[minutes] May 2024 meeting

Hi,

The minutes of the WebRTC WG meeting held yesterday (May 21st 2024) are 
available at:
   https://www.w3.org/2024/05/21-webrtc-minutes.html
and the video recording at:
   https://www.youtube.com/watch?v=SsruLUC6uew

and copied as text below - thanks to Carine for scribing!

Dom

                         WebRTC Interim, May 21st

21 May 2024

    [2]Agenda. [3]IRC log.

       [2] https://www.w3.org/2011/04/webrtc/wiki/May_21_2024
       [3] https://www.w3.org/2024/05/21-webrtc-irc

Attendees

    Present
           Anssi Kostiainen, Bernard Aboba, Carine Bournez, Elad
           Alon, Florent Castelli, Fredrik Solenberg, Guido
           Urdaneta, Harald Alvestrand, Jan-Ivar Bruaroey, Michiel
           De Backker, Paul Adenot, Peter Thatcher, Sameer
           Vijaykar, Sun Shin, Tony Herre, Tove Peterson, Youenn
           Fablet

    Regrets
           Dom

    Chair
           Bernard, HTA, Jan-Ivar

    Scribe
           caribou

Contents

     1. [4]Captured Surface Control (Elad Alon)
     2. [5]Issue 225: Add captureTimestamp senderCaptureTimeOffset
        to the encoded frame metadata
     3. [6]Issue 226: Expose RTCEncodedAudioFrame interface in
        Worklets
     4. [7]Issue 1003: repo name nit: it'd be nice if this were
        simply w3c/mediacapture
     5. [8]Issue 966: Should devicechange fire when the device info
        changes? (Jan-Ivar)
     6. [9]Local Peer-to-Peer API (Anssi Kostiainen, Michiel De
        Backker)
     7. [10]RtpTransport (Peter Thatcher)
     8. [11]Summary of resolutions

Meeting minutes

    Recording: https://www.youtube.com/watch?v=SsruLUC6uew

    Slideset: [12]https://lists.w3.org/Archives/Public/www-archive/
    2024May/att-0003/WEBRTCWG-2024-05-21.pdf

      [12] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf

   Captured Surface Control (Elad Alon)

    Elad: API shape proposal, slide 13

    [13][Slide 13]

      [13] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=13

    [14][Slide 14]

      [14] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=14

    Elad: Any browser support zoom levels that are reasonable

    [15][Slide 18]

      [15] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=18

    Peter Thatcher: I'd propbably think of changing the slides, not
    just scrolling/zooming

    Elad: it's right that other things could be possible

    Jan-Ivar: What you showed is useful. UC are appealing
    … remotely controlling user content might be troublesome

    Elad: it's difficult to put the controls at the browser level

    Elad: most convincing case is with multiple scrollbars

    Peter: the JS application controls the scrolling from another
    tab?

    Elad: true

    Peter: I don't know what the scrolling event do in the page
    … not sure the users understand that

    Elad: you don't do screen sharing with any app
    … the context is more constrained
    … there's a mention saying "this is shared and can be scrolled
    and zoomed"
    … and that offers revokation

    Youenn: more intergration would avoid prompting
    … with media elements, there are elements that can be showed to
    users
    … some web devs used them, some put eveything to off and
    reimplement
    … a hybrid approach between prompting and media control would
    be good

    Elad: I'd like to enable apps to put the zooming control
    wherever they want

    Youenn: CSS applied to the text track can be user agent
    specific
    … this idea can be reused there

    Elad: I understand the benefits but it
    … is limiting the UX
    … Scrolling is more difficult, so maybe we should split
    discussion with zooming

    Youenn: you can zoom screens, windows, etc.
    … we'd need to be sure it is applicable

    Elad: our next step is to work on shape for zooming windows

    Bernard: Region capture restricts sharing to a portion of
    screen
    … how does this combine with zooming/scrolling?

    Elad: the application still has access to all the pixels but
    removes the cropped zone

    Bernard: if I call cropTo , will the scrolling stop at the
    boundaries?

    Elad: we can discuss interaction of those APIs

    Jan-Ivar: in the UI exposing the controls
    … [that's visible in slide 12]
    … I'd love to pursue an approach where the application is
    choosing where to show the indicator

    Elad: you're supposed to trust the application

    Guido: @@@

    Elad: are there any measures as security gap?

