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minutes of 2009-04-01 teleconference

From: RaphaŽl Troncy <Raphael.Troncy@cwi.nl>
Date: Wed, 01 Apr 2009 15:04:35 +0200
Message-ID: <49D36663.7000107@cwi.nl>
To: Media Fragment <public-media-fragment@w3.org>
CC: Yves Lafon <ylafon@w3.org>
All,

The minutes of this week telecon are available for review at
http://www.w3.org/2009/04/01-mediafrag-minutes.html (and in text format
below).

During the call, the presents agreed to move the telecon hour to be more 
convenient for Silvia (She will also switch to winter time this 
week-end). From next week, my proposal would be to have the telecon at 
12:00 UTC which means:
   - San Francisco: 05:00 AM
   - Galway: 13:00 PM
   - Amsterdam/Ghent/Nice/Pretoria: 14:00 PM
   - Tokyo: 21:00 PM
   - Sydney: 22:00 PM
http://www.timeanddate.com/worldclock/fixedtime.html?day=08&month=04&year=2009&hour=12&min=00&sec=0&p1=0

If no concern is raised by the end of this week, I would ask Yves if he 
could make the request to change the time slot on Zakim until the end of 
  this (European) summer.

New actions are:
   * ACTION: Jack to enter formally in the tracker the ISSUE he has 
found, regarding a) transcoding and b) spatial cropping [recorded in 
http://www.w3.org/2009/04/01-mediafrag-minutes.html#action05]
   * ACTION: Yves to change the formal grammar to have 'percent' spelled 
[recorded in http://www.w3.org/2009/04/01-mediafrag-minutes.html#action03]
   * ACTION: Yves to change the formal grammar to have unreserved 
characters + %-escaped ones in utf8string and _not_ a set of pchars 
[recorded in http://www.w3.org/2009/04/01-mediafrag-minutes.html#action04]

Cheers!

   Erik & Raphael

-------------
    [1]W3C
       [1] http://www.w3.org/
                                - DRAFT -
              Media Fragments Working Group Teleconference
01 Apr 2009
    [2]Agenda
       [2] 
http://lists.w3.org/Archives/Public/public-media-fragment/2009Mar/0089.html
    See also: [3]IRC log
       [3] http://www.w3.org/2009/04/01-mediafrag-irc
Attendees
    Present
           Erik, Davy, Jack, Raphael, Silvia
    Regrets
           Michael, Yves, Conrad
    Chair
           Erik, Raphael
    Scribe
           Raphael
Contents

      * [4]Topics
          1. [5]1. Admin
          2. [6]2. F2F meeting
          3. [7]3. WD Document
          4. [8]4. Implementation
      * [9]Summary of Action Items
      _________________________________________________________

    <trackbot> Date: 01 April 2009

    <scribe> Scribe: Raphael

    <scribe> scribenick: raphael

1. Admin

    Propose to accept the minutes of 25/03?

    YEs

    RESOLUTION: minutes of 25/03 are accepted

    Raphael: should we move the telecon hour, to be more convenient for
    Silvia ?

    Jack: I will miss one telecon every two weeks

    Raphael: proposal to have the telecon 2 hours later
    ... to be more convenient for Silvia

    <scribe> ACTION: Raphael asks Silvia if she would like to have the
    telecon 2 hours later [recorded in
    [10]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action01]

    <trackbot> Sorry, couldn't find user - Raphael

    trackbot, status

    <scribe> ACTION: RaphaŽl asks Silvia if she would like to have the
    telecon 2 hours later [recorded in
    [11]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action02]

    <trackbot> Created ACTION-54 - Asks Silvia if she would like to have
    the telecon 2 hours later [on RaphaŽl Troncy - due 2009-04-08].

2. F2F meeting

    Erik list the participants: Michael, Jack, Erik, Davy, Raphael,
    Conrad, David, Franck, Guillaume

    scribe: + Yves / Silvia on the phone

3. WD Document

    Erik: we will re-organize the section 5 significantly

    Raphael: my proposal, finish the document by next Wed 8 of April,
    and vote for publishing the document
    ... in our next telecon
    ... make a quick publication request

    and hope to have the document published on the 9th

    Erik: agree

    Jack: Michael took my action, because I was busy ... but perhaps I
    can take over
    ... I will send an email to Michael, to ask him if I can take over

    Erik: difference between reference and informative sections?

    Raphael: informative parts are just for giving hints to the reader,
    generally dtd or schemas

    3.1: Syntax

    Problem 1: not use '%' but spell it

    <scribe> ACTION: Yves to change the formal grammar to have 'percent'
    spelled [recorded in
    [12]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action03]

    <trackbot> Created ACTION-55 - Change the formal grammar to have
    'percent' spelled [on Yves Lafon - due 2009-04-08].

    Problem 2: use of single quote (') and sub-delims in utf8string

    <scribe> ACTION: Yves to change the formal grammar to have
    unreserved characters + %-escaped ones in utf8string and _not_ a set
    of pchars [recorded in
    [13]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action04]

    <trackbot> Created ACTION-56 - Change the formal grammar to have
    unreserved characters + %-escaped ones in utf8string and _not_ a set
    of pchars [on Yves Lafon - due 2009-04-08].

