Video with multiple audio tracks

[rfransdonk]

I have read the video/media section of the HTML 5.0 specification and I am wondering why there is no API for dealing with multiple audio tracks (i.e. multiple languages).
How can the system select the appropriate aduio track or subtitling track? How can the application signal to the user that alternative audio tracks are available?

[zcorpan]

The issue of captions and subtitles is unresolved...

Would you want to implement UI for selecting audio tracks and subtitles with javascript? Or would it be ok to just be available in the browser's native UI (context menu and/or the interface when controls="" is present)?