[linux-audio-dev] a question re: the MIDI spec

[Martijn Sipkema]

[...]
> > MIDI streams need a reliable transport with guaranteed bandwidth. If
> > USB can't provide this, then it is not really suitable for MIDI, but I'm not
> > saying it is unusable, just that it may perform worse then traditional
> > serial multiport MIDI interfaces.
> 
> USB can provide this just fine, as long as you don't share host
> controllers between MIDI and other devices.  Common sense, really.  I
> would think it would work fine even with multiple MIDI devices on the
> same bus, as long as you don't expect to run audio and MIDI over the
> same wire and have it work.

I don't think common sense is to expect MIDI timing to degrade when
using audio on the same bus, especially when a single device combines
these features. With FireWire it _is_ possible to have both audio and
MIDI (both use isochronous transfers) on the same bus without it
hurting MIDI timing. USB audio would probably work with bulk
transfers too if the bus wasn't used for anything else, so why did they
choose isochronous transfers for audio? I don't see why a audio stream
should be less reliable than a MIDI stream.

--ms