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[MEDIA_PIPELINE_TF] minutes - 18 August 2011

From: Kazuyuki Ashimura <ashimura@w3.org>
Date: Fri, 19 Aug 2011 01:38:37 +0900
Message-ID: <4E4D400D.5000506@w3.org>
To: public-web-and-tv@w3.org
available at:

also as text below.

Thanks for taking notes, Francois!



       [1] http://www.w3.org/

                                - DRAFT -

                   Media Pipeline Task Force Teleconf

18 Aug 2011


       [2] http://www.w3.org/2011/webtv/wiki/MPTF/Agenda_Telco_18th_August_2011

    See also: [3]IRC log

       [3] http://www.w3.org/2011/08/18-webtv-irc


           Kazuyuki, rberkoff, JanL, Tatsuya_Igarashi, davidmays,
           francois, Narm, Bob, Clarke, Panu_Markkanen




      * [4]Topics
          1. [5]Procedure for submitting comments to LC bugs
          2. [6]Provide link to MediaStream
          3. [7]Agenda for MPTF F2F meeting in September
          4. [8]Client Ad Insertion (ISSUE-31)
          5. [9]Media Synchronous Web Content (ISSUE-32)
          6. [10]Timed Text (ISSUE-33)
          7. [11]Adaptive Bit Rate Delivery (ISSUE-34)
          8. [12]Continuous Streaming (ISSUE-35)
          9. [13]Parental Controls (ISSUE-36)
      * [14]Summary of Action Items

    <Clarke> Agenda:

      [15] http://www.w3.org/2011/webtv/wiki/MPTF/Agenda_Telco_18th_August_2011

    <inserted> scribe: francois

Procedure for submitting comments to LC bugs

    Kaz: checking with Philippe le Hégaret.

    Clarke: Bob, do you know?

    Bob: to respond to a comment? Just hit Bugzilla and add a comment.
    Pretty straightforward.

    Jan: I didn't want to make the bug look alive when I'm simply
    looking for clarification on proposed solution.

    [I confirm, simply hitting Bugzilla with comment should be good]

    Kaz: you already submitted a bug, right? You need an account

    Bob: That's correct.

Provide link to MediaStream

    Bob: I think I sent that out.

    Jan: Yes, sorry I didn't respond.
    ... We can take it over by email.

Agenda for MPTF F2F meeting in September

    Clarke: It looks like we'll have two to four hours for Media
    Pipeline TF.
    ... We'll ensure no overlap with HNTF meeting.
    ... Agenda for today's call includes a list of possible agenda
    items, let me know if you want to add or refine them.
    ... [going through the list]
    ... Pulling out the requirements from the use cases as we do in the
    HNTF. Third item to get a final recommendation for adaptive bit rate
    media as there's been discussion here.

    Bob: Back on the mapping table, I don't expect there will be many
    resolutions on that. I would expect to discuss what needs to be
    done, and hopefully get some insight from chairs as to whether we
    continue that in the MPTF or move to another group in W3C.
    ... Most of the table, we don't have specifications yet.

    Clarke: ok. Next item is DRM, goal is to start discussion here.

    Bob: I have a number of isolated proposals for the workshop.
    ... A number of people have identified DRM as a problem. No use
    cases so far.
    ... I can propose use cases withing MPTF if you think that would be
    good material for the F2F discussion.

    Clarke: yes, I think it would be good to set some context for the
    ... Anybody disagrees with that?

    Bob: We could also reach out to the authors of the proposals talking
    about DRM for the workshop and ask them to contribute that as use
    case for MPTF.

    Clarke: Makes sense, yes.

    Bob: I'll contact people who mentioned DRM, then.

    Clarke: OK. Final item is consolidation of SVG video and video tags.
    A bit hesitant because the topic is large, but it's been discussed
    ... If we can come up with useful recommendations, that could be
    ... Worst case, we end up with diverging solutions.
    ... Any other items?

    [none heard]

    Clarke: ok, feel free to suggest additional topics.

    Narm: Got a lot of discussion about HTTP Live Streaming in Berlin.
    Is the third item about that?