    Youenn: on event click

    Elad: after the prompt, we don't require user activation

    Jan-Ivar: it'd be good to understand the remote user UC

    Elad: I trust the videoconferencing app to be safe

    Youenn: you already say that some restrictions on the API
    … would not go well with remote control
    … so the model seems to be for remote control UC
    … maybe we do NOT want remote control
    … so not loosen security

    Elad: It's not clear why we want to block remote control

    Jan-Ivar: any kind of remote control has security concerns

    Elad: it's not proven that this API would increase the ability
    to trick people

    Jan-Ivar: most scammed people are told to download remote
    control apps

    Elad: this API does not has a click API

    Bernard: I agree with Florent that we should have no keyboard
    events either
    … very well-defined limits is essential

    Elad: I'd like to discuss whether it's the browser or the app
    that offers
    … next steps?
    … discussion on whether to outscope remote control

    Youenn: where is it?

    Elad: screen capture CG so far

    RESOLUTION: continue discussion in the screen capture CG repo

   [16]Issue 225: Add captureTimestamp senderCaptureTimeOffset to the
   encoded frame metadata

      [16] https://github.com/w3c/webrtc-encoded-transform/issues/225

    [17][Slide 22]

      [17] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=22

    [Florent Castelli presenting]

    Florent: this is for calculation of the delay

    Bernard: it looks like a good idea
    … it would be useful to construct encoded frames

    Youenn: the definition of locally captured frame needs to be
    precise

    Bernard: next step is to review. any objection to this?

    RESOLUTION: next step on issue 225 is to review the PR

   [18]Issue 226: Expose RTCEncodedAudioFrame interface in Worklets

      [18] https://github.com/w3c/webrtc-encoded-transform/issues/226

    [19][Slide 23]

      [19] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=23

    Youenn: with an audio worklet, you'd want to share the buffer
    … a variant of shared buffer would be a readable stream
    … you push the read buffer from the worklet

    Florent: it would be approach (1), but it might be a problem
    for performance
    … so preference to run everything in the worklet

    Youenn: it's worth getting numbers

    Florent: yes, we want to get more data to make sure it's the
    right thing

    Paul Adenot: as an Audio WG person, I'd say that the 2nd
    proposal cna't be done
    … because it requires GC
    … 1st is likely to work with higher performance
    … we can do BYOB

    Paul: can someone send a link to a BYOB approach, for the audio
    WG?
    … it seems to have the right properties
    … if you need something from the Audio WG, please open an issue
    there

   [20]Issue 1003: repo name nit: it'd be nice if this were simply
   w3c/mediacapture

      [20] https://github.com/w3c/mediacapture-main/issues/1003

    Jan-Ivar: this is an chair/editorial? issue
    … can this repo name be changed to be aligned ?

    Harald: when we split WebRTC and mediacapture streams, we
    thought mediacapture would be the main spec, hence the "main"
    here
    … renaming is possible but lots of links might break

    Elad: GH gives you redirect

    Anssi: speaking of experience, make sure to redirect all

    RESOLUTION: Mediacapture-streams will be renamed to
    Mediacapture

   [21]Issue 966: Should devicechange fire when the device info changes?
   (Jan-Ivar)

      [21] https://github.com/w3c/mediacapture-main/issues/966

    [22][Slide 28]

      [22] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=28

    Youenn: I don't think safari violates this
    … Safari is exposing fake devices
    … when the user allows, the real list is exposed
    … it's allowed by the spec

    Jan-Ivar: the stored device list is not changed?

    Youenn: It is changed
    … it's not sending the real list before it's allowed

    Jan-Ivar: I'll amend this slide.

    [23][Slide 29]

      [23] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=29

    Guido: is the device list event enough to see the change?

    Jan-Ivar: the advice is to compare the lists
    … but you can't distinguish when a user really added a device
    … or if it's a change in exposure

    Guido: so you'd fire 2 events?

    Jan-Ivar: yes

    Youenn: suggest to just use a flag on existing event
    … so just devicechange is sufficient

    Jan-Ivar: how do you know which specific device is changed?

