minutes of 2011-04-06 teleconference

Dear all,

The minutes of today's phone telecon are available for review at 
http://www.w3.org/2011/04/06-mediafrag-minutes.html (and in text format
below).

The short executive summary is that we have started to review the UA 
test cases (http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases) 
and that live discussions are very worth to do it.
Everybody has committed to be here next week to continue the discussion. 
Davy has an action to modify the table according to what has been 
discussed / reviewed.
Best regards,

   Raphaël

-----------
    [1]W3C
       [1] http://www.w3.org/
              Media Fragments Working Group Teleconference
06 Apr 2011
    [2]Agenda
       [2] 
http://lists.w3.org/Archives/Public/public-media-fragment/2011Apr/0000.html
    See also: [3]IRC log
       [3] http://www.w3.org/2011/04/06-mediafrag-irc
Attendees
    Present
           Yves, Davy, Yves, Raphael, Jack
    Regrets
           Erik, Silvia, Thomas
    Chair
           Raphael
    Scribe
           raphael
Contents
      * [4]Topics
          1. [5]1. Admin
          2. [6]2. HTML5 Bugs
          3. [7]3. TEST CASES
          4. [8]4. AOB
      * [9]Summary of Action Items
      _________________________________________________________

    <trackbot> Date: 06 April 2011

    <scribe> Scribe: raphael

    <scribe> Scribenick: raphael

1. Admin

    PROPOSED to accept the minutes of the last week telecon:
    [10]http://www.w3.org/2011/03/23-mediafrag-minutes.html

      [10] http://www.w3.org/2011/03/23-mediafrag-minutes.html

    <foolip> +1

    +1

    <davy> +1

    minutes accepted

    <Yves> +1

    close ACTION-215

    <trackbot> ACTION-215 Poke people and encourage them to join the
    telecons closed

2. HTML5 Bugs

    ACTION-213?

    <trackbot> ACTION-213 -- Silvia Pfeiffer to submit the proposed list
    of bugs to HTML5 -- due 2011-03-23 -- OPEN

    <trackbot>
    [11]http://www.w3.org/2008/WebVideo/Fragments/tracker/actions/213

      [11] http://www.w3.org/2008/WebVideo/Fragments/tracker/actions/213

    close ACTIOn-213

    <trackbot> ACTION-213 Submit the proposed list of bugs to HTML5
    closed

    4 bugs now in the tracker

    [12]http://www.w3.org/Bugs/Public/show_bug.cgi?id=10723

      [12] http://www.w3.org/Bugs/Public/show_bug.cgi?id=10723

    [13]http://www.w3.org/Bugs/Public/show_bug.cgi?id=12425

      [13] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12425

    [14]http://www.w3.org/Bugs/Public/show_bug.cgi?id=12426

      [14] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12426

    [15]http://www.w3.org/Bugs/Public/show_bug.cgi?id=12427

      [15] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12427

    <foolip> not really

    <foolip> (sorry, I'm muted)

    <foolip> I've replied

    <foolip> [16]http://www.w3.org/Bugs/Public/show_bug.cgi?id=12426

      [16] http://www.w3.org/Bugs/Public/show_bug.cgi?id=12426

3. TEST CASES

    UA test cases:
    [17]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases.html

      [17] http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases.html

    Server test cases:
    [18]http://www.w3.org/2008/WebVideo/Fragments/TC/server-test-cases.h
    tml

      [18] 
http://www.w3.org/2008/WebVideo/Fragments/TC/server-test-cases.html

    Jack: test cases are made for testing the spec and not for
    particular implementations

    Philip: what does it mean? test cases are made for implementations

    Jack: no, because test cases are made for making sure the wording of
    the spec can at least be interpreted the same way by 2 different
    people

    Davy: I also think we should not battle for this, we mean roughly
    the same thing

    <Yves> well, it's those corner cases that are important, testing the
    spec by implementing is indeed to see if people got the same
    reading, but also if the coverage of the issue raised by
    implementation is good enough in the spec

    Davy: let's start for the UA test cases

    URI:
    [19]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases.html
    ... we have 60 Test Cases

      [19] http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases.html

    Davy: I will go over the list of TC, and you should shout if you
    disagree

    <davy>
    [20]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    1-UA

      [20] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0001-UA

    <foolip> npttimedef = [ deftimeformat ":"] ( npttime [ "," npttime ]
    ) / ( "," npttime )

    <foolip> [21]http://www.w3.org/TR/media-frags/#naming-time

      [21] http://www.w3.org/TR/media-frags/#naming-time

    TC1 is wrong ... syntax is invalid

    scribe: it should be equivalent to TC27
    ... but we should test it

    <davy>
    [22]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    2-UA

      [22] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0002-UA

    Philip: I also disagree on this one ... I think it should be an
    error

    Jack: no, since the intervals are half-open

    Philip: it means that it will be a still image?

