Re: [LAD] making sense of Jack MIDI; or, is this an appropriate use for Jack?

From: Paul Davis <paul@email-addr-hidden>
Date: Fri Feb 15 2013 - 18:12:04 EET

On Fri, Feb 15, 2013 at 11:23 AM, M Donalies <ingeniousnebbish@email-addr-hiddenwrote:

> From what I can tell, the Jack midi interface aspires to hide the
> underlying
> Alsa api so an app developer can just use Jack midi and not have to muck
> with
> Asla.
>

that is a part of the goal, but a deeper one is to provide sample-accurate
and zero-copy delivery of MIDI between JACK clients, with data arriving in
the context of the process() callback where it can be used for synthesis
and control without crossing thread boundaries.

>
> If this is true, then how do I use Jack in the following senerio: I'm
> writing
> a toy gui SMF player that outputs midi events so a program like fluidsynth
> can
> play them.
>
> Using Alsa sequencer, I put events on a queue with a time and Alsa takes
> care
> of the rest. If I just use the Jack midi api, how much of this process can
> Jack do? I'm assuming "not much," since all the apps that I've looked at
> the
> source of use the Alsa sequencer.
>

JACK does not provide sequencing facilities. It simply transports MIDI
between ports.

> If I wanted to do the sequencing myself, what would be involved?

a lot.

Or am I
> completely missing the point of what Jack can do?
>

you seem to understand it reasonably well.

>
> --
> 7:8
> _______________________________________________
> Linux-audio-dev mailing list
> Linux-audio-dev@email-addr-hidden
> http://lists.linuxaudio.org/listinfo/linux-audio-dev
>

_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-dev
Received on Fri, 15 Feb 2013 11:12:04 -0500

This archive was generated by hypermail 2.1.8 : Fri Feb 15 2013 - 20:15:03 EET