How Google detects the page is a video page?
I test some pages with a video and markup and detailed sitemap.But I could not see any video result in universal SERP and video SERP.
But I test some another pages but I could see the video result in SERP both in universal SERP and video SERP.
Before asking this question, I completely check out this links and I didn't find anythings about my question clearly.You can just set some markups and sitemap and meta tags to help Google.But its not working every time.
I need some exact factors that Google uses its for understanding the type pf page content(video).