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Re: How to access several microphones at the same time

From: Hongchan Choi <hongchan@google.com>
Date: Tue, 29 Dec 2015 20:18:30 +0000
Message-ID: <CAGJqXNuJCH1G+HWPOECf97bzZ96h3=piJ8bfVXP7QRXfuwQ2Yg@mail.gmail.com>
To: Chris Wilson <cwilso@google.com>, Yehonathan Sharvit <viebel@gmail.com>
Cc: "public-audio@w3.org Group" <public-audio@w3.org>
I can only speak for Chrome, and not sure how other browsers handle this.
For Chrome:

- getUserMedia takes the default audio device or the device you selected in
the control panel.
- Chrome only can access a single audio device (input/output) at the same
time.
- Unfortunately, getUserMedia does not support multiple channel audio
inputs above 2 (stereo). getUserMedia stream does not reveal the number of
channels, thus WebAudio cannot know how the channel should be configured
and fallback to stereo.
- Furthermore, if you don't disable 'echo cancellation' feature of WebRTC,
your stereo input will be merged into mono first, then duplicated into
identical 2 channel audio streams. So, it is basically mono.

The current status of getUserMedia for the multichannel audio input is
rather sad...

On Tue, Dec 29, 2015 at 8:45 AM Chris Wilson <cwilso@google.com> wrote:

> Hmm, I take it back, I think you technically could have multiple devices
> open for input- output is the place we haven't designed for yet.
> On Dec 29, 2015 8:39 AM, "Yehonathan Sharvit" <viebel@gmail.com> wrote:
>
>> What do you mean by a single multichannel input device?
>> What is the rationale of this limitation?
>>
>> On Tue, Dec 29, 2015 at 6:37 PM, Chris Wilson <cwilso@google.com> wrote:
>>
>>> Yes, but they need to be on a single multichannel input device, and I'm
>>> not sure if chrome still limits to stereo. (+Hongchan)
>>> On Dec 29, 2015 7:43 AM, "Yehonathan Sharvit" <viebel@gmail.com> wrote:
>>>
>>>> Is it possible to access several microphones at the same time using
>>>> getUserMedia()?
>>>>
>>>> Thanks.
>>>>
>>>
>>
Received on Tuesday, 29 December 2015 20:19:08 UTC

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