I was surprised to learn that sitemaps were part of the skin software, and there are skins that don't support this rather important part of the SEO world.
I believe that this functionality would be far better if it was part of the jAlbum core code. Like this everyone can use it without needing to buy a 3rd party sitemap.xml creator. And if sitemap is "On", then no other option should override it. Always get a full sitemap.xml
Also, it is now far better to break the sitemaps into individual files.
sitemap.xml << this file would contains the links to the other sitemaps.
Sitemap-html.xml << contains all the html links
Sitemap-images.xml << contains all the image links
Sitemap-video.xml <<You got it, contains all the video links
It seems that Google prefers this way of working as it does cut down on individual file sizes.
Sounds reasonable. Then these are references from the robots.txt file we assume.
We created image sitemaps on the fly for albums hosted by us, but that feature has been disabled for a while since it brought the servers down on their knees when a search bot ”attacked” us... So adding it to the client seems reasonable, to also make it work for albums not hosted here.
My skins are creating a combined sitemap.xml which contains all of these file types.
I don't see why it's better to use separate files. Perhaps, beyond some 10 000 items, it's easier to access these files individually, but most albums are below 100 items, and in this case, combining the files means fewer transactions. Google bots will scrape all of the files, anyway.