Captures from ( mostly ) flash-videos are usually done with browser-addons. I see that you use Google Chrome, so use the site hxxps://chrome.google.com/webstore/category/extensions?hl=en to search for addons, that fits your needs.

Site rips are done with "content downloader", where you specify the filetypes ( avi, mpeg, flv, or whatever ) and search the hole domain for these filetypes to download them afterwards. But be aware, that most of the webmaster know how to secure their files, so that you won't find what your are looking for this easy - and apart from that, this usage of a domain is mostly illegal. Read the terms and conditions of a website to learn more about it.