Hello Blink owners,
We are asking for a breaking period of 3 weeks to this API,
followed by a renewed experiment for the traditional 6 milestones
(2024-May-14 to 2024-Jun-04). A request
<https://groups.google.com/a/chromium.org/g/blink-dev/c/I4RE2pbocTg>that
seems similar to me was granted in January 2022 for another API,
and later shipped successfully with consensus with Mozilla and Apple.
At the time of writing, we have public support
<https://github.com/screen-share/meetings/blob/main/minutes/2023-02-16.md#appendix-a-poll-for-element-capture>for
this API from such companies as Zoom, Jitsi, Mux, DialPad,
Whereby, Intel and Tella. Tango’s co-founder wrote
<https://github.com/screen-share/element-capture/issues/3#issuecomment-1483660309>“I
can't emphasize enough how instrumental this specification would
be for our product and user experience.” However, none of them
have signed up for the OT as of yet.
From the OT perspective:
This API allows Web developers to build novel new features;
however, it requires a non-trivial investment. We are hoping that
after giving more time, we will see more participation.
From the standardization perspective:
We need time to pick up discussions with Mozilla and Apple again.
As Chrome’s Security and Privacy experts do not share the
concerns Mozilla and Apple have previously voiced, it stands to
reason that additional discussions will allow us to converge -
and we will prioritize these discussions now.
Additionally, some possibilities remain for API changes that
could perhaps allow for a compromise, mostly around cross-origin
isolation. (Full disclosure - this is not my ideal outcome, but
it’s a fallback possibility worth mentioning.)
Progress made:
*
Spec:The spec has evolved and is now more mature, dealing
better with such edge cases as loss of “eligibility for
restriction.”
*
TAG:Previously we held off on the request for a TAG review
until we got some more developer feedback about the API
shape. Having received this initial feedback, the TAG request
<https://github.com/w3ctag/design-reviews/issues/954>has now
been submitted.
*
Signals:Signals have been requested. Mozilla responded. We
intend to prioritize this discussion with them now.
*
Feedback:Outreach for feedback from the spec community -
multiple issues
<https://github.com/screen-share/element-capture/issues?q=is%3Aissue>were
filed on the spec by Web developers.
*
WPT:Coverage has recently been extended
<https://chromium-review.googlesource.com/c/chromium/src/+/5404107/15/third_party/blink/web_tests/external/wpt/mediacapture-streams/BrowserCaptureMediaStreamTrack-restrictTo.https.html>.
Reasons to run a new trial:
Gain additional feedback from new participants. Examples for
remaining areas where new feedback could help include:
*
Uncover new edge cases which were not uncovered by the spec
authors and reviewers, implementers and current OT
participants. The current edge cases here
<https://screen-share.github.io/element-capture/#elements-eligible-for-restriction>demonstrate
how non-obvious these may be.
*
Validate (or refute) the assumptions we have made about the
viability of an MVP that is missing some functionality. Examples:
o
Events notifying apps when an element stops/starts being
“eligible for restriction”.
o
Mechanism to force elements into an “eligible for
restriction” state.
*
Encourage future OT participation by Web developers, by
demonstrating that risks associated with relying on an origin
trial, while real, are partially offset by a commitment to
keep the OT going until discussions conclude.
Thanks,
Elad
On Monday, November 27, 2023 at 4:00:11 PM UTC+1 Elad Alon wrote:
Thank you for updating, Jan-Ivar. I have now updated this
information in the ChromeStatus entry. I am looking forward
to carry on the discussion about your position in your
standards-positions GitHub repo, in the Element Capture spec
repo, in the Screen Capture CG and in the WebRTC WG.
On Monday, November 27, 2023 at 3:53:51 PM UTC+1
jbru...@mozilla.com wrote:
The Gecko position has been updated to negative. See
https://github.com/mozilla/standards-positions/issues/857
On Monday, November 20, 2023 at 6:41:00 AM UTC-5 Elad
Alon wrote:
Contact emails
elad...@chromium.org
Explainer
https://github.com/screen-share/element-capture/blob/main/README.md
<https://github.com/screen-share/element-capture/blob/main/README.md>
Specification
https://screen-share.github.io/element-capture
<https://screen-share.github.io/element-capture>
Summary
API for capturing a subtree of the DOM.
Given a video MediaStreamTrack obtained through
pre-existing means to initiate tab-capture, Element
Capture allows mutating the track to only capture a
subtree of the DOM starting at a given Element.
The API bears some resemblance to the Region Capture
API, but affords greater flexibility for
applications, because occluding and occluded content
are both excluded from the capture.
Blink component
Blink>GetDisplayMedia
<https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EGetDisplayMedia>
TAG review
We are holding off on the request for a TAG review
until we get some more developer feedback about the
API shape.
TAG review status
Pending
Risks
Interoperability and Compatibility
Gecko: Under consideration
(https://github.com/mozilla/standards-positions/issues/857
<https://github.com/mozilla/standards-positions/issues/857>)
WebKit: No signal
(https://github.com/WebKit/standards-positions/issues/280
<https://github.com/WebKit/standards-positions/issues/280>)
Web developers:
Positive See upvotes and comments on the following:
* https://github.com/WICG/proposals/issues/73
<https://github.com/WICG/proposals/issues/73>
* https://twitter.com/quicksave2k/status/1583388663597015042
<https://twitter.com/quicksave2k/status/1583388663597015042>
Other signals:
WebView application risks
Does this intent deprecate or change behavior of
existing APIs, such that it has potentially high risk
for Android WebView-based applications?
Goals for experimentation
* Solicit more informed Web developer feedback to
validate the API shape.
* Ensure that the feature works correctly in
conjunction with adjacent features.
Debuggability
No changes to DevTools are intended.
Will this feature be supported on all six
Blink platforms (Windows, Mac, Linux, Chrome
OS, Android, and Android WebView)?
No
This API is supported on all desktop platforms.
Mobile platforms are unsupported because
screen-capture itself is unsupported on those platforms.
Is this feature fully tested by
web-platform-tests
<https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?
Not yet (but we’re working on extending coverage)
Flag name on chrome://flags
element-capture
Finch feature name
ElementCapture
Tracking bug
https://bugs.chromium.org/p/chromium/issues/detail?id=1418194
<https://bugs.chromium.org/p/chromium/issues/detail?id=1418194>
Launch bug
https://launch.corp.google.com/launch/4240472
<https://launch.corp.google.com/launch/4240472>
Estimated milestones
Shipping on desktop
121
Link to entry on the Chrome Platform Status
https://chromestatus.com/feature/5198989277790208
<https://chromestatus.com/feature/5198989277790208>
Links to previous Intent discussions
Intent to prototype:
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMO6jDO6y5b6y3q9QEd2scsYPWuWLJBnPLgwm%2BaHpKx36CYMwA%40mail.gmail.com
<https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CAMO6jDO6y5b6y3q9QEd2scsYPWuWLJBnPLgwm%2BaHpKx36CYMwA%40mail.gmail.com>
This intent message was generated by Chrome Platform
Status <https://chromestatus.com/>.
--
You received this message because you are subscribed to the
Google Groups "blink-dev" group.
To unsubscribe from this group and stop receiving emails from it,
send an email to blink-dev+...@chromium.org.
To view this discussion on the web visit
https://groups.google.com/a/chromium.org/d/msgid/blink-dev/073738e4-cb2f-4a1a-9299-cf134f971a67n%40chromium.org
<https://groups.google.com/a/chromium.org/d/msgid/blink-dev/073738e4-cb2f-4a1a-9299-cf134f971a67n%40chromium.org?utm_medium=email&utm_source=footer>.
