We now have a Media Analytics plugin that tracks Videos & Audio!
More information is available here: http://www.media-analytics.net/ The plugin gives useful insights into media / video / audio analytics and adds many new reports, widgets and segments to Piwik.
Works with HTML5 video & audio, Vimeo and YouTube out of the box. Support for other players can be added easily and is documented in the developer docs. We are also happy to add support for more players upon request, please ping us. After installation the plugin will in most cases directly start tracking data see the setup guide
For a full list of features check out https://plugins.piwik.org/MediaAnalytics . Docs are available at FAQ, User Guide, Developer docs