    Youenn: maybe more than a boolean flag needed
    … I'd like to extend the existing event

    Guido: same feedback, it's backwards compatible
    … not sure if a boolean is enough, we'll give a bit more
    thinking

   Local Peer-to-Peer API (Anssi Kostiainen, Michiel De Backker)

    [24][Slide 32]

      [24] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=32

    Anssi: this is developed in WICG
    … Driving motivation is trust on local network
    … Martin Thompson also explored https on local network

    [25][Slide 33]

      [25] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=33

    [26][Slide 34]

      [26] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=34

    [27][Slide 35]

      [27] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=35

    Michiel: it's quite similar to WebRTC architecture

    [28][Slide 36]

      [28] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=36

    Michiel: Feedback, Questions?

    Bernard: we have a few minutes

    Youenn: my initial reaction is that local discovery is usually
    behind OS security protection

    Michiel: we use permissions
    … for each origin

    Peter: I really like the use cases
    … also the idea that we can use existing APIs
    … looking foward to participate

    Florent: I hope that we won't duplicate APIs with just little
    differences
    … Can it be used to commumincate between 2 tabs from a local
    browser?

    @@@

    Harald: why replacing all components?
    … transporting rtp packets is well known
    … rtp over QUIC
    … separate components can avoid replacing

    Michiel: we want to be able to introduce the least amount of
    new things

    Harald: if you have a key exchange mechanism it would be a
    smaller change
    … in webRTC the media part is relying on dtls

    Jan-Ivar: I don't think data channel is going to help
    … it's derived from web sockets
    … similarity is superficial
    … Web Transport is currently Client-Server

    Bernard: let's do something at TPAC

    Anssi: We welcome new contributors
    … let's keep exploring. thank you for the time

   RtpTransport (Peter Thatcher)

    [29][Slide 56]

      [29] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=56

    [30]Explainer

      [30] 
https://github.com/w3c/webrtc-rtptransport/blob/main/explainer-use-case-1.md

    [31]More on congestion control etc.

      [31] 
https://github.com/w3c/webrtc-rtptransport/blob/main/explainer-use-case-2.md

    [32][Slide 70]

      [32] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf#page=70

    Peter: feedback requested

    Are all of your (relevant) use cases covered?

    If not, file an issue at [33]https://github.com/w3c/
    webrtc-rtptransport/issues

      [33] https://github.com/w3c/webrtc-rtptransport/issues

    Would you like to comment on the question of Workers?

    Go to [34]w3c/webrtc-rtptransport#33

      [34] https://github.com/w3c/webrtc-rtptransport/issues/33

    Would you like to comment on the API shape while maintaining
    perf

    Go to [35]w3c/webrtc-rtptransport#20

      [35] https://github.com/w3c/webrtc-rtptransport/issues/20

    Have any other thoughts/ideas?

    File an issue at [36]https://github.com/w3c/
    webrtc-rtptransport/issues

      [36] https://github.com/w3c/webrtc-rtptransport/issues

    Bernard: [referring to slide 56] Your AC seems to cover all 4
    webRTC extended UCs

    Peter: the 1st explainer covers a lot

    Youenn: I like the focus on custom packetization
    … we'll probably need a definition of a "packet source"
    … e.g for the new encoded video frame
    … About worker/not worker, it depends on whether you transfer
    dynamically

    Bernard: UC for dynamic transfer?

    Youenn: not really. only very complex
    … a fixed place is simpler and covers most cases

    Harald: a frame level API is more convenient to work with

    Jan-Ivar: there are a lot of security issues
    … security models of browsers ...
    … I hope we can integrate existing tech more
    … API-wise, we have similar low-level APIs in webRTC

    Youenn: I had similar concerns on encoded transform

    Bernard: I think the plan is to refine the UCs
    … the Game Streaming UC may not belong here

    Bernard: this can be a TPAC topic

    Bernard: ADJOURNED

    Slideset: [37]https://lists.w3.org/Archives/Public/www-archive/
    2024May/att-0003/WEBRTCWG-2024-05-21.pdf

      [37] 
https://lists.w3.org/Archives/Public/www-archive/2024May/att-0003/WEBRTCWG-2024-05-21.pdf

Summary of resolutions

     1. [38]continue discussion in the screen capture CG repo
     2. [39]next step on issue 225 is to review the PR
     3. [40]Mediacapture-streams will be renamed to Mediacapture

Received on Wednesday, 22 May 2024 09:21:28 UTC