Comparing two videos with Protern data

How to do side-by-side video analysis using GPS speed and time data so you can better see the impact of technique, mistakes, or line has on speed.

In this article, we show you how to do the following:


  • RaceRender and Protern RaceRender Files installed - Instructions for Mac and instructions for Windows PC
  • Two videos of the same run you want to compare (they can be different athletes)
  • A quantriq that includes the runs you want to compare


Note: The video includes a pervious version of the web app. To download the section data has not changed however. 

Note: This video was recorded on a Windows PC, but the RaceRender program is identical on a Mac.

Selecting videos

  1. Open RaceRender 3
  2. Select the Protern - Compare project template (Don't see the Protern - Compare template? You may have to copy the Protern RaceRender template files - See the Mac instructions or Windows PC instructions)

  3. Select the videos you want to compare. If the video includes GPS data (some GoPros will record GPS speed data), click "No" to import.

Getting data files from and importing them in RaceRender

  1. To add the data files, you will first need to download the run data on Go to and select the quantriq that includes the run data.

  2. Find the runs that match the video and click on the three dots to the far right of the run and select Download Section Data in the window that pops up. This will download a CSV file for the run. Repeat for the second run.

  3. Back in RaceRender, select Add Data File and find the run data you just downloaded. Make sure to load the correct Protern run data file to the video (e.g. Run 5 video should be run 5 from Repeat the step for the second data file.

Syncing videos

  1. There is a bug in RaceRender that hides the bottom video each time.
    To make the bottom video visible, you will need to right of the RaceRender program where it shows the Display Objects. Scroll to the bottom of that list until you see Bottom Video. Select Bottom Video and press the Move Up button until it is above Blue Dots

  2. To synchronize the videos, click the Side by Side button on the right.

  3. Select one video for Sync Input and another video for Reference Input.

  4. Unlink the videos and move the start of the Reference Input video to the start of the quantriq (where you set the first split). Once the Reference Input video is at the correct spot, do move the Sync Input.

  5. Once the videos are lined up to the start of the quantriq, press the link button to link the two together.

Syncing Protern Data to Video

  1. Once you have synced the two videos, you will need to sync the data files to the video. In the Side by Side window, select one of the videos for the Reference Input and one of the data files for the Sync Input. The data might show the map, or speed data. You can choose your preference under Data Display.

  2. Move the Reference Input video to the start of the quantriq, and unlink the video and data file by pressing the link button.

  3. Now move the data file so that the red dot is at the start of the quantriq, then press the link button.

  4. Now we need to repeat the same step for the other data file. When you go to pick the other data file, you will be asked to save the settings and you may be warned that the input file begins after the start of the project. This means you won't see any data until after the skier crosses the start of the quantriq.

  5. Once the data is synced, press ok.

Getting your video ready for export

Disappearing Data

When you complete the syncing, you may see a video has disappeared along with the data. This is because of the order of syncing. Just press play, or move the video to somewhere in the middle to see the data and two videos together.

  • Normal view for the start of the video

  • Data and video appears when you move the video past the sync point.


Naming the runs

  1. You can edit the run names by double clicking on Athlete 1 Name in the Display Objects.

  2. The Display Object Properties window will come up (it may be hidden behind RaceRender). You can change text in the large window where it says Athlete 1. Press Apply when you are done. 
  3. Repeat for the second run video


Creating the video

Now that the videos are named and synced with data, you can export the video.

  1. Click the Create Video button at top of RaceRender program

  2. Save your project.

  3. The Create Output Video File window lets you pick the size of video you want to make. There are several options in the Output Profile list. Pick the best for you.

  4. Click Start Rendering to make the final video.