Thanks Yoav for taking the time to get involved with the issues. As you mentioned, #11 is resolved by a PR we're working to merge, which means there are only 2 "points of contention".
I noticed performance is absent from your points of contention. which I think reflects great progress made in #17 in just a week, since that was a claim from the Chrome team earlier that I think we put to bed. #48 was opened just 5 days ago when we discovered Chrome had previously undisclosed needs here (the spec says it cannot fail). It seems early to call this one (unless you're tied to a certain outcome). I find the characterization of people trying to be helpful as "back-seat implementation design" unfortunate, since Chome's claims to the WG were about implementation hardship, claiming few if any actual web developer benefits from their design. I think that sets the terms of conversation to be about implementation, and short of responding with "not our problem, we disagree this is hard to implement", I'm not sure what we could have said that wouldn't be characterized this way. I'm concerned that what Chrome would ship would not be what ends up being standardized, given how issues are progressing. This is not the same state we found ourselves in earlier, since some issues have been solved and others found. Since a major customer voiced in #17 they were open to any of the proposed spec alternatives, it seems odd that the Chrome team is holding on to what amounts to minor design aspects they've been unable to defend or demonstrate much web developer benefit from. On Tue, May 24, 2022 at 5:46 AM Yoav Weiss <yoavwe...@chromium.org> wrote: > After carefully studying the discussions on the various threads (as well > as participating in them, trying to bridge the gaps), my previous LGTM > still stands. > > I believe there are 3 points of contention: > * API shape esthetics > <https://github.com/w3c/mediacapture-region/issues/11> (#11) > * Async nature of CropTarget minting > <https://github.com/w3c/mediacapture-region/issues/17> (#17) > * Whether CropTarget minting should be able to fail > <https://github.com/w3c/mediacapture-region/issues/48> (#48) > > On API shape esthetics, we've managed to reach a reasonable compromise > that's being defined in #50 > <https://github.com/w3c/mediacapture-region/pull/50>. Please make sure > that we're shipping the shape defined there, as well as that the PR itself > lands at some point. > > As for the need for async minting and their potential failure, I tried to > clarify the processing model in #47 > <https://github.com/w3c/mediacapture-region/pull/47>. It'd be great if we > can land those parts in the spec as well. > At the same time, the discussions on #17 and #48 don't seem to converge, > and revolve mostly around back-seat implementation design, which IMO is > somewhat out-of-place for a WG discussion. > > Going with an *async API that can fail* is justified given the > implementation experience we have so far for this feature, and seems like > an overall more *conservative future-compat choice*, as we can go back on > either of those decisions if future implementations prove that either or > both of those characteristics are not needed. It also seems like these are not > issues that web developers that used the feature as part of its Origin > Trial deem critical > <https://github.com/w3c/mediacapture-region/issues/17#issuecomment-1134934556> > . > > > > On Thu, May 5, 2022 at 10:09 PM Yoav Weiss <yoavwe...@chromium.org> wrote: > >> Hey Jan-Ivar, >> >> Apologies, as I missed the recent activity on issue 11 >> <https://github.com/w3c/mediacapture-region/issues/11#issuecomment-1112514784> >> before >> LGTMing. I'll re-review in that light. >> >> On Thu, May 5, 2022 at 9:22 PM Jan-Ivar Bruaroey <jbruar...