[whatwg] Start position of media resources

[Silvia Pfeiffer]

On Wed, Apr 8, 2009 at 8:37 AM, David Singer <singer at apple.com> wrote:
> At 8:29  +1000 8/04/09, Silvia Pfeiffer wrote:
>>
>>  > My mental analogy was HTML, where an acnhor takes you to that part of
>> the
>>>
>>>  page as a convenience, but nothing stops you from navigating away.  And
>>> in
>>>  the case where the UA optimizes for showing that section (by suitable
>>>  handshakes/translations with the server), again, it could present a UI
>>> which
>>>  offers other times -- at the expense of more handshakes.
>>
>> Yes, I understand that analogy. But because video can be a very long
>> resource, media fragment URIs cannot be restriced to client-side
>> offsetting. Think e.g. about wanting the last 2 minutes out of a 5
>> hour discussion downloaded to your mobile phone.
>>
>> The media fragment WG decided that fragment addressing should be done
>> with "#" and be able to just deliver the actual fragment. (BTW: this
>> is in contrast to the temporal URIs that were specified for Annodex,
>> where chopping happened in the UA for "#"  and on the server for "?").
>
> But there is a huge difference between
>
> a) the UA MUST optimize for the chosen fragment, and may/should offer the
> rest of the resource to the user (at the possible expense of more network
> traffic)
>
> and
>
> b) the UA MUST only offer the chosen fragment to the user, and optimize
> network traffic and downloads for just that section, and MUST NOT allow
> navigation outside the indicated range
>
>
> Unfortunately, it does make a difference to the page author which of these
> is talked about (and, lacking anything else, (a) is probably what is
> expected).

Navigation outside the indicated range could be done in several ways -
it does not have to be through indicating the full length of the
resource in the timeline.

Cheers,
Silvia.