*Contact emails* [email protected], [email protected] *Specification* https://webaudio.github.io/web-audio-api/#dom-baseaudiocontext-renderquantumsize
*Summary* AudioContext and OfflineAudioContext now take an optional renderSizeHint, which allows users to ask for a particular render quantum size when an integer is passed, to use the default of 128 frames if nothing or "default" is passed, or to ask the User-Agent to pick a good render quantum size if "hardware" is specified. *Blink component* Blink>WebAudio <https://issues.chromium.org/issues?q=customfield1222907:%22Blink%3EWebAudio%22> *Web Feature ID* web-audio <https://webstatus.dev/features/web-audio> *TAG review* https://github.com/w3ctag/design-reviews/issues/895 *TAG review status* Issues addressed *Origin Trial documentation link* https://webaudio.github.io/web-audio-api/#dom-audiocontextoptions-rendersizehint *Risks* *Interoperability and Compatibility* Low. The feature is already specified. *Gecko*: No signal (https://github.com/WebAudio/web-audio-api/pull/2469) A Firefox developer wrote the specification change. *WebKit*: No signal *Web developers*: Positive ( https://github.com/WebAudio/web-audio-api/issues/1503) Developers have requested a way to increase the render quantum size, and are looking forward to the feature being implemented. *Other signals*: *Ergonomics* An identified use case of this feature is to match buffer sizes used by other Chromium audio APIs, in order to improve performance. *Activation* There is an ongoing privacy discussion about how to mitigate fingerprinting concerns around the "hardware" hint ( https://github.com/WebAudio/web-audio-api/issues/2659). The "hardware" hint as implemented in Chromium currently will always return the default 128 render quantum size, which exposes no user information. This is allowed by the spec, which says "It is a hint that might not be honored." *Security* There is concern that a very low render quantum size could allow an AudioWorklet to create a high-resolution timer, but very high sample rates are already allowed and have a similar risk so the marginal change in security is probably low. *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? Low. The change is to ship a new API. *Goals for experimentation* Validate performance improvement gained by matching render quantum size to software buffer sizes when using a numeric renderSizeHint. Verify actual audio processing output is unchanged when using a numeric renderSizeHint. We have a primary partner for this Origin Trial, and we would like to see if the performance and ergonomics of the API satisfy this partner's need. This partner is not going to use the "hardware" hint, and we think that it is still valuable to conduct an Origin Trial to gather feedback on the rest of the API. *Ongoing technical constraints* None. *Debuggability* It may be worth exposing the render quantum size value in the DevTools WebAudio pane, similar to sample rate. *Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?* Yes All supported platforms have mechanisms to implement this feature. *Is this feature fully tested by web-platform-tests <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md>?* Yes https://wpt.fyi/results/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-rendersizehint.html https://wpt.fyi/results/webaudio/the-audio-api/the-offlineaudiocontext-interface/offlineaudiocontext-rendersizehint.html *Flag name on about://flags* N/A (launch with --enable-features=WebAudioConfigurableRenderQuantum) *Finch feature name* WebAudioConfigurableRenderQuantum *Requires code in //chrome?* False *Tracking bug* https://crbug.com/40637820 *Launch bug* https://launch.corp.google.com/launch/4416924 *Measurement* UseCounters: WebAudioRenderSizeHint, WebAudioRenderQuantumSize *Availability expectation* We expect that Firefox will implement the feature independently at some point. *Adoption expectation* We expect that specific partners will use this functionality immediately upon its launch in Chrome. *Adoption plan* We are communication with partners, and also in communication with Mozilla via the Audio Working Group. *Non-OSS dependencies* Does the feature depend on any code or APIs outside the Chromium open source repository and its open-source dependencies to function? No. *Estimated milestones* Shipping on desktop 150 Origin trial desktop first 145 Origin trial desktop last 150 DevTrial on desktop 145 Shipping on Android 150 Origin trial Android first 145 Origin trial Android last 150 Shipping on WebView 150 Origin trial WebView first 145 Origin trial WebView last 150 *Anticipated spec changes* Open questions about a feature may be a source of future web compat or interop issues. Please list open issues (e.g. links to known github issues in the project for the feature specification) whose resolution may introduce web compat/interop risk (e.g., changing to naming or structure of the API in a non-backward-compatible way). https://github.com/WebAudio/web-audio-api/issues/2663 https://github.com/WebAudio/web-audio-api/issues/2664 *Link to entry on the Chrome Platform Status* https://chromestatus.com/feature/5078190552907776?gate=5140327991869440 *Links to previous Intent discussions* Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/688d3254.2b0a0220.361edb.0299.GAE%40google.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 [email protected]. 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