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Re: MIDI proposal implemented

From: Robert O'Callahan <robert@ocallahan.org>
Date: Thu, 3 May 2012 10:24:36 +1200
Message-ID: <CAOp6jLbWs1OAg0YV+_upWv+YbpN=C2if3DahbMSGxPfHrVCpQg@mail.gmail.com>
To: Jussi Kalliokoski <jussi.kalliokoski@gmail.com>
Cc: public-audio@w3.org
On Wed, May 2, 2012 at 8:16 PM, Jussi Kalliokoski <
jussi.kalliokoski@gmail.com> wrote:

> On Wed, May 2, 2012 at 3:18 AM, Robert O'Callahan <robert@ocallahan.org>wrote:
>> On Wed, May 2, 2012 at 7:19 AM, Jussi Kalliokoski <
>> jussi.kalliokoski@gmail.com> wrote:
>>> So, we have an experimental implementation already!  We should probably
>>> start drafting a spec soon, too. :)
>> I don't think we want getUserMedia to pass something that's not a
>> MediaStream to its callback. Besides, there's no other way to handle
>> getUserMedia({video:true, audio:true, midi:true}, callback).
> Using gUM was just my best bet at having an existing security/permissions
> model to use to ease the standardization process. I'm open to better ideas.

I think it's the right idea. We just need to attach the APIs you need to

I agree, but the usefulness of MIDI isn't limited to those cases. Hence I
> think we should have a separate MIDI API that has integration points with
> Media Streams rather than making a lot of common use cases more complicated
> than they are on other platforms. For example having to set up a processing
> graph, possibly in another thread, just to have access to a MIDI game
> controller is not desirable.

Sure. Most of the APIs you want can probably be attached to a
MIDIMediaStreamTrack object, or the MediaStream itself if we want to
support dynamic device selection there for example.

>> I'm still not convinced that MIDIAccess-style enumeration of MIDI devices
>> is something that Web browsers should support. It would be much better if
>> we can express the applications' requirements declaratively in parameters
>> to getUserMedia and let the browser handle device selection. Although it
>> would probably be OK to expose the MIDIDevice properties on MIDI streams
>> the browser has chosen to send to the application.
> IMHO being able to select the device is very crucial to a MIDI API. Let's
> take a DAW in a recording studio for example: there's a MIDI keyboard to
> control a synth that's being played live and recorded and in addition the
> recording engineer has a control table to interact with the user interface
> of the DAW, for play, record, rewind, save, etc. In most cases its highly
> desirable to be able to select the device, because different devices have
> different purposes.

Yeah. The question is how much needs to be exposed through API and how much
can be handled entirely through browser UI.

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Received on Wednesday, 2 May 2012 22:25:06 UTC

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