@mozilla.com> >> wrote: >> >>> Hi Youav, the WG is making progress in >>> https://github.com/w3c/mediacapture-region/issues/11#issuecomment-1112514784 >>> with good feedback from other Google folks. This progress suggests a >>> likelihood the WG will go a different direction here, which means Chrome >>> shipping now would most likely create a web compatibility headache. Can it >>> be held off a month to resolve this? >>> >>> The referenced TAG meeting notes, say it's "*Not the TAG's job to pick >>> a winner*" which seems to conflict with a LGTM. The WG is making >>> progress, so it seems premature to expect the TAG to call disputes, which >>> it sounds like they're saying. Also: >>> >>> 1. The statement *"interoperability is an imperative ... not what is >>> most technically pure"* seems out of place wrt Origin trials. If >>> interoperability with an Origin Trial is now a thing, it's an argument to >>> stop having them. >>> >>> I don't think anyone is arguing in favor of interoperability with the >> existing Origin Trial. >> >> >>> >>> 1. Web APIs are forever. If we can't consider "technical purity" of >>> a brand new API ahead of shipping, then when? >>> >>> 2. The statement *"a lot of elements not visible... these make no >>> sense to set a crop target on"* — means the current API is >>> misleading: The "target" construct (which isn't "set") has nothing >>> inherently to do with cropping, but is merely solving the sub-problem of >>> passing an element from a different realm into the track.cropTo() method. >>> As discussed in #11 better ways would be to reuse element.id or a >>> new element.weakRef serializable interface. >>> >>> Finally, the absence of any argument that the present API is better in >>> ANY respects for web developers, should cause pause. All arguments I've >>> heard instead seem centered on what's easier for browsers to implement >>> (where "easier" subjectively seems tied to choices the Chrome >>> implementation has made). Better API shapes are on the table, and no-one's >>> arguing they're unimplementable. >>> >>> We should do better for web developers here and get the shape right. >>> >>> Cheers, >>> >>> On Monday, May 2, 2022 at 7:16:33 AM UTC-4 yoav...@chromium.org wrote: >>> >>>> LGTM1 >>>> >>>> Thanks for initiating those discussions. My read of the minutes is that >>>> they consider the async approach to be fine, and don't arbitrate on the >>>> naming questions, other than saying that none of the proposals seem better >>>> than where this API has landed. (and some may add confusion) >>>> As such it seems that going with the API as currently defined doesn't >>>> bear significant interoperability risk. >>>> >>>> >>>> >>>> On Mon, May 2, 2022 at 1:03 PM Elad Alon <elad...@google.com> wrote: >>>> >>>>> The discussions around Region Capture have been brought up with TAG >>>>> again (after their original approval >>>>> <https://github.com/w3ctag/design-reviews/issues/710#issuecomment-1055212077> >>>>> of the design). Here are the minutes from that second meeting: >>>>> >>>>> https://github.com/w3ctag/meetings/blob/gh-pages/2022/telcons/04-25-minutes.md#media-capture-region >>>>> >>>>> On Wednesday, April 20, 2022 at 6:33:52 PM UTC+2 yoav...@chromium.org >>>>> wrote: >>>>> >>>>>> Just to (belatedly) update this thread: Following a discussion with >>>>>> the API owners and the intent owner a few weeks back, they are planning >>>>>> to >>>>>> try and get more folks to weigh in on the open issues, and hopefully >>>>>> break >>>>>> the tie. >>>>>> >>>>>> On Wednesday, March 23, 2022 at 6:28:30 PM UTC+1 Elad Alon wrote: >>>>>> >>>>>>> It may be better to ask actual web developers regarding the least >>>>>>>> confusing option amongst those proposed. >>>>>>> >>>>>>> >>>>>>> The Web-developers I am in contact with are happiest with >>>>>>> CropTarget. One of them has mentioned that on issue #18 >>>>>>> <https://github.com/w3c/mediacapture-region/issues/18>. >>>>>>> Other Web-developers have not shown up with a preference one way or >>>>>>> another. >>>>>>> >>>>>>> It bears mentioning that we have been discussing the API in the >>>>>>> WebRTC Working Group for approximately 14 >>>>>>> <https://docs.google.com/presentation/d/1crumgYj4eHkjo04faLktPTg0QoYJhTFoosEBudfJBuw/edit#slide=id.g7954c29f8a_2_0> >>>>>>> months >>>>>>> <https://docs.google.com/presentation/d/1crumgYj4eHkjo04faLktPTg0QoYJhTFoosEBudfJBuw/edit#slide=id.g7954c29f8a_2_0>. >>>>>>> The