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Re: How to access several microphones at the same time

From: Hongchan Choi <hongchan@google.com>
Date: Mon, 04 Jan 2016 17:19:00 +0000
Message-ID: <CAGJqXNvqOp2jjFJH0b4v9AEgH3eHEQmhDeW1U8YT62mBPempjw@mail.gmail.com>
To: Alex Russell <slightlyoff@google.com>
Cc: Chris Wilson <cwilso@google.com>, Yehonathan Sharvit <viebel@gmail.com>, "public-audio@w3.org Group" <public-audio@w3.org>
Yes, Alex. I tried to raise the issue before, but had the lukewarm response.

https://code.google.com/p/chromium/issues/detail?id=453876

However, if we want to solve this issue in terms of the spec, I believe we
need something like Audio Output Devices API for the audio input as well.

http://www.w3.org/TR/audio-output/
https://www.chromestatus.com/feature/4621603249848320

When I first heard about this API, I was curious why this API only cares
about the  output. Anyhow, this is an already done deal in Chrome and
currently the implementation is under the review.


On Sat, Jan 2, 2016 at 12:56 AM Alex Russell <slightlyoff@google.com> wrote:

>
>
> 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> 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 Monday, 4 January 2016 17:19:38 UTC

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