Requirements

Install the Genlock app

During the training

After the training


One of the main challenges of merging data streams with videos is to get a precise synchronization between the data and the video. In some cases, it is possible to link a data point to a precise event in the video (e.g. a swimmer diving at the start of the 100m freestyle). However, in many other situations there is no obvious event on the video and the data stream that you can use as synchronization point. Think about long distance running or cycling for instance, where you may get a data stream of 1+ hour and you want to synchonize it with a 5 minutes video that happens in the middle of the route.


Dartfish implemented a way to synchronize video and data at any point with a precision of more than 1/10th of a second. At the end of each video, the coach films a QR Code. Dartfish software can extract the exact time from this QR Code and synchronize it with the time of the data stream



Requirements

  • myDartfish Pro or myDartfish Pro S
  • Genlock Android app
  • Android phone
  • CSV data stream from a sensor meeting the specific format (see below)


Install the Genlock app


During the training

  • Set up the sensor as usual
  • Place the mobile device next to you and start Genlock
  • Capture the video with your camera
  • Film the QR Code for 5s and stop the recording. Make sure the image is not blurry and the camera is stable whn capturing the QR code

After the training

  • Open the csv file from the sensor and make sure that the following points are valild
    • The first column is the time
    • Time format is YYYYMMDDHHMMSSCCC (example: 20190116T121955700)
    • Column delimiter is ","
  • Launch Dartfish software
  • Go to Edit and add the video to the montage
  • Import the data stream from the csv file
  • Pause the video when the QR Code is visible
Tip: for an ideal synchronization, make sure to pause the video with 1-2s of QR Code visible before and after the playhead


  • Click on Detect Synchronization

  • Tick QR-Code detection and click on Detect Synchronization
  • Close the window and click on Reset Synchronization

The data stream is now accurately synchronized to the video