[wdmaudiodev] Re: USB midi driver?
- From: Tim Roberts <timr@xxxxxxxxx>
- To: wdmaudiodev@xxxxxxxxxxxxx
- Date: Tue, 23 Nov 2004 08:58:42 -0800
Bert Schiettecatte wrote:
up two MIDI devices with different capabilities, doesn't MIDI have
custom messages for reporting capabilities so you can tell the
difference that way?
No, MIDI doesn't have anything like that.
Actually, it does. Every system exclusive message has a manufacturer's
identification code. An app that knew it was getting multiple devices
on separate MIDI controllers could distinguish them by using that.
And if you connect up two identical MIDI devices,
why would it matter?
Yes it does, because I don't think Windows will let you connect two
Identical devices, and load the driver for them and still be able
To distinguish between them (correct me if I'm wrong here).
The question in my mind is this: what do you mean by "distinguish"
them? Windows will certainly let you plug in two identical devices, it
will load drivers for the two devices, and it will expose interfaces for
both devices. An application that enumerates all the MIDI devices will
find two of them, with different device IDs. If the app KNOWS there
will be two different devices, it can open one instance to each.
Now, it isn't trivial for the app to know which MIDI controller is
plugged into USB hub 2 slot 1, and which is plugged into the base USB
controller slot 3, but how is that any different from plugging in two
PCI MIDI cards?
How would you EXPECT to be able to distinguish them? Describe for me a
use case in which this is important, and how you visualize things working.
--
- Tim Roberts, timr@xxxxxxxxx
Providenza & Boekelheide, Inc.
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