[LAD] A question for USB/MIDI experts
fons at linuxaudio.org
Fri Apr 8 20:26:20 UTC 2016
On Fri, Apr 08, 2016 at 10:13:27PM +0200, Philippe Wicker wrote:
> What you see seems to be the MIDI encoding used by a USB device.
> Every “simple” MIDI event (that is less that 3 bytes) are encoded
> as a 4 bytes word. The 1st byte (MSB) is - if I remember correctly
> - the concatenation of the MIDI port and a USB specific code for the
> event. The 3 remaining bytes contains the MIDI event as it is encoded
> on a standard serial MIDI line.
That makes perfect sense.
OTOH I also have some other devices for which the USB bytes are
exactly the same as the MIDI bytes - no extra ones.
Is it the
bInterfaceClass 1 Audio
bInterfaceSubClass 3 MIDI Streaming
that would imply the format you describe ?
I will also need to send some sysexes, and would prefer to use
this device directly as a USB one without going via any MIDI
layer - the application has nothing at all to do with audio
or music. Is there any documentation on what those extra bytes
are supposed to be ?
Many thanks !
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