10 Nov
2008
10 Nov
'08
11:28 a.m.
Le 10 nov. 08 à 16:01, Alex Montgomery a écrit :
Hello and thanks for the response :)
I've inlined my responses below:
JACK does not and will not support varispeed. Therefore slaving to MTC
is going to be pretty limited. MMC also sends some speed commands that
could not be supported by JACK.
I understand, but I think limited MTC support is better than
nothing. That being said, I don't think it's necessary to change
JACK for this purpose, jackctlmmc's approach of being a jack
compliant app that can drive JACK transport by listening to MMC
signals seems like an elegant approach.
I think this kind of tools is a good candidate to be developed as an
"in server" JACK client. With the dbus based dynamic access of
available "in server" clients installed on a machine, it will be
quite easy to load/unload this kind of tool when needed (Netjack2
uses this model of "in server" clients).
Stéphane
There's a small program called jackctlmmc
that seems to do want I
want, but it's a bit limited (seems pretty hardcoded) and I think
that
such a desirable feature should be integrated
into a more widely
used
program. Any thoughts?
what does "hardcoded" mean?
I made that comment in ignorance. I didn't see a place in the code
where you could choose which MIDI device/port you were reading
from, so I assumed that it just took the first registered one or
hardcoded (specified in code instead of parameters passed into the
program) a particular port. On closer inspection, it seems that you
either have to patch a midi port to the application via JACK so it
knows which one to read from, or it just reads from all alsa midi
signals, either of which is perfectly reasonable. I'm new to the
JACK and ALSA APIs, and I'm still waiting on a cable order to get
my 8-track to talk to my PC, so I can't really test to see how this
stuff works.
Currently jackctlmmc supports the "play", "stop", and
"rewind"
messages from MMC, and I'm going to play with the code to see if I
can add support for "locate" using jack_transport_locate() so that
players can have a primitive seek-to type of function. I think that
even this limited subset of MMC functionality is very desirable for
linux audio engineers. I just want to be able to sit at my 8-track
with my guitar and play/stop, rewind, and maybe seek around without
having to keep clicking a mouse on a JACK app.
I'm surprised that jackctlmmc doesn't seem to be that widely used
(I can't find any packages for it in the major linux distros, and
it only seems to be distributed via source code) when it provides
such useful functionality. I'd love to see it's functionality
integrated into a GUI app like QJackCtl (which already has JACK
transport buttons for play, rewind, fast-forward) instead of being
a console application, but that's a subject for another email.
Thanks for your reply,
-- Alex