Intent to Ship: Playback Statistics API for WebAudio

[Chromestatus]

Contact emails

hong...@google.com, fhern...@google.com, ol...@google.com

Explainer

https://github.com/WICG/web_audio_playout

Specification

https://webaudio.github.io/web-audio-api/#AudioPlaybackStats

Summary

This feature adds an AudioContext.playbackStats attribute which returns an AudioPlaybackStats object. This object provides audio playback statistics such as average latency, minimum/maximum latency, underrun duration, and underrun count. This API allows web applications to monitor audio playout quality and detect glitches. Note: This feature was previously tracked as AudioContext.playoutStats. It has been renamed to AudioContext.playbackStats to align with the final Web Audio API specification. The old name is supported as a deprecated alias for backward compatibility.

Blink component

Blink>WebAudio

Web Feature ID

web-audio

Motivation

There is currently no way to detect whether WebAudio playout has glitches (gaps in the played audio, which typically happens due to underperformance in the audio pipeline). There is an existing way to measure the instantaneous playout latency using AudioContext.outputLatency, but no simple way to measure average/minimum/maximum latency over time. With this API, we want to propose a way to be able to measure the delay of that audio and the glitchiness of the audio.

Initial public proposal

https://github.com/WICG/proposals/issues/142

TAG review

Early TAG review request: https://github.com/w3ctag/design-reviews/issues/939

TAG review status

Issues addressed

Origin Trial Name

Playout Statistics API for WebAudio

Chromium Trial Name

AudioContextPlayoutStats

Origin Trial documentation link

https://github.com/WICG/web_audio_playout

WebFeature UseCounter name

kAudioContextPlayoutStats

Risks

Interoperability and Compatibility

No information provided

Gecko: Positive (https://github.com/WebAudio/web-audio-api/pull/2645) The spec PR was reviewed and approved by a Mozilla engineer.

WebKit: No signal

Web developers: Positive (https://github.com/WICG/proposals/issues/142#issuecomment-1981012486)

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?

None.

Debuggability

Can be tested by creating an AudioContext and evaluating context.playoutStats in the console.

Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, ChromeOS, Android, and Android WebView)?

Yes

Is this feature fully tested by web-platform-tests?

Yes
https://wpt.fyi/results/webaudio/the-audio-api/the-audiocontext-interface/audiocontext-playoutstats.html?label=experimental&label=master&aligned These will be updated if the API shape changes.

Flag name on about://flags

No information provided

Finch feature name

AudioContextPlayoutStats

Rollout plan

Will ship enabled for all users

Requires code in //chrome?

False

Tracking bug

https://g-issues.chromium.org/issues/475838360

Launch bug

https://launch.corp.google.com/launch/4308993

Availability expectation

Feature is available only in Chromium browsers for the foreseeable future.

Adoption expectation

Feature is used by specific partner(s) to provide functionality within 12 months of launch in Chrome.

Adoption plan

Nothing specific planned.

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?

None.

Estimated milestones

Shipping on desktop	146
Origin trial desktop first	131
Origin trial desktop last	136
Origin trial extension 1 end milestone	145
Origin trial extension 2 end milestone	142
Origin trial extension 3 end milestone	139
DevTrial on desktop	129
Shipping on Android	146
Shipping on WebView	146

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).

None.

Link to entry on the Chrome Platform Status

https://chromestatus.com/feature/5172818344148992?gate=5078819495215104

Links to previous Intent discussions

Intent to Prototype: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACazmWW4MYVa_iGjN%3DK4O9B1DE3rt4_2Vkqnq6sKswHFjn6BzQ%40mail.gmail.com
Intent to Experiment: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACazmWWV6S6Ba%3Dd%3DgvjhERm1OnPyBMRJx5fbkP%3Df9zb3k%3DrNDA%40mail.gmail.com
Intent to Extend Experiment 1: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/691455eb.2b0a0220.e30ce.7e1f.GAE%40google.com
Intent to Extend Experiment 2: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/686d135c.2b0a0220.3a1521.0081.GAE%40google.com
Intent to Extend Experiment 3: https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACazmWVkWb8DJM_aCRGOFpskBs-7h%3DO_yggKc3YBUkiieEO-UA%40mail.gmail.com

This intent message was generated by Chrome Platform Status.