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Re: Draft Updated Charter adding Mouse Lock and Gamepad

From: Chris Wilson <cwilso@google.com>
Date: Tue, 4 Oct 2011 17:11:09 -0700
Message-ID: <CAJK2wqWLMpuKz+k=9fFekegach46+5n2aKNdo89Hg-FbCuLszQ@mail.gmail.com>
To: Olli@pettay.fi
Cc: public-webevents@w3.org, "Robert O'Callahan" <robert@ocallahan.org>
I think you're thinking of an API that would say "play this .MID file".
 That is one possible function - but typically, that's handled at a media
player level.  (I.e., I'd expect that this the same problem as synchronizing
a separate audio track to a video track - in fact, I would expect this to be
accomplished with "<audio src='playme.mid'>", or accomplished via the normal
media streams synchronization as just another type of audio track.)  That's
not the same scenario and set of use cases as the more common "I want to
implement a synthesizer/controller/sequencer and communicate with the real
world."

Both Windows and Mac (as I understand it) allow you to buffer-send MIDI
packets with timestamped "streams".  Neither platform, to my knowledge,
enables synchronization with simultaneous audio/video through this
mechanism; if you had a real need for this kind of synchronization (e.g.,
you're building a video production app and want to synchronize outbound
MIDI), you would ignore the buffer send and send the messages at the
appropriate time yourself - i.e. roll your own cross-media synchronization.
 That's not as hard as it sounds, since MIDI is really just a relatively
quite sparse string of events (messages) to fire anyway. Both platforms
expect you to use different services to play MIDI files out ("You should use
the MCI MIDI sequencer to play MIDI files whenever you can" -
http://msdn.microsoft.com/en-us/library/dd743676(v=VS.85).aspx).

The far more interesting space to me is the interactive processing and
dispatching of MIDI messages, that would let me build synthesizers in
HTML/CSS/JS (like http://www.audiotool.com/app/, but not with Flash) and use
physical MIDI controllers to play them.  The most interesting use cases here
to me - a la the couple hundred bucks of iPad music apps I've bought in the
last year - is in the realtime production and consumption of MIDI to use
real controllers with the music apps.  Now that CoreMIDI is not only
supported on iOS, but is starting to be supported in apps, I can plug a USB
keyboard directly into my iPad (via the camera connection kit) and play a
world-class organ simulation, play an emulation of a Korg analog synth, have
a sequencer on one device play instruments on another, or simply record my
keyboard playing into the GarageBand sequencer.  This is all done through
fairly low-level controller event handling and message sending, which is the
part that I think is most important to fit together with the rest of how
events and messages are used in the web.

On Tue, Oct 4, 2011 at 2:27 PM, Olli Pettay <Olli.Pettay@helsinki.fi> wrote:

> Since MIDI must to be synchronized with audio and video, I'd assume
> the API would need to be somewhere close to Media Stream APIs.
> So, I believe MIDI has in fact quite different requirements than
> Gamepad API.
>
>
>
> -Olli
>
>
>
>
> On 10/05/2011 12:06 AM, Chris Wilson wrote:
>
>> I'd been talking with a variety of people about the need for a Music
>> Controller API - i.e. MIDI input/output, so I can synchronize music
>> apps, as well as interface my physical keyboard controllers,
>> synthesizers and drum machines with the web platform.  After some
>> thought, I'd like to propose that Music Device Communication be added to
>> the Web Events charter - I believe the challenges of this API are quite
>> similar to the Gamepad API (different API, but the same general kind of
>> patterns, and heavily event-based). This would be the web platform's
>> analog to CoreMIDI on MacOS/iOS, or the Windows MIDI API. Proposed
>> charter text would read something like this:
>>
>>
>>      Music Device Communication
>>
>> Some user agents have connected music devices, such as synthesize
>>
>>
>
Received on Wednesday, 5 October 2011 00:11:45 UTC

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