Yes, you can analyse videos from your PC with the Toolkit. Go to Input tab and select the video file you want to use under the Video File option. You can check the Loop video checkbox if you want it to keep rolling. Double check if Show Visualisation checkbox is checked (by default).
If your video file has low-resolution go to Input Settings and use Scale to improve the accuracy. If your video file has very high resolution (4K or 2K) image scaling is not advised as this can influence the speed of the analysis.