    3.2: Technologies Survey

    Erik and Davy will work on it on Monday / Tuesday

    3.3: HTTP implementation

    [14]http://www.w3.org/2008/WebVideo/Fragments/wiki/HTTP_implementati
    on

      [14] 
http://www.w3.org/2008/WebVideo/Fragments/wiki/HTTP_implementation

    close ACTION-52

    <trackbot> ACTION-52 Replace all examples in the HTTP implementation
    wiki page with the video Jack took closed

    Raphael: how can I have the byte ranges that correspond to my
    temporal interval?

    Jack: now we are entering into a different problem, that is, should
    we do transcoding or not?
    ... the bytes range will be different depending on transcoding or
    not
    ... I have just sent an email stating we should consider more the
    user
    ... see:
    [15]http://lists.w3.org/Archives/Public/public-media-fragment/2009Ap
    r/0003.html

      [15] 
http://lists.w3.org/Archives/Public/public-media-fragment/2009Apr/0003.html

    Raphael: I think we should go for your option 2, and define what is
    reasonable
    ... what is the point 4? Is it related to the in-context discussion?

    Jack: no, no, no

    Point 5: we leave that away, we haven't specified what the spatial
    cropping will actually do!

    Point 3: it seems to be related to the issue: transcoding or not

    Davy: if we want to re-syn the audio and video, then we need to
    transcode

    Raphael: what is the worst thing that can happen?

    Davy: the audio and video might not be aligned

    Jack: the reason while I use a wget example, is that you want to
    store this piece and re-use it later on

    Davy: my proposal was to do no transcoding and have a reasonable
    out-of-synch
    ... same than for the I-Frame
    ... we choose the closest timeframe

    Jack: what is reasonable?

    Davy: I think there is studies which show what is the largest
    not-synch temporal interval that users can support
    ... you and I have different interpretation of what we allow for
    transcoding
    ... I prefer Jack's interpretation

    Jack: I had interpreted it as "we will not standardise any type of
    fragmenting that we think cannot be implemented without using
    transcoding".

    Davy: I interpret it as "an implementation is not allowed to do any
    transcoding".

    Davy also now prefers Jack's interpretation

    Jack: I think we can standardize a spec that can be implemented
    without transcoding

    Raphael: I'm also now confused, it is different from your previous
    statement

    Jack: if we have no boundary cases for media fragments, it should
    work

    Raphael: should we make the algorithm in the spec, that says, jump
    to the previous I-Frame, etc.

    Jack: no, we should have in the spec, the user expectation

    Silvia: we should send larger sequence, in order to not transcode

    <davy> +1 to Silvia

    +1 to Silvia

    Silvia: get wider intervals, on a best-effort basis

4. Implementation

    Silvia: talk about the new ogg spec

    <davy> I think mp4 is also capable of skipping frames

    Silvia: the YouTube player is also working on a best effort, if you
    click on a time offset, then the player goes to the closest frame he
    can start to play

    Raphael: what is the closest? can it be after?

    Silvia: I think it always goes back in time
    ... I need to check, but this is my experience

    close ACTION-53

    <trackbot> ACTION-53 Check whether ffmpeg can slide movies easily,
    need for implementation on client and server side closed

    <jackjansen> give me an action

    <scribe> ACTION: Jack to enter formally in the tracker the ISSUE he
    has found, regarding a) transcoding and b) spatial cropping
    [recorded in
    [16]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action05]

    <trackbot> Created ACTION-57 - Enter formally in the tracker the
    ISSUE he has found, regarding a) transcoding and b) spatial cropping
    [on Jack Jansen - due 2009-04-08].

    Silvia: I would like to have the telecon 2 hours later
    ... I think the section use case and requirements is ready

    <Gui> I agree

    Look at
    [17]http://www.w3.org/2008/WebVideo/Fragments/wiki/HTTP_implementati
    on

      [17] 
http://www.w3.org/2008/WebVideo/Fragments/wiki/HTTP_implementation

    <Gui> Looking

    <Gui> I am all sorry for myself, I didn't know I was late till now !
    :-( I thought we were back to normal hours.

    Davy: I will use our platform to discover the mapping between
    seconds and bytes for this particular video
    ... and update the wiki

    No, AOB, Meeting adjourned

Summary of Action Items

    [NEW] ACTION: Jack to enter formally in the tracker the ISSUE he has
    found, regarding a) transcoding and b) spatial cropping [recorded in
    [18]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action05]
    [NEW] ACTION: Raphael asks Silvia if she would like to have the
    telecon 2 hours later [recorded in
    [19]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action01]
    [NEW] ACTION: RaphaŽl asks Silvia if she would like to have the
    telecon 2 hours later [recorded in
    [20]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action02]
    [NEW] ACTION: Yves to change the formal grammar to have 'percent'
    spelled [recorded in
    [21]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action03]
    [NEW] ACTION: Yves to change the formal grammar to have unreserved
    characters + %-escaped ones in utf8string and _not_ a set of pchars
    [recorded in
    [22]http://www.w3.org/2009/04/01-mediafrag-minutes.html#action04]

    [End of minutes]

-- 
RaphaŽl Troncy
CWI (Centre for Mathematics and Computer Science),
Science Park 123, 1098 XG Amsterdam, The Netherlands
e-mail: raphael.troncy@cwi.nl & raphael.troncy@gmail.com
Tel: +31 (0)20 - 592 4093
Fax: +31 (0)20 - 592 4312
Web: http://www.cwi.nl/~troncy/
Received on Wednesday, 1 April 2009 13:05:22 GMT

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