W3C home > Mailing lists > Public > public-media-fragment@w3.org > May 2011

Re: a question about dimensions...

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Fri, 6 May 2011 14:50:36 +1000
Message-ID: <BANLkTimGgGGFC3qW36sTjkKVO5VCH-Gp1Q@mail.gmail.com>
To: Davy Van Deursen <davy.vandeursen@ugent.be>
Cc: David Singer <singer@apple.com>, Media Fragment <public-media-fragment@w3.org>
On Tue, Mar 22, 2011 at 6:25 PM, Davy Van Deursen
<davy.vandeursen@ugent.be> wrote:
> Hi David,
> On 21/03/2011 15:55, David Singer wrote:
>> Guys
>> I am not sure that 'named' is really a dimension.
>> I understand focusing on time; focusing on a spatial area; and focusing on
>> tracks.  These are indeed orthogonal axes.
>> But you use names to focus on a section, which seems to be a named
>> time-subpart.
>> Specifically, can I use names for subsetting in any of the dimensions?  If
>> I have a track called 'fred', are these equivalent?
>> http://www.example.com/thing#track=fred
>> http://www.exampke.com/thing#id=fred
>> Would it not be cleaner to allow selection by name on any of the three
>> axes (i.e. named timed periods, named spacial regions, named tracks)?
> To me, 'named' can be seen as a kind of virtual dimension, which points to a
> combination of any of the three "real" dimensions (i.e., time, spatial, or
> track). The mapping between a named fragment and a combination of time,
> spatial, or track is left to the application.
> So for example: #id=fred_low could correspond to
> #t=10,20&track=low&xywh=20,20,30,30. It is of course not required to combine
> all dimensions: #t=30,40 could for example correspond to #id=blooper.
> Similarly, #track=fred could correspond to #id=fred if this is defined
> within the application; but as I said, the mapping is out of scope of the MF
> spec.

I typically use #id to reference chapters, which are a subpart of the
time dimension.

I'm currently dealing with a demo where I use WebVTT chapters to
navigate a video. It would be really nice if the browser would just
understand video.ogv#chapter2 and I wouldn't have to use script to set
the currentTime to the chapters2 start and catch the ontimeupdate
event to test if I've already gone beyond the end of the chapter2 to
stop playback.

OTOH, this feature is not urgently needed compared to the temporal and
track dimensions. If I could just convert the label to a time range
through script and then do the media fragment addressing with #t, that
would help a lot, too.

Received on Friday, 6 May 2011 04:51:24 UTC

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