    Jack: no, it means TC2 and TC3 are equivalent
    ... start of the interval is inclusive, and end of the interval is
    exclusive

    <Yves> TC2 with start=end mean display this point in time (one
    picture in a video?)

    Should we enforce e>s

    Philip: it is also reasonable to have e=s

    Jack: I think I would prefer half-open intervals

    Raphael: but Jack, is [3,3) valid?

    Philip: I think it should be considered as an invalid range
    ... so the whole resource should be requested
    ... the UA has detected with its logic that this is an invalid range

    Davy: instead of requesting the whole resource, we could just
    request the include-setup

    Philip: this is the general problem of what to do with invalid range
    ... again similar to TC27

    Raphael: Philip and Davy prefer to request the whole resource
    ... Silvia will perhaps prefer to request only the setup data
    ... Jack does not care, Yves has a slight preference to display a
    still image but just want we specify what should it be

    Philip: I think we should just ignore invalid ranges to simplify
    implementations

    <jackjansen> I don't care, but I agree with Yves that we should
    specify it.

    Raphael: TC2, TC3, TC27 (and perhaps other TC) will request the
    entire resource ... except if Silvia strongly disagree

    [23]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    3-UA

      [23] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0003-UA

    <scribe> done

    <davy_>
    [24]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    4-UA

      [24] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0004-UA

    <davy_>
    [25]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    8-UA

      [25] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0008-UA

    <davy_>
    [26]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC001
    3-UA

      [26] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0013-UA

    <Yves> you can't know in advance that you are requesting the whole
    resource, right?

    <foolip> Range: bytes=x-y

    Davy: I can add a 4th option with a Range request expressed in bytes

    Philip: we should not specify all the possible ways, but just make
    sure we can request byte ranges request for TC4

    Raphael: for TC4, add the possibility to issue a Range request
    expressed in bytes

    [27]http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC000
    5-UA

      [27] 
http://www.w3.org/2008/WebVideo/Fragments/TC/ua-test-cases#TC0005-UA

    Philip: the byte ranges could be different
    ... should we just write x-y ?

    Jack: I'm concerned about readability of the table
    ... so we could add at the top this is just possible outcomes
    ... for the byte ranges requests (depending on how UA caches things
    anyway)

    Philip: we should also add on the top of the table that we could
    have a number of range requests (not a single one)

    Davy: the column 4 meant that either the UA has knowledge about the
    media or it has not ... it does say how he got this information

    Jack: will this column 4 be used for automatic testing ?
    ... if yes, then Philip's implementation will fail on all test cases

    Davy: we just ignore the first request of Philip's implementation
    ... the include-setup one
    ... is it important that we log/check the HTTP request?
    ... is it important how the UA get the MF visualization right?

    Philip: checking the HTTP implementation is secondary, we absolutely
    need to test the playback behavior

    <Yves> main thing is defining the semantic of the #frag, then the
    http interaction is optional

    Raphael: my UA download the entire resource and just seek to the
    start of the fragment on client side, and stop playing at the end of
    the fragment ... is this a conforming implementation ?

    Yves: we need to check the playback in the UA, not the network

    Jack: servers might not be MF compliant and the UA should not be
    penalized

    Raphael: it's noon, thanks all for attending
    ... are you all here next week

    ALL: yes

4. AOB

    Next week, we keep discussing all TC, that will include the changes
    of Davy!

    Round of applause for his work

    Meeting adjourned

Summary of Action Items

    [End of minutes]
      _________________________________________________________

-- 
Raphaël Troncy
EURECOM, Multimedia Communications Department
2229, route des Crêtes, 06560 Sophia Antipolis, France.
e-mail: raphael.troncy@eurecom.fr & raphael.troncy@gmail.com
Tel: +33 (0)4 - 9300 8242
Fax: +33 (0)4 - 9000 8200
Web: http://www.eurecom.fr/~troncy/

Received on Wednesday, 6 April 2011 11:49:06 UTC