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RE: [me] minutes - 7 December 2017

From: Chris Needham <chris.needham@bbc.co.uk>
Date: Mon, 11 Dec 2017 08:27:08 +0000
To: Kazuyuki Ashimura <ashimura@w3.org>, "public-web-and-tv@w3.org" <public-web-and-tv@w3.org>
Message-ID: <590FCC451AE69B47BFB798A89474BB363D9F410B@bgb01xud1006>
Thanks Kaz,

For those not able to join the call yesterday, here's a short summary of the outcomes:

- Mounir and Francois from Google talked through the Media Capabilities API [1]. The explainer [2] gives a good introduction, which I encourage you to read.

- A next step is to extend the API to cover HDR displays. Input from IG members on this is welcome.

- Another gap is the ability to query the UA's ability to seamlessly playback streams that switch between different encodings. At TPAC, Mark Vickers presented a document from CTA WAVE with requirements for Media Source Extensions [3].

- Will raised a couple of specific points regarding MPEG CMAF (which Cyril mentioned during the IG meeting at TPAC [4]):

-- Can the video and audio configurations have an optional definition mode in which the corresponding init segment of the media is supplied as a binary object? This will help address deficiencies in codec strings which are insufficient in describing the dynamic range and color volume combinations which may occur in media. These attributes are not captured by the current defined fields of width, height, bitrate and framerate.

-- Can the video and audio configurations have an optional definition mode in which the ISO 23000-19 CMAF presentation profile (for example 'cmfhd', 'cmfhdc', 'cmfhds') is supplied? This provides a cleaner, extensible and more standards-based alternative to the player supplying all the individual properties such as codec, width, height, bitrate and framerate for both audio and video.

- Could the API report on the user agent's ability to decode multiple streams at the same time?

- Although the API is not considered ready for standardisation yet, a Working Group will need to be chartered to continue on the standards track. The scope of this WG could also include related updates to Media Source Extensions.

- Comments or feedback on the API should be submitted as GitHub issues [5].

Kind regards,

Chris (Co-chair, W3C Media & Entertainment Interest Group)

[1] https://github.com/WICG/media-capabilities/blob/master/explainer.md
[2] https://wicg.github.io/media-capabilities
[3] https://www.w3.org/wiki/images/8/8c/Mse-eme-v2-use-cases-reqs-wave.pdf
[4] ISO/IEC JTC1/SC29/WG11 N17098 (not public)
[5] https://github.com/WICG/media-capabilities/issues

From: Kazuyuki Ashimura [ashimura@w3.org]
Sent: 07 December 2017 21:35
To: public-web-and-tv@w3.org
Subject: [me] minutes - 7 December 2017

available at:

also as text below.

Thanks a lot for reviewing/modifying the draft minutes, Chris!




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

                               - DRAFT -

                        Media & Entertainment IG

08 Dec 2017


      [2] https://lists.w3.org/Archives/Member/member-web-and-tv/2017Nov/0007.html


          Kaz_Ashimura, Chris_Needham, Francois_Daoust,
          Francois_Beaufort, Mounir_Lamouri, Peter_Pogrzeba,
          Tatsuya_Igarashi, Alex_Deacon, Giridhar_Mandayam,
          Kazuhiro_Hoya, Will_Law



          kaz, tidoust


     * [3]Topics
         1. [4]Introduction
         2. [5]Media Capabilities API
         3. [6]Next call
     * [7]Summary of Action Items
     * [8]Summary of Resolutions


   <kaz> scribenick: kaz

   Chris: tx for joining
   ... the purpose of this call is sharing information on what's
   going on and new topics
   ... so far, have had calls focusing on second
   screen/presentation api/tv control
   ... a particular interest of the group is the Media
   Capabilities API
   ... so I invited Mounir Lamouri from Google
   ... to share this with us
   ... for discussion and feedback
   ... what is the current status, etc.
   ... what the IG members can do to help it
   ... any other business?
   ... i'd also like to invite topics for future calls of the IG
   ... anything you want the group to look at
   ... tx, Mounir and Francois to join the call today

Media Capabilities API

   Francois_Beaufort: from Google
   ... working on media APIs, getting developer feedback

   Mounir: engineer from Google

   <cpn> [9]https://wicg.github.io/media-capabilities/

      [9] https://wicg.github.io/media-capabilities/

   Chris: current draft above

   Mounir: explainer:
   ... want to know if the browser is able to render the media
   ... need a better solution than the existing canPlayType method
   ... three categories: whether it's supported, whether it will
   play back smoothly,
   ... and whether decoding is power efficient
   ... we didn't want to talk in terms of hardware decoder

     [10] https://github.com/WICG/media-capabilities/blob/master/explainer.md

   ainer.md#decoding-capabilities decoding capabilities

     [11] https://github.com/WICG/media-capabilities/blob/master/explainer.md#decoding-capabilities

