On Apr 8, 2011, at 8:54 AM, Ian Hickson wrote: >> but should be linked to the main media resource through markup. > > What is a "main media resource"? > > e.g. consider youtubedoubler.com; what is the main resource? > > Or similarly, when watching the director's commentary track on a movie, is > the commentary the main track, or the movie?
In systems like MPEG TS and DASH, there's the notion of the "system clock". This is the overarching resource to which all audio, meta, text and video tracks are synced. The clock has no video frames or audio samples by itself, it just acts as the wardrobe for all tracks. Perhaps it's worth investigating if this would be useful for media elements? - Jeroen