    Clarke: yes, that's exactly meant for that.
    ... The only agenda item I have for today is to review issues. We've
    started to discuss them, but right now there are in the "raised"
    ... I suggest we go through them and see if we're satisfied with
    discussion and can accept use case(s) or need more time.

    <Clarke> issue 31: [16]http://www.w3.org/2011/webtv/track/issues/31

      [16] http://www.w3.org/2011/webtv/track/issues/31

    <kaz> issue-31?

    <trackbot> ISSUE-31 -- Client Ad Insertion -- raised

    <trackbot> [17]http://www.w3.org/2011/webtv/track/issues/31

      [17] http://www.w3.org/2011/webtv/track/issues/31

Client Ad Insertion (ISSUE-31)

    Clarke: we can move it to various status and close it or say it's

    Jan: Looking at the ability to put in the video a cue to play an ad
    at specific time.

    <kaz> [18]Client Ad Insertion

      [18] http://www.w3.org/2011/webtv/wiki/MPTF/MPTF_Discussions/Client_Ad_Insertion

    Bob: Targeted use case is advertising. One of the media stream would
    carry the ad at specific time. You'd like an API so that an
    application can react to the ad.
    ... To replace the ad in the initial stream.
    ... Another use case is to stop the primary stream, play the ad, and
    restart the primary one immediately after.

    [scribe missed last exchanges because of echo]

    Bob: Two fundamental concepts. You have an existing media stream and
    you want to insert something in that. The other idea is that you
    just provide a playlist to the video tag to start with, and the
    browser just plays the playlist.

    Jan: trying to create a very basic type of playlist. Not having to
    do a long playlist.

    Bob: First use case that's described is meant to address this. You
    can easily say: play at the end of the first one.
    ... Then you can create a chain.

    Clarke: Jan, if you can make sure your comment is captured in the
    use case, feel free to do that.

    Jan: will do.

    francois: just to clarify status really mean whatever you want them
    to mean.

    Clarke: suggest to move it to open.
    ... I don't think we should close it right now.

Media Synchronous Web Content (ISSUE-32)

    <Clarke> Issue 32: [19]http://www.w3.org/2011/webtv/track/issues/32

      [19] http://www.w3.org/2011/webtv/track/issues/32


    <trackbot> ISSUE-32 -- Media Synchronized Web Content -- raised

    <trackbot> [20]http://www.w3.org/2011/webtv/track/issues/32

      [20] http://www.w3.org/2011/webtv/track/issues/32

    Clarke: Adequately covered? Do you want to move it to accepted or do
    you think more discussion is needed?

    <kaz> [21]Media Synchronous Web Content

      [21] http://www.w3.org/2011/webtv/wiki/MPTF/MPTF_Discussions/Media_Synchronous_Web_Content

    Bob: I'd like to see this accepted.

    [looks good to me]

    Clarke: OK, let's accept it. If you have further comments, feel free
    to pass them on.

    RESOLUTION: Accept and close ISSUE-32

Timed Text (ISSUE-33)

    Clarke: Two important use cases: closed captions and subtitles.
    There may not be anything new to do, probably covered

    Bob: Yes, this one and ISSUE-32 are pretty much handled but
    worthwhile being explicit, I think as still under development.

    Clarke: right, let's move it to accepted then.

    RESOLUTION: Accept and close ISSUE-33

    Close ISSUE-32

    <trackbot> ISSUE-32 Media Synchronized Web Content closed

    Close ISSUE-33

    <trackbot> ISSUE-33 Timed Text closed

Adaptive Bit Rate Delivery (ISSUE-34)

    Clarke: covers DASH and other formats, how we handle them. I think
    we should continue the discussions online and try to resolve it
    during F2F. Big enough issue to benefit from F2F.

Continuous Streaming (ISSUE-35)

    Clarke: one way to do streaming is to do it as a playlist that gets
    continuously updated.
    ... another is an infinite segment

    <kaz> issue-35?

