By VideoZen, put Self hosted video on your WordPress or WordPress multisite, be as simple as activating the plugin, get an account at Amazon S3 and Zencoder, upload a video in Media and put a simple WordPress shortcode in a page or post.
When the page or post is viewed, the plugin will build everything you need with all the videos formats needed to be reproduced in any browser, tablet or mobile from Amazon S3. And with Flash fallback.
The Plugin also supports subtitles type VTT, which are the standard HTML5 . Just have to upload it to WordPress media with the name that indicate you the plugin and will be automatically inserted into the video.