initial name for this part of the API was CropID. It was changed >>>>>>> <https://github.com/w3c/mediacapture-region/commit/a60b62cb8946d2c6f79de57ff54bb8cd2a0b8550> >>>>>>> to >>>>>>> CropTarget ~4 months ago, following discussions in the WG. Youenn filed >>>>>>> issue >>>>>>> #18 <https://github.com/w3c/mediacapture-region/issues/18> ~2 >>>>>>> months ago. During those two months, no WG member, browser-implementer >>>>>>> or >>>>>>> Web-developer voiced concerns about the "CropTarget" name. Youenn has >>>>>>> made >>>>>>> several suggestions (Viewport, LayoutBox). I believe I have addressed >>>>>>> these >>>>>>> suggestions. I do not think there is interest in the WG for changing the >>>>>>> name. I think the name CropTarget will end up sticking, and not produce >>>>>>> a >>>>>>> compat risk. >>>>>>> >>>>>>> Sync vs. async cropTarget creation seems like something you'd want >>>>>>>> to decide on before shipping. >>>>>>> >>>>>>> >>>>>>> It is something we have tried reaching consensus on. But I am not >>>>>>> observing convergence. I proposed the following: >>>>>>> >>>>>>> - For Chrome, it is important to use a Promise<CropTarget>. >>>>>>> - For any browser that does not feel a Promise is necessary, >>>>>>> they can immediately return a pre-resolved Promise<CropTarget>. >>>>>>> - Web-developers would be virtually unaffected by the addition >>>>>>> of a Promise even - for the sake of argument - if it isn't strictly >>>>>>> necessary. (I still think it is necessary.) >>>>>>> >>>>>>> You mentioned on the thread that the browser can refuse to mint new >>>>>>>> cropTargets in some cases. What happens then? Is it specified? How are >>>>>>>> developers supposed to defensively program their API use against that? >>>>>>> >>>>>>> >>>>>>> Failure to mint additional tokens happens if excessive tokens are >>>>>>> minted. (Defends against memory-overuse in the browser process.) >>>>>>> Failure is reflected by a Promise being rejected rather than >>>>>>> fulfilled - which is an established pattern and well-understood by >>>>>>> Web-developers. >>>>>>> >>>>>>> >>>>>>> If minting couldn't fail, then (naively) writing the >>>>>>>> process/origin<->token mapping in the browser process could've been >>>>>>>> done >>>>>>>> async, while the creation of the token could be sync. >>>>>>> >>>>>>> >>>>>>> That is an interesting alternative; thank you for suggesting it. I >>>>>>> have given it thought, and I see some issues with it. To start with, an >>>>>>> application could be given a "dead" token. Such a token will never be >>>>>>> useful, but the application would not be able detect that until it calls >>>>>>> cropTo(token), and that call fails. Then, this failure would only be >>>>>>> detected by inspecting the error returned by cropTo(). But note that >>>>>>> often, >>>>>>> produceCropTarget() and cropTo() are called by different documents, so >>>>>>> now >>>>>>> we even need to postMessage() back a message that "your call to >>>>>>> produceCropTarget didn't really work, you have a dead token." >>>>>>> >>>>>>> So, if minting itself fails, that's preferable in two ways: >>>>>>> >>>>>>> 1. The failure is recognized closer to the actual point of >>>>>>> failure. (And detected by the concerned entity.) >>>>>>> 2. The application might even wish to *forego calling >>>>>>> getDisplayMedia()* if it knows it's got a bad token (or rather - >>>>>>> no token). >>>>>>> 3. The application is *not* left holding a "dead" token. >>>>>>> Instead, it holds a rejected Promise<CropTarget> - an established >>>>>>> pattern >>>>>>> for failed async-construction. >>>>>>> 4. If the conditions that caused minting to fail change, then >>>>>>> it's clear that calling produceCropTarget() again might work. >>>>>>> (Whereas a >>>>>>> dead token raises a question - is it *now* OK to use, or should we >>>>>>> produce >>>>>>> a new non-dead token?) >>>>>>> >>>>>>> Does that make sense? >>>>>>> >>>>>>> This seems mostly like a developer ergonomics question. As such, >>>>>>>> (and like above) a signal from web developers could go a long way to >>>>>>>> break >>>>>>>> the tie. >>>>>>> >>>>>>> >>>>>>> One of my partners from Google Slides has commented >>>>>>> <https://github.com/w3c/mediacapture-region/issues/11#issuecomment-1076543965> >>>>>>> as >>>>>>> much. She prefers the approach we took - MediaDevices.produceCropTarget. >>>>>>> (No Web-developers have mentioned a preference for the other approach - >>>>>>> Element.produceCropTarget.) >>>>>>> >>>>>>> On Wed, Mar 23, 2022 at 7:01 AM Yoav Weiss <yoav...