GPI was not without its complexities, but the simplicity of its function in terms of putting a short or a voltage on a wire, is unmatched by any other system we use in broadcasting. So the question here is, how do we do ‘GPI’ with IP given all the complexity, and perceived delay, in networked communication. CTO of Pebble Beach, Miroslav Jeras, is here to explain.
The key to understanding the power of the new specification for GPI from NMOS called IS-07 is to realise that it’s not trying to emulate DC electronics. Rather, by adding the timing information available from the PTP clock, the GPI trigger can now become extremely accurate – down to the audio sample – meaning you can now use GPI to indicate much more detailed situations. On top of that, the GPI messages can contain a number of different data types, which expands the ability of these GPI messages and also helps interoperability between systems.
Miroslav explains the ways in which these messages are passed over the network and how IS-07 interacts with the other specifications such as IS-05 and BCP-002-01. He explains how IS-07 was used in the Techno Project – tpc, Zurich and then takes us through a range of different examples of how IS-07 can be used including synchronisation of the GUI and monitoring as well as routing based on GPI.
The still-growing NMOS suite of specifications from AMWA defines ways in which your IP network can find and register new devices plugged in to it (e.g. camera, microphone etc.), manage their connections and control them. They fit neatly along side the SMPTE ST 2110 suite of standards which define the way that the essences (video, audio, metadata) are sent over networks intended for professional media.
As such, they are core to a network and as the market for uncompressed media products matures, the attention is on the details such as whether they scale and security.
In this talk, Simon Rankine from BBC R&D starts by explaining the objectives which means looking at the different aspects of security which is split into three; securing data transfer, ensuring data goes to the right place, ensuring only authorised people can act.
TLS, standing for Transport Layer Security, is the same protocol used for secure websites; those which start with https://. It is also referred to by the name of the protocol it replaced, SSL. Given the NMOS APIs are sent over HTTP, TLS is a perfect match for the use case. TLS provides not only the ability to encrypt the connection but also provides the basis for certificate exchange which allows us trust that the data is being sent to the right place. Simon then covers ciphers and TLS versions before talking about certificate management.
This talk was given at the IP Showcase at NAB 2019.
With all the talk of the SMPTE ST 2110 standards suite, it’s sometimes forgotten that it only deals with content. If you want a working system, you’ll need to do a few more things – find new devices on the network, work out what they can do, control them, guarantee the bandwidth and often deal with metadata that arrives separately like tallies.
This is what the AMWA NMOS specifications do. Peter Brightwell and Thomas Edwards have been heavily involved in creating them and in this video lead us through what each one does and how they are used.
VP Engineering & Development
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