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Re: ACTION-158: Exhaustive list of Test Cases for the temporal dimension in the Media Fragment URI

From: Silvia Pfeiffer <silviapfeiffer1@gmail.com>
Date: Thu, 15 Apr 2010 12:21:41 +1000
Message-ID: <l2s2c0e02831004141921z3a243c15u25f7eb6f822cca9f@mail.gmail.com>
To: raphael.troncy@eurecom.fr, Yves Lafon <ylafon@w3.org>
Cc: Media Fragment <public-media-fragment@w3.org>
All, in particular Yves,

I just came across an interesting problem in our spec.

In section 4.3.1 we have an example:
t=10,     # => results in the time interval [10,end)

But our production rule states:
npttimedef    = [ deftimeformat ":"] ( npttime  [ "," npttime ] ) / (
"," npttime )

Making this a invalid specification.

I don't think we want this, since there is not really a difference
between t=10 and t=10,

Thus I suggest to adapt the production rule to:
npttimedef    = [ deftimeformat ":"] ( npttime  [ "," npttime ] ) / (
"," npttime ) / ( npttime ",")


On Wed, Apr 7, 2010 at 12:02 PM, Silvia Pfeiffer
<silviapfeiffer1@gmail.com> wrote:
> 2010/4/7 RaphaŽl Troncy <raphael.troncy@cwi.nl>:
>>> 10, 11 and 12 have to be diversified based on whether a lies before or
>>> after the beginning of the media resource. In fact, we need to
>>> introduce something like s=start time and e=end time everywhere. Thus
>>> we need to adapt/introduce the following:
>>> no5: t=a,b with s<=a, a<b, b<=e †=> †play a to b
>>> introduce no5a: t=a,b with a<s, a<b, s<b, b<=e => †play s to b
>>> introduce no5b: t=a,b with a<s, a<b, b<s, b<=e => †empty fragment
>>> (these include no6 now)
>>> no7: t=a,b with s<=a, a<b, a<e, b>e => †play a to e
>>> no7a: t=a,b with a<s, a<b, a<e, b>e => †play s to e
>>> no7b: t=a,b with a<b, a=>e, b>e => †empty fragment
>>> (this last one includes no8 and no9)
>>> no10: t=a, with a>=s, a<e => †play a to e
>>> no10a: t=a, with a<s, a<e => †play s to e
>>> no14: t=,a with a>s, a< †d => †play s to a
>>> no14a: t=,a with a<=s, a<d => †empty fragment
>> OK, so for all these test cases, you assume fairly that the start time of a
>> media resource is not necessarily 0. Is this a frequent case? How many media
>> files out there have this property?
> It doesn't matter how many exist, but that this case can occur. Thus
> we have to cover it in the test case.
>>> Yup, listed above as a/b numbers and additional conditions to the ones
>>> in the existing list. Mostly related to missing out on defining the
>>> "start" time of the resource.
>> I would add all these ones if the group feels it is necessary, i.e. there
>> _are_ videos that will fall in these cases.
> Yes, there definitely will be. The first media fragment server that
> provides media fragment queries will create such resources. As we
> encourage people to implement such services, we should also provide
> for the possibility that such files will exist. Even if only 0.1% of
> all files that now exist have that property.
> Cheers,
> Silvia.
Received on Thursday, 15 April 2010 02:22:34 GMT

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