IS-08 - device channel mapping API endpoint

[tljdebrouwer]

First of all thanks for the NMOS library, it is great work!

We are implementing NMOS for a node with many device(s), where each device can only route in/outputs within it's own device.

When looking in IS-08, there seems to be a perfect solution for this (IS-08 instance per device), however this isn't part of the library.

Would this be a feature which can be put on the backlog of implementation?

Thanks in advance.

[garethsb]

The API "selector" that IS-08 allows could help, but have you considered whether you would be able to use Output Routing Constraints to describe these routing restrictions even within one API instance?

https://specs.amwa.tv/is-08/releases/v1.0.1/docs/4.0._Behaviour.html#output-routing-constraints

[tljdebrouwer]

Hi @garethsb ,

Thanks for the quick response.

Yes we did that, and functionally I believe that with doing so it's all set, a controller can figure out what is and isn't allowed.

With the request we are more considering the burden you would put on a controller to figure out the relations between inputs/outputs and their respective device (which requires iterating for each device towards senders / receivers and so on).

[garethsb]

Do you have feedback from any Controller vendors on this?

Note that there's a hint of how this would be implemented here:

nmos-cpp/Development/nmos/channelmapping_api.cpp

Lines 44 to 49 in a0ff5f3

	// At the moment, it doesn't seem necessary to enable support multiple API instances via the API selector mechanism
	// so therefore just mount the Channel Mapping API instance directly at /x-nmos/channelmapping/{version}/
	// If it becomes necessary, nmos::node_mode::channelmapping_resources could become a map from {selector} to nmos::resources
	// and the 'unmounted' API instance handler also mounted after a "child resources" handler based on the API selectors
	// See https://specs.amwa.tv/is-08/releases/v1.0.1/docs/2.0._APIs.html#api-paths
	channelmapping_api.mount(U("/x-nmos/") + nmos::patterns::channelmapping_api.pattern + U("/") + nmos::patterns::version.pattern, make_unmounted_channelmapping_api(model, validate_merged, gate));