Organizing and making data shareable, searchable and classifiable is in increasingly vital practice within the field of web design. Designers must understand that their art is more than the intersection of verbal and non-verbal communication but it is also a practice of communication to machines, as well--ultimately, web designer is a multi-dimensional practice.
Data can be thought of as a currency like oil, and like oil, it must be collected and refined to be usable by others. Video content has been much harder to classify, understand and provide results for compared to text content. In order to organize video content into something that it interesting, it is necessary to have additional data about that video that can be interpreted by machines. Webmasters are beginning to focus more intently on making their online video content more accessible by the use of meta data.
Generally, there are two popular purposes for providing meta data alongside video content: classify the content so it can be interpreted easily and aid in the discovery of that video content. Technology like video sitemaps, mRSS, RFDa and Facebook Share all help webmasters and designers provide additional, machine-readable information like video titles and descriptions to search engines.
Video sitemaps and mRSS (Media RSS specification) can help search engines discover and track video content. Google has been making great strides in the effort to improve their index of video content. These tools give web designers and webmasters more control over their content inclusion strategy.
On-page markup like RDFa and Facebook Share may fall short with helping search engines discover new URLs with video content, but they are great for helping search engines that don't have sitemap/mRSS support to organically gather meta data about video content within a website. On-page mark-up does not however have extra meta data like duration, whereas mRSS does.