4 Jan
2010
4 Jan
'10
6:30 a.m.
Hi,
Is there an audio app which supports Jack Transport bpm changes in
realtime? I know some midi apps like hydrogen and non-sequencer, but not
audio apps which can play and/or record audio.
Regards,
\r
4 Jan
4 Jan
8:29 a.m.
Hi,
On Monday 04 January 2010 11:28:31 rosea grammostola wrote:
Is there an audio app which supports Jack Transport
bpm changes in
realtime? I know some midi apps like hydrogen and non-sequencer, but not
audio apps which can play and/or record audio.
Last time I looked (two years back sadly), even hydrogen did the bpm changes
wrong. On a new bpm it would recalculate the position from the beginning of
playtime with the new bpm. Which meant missing beats...
It would be pretty cool if jack had functions to do the time<->beat
calculation but sadly most jack developers seem to think that tempo and tempo-
maps (not even live) do not belong into jack...
Arnold
8:38 a.m.
Arnold Krille wrote:
Hi,
On Monday 04 January 2010 11:28:31 rosea grammostola wrote:
There is a discussion about Jack Transport now on jack-devel...
One result of it is that the limitations of Jack Transport are written down:
http://trac.jackaudio.org/wiki/TransportLimitations
\r
Is there an audio app which supports Jack
Transport bpm changes in
realtime? I know some midi apps like hydrogen and non-sequencer, but not
audio apps which can play and/or record audio.
Last time I looked (two years back sadly), even hydrogen did the bpm changes
wrong. On a new bpm it would recalculate the position from the beginning of
playtime with the new bpm. Which meant missing beats...
It would be pretty cool if jack had functions to do the time<->beat
calculation but sadly most jack developers seem to think that tempo and tempo-
maps (not even live) do not belong into jack...
5 Mar
5 Mar
8:32 a.m.
On Mon, Jan 4, 2010 at 12:37 PM, rosea grammostola
<rosea.grammostola(a)gmail.com> wrote:
There is a discussion about Jack Transport now on
jack-devel...
I'm not currently subscribed to jack-devel, so I thought I should go
and check the archives -- but I couldn't find a working archive!
The one at http://boudicca.tux.org/hypermail/ referred to from the
list info page is not responding at all, and the one at
http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org seems
to be members only. Now I could (re?)subscribe, but is there any
reason why it's closed like that in the first place?
Chris
8:57 a.m.
On Fri, Mar 5, 2010 at 7:32 AM, Chris Cannam
<cannam(a)all-day-breakfast.com> wrote:
On Mon, Jan 4, 2010 at 12:37 PM, rosea grammostola
<rosea.grammostola(a)gmail.com> wrote:
the archives have been opened.
it required some words in an ancient elvish tongue and the use of a
staff made from the wizened roots of jazz++ ...
There is a discussion about Jack Transport now on
jack-devel...
I'm not currently subscribed to jack-devel, so I thought I should go
and check the archives -- but I couldn't find a working archive!
The one at http://boudicca.tux.org/hypermail/ referred to from the
list info page is not responding at all, and the one at
http://lists.jackaudio.org/listinfo.cgi/jack-devel-jackaudio.org seems
to be members only. Now I could (re?)subscribe, but is there any
reason why it's closed like that in the first place? 
4 Jan
4 Jan
8:58 a.m.
On Mon, 4 Jan 2010, Arnold Krille wrote:
Last time I looked (two years back sadly), even
hydrogen did the bpm changes
wrong. On a new bpm it would recalculate the position from the beginning of
playtime with the new bpm. Which meant missing beats...
While Hydrogen's transport code is... erm... not good -- I
don't think I ever got a missed beat from a tempo change.
It would be pretty cool if jack had functions to do
the time<->beat
calculation but sadly most jack developers seem to think that tempo and tempo-
maps (not even live) do not belong into jack...
I'm still thinking about the whole "tempo map" proposal
(which doesn't make much sense for a "live" client)...
...but time<->beat calculations have proven to be so
error-prone, I think that some helper functions in Jack to
do the calculations would be a Good Thing. I have a C++
class that does this[1]. It's for Composite's internal
transport -- but it's largely inspired Jack's transport.
This class is intended to be used like a local variable.
TransportPosition pos = get_current_position();
jack_nframes_t end = pos.frame + nframes;
pos.ceil(TransportPosition::TICK);
while( pos.frame < end ) {
// Do operations on this tick.
++pos; // advance to next tick.
}
I imagine an equivalent C API would look like:
jack_position_t pos;
jack_transport_query(client, &pos);
jack_nframes_t end = pos.frame + nframes;
assert(pos.valid & JackPositionBBT);
jack_position_ceil(&pos, JackPositionTick);
while( pos.frame < end ) {
// Do operations on this tick.
jack_position_advance(&pos, JackPositionTick); // advance to next tick.
}
-gabriel
[1]
http://gitorious.org/composite/composite/blobs/9b5b20671ad187bd3f6733838447…
10:57 a.m.
On Mon, Jan 4, 2010 at 7:27 AM, Arnold Krille <arnold(a)arnoldarts.de> wrote:
It would be pretty cool if jack had functions to do
the time<->beat
calculation but sadly most jack developers seem to think that tempo and tempo-
maps (not even live) do not belong into jack...
i don't agree with this assessment. the reason that tempo information
is not more usefully presented in JACK is that at least at the time
that work on JACK transport was done, we did not feel that there was
any reasonable consensus on how to present a shared tempo map to
applications.
2:45 p.m.
Hello,
SooperLooper has that functionality (among a lot of other nice things
you can do with tempo). You can find it here:
http://www.essej.net/sooperlooper/
Hope this helps.
Regards,
Guru
rosea grammostola wrote:
Is there an audio app which supports Jack Transport
bpm changes in
realtime? I know some midi apps like hydrogen and non-sequencer, but not
audio apps which can play and/or record audio.
2:47 p.m.
Guru Prasad B. R. wrote:
Hello,
SooperLooper has that functionality (among a lot of other nice things
you can do with tempo). You can find it here:
http://www.essej.net/sooperlooper/
Hope this helps.
It support Jack Transport?
\r
2:53 p.m.
On Mon, Jan 4, 2010 at 12:45 PM, rosea grammostola
<rosea.grammostola(a)gmail.com> wrote:
It support Jack Transport?
*literally* two clicks and I had the info:
http://www.essej.net/sooperlooper/doc_sync.html
--
Josh Lawrence
http://www.hardbop200.com
2:54 p.m.
On Mon, 4 Jan 2010, rosea grammostola wrote:
Guru Prasad B. R. wrote:
Yes.
-gabriel
Hello,
SooperLooper has that functionality (among a lot of other nice things
you can do with tempo). You can find it here:
http://www.essej.net/sooperlooper/
Hope this helps.
It support Jack Transport?
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10 comments
7 participants
participants (7)
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Arnold Krille -
Chris Cannam -
Gabriel M. Beddingfield -
Guru Prasad B. R. -
Josh Lawrence -
Paul Davis -
rosea grammostola