This was first posted 12/13/2007 04:46:14.
Today we have been discussing and reviewing the OSC namespace. As the functionalities implemented in parameters are growing more complex, it is an ongoing process reviewing and structuring the resulting OSC namespace. It is not only a question of moving towards syntax specific to Jamoma, but also trying to understand the underlying mechanisms and problems that maker us move in the directions we do. By searching for more general underlying principles we might be able to make more informed choices for Jamoma, but the discussions can also be presented and reviewed in a more general context, and we are currently considering writing a paper for e.g. NIME on the topic.
The discussions seems to be suggesting a partly standardization or organization of OSC namespaces, approached through the specific problems, issues and needs we run into along the way. Currently there are at least three areas of work that hint in this direction:
- The tree-like structuring that is typically in the form of
- The introduction of classes inside modules, such as the /limiter, /saturation and /record classes in the jmod.output~ module, and
- The namespace for accessing the attributes of each parameter.
The following OSC message has served as a “worst case” scenario for the discussion:
Having discussed different ways of designing a message like this one, we seem to have agreed that the meaning of the different separating signs used need to be precisely defined:
.(dot): Used to indicate instances of a specific class.
/(slash): Used to indicate branching according to the OSC specification.
:(colon): Colon is used to split the total OSC message into two parts. The first part is describing where you want to go. The second part describe what you want to access there.
The separation is a result of the functionalities implemented as part of jcom.parameter and jcom.message (ramping, clipping, unit conversion, etc.). These functionalities are commonly available to all parameters. While the part before the colon describe what parameter to access, the section after the colon provides access to the various functionalities available for each parameter, and represents a standardized namespace. Dave introduced the analogy to how URLs are generally designed. The first part of the url (www.jamoma.org) describes what server to access, while the next part (/wiki/workshops) describes what to access on the server.
Below is an attempt at structuring the namespace inside the paramers. This is very much a work in progress.
Message Category Description - [ ] /module/parameter - [ ] General for the module - [ ] :namespace/dump - [ ] :dump/values - [ ] value stuff These ones are not fixed. - [ ] :value/get value get the value of the parameter - [ ] :value value set the value (why would you want to do it this way?) - [ ] :value/range range - [ ] :value/range/get range - [ ] :value/range/clipmode range - [ ] :value/range/clipmode/get range - [ ] :value/step/inc value Increase by one step - [ ] :value/step/dec value Decrease by one step - [ ] :value/step/size value Set the step size - [ ] :value/step/size/get value Get the step size - [ ] :value/unit - [ ] :value/type type - [ ] :value/type/get type - [ ] Conditioning - [ ] :repetitions repetitions - [ ] :repetitions/get repetitions - [ ] ramp stuff - including drive and function - [ ] :ramp/drive ramp/drive Select what mechanism is driving the ramp - [ ] :ramp/drive/get ramp/drive - [ ] :ramp/drive/parameter ramp/drive Pass additional parameters to the driving mechanism - [ ] :ramp/drive/parameter/get ramp/drive - [ ] :ramp/function ramp/drive Select what mapping function to use for the ramp - [ ] :ramp/function/get ramp/function - [ ] :ramp/function/parameter ramp/function Pass additional parameters to the function - [ ] :ramp/function/parameter/get ramp/function - [ ] :ramp/function/parameter/names/dump ramp/function Get the name of all parameters for the currently used function - [ ] :ramp/function/parameter width ramp/function This is an example (valid for the tanh function) - [ ] :ramp/function/parameter/get width ramp/function This is an example (valid for the tanh function) - [ ] ui - [ ] :ui/freeze ui - [ ] :ui/freeze/get ui