Media Fragments in Opera

For those of you who were not at FOMS, here's a little FYI:

The first native browser implementation of Media Fragments was demoed at  
FOMS, that is: something I hacked into Opera. This is not ready to ship,  
so don't expect to see it in desktop Opera just yet. Here's some  
implementation feedback:

About t:

* We should consider making the HH component optional. Most clips online  
are less than an hour, and being able to say #t=9:23 would be useful.

* It's not clear to me what to do with the smpte formats. In our  
underlying media framework (GStreamer) time is expressed in nanoseconds,  
so it doesn't actually give any great precision that using 9 decimals. For  
now, I've not added support for the smpte formats at all. Are there any  
existing implementations or indications that anyone does want to implement  

* The use case for 'clock' syntax is pretty clear, but AFAIK the time in  
UTC isn't available in Ogg or WebM, so I'm not sure what to do with it.

(In short, I've only implemented the npt syntax.)

About xywh:

I think this would be useful for cropping away black borders, but I didn't  
have time to implement it for FOMS. It's not clear what 'pixels' means,  
should these be physical pixels of the video frames, or after correcting  
for pixel aspect ratio? Either would be fairly easy to implement, but  
possibly the risk of rounding errors is smaller when applying it to the  
physical pixels. On the other hand, everything else exposed via <video> is  
in CSS pixels after aspect ratio has been corrected for, so it would be a  
bit odd to suddenly use physical pixels here...

Philip Jägenstedt
Core Developer
Opera Software

Received on Monday, 18 October 2010 08:57:16 UTC