[web-audio-api] There should be notification when the destination output changed (#27)

> Originally reported on W3C Bugzilla [ISSUE-21345](https://www.w3.org/Bugs/Public/show_bug.cgi?id=21345) Wed, 20 Mar 2013 06:04:34 GMT
> Reported by Wei James
> Assigned to 

When changing accessories, the max number of channels can change, which has an impact on virtualization and 3D positioning, you wouldn't use the same settings and algorithms when switching from headset to speakers.

In case you are switching from local speakers to headphones, you are really sending the same stream to the same low-level driver, and the switch is typically handled in the audio codec hardware. You will have continuity of the playback by construction, and the only time you'd need to reconfigure the graph is if you have any sort of 3D positioning.
But if the new output is HDMI, Bluetooth A2DP, USB, there will be a delay and volume ramps when switching, and it'd be perfectly acceptable to stop and reconfigure without any impact to user experience. It'd be interesting to capture this difference in the notification.

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Reply to this email directly or view it on GitHub:
https://github.com/WebAudio/web-audio-api/issues/27