How do I extend the xmlsitemap module to include the google news / images and videos formats The xmlsitemap module covers the standard google xml site map. However, https://support.google.com/webmasters/answer/178636?hl=en is the information for the google image search and the specific markup for creating a sitemap for image content. Likewise https://support.google.com/webmasters/answer/80472?hl=en is for video content. I don't think that the xmlsitemap module supports these additional types.  (Google news sitemap is another one). Can anyone offer any more information about extending the module or if there are any patches that will achieve the above.
For news there's the Google News sitemap module


  The Google News module generates a Google news compatible sitemap feed from your Drupal site's content.


I don't think there are existing modules for images/video (I've looked for the same thing before myself and ended up hacking something together).

There's a feature request in the XMLSitemap module's issue queue for exactly this, but it's currently postponed. There are a couple of links on that thread pointing to how others have achieved it, those might be worth a look.