- From: Eric Carlson <eric.carlson@apple.com>
- Date: Tue, 2 Feb 2010 07:24:33 -0800
- To: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
- Cc: Philip Jägenstedt <philipj@opera.com>, HTML Accessibility Task Force <public-html-a11y@w3.org>, Ken Harrenstien <klh@google.com>
On Feb 2, 2010, at 7:18 AM, Eric Carlson wrote: > > On Feb 1, 2010, at 10:31 PM, Silvia Pfeiffer wrote: > >> >> You mentioned there are unique track identifiers in MPEG/QuickTime. >> Are those strings or numbers? >> > It is a 32-bit integer that uniquely identifies the track, see section 8.4 of ISO/IEC 14496-12 for MPEG-4 or http://developer.apple.com/mac/library/documentation/QuickTime/QTFF/QTFFChap2/qtff2.html#//apple_ref/doc/uid/TP40000939-CH204-25550 for QuickTime. > Although the unique identifier is an integer in QuickTime and ISO files, this is an implementation detail that we shouldn't be constrained by. Other formats could use an identifier, like a UUID, that is more naturally expressed as a String. eric
Received on Tuesday, 2 February 2010 15:25:06 UTC