Then, in section 3.11 we talk about "parameters" and say that
plugins expose their parameters to the host and that parameters are
automatable (thus directly modifiable by the host).
We weren't clear on this. I see it one of two ways:
"Parameters" are the sinks for control data - when you send control
data it must terminate at a parameter. For example, the cutoff
frequency knob of a filter plugin would be a parameter, as would be
the host-to-plugin tempo syncronization of an LFO plugin.
"Control inputs" are the sinks for control data. Control streams are
made between control outs and control ins. "Parameters" are the
user-interactive control inputs. For example, the cutoff frequency
knob of a filter plugin would be a parameter, where as the
host-to-plugin tempo syncronization of an LFO plugin would not.
Of these, I think I prefer the first - "parameter" is just an alias
for "control input". What think? I am trying to keep track of these
clarifications for the fledgeling specification.
- parameter changes (either incoming or outgoing) all come through
GMPI events (= controls)?
yes
a. "start audio sample generation for a new C4 note"
b. "signal a snare drum event detection at time offset xyz"
c. "change the cutoff frequency of the filter to 200 Hz"
must come in to (a and c), respectively out off (b) the plugin using
GMPI events through a control port (aarghh, another term...)?
Pretty much. Whenever you go between plugins, you need some sort of
"wire". That wire is a control signal which starts at a control
output and ends at a control input. (we could switch to "source" and
"sink" terminology if that is clearer to people..)
Or can a parameter change be done without going through a control
port using GMI events?
Do you mean internal to a plugin or between plugins?
