Distinguishing between "Impression" and "Full Play"

[patrick-here]

Until now I had been hosting my videos on Vimeo. Vimeo offers a way of distinguishing between a visitor who simply gets an "Impression" (ie: just looks at the initial video image) and visitors who play the video in full (or in part, I think). Is there a way for me to do this when self-hosting my videos via video.js. I'm running Apache webserver; the log file gives me a way of seeing visitors who initially download a video but I'm wanting to distinguish them from visitors who actually watch the video. Thanks in advance for the help.