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Minutes from Media & Entertainment IG call, 3 July 2018

From: Chris Needham <chris.needham@bbc.co.uk>
Date: Thu, 5 Jul 2018 16:04:59 +0000
To: "public-web-and-tv@w3.org" <public-web-and-tv@w3.org>
Message-ID: <590FCC451AE69B47BFB798A89474BB363E146DEB@bgb01xud1006>
Hi all,

The minutes from the last Interest Group call on Tuesday 3rd July are available [1], and copied below. Many thanks to Kaz for helping to scribe. My audio connection was bad, so unfortunately I wasn't able to capture everything.

Our next call is Tuesday 7th August. Please get in touch if you have specific topics you'd like to suggest for the next call.

Kind regards,

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

[1] https://www.w3.org/2018/07/03-me-minutes.html


Media & Entertainment IG monthly call

03 Jul 2018


        Kaz_Ashimura, Francois_Daoust, GeunHyung_Kim, Mark_Vickers, Steve_Morris, Tatsuya_Igarashi, Chris_Needham, Will_Law, Nigel_Megitt, Masaru_Takechi, Ali_C_Begen


    Chris_Needham, Mark_Vickers, Tatsuya_Igarashi

    cpn, kaz


    CTA WAVE HTML5 API Task Force
    Web Media API spec
    Web Media Application Developer Guidelines
    Web Media User Agent Intergration
    Next call

Summary of Action Items

Summary of Resolutions

<cpn> scribenick: cpn

<kaz> minutes from the previous IG call

Mark: Thanks everyone. This is the second meeting about the CTA WAVE programme
.... Last month we gave an overview of the organisation, and focused on the content part of the spec.
.... This month I'll talk about the HTML5 part of the effort.
.... I'm not only co-chair of the M&E IG, but also the HTML5 API TF at CTA WAVE, and also co-chair of the Web Media API CG
.... These two groups are really the same thing. It's the same people doing the same work. The work is publicly visible, as with other CGs.
.... I'll describe the overall aspects, then the 3 specs we're working on.
.... The work sits between the MPEG world and W3C.
.... There's the Content Spec TF, Device Playback Capabilities TF, and HTML5 API TF.
.... The overall goals are unifying media formats for HLS and DASH, in the content spec.

<kaz> Mark's slides

Mark: The HTML5 group is not advocating a world where all devices need to have HTML5,
.... we're trying to unify HTML and CE platforms.
.... There are three specs we're working on now.
.... The first is the Web Media API spec. This is a spec and associated tests to bring consistent HTML across devices.
.... The next document is Web Media Application Developer Guidelines, i.e., guidelines for how to make media web apps. This is close to being finished.
.... The other is an integrators spec, the Web Media User Agent Integration spec.
.... We're also working at W3C and WHATWG on gaps identified.
.... There's a 100% overlap with the M&E IG, i.e., improving support for media in HTML5.
.... At the beginning, we considered doing this inside the IG, but we can't write specs in the IG, hence creating a CG.
.... This also allowed WAVE members to participate.

Web Media API spec
<kaz> Web Media API CG GitHub repo

<kaz> CG Report

Mark: The first published version of the Web Media API Snapshot - this is a snapshot of APIs that all devices should support.
.... It was published in December 2017, and then at least once annually, next in Q4 2018.
.... There's a formal agreement between CTA and W3C to co-publish the spec, as the W3C CG spec and the CTA spec.
.... This way we're keeping CTA and W3C standards tied-in, to avoid branching from W3C.
.... We had a plan to move the CG spec to W3C standards track. We've not done that yet, no urgency to do so.
.... We're working with Fraunhofer Fokus to create a test suite based on the W3C API tests.
.... Every device should support the APIs, so the API tests are to collect together the W3C tests, EME, MSE, other specs as listed in the API snapshot.
.... This will be made available freely and publicly.
.... The changes to the snapshot and test suite will be incremental.
.... The browsers are four major code bases, three of which are open source. CE devices typically use the open source codebases,
.... but sometimes based on older versions, so out of date.
.... The final spec is at the porting layer, where you take a general purpose software stack, e.g., Webkit, and tie it to the device.
.... Considerations include mapping of keys on a remote device, all aspects of hardware integration. This spec hasn't been released yet.
.... This is not an area generally addressed at W3C, but one we feel is needed.
.... Issues are open to the public, anyone can add and contribute.
.... Dave Evans from BBC and myself are the co-editors of the Web Media API spec.
.... All the specs listed in the Web Media API are supported by all four codebases.
.... We'll have tests for each spec that will tell you if your version is compatible. We're taking these specs and our tests will be a subset of the W3C tests that run correctly on all 4 codebases.
.... Currently, not all codebases pass all the tests. The only way you won't pass is if you're running an old version of a browser.
.... It's not unusual for CE products to release with 3 or 4 year old browsers, so we use this to encourage CE manufacturers to bring their browsers up to date, and using the tests to do that.