    <trackbot> ISSUE-35 -- Continuous Streaming -- raised

    <trackbot> [22]http://www.w3.org/2011/webtv/track/issues/35

      [22] http://www.w3.org/2011/webtv/track/issues/35

    <kaz> [23]Continuous Streaming

      [23] http://www.w3.org/2011/webtv/wiki/MPTF/MPTF_Discussions/Continuous_Streaming

    Bob: There is nothing that prevents the video tag from playing a
    stream that is created by a recorder. The second, the ability to
    play a playlist, does not exist.
    ... The requirements would be quite different. I suggest splitting
    the two.

    Clarke: Yes. I think it's a good idea.

    +1 to splitting

    <kaz> +1

    Clarke: I'll split this into two use cases.
    ... The first one is covered, I think we can accept it.

    Jan: Have you considered streaming from [??echo]

    Bob: That's what I had in mind, if you feed stream from a satellite
    or cable and take it to a recorder and then stream it to the browser
    doesn't create any problem as far as we could see.
    ... The play time will wrap around because it's a finite number of
    bits, but that resolves in about 100 years, so no problem.
    ... This is broader than adaptive streaming. Independent of the
    transport, the goal is to support the fact that the stream has not
    start and no end.

    Jan: I think it should cover any form of broadcast.
    ... You could have a dvb scheme and tune directly to a channel.

    Bob: we agree with that scenario. You could have a gateway that
    makes broadcast content available as IP on local network.

    Jan: well, let's take a TV, no need for a gateway, you have a
    broadcast termination here.
    ... You could do VOD on cable.
    ... Understand the focus on video tag in Web browser, but not
    necessarily restricted to that.

    Bob: so you're suggesting to include broadcasting use case here.

    Jan: Yes, I just want to extend it.

    David: Another idea, [linked to program boundaries but scribe

    Bob: related to parental controls. I think we have a use case on
    ... Program boundaries with change of rating.

    [discussion missed because of echo]

    Bob: what I'm suggesting is support for time signals, including
    signals that could be used to identify program boundaries

    David: I understand your comment here.

    Clarke: on ISSUE-35, I'll create a separate use case on playlist
    ... and extend the remaining part to broadcasting (?)

    Jan: [comment on some form of playlist]. It's streaming from the

    Bob: One way to accomplish that is that the JavaScript creates a new
    video element with a unicast stream.

    Jan: that's what I'm trying to avoid: creating another video tag.
    ... I'd like to create a seamless user experience and reuse the
    existing video tag, also easier for developers.

    Bob: Two concepts it seems. You can provide a new source to the
    video tag as of today. It stops playing the first and starts playing
    the second. The first is stopped, not paused.
    ... Not sure what "pause" means for a continuous stream.

    Jan: Not clear on the transition.
    ... Tricky transition.

    Bob: you want both of them displayed?

    Jan: Exactly.

    Bob: sounds you need two video tags, here.

    [echo remains, scribe missed next steps on issue]

Parental Controls (ISSUE-36)

    <kaz> issue-36?

    <trackbot> ISSUE-36 -- Parental Controls -- raised

    <trackbot> [24]http://www.w3.org/2011/webtv/track/issues/36

      [24] http://www.w3.org/2011/webtv/track/issues/36

    Clarke: [going through use case]

    <kaz> [25]Parental Controls

      [25] http://www.w3.org/2011/webtv/wiki/MPTF/MPTF_Discussions/Parental_Controls

    David: independent parental controls, what does it mean?

    Clarke: a bit fuzzy here. The idea is that you would subscribe to
    parental control service.
    ... Perhaps already covered by existing technologies. Need to check.

    David: One challenge here is to have a GUID to give to your

    Bob: why do we need W3C to do this?

    David: Important to identify the level.

    Bob: yes, need some mechanism for content rating to be extracted and
    provided by the application.

    Clarke: Suggestion is to continue the discussion here.
    ... Any other comment?

    [Call adjourned]

    <Clarke> Francois, thanks for scribing

Summary of Action Items

    [End of minutes]
Received on Thursday, 18 August 2011 16:38:19 UTC

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