Thanks for your feedback! We updated the explainer <https://github.com/WICG/web_audio_playout> to address your questions about why the current APIs are insufficient and what we need this API for.
As for correlation between audio and video glitches we can address it here first and add it to the explainer if necessary: If audio glitches occur due to high CPU load, they may be correlated with video glitches/frame drops. The closest existing thing to a uniform set of properties for audio and video are the stats for audio <https://w3c.github.io/mediacapture-extensions/#the-mediastreamtrackaudiostats-interface> and video <https://w3c.github.io/mediacapture-extensions/#the-mediastreamtrackvideostats-interface> glitches in MediaStreamTrack. However, these stats track glitches originating between the source and the point at which they're measured in the MediaStreamTrack. For audio, this means that they're useful for capture (they can measure glitches from the microphone to the track) but not for playout (they cannot measure glitches from the track to the speaker). Because MediaStreams do not know where the media will end up (which might even be several different places), it's hard to define a stats API that measures glitches from audio originating from the MediaStreamTrack. Unlike audio MediaStreamTracks, WebAudio playout is completely separate from video and does not necessarily interface with MediaStreams, so it makes sense for it to have its own audio-specific API. Best, Fredrik On Thursday, October 17, 2024 at 12:25:55 PM UTC+2 sligh...@chromium.org wrote: > The explainer doesn't really show why the code developers have to use > today is problematic (or what's impossible), and it's a bad smell for > Explainers to lead with IDL. Is it possible to refactor that doc to explain > *why* developers want to calculate these statistics? And is there > correlation with dropped frame stats here and in other media areas, e.g. > video? Should we be building a uniform set of properties across those > interfaces? > > Best, > > Alex > > On Tuesday, October 15, 2024 at 4:17:55 PM UTC+5:30 fhern...@google.com > wrote: > >> We are also going to send this API to the PING for review. >> On Monday, October 14, 2024 at 4:11:16 PM UTC+2 Fredrik Hernqvist wrote: >> >>> Contact emailsfhern...@google.com, ol...@google.com, hong...@google.com >>> , agp...@google.com, gui...@google.com >>> >> >>> >>> Explainerhttps://github.com/WICG/web_audio_playout >>> >>> Specificationhttps://wicg.github.io/web_audio_playout >>> >>> Summary >>> >>> The AudioContext.playoutStats API allows an application to measure the >>> quality and latency of audio playout using WebAudio. >>> >>> >>> Blink componentBlink>WebAudio >>> <https://bugs.chromium.org/p/chromium/issues/list?q=component:Blink%3EWebAudio> >>> >>> TAG reviewEarly TAG review request: >>> https://github.com/w3ctag/design-reviews/issues/939 >>> >>> TAG review statusIssues addressed >>> >>> Risks >>> >>> >>> Interoperability and Compatibility >>> >>> None >>> >>> >>> *Gecko*: No signal >>> >>> *WebKit*: No signal >>> >>> *Web developers*: Positive (https://github.com/WICG/proposals/issues/142 >>> ) >>> >>> *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 >>> >>> >>> Goals for experimentation >>> This experiment will allow us to evaluate: >>> * How the API can be used by developers to improve Web Applications >>> * How the API can be used by developers to evaluate the user audio >>> experience in their Web Applications. >>> >>> >>> Ongoing technical constraints >>> >>> 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 >>> <https://chromium.googlesource.com/chromium/src/+/main/docs/testing/web_platform_tests.md> >>> ?No >>> >>> We have not added these because the API shape might yet change. We will >>> add these before launch. >>> >>> >>> Flag name on chrome://flagsNone >>> >>> Finch feature nameAudioContextPlayoutStats >>> >>> Requires code in //chrome?False >>> >>> Estimated milestones >>> Origin trial desktop first 131 >>> Origin trial desktop last 136 >>> DevTrial on desktop 129 >>> >>> Link to entry on the Chrome Platform Status >>> https://chromestatus.com/feature/5172818344148992?gate=4747770865123328 >>> >>> Links to previous Intent discussionsIntent to Prototype: >>> https://groups.google.com/a/chromium.org/d/msgid/blink-dev/CACazmWW4MYVa_iGjN%3DK4O9B1DE3rt4_2Vkqnq6sKswHFjn6BzQ%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+unsubscr...@chromium.org. To view this discussion on the web visit https://groups.google.com/a/chromium.org/d/msgid/blink-dev/0fb28935-20ed-4fe1-a489-96fe7f3353f9n%40chromium.org.
