Rui Nuno Capela rncbc at rncbc.org
Tue Sep 20 15:03:56 UTC 2016

On 09/20/2016 01:25 PM, Robin Gareus wrote:
> Rui already has a working standalone prototype (no timebase support yet,
> but it's a good start).

jftr. there's these posted upstream:

however, for the time being, this is only about adding example 
applications (linkhut, qlinkhut, etc.) with jack audio support, as in 
alternative to portaudio on linux.

again for the time being, it has nothing to do with jack-timebase, at 
least yet, and for x sake, it probably won't do anything about 
jack-transport, which i believe is not applicable nor substitute

i see each, jack-transport and ableton-link, as orthogonal in function 
and purpose. iow., an application either adopts jack-transport *or/and* 
ableton-link protocol (possibly through a jack-timebase proxy) to sync 
its "play time".

afaiu. jack-tranpsort is about absolute sample/frame real-time 
positioning; otoh. ableton-link is about relative tempo, beat and/or 
phase (within a bar or measure)  musical-time ie. it's better described 
as a shared *metronome* over the LAN (wether it's wired or wireless: low 
level is multicast udp/ip, so that it works on the local net segment 
switches but never across routers). iow. ableton-link is *not* a 
wall/word-clock for keeping media streams in sync. and it doesn't do 
WAN, so you can keep your tinfoil in the closet :).

point is, applications using the ableton-link facility have to implement 
special, dedicated sync patterns, which are not bearable to a linear 
real-timeline, so to speak. it is best suited, or recommended, for 
syncing loopers on musical BBT and tempo (BPM) units, abstract time 
boundaries if i may, not to concrete linear/real-time stream players.

on the practical side of thoughts, i mean, i'd say to scrap any 
jack-transport implementation on superlooper or seq24, for example. make 
those sync to ableton-link instead. hydrogen would have a great boost in 
usability too, i'm sure. though, old plain linear timeline based DAWs, 
eg. ardour, (or sequencers for that matter) qtractor, muse(score), 
rosegarden, etc. would be better still set to jack-transport as 
master/slave as usual, maybe set ableton-link tempo and beat/bar phases 
according to their rolling playback state, that is as long as to 
function as timebase masters.

as a final note, and conclusive perhaps, ableton-link integration is an 
application/client option, not quite on the JACK server/service side if one.

just my 2eur.
rncbc aka. Rui Nuno Capela

More information about the Linux-audio-dev mailing list