[linux-audio-user] Ardour and Hydrogen sync through Jack!!

Jack O'Quin joq at io.com
Wed Dec 17 09:54:48 EST 2003

R Parker <rtp405 at yahoo.com> writes:

> Hydrogen retains the "slave" concept, now officially inappropriate
> in California, and when in "slave" mode, Hydrogen is unable to
> initiate Transport actions. It only responds, ie hit Play in JAMin
> and Hydrogen plays right along.

Yes, I noticed that and wondered about it.  

There are often good reasons for an application to provide an option
whether to transmit local transport commands to JACK.  In the case of
GUI-based applications like hydrogen, I think it should be done by
default.  If the user presses "play", then go ahead and call
jack_transport_start().  That is almost certainly what was intended.

One of the goals of the transport design was to improve usability by
allowing these commands to be issued from any client.

> Jack, as I understand your design, one client must be time base
> master but any client can initiate Transport actions. Is this
> correct?


At most one timebase master.  None is really needed in most cases.
But, hydrogen could usefully provide a (conditional) timebase callback
that counts bars, beats and ticks (BBT).

Ardour will generally provide this information unconditionally, but
when running without ardour, hydrogen would sometimes be the only
client with the necessary information available.

But, these are minor points.  What Paul and Comix have accomplished is
already an important milestone in Linux audio.  There is a lot of
demand for this, and it fits the open source development model well.

> --- Jack O'Quin <joq at io.com> wrote:
> > Controlling ardour and hydrogen in sample sync is really a
> > powerful combination.  I bet one or two of our favorite MIDI
> > sequencers will not be far behind.  :-)
> You got some inside information you're holding? :)

Not at all.  My comment was based entirely on public statements of the
MUSE and rosegarden developers.

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