Assignments to parameter properties are not permitted because the plugin host cannot detect the parameter change, leaving the host and the plugin out of sync.
A possible workaround for this limitation is shown in the code below. Audio gain is applied using a private property safeGain. Whenever the parameter property gain is changed, safeGain is set to that value, and gain reduction is applied to safeGain similar to before. This gives you the desired gain reduction behavior, although the actual gain being used is not visibile in the plugin interface.
hope this helps,
Charlie
classdef safeBoost < audioPlugin
properties
gain = 1;
end
properties (Access = private)
update = 10^(-3/20);
safeGain = 1
end
properties (Constant)
PluginInterface = audioPluginInterface( ...
audioPluginParameter( 'gain' , ...
'DisplayName' , 'Boost' , ...
'Mapping' , { 'log' , 10^(-120/20) , 10^(120/20) } ) );
end
methods
function out = process(plugin, in)
out = in*plugin.safeGain;
if max(out(:)) > 1
plugin.safeGain = plugin.safeGain*plugin.update;
end
end
function set.gain(plugin, value)
plugin.gain = value;
plugin.safeGain = value; %#ok<MCSUP>
end
end
end
