LADSPA is a standard that allows software audio processors and effects to be plugged into a wide range of audio synthesis and recording packages.
If enabled, Liquidsoap supports LADSPA plugins. In this case, installed plugins are detected at run-time and are all available in Liquidsoap under a name of the form:
ladspa.plugin, for instance
The full list of those operators can be found using
liquidsoap --list-plugins. Also, as usual,
liquidsoap -h ladspa.plugin returns a detailed description of each LADSPA’s operators. For instance:
./liquidsoap -h ladspa.flanger *** One entry in scripting values: Flanger by Steve Harris <firstname.lastname@example.org>. Category: Source / Sound Processing Type: (?id:string,?delay_base:'a,?feedback:'b, ?lfo_frequency:'c,?max_slowdown:'d, source(audio='#e,video='#f,midi='#g))-> source(audio='#e,video='#f,midi='#g) where 'a, 'b, 'c, 'd is either float or ()->float Flag: hidden Parameters: * id : string (default "") Force the value of the source ID. * delay_base : anything that is either float or ()->float (default 6.32499980927) Delay base (ms) (0.1 <= delay_base <= 25). * feedback : anything that is either float or ()->float (default 0.) Feedback (-1 <= feedback <= 1). * lfo_frequency : anything that is either float or ()->float (default 0.334370166063) LFO frequency (Hz) (0.05 <= lfo_frequency <= 100). * max_slowdown : anything that is either float or ()->float (default 2.5) Max slowdown (ms) (0 <= max_slowdown <= 10). * (unlabeled) : source(audio='#e,video='#f,midi='#g) (default None)
For advanced users, it is worth nothing that most of the parameters associated with LADSPA operators can take a function, for instance in the above:
max_slowdown : anything that is either float or ()->float . This means that those parameters may be dynamically changed while running a liquidsoap script.