It's been a while since I had a working interest in SEO, and even if (when?) I get back into that line of creativity, I don't think I'd be bothered. As far as I'm concerned, Google has broken SEO forever by trying too hard to feed users results that they think they want, based on what they already have and where they are ... which might not be where they actually are! As a user of Google, I know that these days I have to effectively tell it what results I want, otherwise I'll get a pagefull of links to C&P web scrapers, pinterest and Amazon.
Well, it depends on what traffic you want. It not clear from your post whether you're asking just about using video clips as part of an SEO strategy for any web-page, or whether you're specifically interested in driving traffic to a video presentation or a web-page associated with a video for sale (or other direct commercial intent).
In the case of promotional video clips, that's really a job for the social media manager, not the creative team that actually scripts and shoots the video. If it's the video itself that you're trying to get seen, then SEO is more or less irrelevant because the best you can achieve is to piggy-back onto an undefined user's random choice of search terms and hope a fraction of them click through. That's incredibly inefficient when you have the option of going directly to your target audience on various social media platforms, and leveraging those users to raise your profile.
I am not exactly sure what on-page video has to do with social media...
To be clear, I am not talking about YouTube or Facebook video. I am wondering if people are using video-specific SEO tactics, not traditional SEO, to drive traffic via rich snippets on SERPs, and if so, what seems to be working and what doesn't.