Using read-only parameters to send data to UI, OK to send plain values?

Developer VST 3 SDK
1

Hi, I’m working on a project where I’m using read-only parameters and outputParameterChanges to send data to the UI, for example an audio peak meter. Does the spec allow us to send plain values or do we need to normalize these as well? For example if you clip, the level you want to send to the UI will be over one, or maybe you want to do some shenanigans with std::bit_cast to send some custom bits.

I’ve tested in a couple hosts and see that values outside the 0…1 range are indeed passed to the controller but am curious if this is guaranteed OK by the spec.

Thanks

2

the value has to be normalized. You could apply a transformation to your value to compress it for example:

before sending to the host: if your value is between 0 and 2,

ValueOut = value / 2.0;

and in your controller:

value = valueIn * 2.0;