@chromium.org> >>>>>>> wrote: >>>>>>> >>>>>>>> >>>>>>>> >>>>>>>> On Monday, March 21, 2022 at 9:15:21 PM UTC+1 Elad Alon wrote: >>>>>>>> >>>>>>>>> P.S: Requesting to ship gaplessly. >>>>>>>>> >>>>>>>>> On Monday, March 21, 2022 at 9:13:30 PM UTC+1 Elad Alon wrote: >>>>>>>>> >>>>>>>>>> Contact emailselad...@chromium.org, mfo...@chromium.org, >>>>>>>>>> jop...@chromium.org >>>>>>>>>> >>>>>>>>>> Explainer >>>>>>>>>> https://github.com/w3c/mediacapture-region/blob/main/README.md >>>>>>>>>> >>>>>>>>>> Specificationhttps://w3c.github.io/mediacapture-region/ >>>>>>>>>> >>>>>>>>>> Summary >>>>>>>>>> >>>>>>>>>> We introduce a performant and robust API for cropping a >>>>>>>>>> self-capture video track. (Recall that applications may *already* >>>>>>>>>> video-capture the tab in which the application is run using >>>>>>>>>> getDisplayMedia(). Using our new Region Capture, such an application >>>>>>>>>> may >>>>>>>>>> now *crop* that track and remove some content from it; typically >>>>>>>>>> before >>>>>>>>>> sharing it remotely.) >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Blink componentBlink >>>>>>>>>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink> >>>>>>>>>> >>>>>>>>>> TAG reviewhttps://github.com/w3ctag/design-reviews/issues/710 >>>>>>>>>> >>>>>>>>>> TAG review statusNot applicable >>>>>>>>>> TAG was positive: "Thank you for bringing this to our attention, >>>>>>>>>> and we are happy to see this proposal move forward." >>>>>>>>>> They did suggest a change of name (Region Capture -> Tab Region >>>>>>>>>> Capture), but that does not affect the API. This proposal to refine >>>>>>>>>> the >>>>>>>>>> name will be brought up with the WG. >>>>>>>>>> >>>>>>>>>> Risks >>>>>>>>>> >>>>>>>>>> Interoperability and Compatibility >>>>>>>>>> >>>>>>>>>> Remaining open issues with Mozilla and Apple: >>>>>>>>>> >>>>>>>>> >>>>>>>> Thanks for summing up the open issues! :) >>>>>>>> >>>>>>>>> >>>>>>>>>> - The name "CropTarget" - see >>>>>>>>>> https://github.com/w3c/mediacapture-region/issues/18. No >>>>>>>>>> alternative has yet been presented which garnered more support >>>>>>>>>> than >>>>>>>>>> "CropTarget". This seems unlikely to change. >>>>>>>>>> >>>>>>>>>> It may be better to ask actual web developers regarding the least >>>>>>>> confusing option amongst those proposed. >>>>>>>> In the past I've used Twitter polls and developer surveys for that >>>>>>>> purpose. Is this something you considered? >>>>>>>> Maybe devrel folks can help on that front. >>>>>>>> >>>>>>>>> >>>>>>>>>> - Whether produceCropTarget should return a >>>>>>>>>> Promise<CropTarget> or a CropTarget - see >>>>>>>>>> https://github.com/w3c/mediacapture-region/issues/17. In >>>>>>>>>> internal discussions we have consensus that returning a Promise is >>>>>>>>>> preferrable. However, if the WG settles on returning a CropTarget >>>>>>>>>> directly, >>>>>>>>>> a migration plan would be needed to ensure Web applications are >>>>>>>>>> not broken. >>>>>>>>>> This would be easier if such a change is either not made at all, >>>>>>>>>> or is made >>>>>>>>>> in concert with the next bullet-point. >>>>>>>>>> >>>>>>>>>> Sync vs. async cropTarget creation seems like something you'd >>>>>>>> want to decide on before shipping. You mentioned on the thread that the >>>>>>>> browser can refuse to mint new cropTargets in some cases. What happens >>>>>>>> then? Is it specified? How are developers supposed to defensively >>>>>>>> program >>>>>>>> their API use against that? >>>>>>>> If minting couldn't fail, then (naively) writing the >>>>>>>> process/origin<->token mapping in the browser process could've been >>>>>>>> done >>>>>>>> async, while