   Mounir: work in progress, e.g., vp9

   ainer.md#adaptive-playback-and-transitions adaptive playback
   and transitions

     [12] https://github.com/WICG/media-capabilities/blob/master/explainer.md#adaptive-playback-and-transitions

   Mounir: some use cases
   ... every browser needs to switch codecs
   ... if I try to transition
   ... going back 1k from 4k, etc.
   ... can I decode that?
   ... browser needs to know
   ... we're not looking at getting live feedback with this API
   ... share the information with web sites
   ... quick overview of the API
   ... decoding part mostly there
   ... HDR is a next step
   ... it's in Chrome 64 behind an experimental flag
   ... and planned for Chrome 65 due Q1 next year
   ... Mozilla, Apple expressed interest, also Microsoft
   ... any feedback for the API?

   Giri: privacy concerns

   Mounir: good question
   ... making a lot of information easily available on a web site
   ... finger printing is limited by device's capability
   ... video quality
   ... we think won't be a huge concern

   Igarashi: wondering if it's possible to handle multiple streams

   Mounir: inside of navigator?

   Igarashi: query multiple streams simultaneously

   Mounir: multiple streams at the same time?

   Igarashi: yes

   Mounir: that was a use case
   ... very narrow use case in general
   ... e.g., video conference software
   ... very hard for a browser to get that information
   ... it's very hard to handle multiple streams at the same time
   ... would hear more details for the use case

   Igarashi: will think about that

   Alex: quick question
   ... curious about HDR for next version
   ... can you share what capability for HDR to be added?

   Mounir: decoding side
   ... most of that is streaming side
   ... netflix is pushing it

   Alex: will take a look into that

   Will: focus on mimetype and codec
   ... what about media profile?

   -> [13]https://wicg.github.io/media-capabilities/ draft spec

     [13] https://wicg.github.io/media-capabilities/

   Mounir: not familiar enough
   ... dictionary can be updated

   ions mediaconfiguration

     [14] https://wicg.github.io/media-capabilities/#media-configurations

   Will: may not know about the codec
   ... the second option, to get some ambiguous guess?

   Mounir: not a top use case
   ... we could get some information

   Chris: how this api relates to the information in the dash

   Will: in dash, we don't have actual representation there

   Chris: in terms of the next step
   ... what kind of feedback do you expect?

   Mounir: any feedback would be helpful
   ... we're mostly looking at browser feedback
   ... HDR content, ...
   ... method to decode information
   ... figure out codecs
   ... decode info streaming directly
   ... if you have any issue

   Igarashi: may I ask about the schedule on the implementations?

   Mounir: decoding capability is in Chrome
   ... currently Chrome Dev
   ... Chrome 65 depending on the feedback

   Igarashi: any plan to finalize the CG spec?
   ... timeline?

   Mounir: no concrete plan yet
   ... move forward to a WG
   ... spec itself still need some time

   Igarashi: tx

   Chris: switching between different encodings
   ... requires changes to MSE?

   Mounir: don't remember

   Francois_Beaufort: think it does

   Chris: if we charter a WG to continue this
   ... whether it should be a single WG
   ... as there are related specs such as MSE to update
   ... HTML Media Extensions WG
   ... what's the current status there?

   Fraoucois_Daoust: HTML Media Extensions WG is now for
   ... so no new work
   ... if there is need for new work, need to recharter the WG

   Mounir: same understanding
   ... thinking of knocking at the door of the Web Platform WG

   Fraoucois_Daoust: everything is possible but requires
   ... AC review, etc.

   Mounir: make sense to start to think about WG

   Chris: Mark Vickers presented Media API CG
   ... during TPAC, also use cases for MSE changes coming from CTA

   <inserted> scribenick: tidoust

   Kaz: Have you already had some talk with W3C Team such as
   Wendy, to bring this work to a Working Group?

   Mounir: Not yet

   <kaz> scribenick: kaz

   kaz: at some point, you might want to talk with her

   Chris: are you also working on the Media Playback Quality spec,
   what's the status?

   Mounir: gathering some feedback on different web sites

   Chris: group of specs related to MSE
   ... could be useful to have them under some common WG
   ... not sure if we're ready to do that, though
   ... any more comments/questions?

Next call

   Chris: based on our original plan
   ... maybe Jan. 4
   ... does that work for everybody?

   <alex_deacon> I won't be available on the 4th.

   Chris: and what to be discussed?
   ... organize specific topics around APIs
   ... wondering if we would like to follow up on topics we
   discussed during TPAC
   ... what would be the best usage for this call?
   ... please let us know what you're interested in
   ... we can arrange that
   ... if nothing else for today
   ... would like to thank Mounir and Francois

   Mounir: tx!

   Chris: raise issue on GitHub ok?

   Mounir+Francois_Beaufort: yes

   <alex_deacon> Thanks to all.


Summary of Action Items

Summary of Resolutions

   [End of minutes]

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Received on Monday, 11 December 2017 08:31:08 UTC

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