Media Library + Player application (HTML5)

I need to build an application for browsing media library and playing selected content. The application will be bundled with a desktop application. These are some requirements:

- a single HTML page including all the layout and JavaScript/Ajax logic
- communicates with the server component using Ajax / JSON (will provide message examples)
- includes a login page, media library browsing (videos, music, images) and player component (video player will use an existing component - FlowPlayer)
- should include nice transitions when browsing the library - modern media feel
- will include dynamic content so must properly handle long string floating / trimming, etc.
- should be written in HTML5, support only the resent versions of modern browsers
- should properly display on different resolutions
- should be lightweight and if using external libraries these should be also lightweight
- must properly handle error messages in the server responses by displaying an appropriate message box