VBO) file are created in a ‘media’ folder on the SD card or USB device every time the vehicle begins to move or the ‘REC’ button is pressed.
The current files are closed when the vehicle comes to a stop or the ‘REC’ button is pressed again. The filename format is as follows: VBOX####.VBO, and VBOX####.AVI, where #### represents an incrementing number. Both files are required to play back the recorded video, synchronised to the Labsat GPS data.
Replaying synchronised video using a Racelogic Video VBOX
In order to replay the Video synchronised to the LabSat playback, Racelogic provides free video synchronisation files to demonstrate this feature. The Video Sync application is included in the software supplied with the LabSat. No installation is required and it can easily be demonstrated using the files included in the LabSat Hard Disk Drive (HDD). The files are included in the Video Synchronisation folder.
To start playing back video, synchronised with the LabSat 2 GPS RF playback, connect the PC’s USB port to the LabSat using the mini USB cable to the GPS monitor on the LabSat 2.
To replay a LabSat scenario, synchronised with video playback, you must first make sure that the VBOX####.VBO, and VBOX####.AVI are in the same folder. The LabSat scenario file #####.ls2 can be located in any location
To run the Video VBOX synchronisation demonstration:
- First start the LabSat software and ensure that the GPS monitor function is enabled and the Video Sync is ticked in the Settings menu. Click the Replay button and select the LabSat 2 scenario that was recorded at the same time as the Video VBOX file. This file is located on the LabSat HDD in the Video Synchronisation folder called vidSync3.ls2.
- Click the dropdown menu Video Sync, and locate the Video VBOX file called VBOX0003.vbo (This ###.vbo file file must be located in the same folder as the ###.avi file). Wait for the file to load.
- Click the Play button and both the LabSat 2 scenario file and the Video VBOX file will play together in synchronisation.
- Cold start the device under test (DUT).
- The files have a four minute stationary period to allow for DUT to acquire the RF signals and start navigating.
- The Video will show the vehicle driving off and the speed display in the GPS Monitor will show the speed increasing.
- You can click the video screen in the software to maximise to the computer screen size. Click escape to return to normal size display.
- Both files can be stopped by clicking the Stop button.
See this article on for more information on replaying Video and GPS data.
Because the Video VBOX is also a GPS data-logger with CAN Bus connectivity, it is possible to record many other signals at the same time, and overlay these on the video, producing a very powerful test environment. All overlaid graphics are user-customisable. The LabSat video synchronisation example playing into a DUT is shown below.