[LAU] Bridging alsa and jack midi

[Len Ovens]

On Fri, 26 Sep 2014, Philipp Überbacher wrote:

> Alles klar. Well, mostly. I guess that alsa_midi only makes sense
> when alsa is used as a backend, so I don't quite see why it is a server
> option instead of a backend option. Anyway, using the -X alsa_midi as
> server option works.

That is not true at all, Audio and MIDI are separate  and so it is very 
possible (even likely) that the backend for audio may not be relevant to MIDI. 
MIDI is handled by ALSA, but is not treated as a part of the same audio 
interface as the sound that goes with it. So the user who has a FW audio IF 
with no MIDI would not be able to use a USB MIDI along with it if this was in 
the backend only. Along the same lines is the FW user who does have MIDI in 
their FW IF wants to use a lot of the older SW that creates ALSA MIDI ports 
they are again stuck if it is only available in the ALSA back end.

The only thing I would like to see different in a2jmidi is the naming.  (I am 
not sure how jack1 works) a2j opens as one client called a2j that when expanded 
has the alsa client name followed by the actual port name. This is hard to read 
and use. It is also confusing to new users who ask where the port is just 
because a2j has not been expanded. I would guess the best thing (from a user 
POV) would be for a2j to open a new jack client for each ALSA client with the 
ALSA name. I am not sure what other consequences this would have though :)

--
Len Ovens
www.ovenwerks.net