I’ve been browsing the source code to try to understand the audio routing thought the effect chain. From zynthian_gui_engine.py lines 119ff:
if eng not in self.zyngines:
info=self.engine_info[eng]
it seems that every plugin and therefore every effect is instantiated only ever once. But the screen tells me different: a hashtag sign and a number is appended for every new instance. Where does that happen?
From zynthian_autoconnect.py lines 171ff:
def get_fxchain_end(self, exclude=[]):
for eng in reversed(self.zyngines):
if eng in exclude:
continue
if 'system' in self.zyngines[eng].audio_out:
return self.zyngines[eng]
I read that a new effect is first only connected to the next previous plugin? But that can be changed in the Layer Options.
Does it make a difference, which midi Channel I put an effect on?
The routing is redone every 2 seconds by zynthian_autoconnect.py including disconnecting and reconnedting everything. Does that not hurt audio continuity?
Currently, there are some architectural limitations in the zynthian software. The next standalone engines:
ZynAddSubFX
FluidSynth
LinuxSampler
setBfree
Aeolus
Run as “multi-timbrical” engines, so only one instance exists and all layers using the same engine will use the same instance, having common audio/midi input/output.
It has advantages and drawbacks;
Advantages:
Lower memory usage
Faster layer creation
Allows using internal inter-layer routing, System FX and other related features (ZynAddSubFX)
Drawbacks:
common audio/midi input/output, that limit the routing possibilities
in some cases (ZynAddSubFX!!), limit to 1 CPU-core. Having several instances would allow every instance to use a different CPU-core.
Probably, sooner or later, the balance (having more memory!!) will end driving the development towards a multi-instance approach, but until then, we have to know and accept such limitations.
I’ve to improve this because is not very nice now. FX layers are really newcomers to Zynthian-UI …
Right now, MIDI channel should be relevant only for receiving MIDI CC messages (MIDI-learning).
Noooo! Not everything is disconnected my friend. Only what it’s not connected
#Connect to assigned ports and disconnect from the rest ...
for ao in input_ports:
try:
if ao in zyngine.audio_out:
#logger.debug("Connecting to {} ...".format(ao))
jclient.connect(ports[0],input_ports[ao][0])
jclient.connect(ports[1],input_ports[ao][1])
else:
jclient.disconnect(ports[0],input_ports[ao][0])
jclient.disconnect(ports[1],input_ports[ao][1])
except:
pass
Anyway, you shouldn’t be adding new FX layers in the middle of a performance, unless it’s a experimental Jam
It’s better to do that work at home and save everything as snapshots.
the situation has improved quite a bit and now 2 of the more used engines have per-layer audio output, so you can set independent FX-chains for its layers.
