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Re: getUserMedia use cases

From: Samuel Goldszmidt <samuel.goldszmidt@ircam.fr>
Date: Wed, 01 Feb 2012 10:09:27 +0100
Message-ID: <4F290147.4030101@ircam.fr>
To: public-audio@w3.org
May be we could have to distinguish two types of use cases for dealing 
with this question ?

* A simple website (which need one simple input and/or output).
For those, a javascript introspection (for instance) of available 
devices with their possibilities (can it records, plays, how many audio 
inputs, audio output ...), and a Javascript way to select the good one 
programatically if it meet the needs may be sufficient.
* An advanced website, like a DAWwebsite, which need more configuration 
process from the user to route signals, select between available 
inputs/outputs would also need a way to list available devices, and 
could let the user to select the one he wants to use for audio(/video) 

Like in old Flash files which required webcam input, and also like HTML5 
geolocation, t he browser could ask the user to allow the detection and 
selection of audio(/video) input / output that are available from 
javascript ?


Samuel Goldszmidt

Le 01/02/12 08:44, Jussi Kalliokoski a écrit :
> I'd like to one up what Tom just said, but also share a bit of 
> thoughts on the matter... As useful as it is to enumerate the MIDI 
> devices, and get I/O access to them, another really useful aspect of 
> MIDI are virtual devices. For example, if I make a virtual keyboard or 
> a sequencer for the browser, to stream to most of the DAWs, I need a 
> virtual device that will act as an output for my app, and an input for 
> the DAW. In the same way, if I have native sequencer application, and 
> I would like to stream it's output to my in-browser-DAW, I need a 
> virtual device that will act as the input for my DAW and output for 
> the sequencer.
> I'm not sure how this would be achieved, but I think it applies to 
> concepts such as webcams as well, would be pretty cool to create a 
> virtual webcam, that streams the contents of a canvas for example, 
> then use existing applications such as Skype to harness it. This would 
> allow great interaction with existing applications out there. Of 
> course, you must not forget the security aspects that come along with 
> this, as such proxy devices would also allow some malicious transfer.
> Jussi Kalliokoski
> Official.fm labs
> On Wed, Feb 1, 2012 at 2:25 AM, Tom White (MMA) <lists@midi.org 
> <mailto:lists@midi.org>> wrote:
>     Chris Rogers said
>         it would be good to have an introspection API to enumerate the
>         available audio devices for both audio input and output.  A
>         built-in microphone would be one such device.  Also commonly
>         available is the line-in analog audio input on a laptop or
>         desktop computer.  And, of course, any externally connected
>         multi-channel USB or Firewire audio devices.  Some of these
>         can present eight (or more) simultaneous audio input and
>         output channels simultaneously.
>         It's important to not consider audio input in isolation, but
>         also audio output capabilities when enumerating the devices.
>     I can't help but point out that MItDI devices (software and
>     hardware ports) are commonly used for audible* input/output and
>     thus would also be a candidate for enumeration...
>     Tom White
>     www.midi.org <http://www.midi.org>
>     *I say "audible" instead of "audio" so there is no confusion
>     between MIDI and audio <g>
Received on Wednesday, 1 February 2012 09:10:18 UTC

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