Web Media Application Developer Guidelines
<kaz> Web Media Application Developer Guidelines

Mark: Looking at the Web Media Application Developer Guidelines, we have 3 editors. The document talks about media playback use cases, content encoding issues, web app structure and issues.
.... Anyone making web apps using HTML5 video is encouraged to look at this and file issues.
.... Any comments are welcome now. The GitHub issues are public.

Web Media User Agent Intergration
<kaz> Web Media User Agent Integration

Mark: The third spec, the UA Integration spec. This is the link between the portable codebases, eg., Chromium, and the underlying hardware.
.... This is where we can find portability issues.
.... Some example issues in the issue tracker. For example, key codes, minimum graphics performance, UA string formatting, URL length requirements.
.... These are things which are either issues for portability or may need testing. No final decision yet as to which of these are to be included.
.... What is really needed on this spec is additional editors. Jon Piesing is on this, but he's not had time to write the whole spec. Is someone in our community interested in signing up to work with us?

Mark: So that's a summary of the CTA WAVE HTML5 API work. Any questions?

<kaz> scribenick: kaz

Chris: Is there any work on automation of the web platform tests for CE devices?

Mark: Good point. In addition to taking the available W3C specs,
.... and looking for which tests pass across the main browser codebases,
.... the RFP for the testing work included using smart TV and set top box, picking 3 CE devices.
.... We have had to make changes to the W3C Test Platform, giving feedback for the test runner.
.... We have very good representation from manufacturers at CTA WAVE (shows WAVE Membership list),
.... and contributions into W3C.

Chris: What's the criteria to select tests? As the WPT is continually updated, do you select a baseline set of browser versions to test against?

Mark: Yes, we have to pick a version.
.... The four main codebases are Google Chrome, Firefox, Webkit, MS Edge.
.... These tests can uncover porting issue as well.
.... We run the test suite against some known version of the browser, typically we'd choose a particular snapshot at Q4 in the year

<Zakim> nigel, you wanted to ask if the tests only apply to APIs or also to conformant support of media formats

Nigel: Are these test about APIs only, or do they also cover support for media formats?

Mark: This is addressed more through the Content Spec.
.... The Content Spec TF extends MPEG CMAF spec,
.... and the group also generates streams which are conformant.
.... The Device Playback Capabilities TF works on dynamic content changes.
.... I would encourage you to take a look what is done by the TF, the specs are in draft.

Chris: About the HTML5 API spec, it would seem to have broader value than just CE TV devices, e.g., mobile. Any contact with mobile manufactures?

Mark: Absolutely, there are mobile manufacturers in WAVE. The scope of what we're doing isn't just TV and game consoles, it includes mobile devices and PCs too.
.... (shows WAVE member list)
.... The target devices will include any device that runs a modern HTML user agent, including televisions, game machines, set-top boxes, mobile devices and personal computers.

Chris: One final question. The porting spec is interesting, I imagine this could uncover issues in other specs,
.... an example I've seen recently is work happening now to tighten up the Document.cookie API, which may be underspecified right now.

<cpn> -> https://github.com/whatwg/html/issues/804 and https://github.com/w3ctag/design-reviews/issues/290

Chris: I expect the porting spec could uncover similar such issues.

Mark: That's exactly how it is.
.... We have an issue about explicitly requiring cookies, as the cookie spec is optional.

https://github.com/w3c/webmediaporting/issues/6 issue 6

Mark: There is another issue we found, a gap on the full-screen spec, which we reported to WHATWG
.... and had discussion with them.

https://github.com/w3c/webmediaapi/issues/22 issue 22

Chris: Thanks a lot for giving this presentation, Mark.

Chris: One final thing I would like bring to people's attention is that there is now work ongoing in WICG to update Media Source Extensions.
.... I raised this on the IG's issue tracker, but now is a good time to revisit the WAVE requirements around MSE.

Next call
Chris: Our next call will be on Tuesday, August 7th.


Summary of Action Items
Summary of Resolutions
[End of minutes]
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$Date: 2018/07/05 04:49:52 $

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Received on Thursday, 5 July 2018 16:57:52 UTC

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