December 2021 - webkit-dev - lists.webkit.org

Re: [webkit-dev] Request for position on AudioContext.outputLatency
by youenn fablet 15 Dec '21

15 Dec '21

Thanks Hongchan, It is good to hear that these discussions are happening. A first good step would be to add the corresponding fingerprinting markup to the web audio spec. A few additional thoughts: https://w3c.github.io/mediacapture-output/ allows listing devices that a user granted. In case devices are exposed to JS, exposing latency for those devices seems fine. I also wonder whether output latency might be useful outside of AudioContext and whether it would make sense to expose this information on MediaDevices as well. Could that be a device selection choice? The main issue is with the default system audio output. Passive filtering should not be allowed in that case. For instance, if the AudioContext is not producing audio, exposing latency does not make sense. I am a bit unclear about when latency can change, for instance say audio context is running and the default system speaker is changed. If it can change, should there be some form of events to let the application know. Or should it be left to things like MediaDevices.ondevicechange? Le lun. 13 déc. 2021 à 20:00, Hongchan Choi <hongchan(a)chromium.org> a écrit : > Hi Youenn, > > Thanks for your response. > > Say I switch from builtin speakers to Bluetooth headset using MacOS system >> menu. >> > > If changing a device doesn't reflect the current status correctly, the > feature is not useful. That said, the accuracy/precision of a value being > served is up to the user agent's discretion. > > If so, the spec should identify this as potential fingerprinting and >> should provide mitigations. >> And we should evaluate fingerprinting-free alternatives. > > > We are aware of the issue and it is being discussed in the blink-dev I2S > thread. > > What does PING WG think about this? > > > Please note that Web Audio API is currently a W3C Recommendation. > - The WG went through several PING reviews in 2020, for example: > https://github.com/WebAudio/web-audio-api/issues/2061 > - One of device-related PING threads: > https://github.com/w3cping/tracking-issues/issues/50 > > As a result of the privacy discussion, the spec has a dedicated section on > security and privacy: > https://webaudio.github.io/web-audio-api/#priv-sec > > The relevant excerpt: > "Fingerprinting via latency is also possible; it might be possible to > deduce this from baseLatency and outputLatency. Mitigation strategies > include adding jitter (dithering) and quantization so that the exact skew > is incorrectly reported. Note however that most audio systems aim for low > latency, to synchronise the audio generated by WebAudio to other audio or > video sources or to visual cues (for example in a game, or an audio > recording or music making environment). Excessive latency decreases > usability and may be an accessibility issue." > > Cheers, > Hongchan > > > On Mon, Dec 13, 2021 at 1:15 AM youenn fablet <youennf(a)gmail.com> wrote: > >> Looking at https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency, >> it states that: >> > If the audio output device is changed the outputLatency >> <https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency> attribute >> value will be updated accordingly. >> >> The use case seems ok, but I worry about fingerprinting if it means this >> allows a web page to passively identify user speakers. >> Say I switch from builtin speakers to Bluetooth headset using MacOS >> system menu. >> >> If so, the spec should identify this as potential fingerprinting and >> should provide mitigations. >> And we should evaluate fingerprinting-free alternatives. >> What does PING WG think about this? >> >> Le lun. 13 déc. 2021 à 09:39, Yoav Weiss via webkit-dev < >> webkit-dev(a)lists.webkit.org> a écrit : >> >>> (Sent on behalf of Hongchan Choi, who failed to subscribe to this >>> mailing list) >>> >>> Hey folks! >>> >>> AudioContext.outputLatency is to inform the time at which the first >>> sample in the buffer is actually processed by the audio output device. This >>> is useful when synchronizing the audio generated by Web Audio to other >>> audio or video sources or to visual cues [1]. >>> >>> This is already implemented in FireFox and we're looking to ship it in >>> Chrome soon [2][3]. Would you all be interested in this feature? >>> >>> Thanks, >>> Hongchan >>> >>> [1] https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency >>> [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1324552 >>> [3] >>> https://groups.google.com/a/chromium.org/g/blink-dev/c/dTQniJNVVMY/m/hPFwY1… >>> >>> _______________________________________________ >>> webkit-dev mailing list >>> webkit-dev(a)lists.webkit.org >>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>> >>

