SIENNA ND INFRASTRUCTURE

NDI Inferred Routing

Working together the ND Processing Engine and NDI Router deliver a unique infrastructure mechanism known as NDI Inferred Routing.

The purpose of NDI Inferred Routing is to provide a hybrid infrastructure where the core content is MPEG Transport streams, for example in a modern MCR workflow, but you want to use NDI for monitoring, multiviews, alarms etc, and of course for signal Routing.

In a perfect world you might convert all MPEG TS to NDI, pass them *through* the NDI Workflow, and then convert back to MPEG TS at the delivery. However, in practice this is very challenging since there is no direct correlation between the sometimes complex structure of MPEG TS and NDI which makes transparently replicating the MPEG TS stream almost impossible within an NDI Stream.  Note that Sienna has published a number of recommended practice specifications on how this can be done partially, but that is more about consuming MPEGTS data for consumption within NDI, rather than carrying it transparently through NDI and back out again.

To solve this hybrid challenge Sienna presents the NDI Inferred Routing mechanism which allows MPEG TS streams to be converted to NDI but to retain the ability to transparently carry a reference to the original stream so it can be restored with a special module at the end of the monitoring and routing workflow.

This process is documented in the white paper

The Src Stream Repeater Module is usually controlled by following NDI Routing, but can also be explicitly controlled via TCP, WebSocket, REST or explicit NDI Metadata messages, including automation from Node:Red, which could for example change the udp stream source via a text message.  Also, the DTMF decoder in the ND Processing Engine can be used to drive this module, to change udp sources.