[LAU] MIDI over firewire on Linux?

[Robin Gareus]

On 04/19/2014 10:22 AM, Jörn Nettingsmeier wrote:
> On 04/19/2014 03:43 AM, Jonathan E Brickman wrote:
>> I realized there was a possibly significant gap in my knowledge of
>> hardware, so I searched, and found that there have been a few Firewire
>> devices with both audio and MIDI.  The questions I have are (a) are any
>> of them known to work well with current Linux, and (b) how is the MIDI
>> supported on the backend, is it ALSA?
> 
> i have used focusrite sapphires with good success, both the now
> discontinued pro26 and the pro56. FFADO makes midi available as a
> jackmidi port, so (as others have noted) you will need to run aj2midid
> -e to bridge them to ALSA sequencer clients. i just added it as a
> post-startup command in qjackctl and forgot about it.
> can't comment on MIDI timing performance, i only ever used it for
> controllers, but i don't see any reason to have doubts.
> 

One of the great things about Firewire Audio is the iso-synchronous
protocol that is used there. Audio + Midi are sent in the same
data-stream, interleaved.

As opposed to most PCI and USB sound-cards firewire midi is not a
separated on the bus or data-link level.

It still depends on what the hardware does but everything starting at
the firewire-end all the way up to jack-midi can be in perfect sync,
zero jitter, identical latency as audio.

best,
robin