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Re: [webkit-dev] Request for position on AudioContext.outputLatency
by Yoav Weiss 15 Dec '21

15 Dec '21

Copying Hongchan's reply to the list.. On Mon, Dec 13, 2021 at 8:00 PM Hongchan Choi <hongchan(a)chromium.org> wrote: > Hi Youenn, > > Thanks for your response. > > Say I switch from builtin speakers to Bluetooth headset using MacOS system >> menu. >> > > If changing a device doesn't reflect the current status correctly, the > feature is not useful. That said, the accuracy/precision of a value being > served is up to the user agent's discretion. > > If so, the spec should identify this as potential fingerprinting and >> should provide mitigations. >> And we should evaluate fingerprinting-free alternatives. > > > We are aware of the issue and it is being discussed in the blink-dev I2S > thread. > > What does PING WG think about this? > > > Please note that Web Audio API is currently a W3C Recommendation. > - The WG went through several PING reviews in 2020, for example: > https://github.com/WebAudio/web-audio-api/issues/2061 > - One of device-related PING threads: > https://github.com/w3cping/tracking-issues/issues/50 > > As a result of the privacy discussion, the spec has a dedicated section on > security and privacy: > https://webaudio.github.io/web-audio-api/#priv-sec > > The relevant excerpt: > "Fingerprinting via latency is also possible; it might be possible to > deduce this from baseLatency and outputLatency. Mitigation strategies > include adding jitter (dithering) and quantization so that the exact skew > is incorrectly reported. Note however that most audio systems aim for low > latency, to synchronise the audio generated by WebAudio to other audio or > video sources or to visual cues (for example in a game, or an audio > recording or music making environment). Excessive latency decreases > usability and may be an accessibility issue." > > Cheers, > Hongchan > > > On Mon, Dec 13, 2021 at 1:15 AM youenn fablet <youennf(a)gmail.com> wrote: > >> Looking at https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency, >> it states that: >> > If the audio output device is changed the outputLatency >> <https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency> attribute >> value will be updated accordingly. >> >> The use case seems ok, but I worry about fingerprinting if it means this >> allows a web page to passively identify user speakers. >> Say I switch from builtin speakers to Bluetooth headset using MacOS >> system menu. >> >> If so, the spec should identify this as potential fingerprinting and >> should provide mitigations. >> And we should evaluate fingerprinting-free alternatives. >> What does PING WG think about this? >> >> Le lun. 13 déc. 2021 à 09:39, Yoav Weiss via webkit-dev < >> webkit-dev(a)lists.webkit.org> a écrit : >> >>> (Sent on behalf of Hongchan Choi, who failed to subscribe to this >>> mailing list) >>> >>> Hey folks! >>> >>> AudioContext.outputLatency is to inform the time at which the first >>> sample in the buffer is actually processed by the audio output device. This >>> is useful when synchronizing the audio generated by Web Audio to other >>> audio or video sources or to visual cues [1]. >>> >>> This is already implemented in FireFox and we're looking to ship it in >>> Chrome soon [2][3]. Would you all be interested in this feature? >>> >>> Thanks, >>> Hongchan >>> >>> [1] https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency >>> [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1324552 >>> [3] >>> https://groups.google.com/a/chromium.org/g/blink-dev/c/dTQniJNVVMY/m/hPFwY1… >>> >>> _______________________________________________ >>> webkit-dev mailing list >>> webkit-dev(a)lists.webkit.org >>> https://lists.webkit.org/mailman/listinfo/webkit-dev >>> >>

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Request for position on AudioContext.outputLatency
by Yoav Weiss 13 Dec '21

