Re: [Linuxsampler-devel] multiple LSs or lscps

[Christian S. <sch...@li...>]

On Monday 12 March 2012 18:14:10 rosea.grammostola wrote:
> Thanks for your reply. There certainly are no stupid questions... I
> thought, just ask, but it's actually possible!?!

Yes, it is definitely possible to spawn multiple instances of the sampler. But 
right now I cannot imagine a scenario in practice where this would make sense.

For example if you want to leverage a SMP/multi core system, or a system with 
multiple independent hard discs, you could simply create (in the same sampler 
instance) multiple JACK audio output devices (assuming JACK2 or JACKMP), like:

CREATE AUDIO_OUTPUT_DEVICE JACK
CREATE AUDIO_OUTPUT_DEVICE JACK
...

(or do that with some clicks in Fantasia or QSampler). For each audio output 
device in the sampler, a separate audio rendering thread and disk streaming 
thread is spawned. And by connecting a part to one of those audio output 
devices you can control which audio rendering thread & disk streaming thread 
the part shall be part of.

> A typical situation is that you have made a template for let say
> bigband. One or two types of instruments are not in a typically bigband,
> but then you have a midi file / composition with that instruments, or
> just want to try how it sounds. Then it's nice if you have the
> possibility to try it without rewriting the template first.

Sure, but maybe a "MIDI instrument map" is a better way for you to achieve 
such a flexible configuration. This feature allows you to define a MIDI program 
change map with instruments, thus to turn the sampler in some standard General 
MIDI sound generator. For each entry you define at least a MIDI bank select and 
program change number and a sound file (.gig, .sfz, .sf2 ) to be loaded. For 
each entry you can also define a volume factor (for fine tuning your 
performance) and a load strategy. The latter defines whether the sound shall be 
loaded:
a) immediately and always kept in memory ("PERSISTENT"), or
b) instead be loaded on demand and freed automatically when its not in use 
anymore on any sampler part ("ON_DEMAND") or
c) be loaded on demand, but kept in memory afterwards even if not used anymore 
by any sampler part ("ON_DEMAND_HOLD")

http://www.linuxsampler.org/api/draft-linuxsampler-
protocol.html#MIDI%20Instrument%20Mapping

On most master keyboards you can define "performances" which will send the 
appropriate MIDI program change messages to the sampler. So you would just 
need to select the respective performance on your master keyboard and you are 
ready to play.

You can also manage MIDI instrument maps with the two GUI frontend 
applications.

CU
Christian