Intent to Implement: Audio Output Devices API

[Guido Urdaneta]

Contact emails gui...@chromium.org,to...@chromium.org Spec http://w3c.github.io/mediacapture-output Summary 

This feature will incorporate a set of JavaScript APIs that let a Web application direct the audio output of a media element to authorized devices other than the system or user agent default.

Motivation

A significant number of Web developers have expressed interest in being able to  programmatically direct audio to nondefault audio output devices when multiple such devices exist. Currently, this functionality is not available, which makes it impossible to develop certain types of applications. Some examples are multilingual applications that output different languages to different devices, or music applications that output one song to a loudspeaker and a different one to a headset (see [1,2,3,4,5] for more examples).

[1] https://crbug.com/437405

[2] https://code.google.com/p/webrtc/issues/detail?id=3606

[3] http://stackoverflow.com/questions/14760578/is-there-a-way-to-select-the-output-device-for-an-audio-from-a-web-page

[4] http://stackoverflow.com/questions/22976407/html5-audio-output-patching

[5] http://superuser.com/questions/648860/is-there-any-way-to-select-the-sound-device-for-html5-audio-playback

Compatibility Risk Firefox: No public signals Internet Explorer: No public signals Safari: No public signals Web developers: Positive

We do not anticipate any compatibility risks. This feature is to be implemented behind a runtime flag.

Ongoing technical constraints None. Will this feature be supported on all six Blink platforms (Windows, Mac, Linux, Chrome OS, Android, and Android WebView)? Yes or no. Yes. OWP launch tracking bug

None yet.

https://crbug.com/438023 was originally set up to track the implementation of this feature. Link to entry on the Chromium Dashboard https://www.chromestatus.com/features/4621603249848320 Requesting approval to ship?

No.

[Chris Wilson]

I'd really like to see more participation and review from the Web Audio team on this.  I think implementation experience is good, but there are a lot of unanswered questions on the interaction with web audio (and in extensible-web style, we should be thinking about how the high-level "play this media to this output device" is mapped to low-level features).  Not only is the web audio link not discussed with the WG, there are significant issues around symmetry with getUserMedia (knowing it's the same audio clock for both devices is important), multichannel support isn't clear, ...

I don't think this needs to block any progress here, but I think it will need to be a clear partnership and picture between Web Audio and this feature prior to shipping.

(+Hongchan, Raymond and Jan for Web Audio)

[Philip Jägenstedt]

Has there been any progress on this issue? Is implementation proceeding?

The spec is pretty small, and only the bit about HTMLMediaElements looks ready to implement:

http://w3c.github.io/mediacapture-output/#htmlmediaelement-extensions

Is the plan to implement only that, or what about Web Audio?

One mildly odd thing is the mix of the terms input/output and source/sink in the specs. The MediaDeviceKind enum uses the terminology input/output, but the HTMLMediaElement extensions calls it a sink. I doubt this will really confuse anyone, but is there a reason to not use the input/output terminology everywhere?

Philip

To unsubscribe from this group and stop receiving emails from it, send an email to blink-dev+...@chromium.org.

[gui...@google.com]

On Friday, April 17, 2015 at 2:31:04 PM UTC+2, Philip Jägenstedt wrote:

Has there been any progress on this issue? Is implementation proceeding?

Implementation is proceeding.

 

The spec is pretty small, and only the bit about HTMLMediaElements looks ready to implement:

http://w3c.github.io/mediacapture-output/#htmlmediaelement-extensions

Is the plan to implement only that, or what about Web Audio?

The current plan is to implement the HTMLMediaElements part.

[Yehonathan Sharvit]

When will the WebAudio part be implemented?