13 Dec '21

(Sent on behalf of Hongchan Choi, who failed to subscribe to this mailing list) Hey folks! AudioContext.outputLatency is to inform the time at which the first sample in the buffer is actually processed by the audio output device. This is useful when synchronizing the audio generated by Web Audio to other audio or video sources or to visual cues [1]. This is already implemented in FireFox and we're looking to ship it in Chrome soon [2][3]. Would you all be interested in this feature? Thanks, Hongchan [1] https://www.w3.org/TR/webaudio/#dom-audiocontext-outputlatency [2] https://bugzilla.mozilla.org/show_bug.cgi?id=1324552 [3] https://groups.google.com/a/chromium.org/g/blink-dev/c/dTQniJNVVMY/m/hPFwY1…

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Request for HTMLInputElement showPicker()
by François Beaufort 🇫🇷 13 Dec '21

13 Dec '21

Hi webkit-dev, This is a request for WebKit's position on adding showPicker() to <input> elements as newly specified by the HTML spec. It addresses a very common request from web developers: programmatically showing a picker for controls like date etc. Spec: https://html.spec.whatwg.org/multipage/input.html#dom-input-showpicker Discussion: https://github.com/whatwg/html/pull/7319 WebKit bug: https://bugs.webkit.org/show_bug.cgi?id=234009 Best. François

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Chris Lord is now a WebKit reviewer!
by Alejandro G. Castro 11 Dec '21

11 Dec '21

Hello! I'm delighted to announce that Chris Lord is now a WebKit reviewer. He added OffscreenCanvas support, helped with the scrolling architecture and has contributed a lot of code to WPE and GTK ports in the graphics area, if you need a review in those areas now you can add him to the bugs. Please join me in congratulating Chris on his reviewer status! Alex

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Request for Position: Origin-Agent-Cluster default / deprecating document.domain
by Daniel Vogelheim 09 Dec '21

09 Dec '21

Hello webkit-dev, I'd like to get your position on assigning documents to origin-keyed agent clusters by default. This would effectively deprecate document.domain setting, and make it available only as an opt-in feature. Explainer: https://github.com/mikewest/deprecating-document-domain Details: We'd like to change the treatment of Origin-Agent-Cluster <https://html.spec.whatwg.org/multipage/origin.html#origin-isolation> so that the default - an absent or malformed header - would be treated as enabling origin-keyed agent clusters. This would turn the Origin-Agent-Cluster:-header from an opt-in into an opt-out feature. As a consequence, browsers could origin-isolate more pages. The developer-visible consequence is that modifying document.domain in order to relax same-origin restrictions, which is already deprecated <https://html.spec.whatwg.org/#relaxing-the-same-origin-restriction>, will turn into an opt-in feature that must be explicitly requested. Further info: TAG discussion on the subject: https://github.com/w3ctag/design-reviews/issues/564 Explainer: https://github.com/mikewest/deprecating-document-domain HTML Spec on Origin-Agent-Cluster: https://html.spec.whatwg.org/multipage/origin.html#origin-isolation HTML Spec on document.domain: https://html.spec.whatwg.org/#relaxing-the-same-origin-restriction

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Request for Position: Canvas2D Layers
by Juanmi Huertas 08 Dec '21

08 Dec '21

Hello! I´d like to get WebKit's position on adding Layer (through beginLayer and endLayer), that would allow authors to draw a series of instructions as a single unit, rather than having to use a temporary canvas. Here is the explainer: https://github.com/fserb/canvas2D/blob/master/spec/layers.md Here the WHATWG issue: https://github.com/whatwg/html/issues/7329 Here is the ChromeStatus link: https://chromestatus.com/guide/edit/5629802309484544 Thanks! Juanmi

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Request for Position: EditContext
by Alex Keng 01 Dec '21

01 Dec '21

Hi! I'd like to get WebKit's position on EditContext which allows authors to more directly participate in the text input process. Here is the spec: https://w3c.github.io/editing/docs/EditContext/ And the explainer: editing/explainer.md at gh-pages * w3c/editing (github.com)<https://github.com/w3c/editing/blob/gh-pages/docs/EditContext/explainer.md> Also a 2 min quick intro video: https://w3c.github.io/editing/docs/EditContext/EditContext_tpac2021.mp4 Thanks! Alex Microsoft Edge

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