the creation of the token could be sync. >>>>>>>> >>>>>>>> >>>>>>>>>> - API surface of produceCropTarget - see >>>>>>>>>> https://github.com/w3c/mediacapture-region/issues/11. We want >>>>>>>>>> MediaDevices.produceCropTarget(), whereas Apple wants >>>>>>>>>> Element.produceCropTarget or possibly Element.cropTarget(). >>>>>>>>>> Should the WG >>>>>>>>>> settle on Apple's current preference, migration would be very >>>>>>>>>> easy, as we >>>>>>>>>> can first expose on the new surface *in addition* and then >>>>>>>>>> deprecate the >>>>>>>>>> old surface gradually. Moreover, such a migration would actually >>>>>>>>>> have the >>>>>>>>>> potential of making a (Promise<CropTarget> -> CropTarget) >>>>>>>>>> migration >>>>>>>>>> simpler, should such a change also be adopted by the WG. >>>>>>>>>> >>>>>>>>>> This seems mostly like a developer ergonomics question. As such, >>>>>>>> (and like above) a signal from web developers could go a long way to >>>>>>>> break >>>>>>>> the tie. >>>>>>>> >>>>>>>>> Other topics under discussion mostly deal with changes to >>>>>>>>>> spec-language, and will not affect the shipped API. Exception - >>>>>>>>>> serializability, but that wouldn't break Web-apps (since it's mostly >>>>>>>>>> opaque >>>>>>>>>> to the application, which would typically only postMessage the >>>>>>>>>> CropTarget >>>>>>>>>> and use it on the other side). >>>>>>>>>> >>>>>>>>>> *Gecko:* No signal ( >>>>>>>>>> https://github.com/mozilla/standards-positions/issues/621) See >>>>>>>>>> above clarification about remaining open issues under discussion. >>>>>>>>>> >>>>>>>>>> *WebKit:* No signal ( >>>>>>>>>> https://lists.webkit.org/pipermail/webkit-dev/2022-March/032157.html >>>>>>>>>> ) See above clarification about remaining open issues under >>>>>>>>>> discussion. >>>>>>>>>> >>>>>>>>>> *Web developers:* Strongly positive This work saw strong support >>>>>>>>>> from Web developers inside of Google (Meet, Docs, Slides). >>>>>>>>>> >>>>>>>>>> Other signals: >>>>>>>>>> >>>>>>>>>> Ergonomics >>>>>>>>>> >>>>>>>>>> N/A >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Activation >>>>>>>>>> >>>>>>>>>> Unchallenging to use. >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Security >>>>>>>>>> >>>>>>>>>> This is a mechanism by which an application purposefully strips >>>>>>>>>> away information which it already has access to (via pre-existing >>>>>>>>>> mechanisms such as getDisplayMedia). >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> WebView Application Risks >>>>>>>>>> >>>>>>>>>> N/A >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> Debuggability >>>>>>>>>> >>>>>>>>>> - >>>>>>>>>> >>>>>>>>>> Is this feature fully tested by web-platform-tests >>>>>>>>>> <https://chromium.googlesource.com/chromium/src/+/master/docs/testing/web_platform_tests.md> >>>>>>>>>> ?No >>>>>>>>>> >>>>>>>>>> Flag nameRegionCapture >>>>>>>>>> >>>>>>>>>> Tracking bug >>>>>>>>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1247761 >>>>>>>>>> >>>>>>>>>> Launch bug >>>>>>>>>> https://bugs.chromium.org/p/chromium/issues/detail?id=1168076 >>>>>>>>>> >>>>>>>>>> Sample linkshttps://w3c.github.io/mediacapture-region/demo/ >>>>>>>>>> >>>>>>>>>> Estimated milestones >>>>>>>>>> OriginTrial desktop last 101 >>>>>>>>>> OriginTrial desktop first 98 >>>>>>>>>> >>>>>>>>>> Link to entry on the Chrome Platform Status >>>>>>>>>> https://chromestatus.com/feature/5712447794053120 >>>>>>>>>> >>>>>>>>>> Links to previous Intent discussionsIntent to prototype: >>>>>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/dib14W1B0Xc >>>>>>>>>> Intent to Experiment: >>>>>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/yFUX0KfuUlo >>>>>>>>>> Intent to Extend Experiment: >>>>>>>>>> https://groups.google.com/a/chromium.org/g/blink-dev/c/ZqndGb9e1wM >>>>>>>>>> >>>>>>>>>> >>>>>>>>>> This intent message was generated by Chrome Platform Status >>>>>>>>>> <https://chromestatus.com/>. >>>>>>>>>> >>>>>>>>> -- .: Jan-Ivar :. -- You received this message because you are subscribed to the Google Groups "blink-dev" group. 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