What sitemap format should be used for a video platform site like YouTube?
I want to submit our video site's sitemap to Google search.
Note how the sitemap points to the "yt" subdirectory. That subdirectory is a gateway to other YouTube sites like "YouTube for Developers" and "YouTube Advertise" (which has its own unstyled sitemap). They don't even bother listing the regular website that is so popular and so widely shared. Honestly, unless there is a larger strategy involved here, the sitemap seems a tad random. Maybe they haven't maintained it in a while.
An XML Sitemap does not mean that everything in it will definitely be indexed (this is up to the search engines). Nor does it mean that whatever's not in there will not be indexed. It is a suggestion for search engines to pay specific attention to certain folders and files.
Based on the above, if you create an XML Sitemap, place it at the root (or near the root, in an accessible folder), and list your most important pages (home page, category pages, etc.) the search engines will follow that and index the contents of those folders (like individual videos, posts, etc.). Just make sure those contents aren't noindexed/nofollowed elsewhere in your settings, and the XML Sitemap (or multiple ones, depending on your structure and strategy) should suffice.
Google has an extension to the Sitemap protocol called the Google Video Sitemap. This is the kind of sitemap you will want to use for a video site.
Read more about Google Video Sitemaps on Google Search Console Help.
Here is the sitemap example they use, which includes all the metadata about each video:
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9" xmlns:video="http://www.google.com/schemas/sitemap-video/1.1"> <url> <loc>http://www.example.com/videos/some_video_landing_page.html</loc> <video:video> <video:thumbnail_loc>http://www.example.com/thumbs/123.jpg</video:thumbnail_loc> <video:title>Grilling steaks for summer</video:title> <video:description>Alkis shows you how to get perfectly done steaks every time</video:description> <video:content_loc> http://streamserver.example.com/video123.mp4</video:content_loc> <video:player_loc> http://www.example.com/videoplayer.php?video=123</video:player_loc> <video:duration>600</video:duration> <video:expiration_date>2021-11-05T19:20:30+08:00</video:expiration_date> <video:rating>4.2</video:rating> <video:view_count>12345</video:view_count> <video:publication_date>2007-11-05T19:20:30+08:00</video:publication_date> <video:family_friendly>yes</video:family_friendly> <video:restriction relationship="allow">IE GB US CA</video:restriction> <video:price currency="EUR">1.99</video:price> <video:requires_subscription>yes</video:requires_subscription> <video:uploader info="http://www.example.com/users/grillymcgrillerson">GrillyMcGrillerson </video:uploader> <video:live>no</video:live> </video:video> </url> </urlset>