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Re: How to access several microphones at the same time

From: Alex Russell <slightlyoff@google.com>
Date: Sat, 2 Jan 2016 00:56:18 -0800
Message-ID: <CANr5HFW0QQo56Pd9nVhDa=aMDc4=GGviYQp594L+_4wr+rZqkQ@mail.gmail.com>
To: Hongchan Choi <hongchan@google.com>
Cc: Chris Wilson <cwilso@google.com>, Yehonathan Sharvit <viebel@gmail.com>, "public-audio@w3.org Group" <public-audio@w3.org>
On Tuesday, December 29, 2015, Hongchan Choi <hongchan@google.com> wrote:

> 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.
>

This seems like a major error in the spec. Is a fix planned?


> - 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
> <javascript:_e(%7B%7D,'cvml','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
>> <javascript:_e(%7B%7D,'cvml','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
>>> <javascript:_e(%7B%7D,'cvml','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
>>>> <javascript:_e(%7B%7D,'cvml','viebel@gmail.com');>> wrote:
>>>>
>>>>> Is it possible to access several microphones at the same time using
>>>>> getUserMedia()?
>>>>>
>>>>> Thanks.
>>>>>
>>>>
>>>
Received on Saturday, 2 January 2016 08:56:46 UTC

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