- From: Thomas Steiner <tomac@google.com>
- Date: Thu, 24 Nov 2011 11:37:37 +0100
- To: Philip Jägenstedt <philipj@opera.com>
- Cc: Davy Van Deursen <davy.vandeursen@ugent.be>, Erik Mannens <erik.mannens@ugent.be>, Yunjia Li <yl2@ecs.soton.ac.uk>, Media Fragment <public-media-fragment@w3.org>
Hi Philip, Davy, > I'll let Thomas answer in detail, but given the current state of browser > implementations, I'd say the following cannot be supported via a polyfill: > > * stopping at accurate end time in #t=start,end > > * smpte and clock time formats > > * track dimension > > * id dimension. > > Or, in short, what *can* be supported via a polyfill is: > > * time dimension with start time in NPT format > > * spatial dimension Nothing to be added to this list. For NPT start and end times, I would say a rough guarantee of about 1s accuracy for both start and end can be given, however, I am not sure if such thing as a "rough" guarantee (empirically determined) makes sense. > As mentioned in the teleconf via IRC, I don't think it is acceptable to > count polyfills as implementations for state transition purposes. That is > not to say that they aren't useful, just that they aren't proof that a > feature is implementable in shipping software with all the extra issues that > come up there. The delivered User Script adds Media Fragments URIs support with the acknowledged constraints, asterisks, small prints, and limitations to browsers that support User Scripts. Now I am a W3C newbie and not sure about the strictness of the implementation requirements. Strictly speaking, I agree with Philip that polyfills are _not_ sufficient. Wearing my pink glasses I would say that polyfills serve nicely to show how implementations can more or less look and feel like if implemented natively. The real thing will certainly be more accurate, polished, error-proof, etc. I just had fun developing the JavaScript library and User Script, and hope to have contributed something others can build upon. If it's useful for the state transition of the document produced by the WG, perfect. If not, no questions asked and no hard feelings. Really. Up to the WG heads to decide. Best, Tom -- Thomas Steiner, Research Scientist, Google Inc. http://blog.tomayac.com, http://twitter.com/tomayac
Received on Thursday, 24 November 2011 10:38:37 UTC