Video: What is NMOS? with a Secure Control Case Study

Once you’ve implemented SMPTE ST 2110‘s suite of standards on your network, you’ve still got all your work ahead of you in order to implement large-scale workflows. How are you doing to discover new devices? How will you make or change connections between devices? How will you associate audios to the video? Creating a functioning system requires an whole ecosystem of control protocols and information exchange which is exactly what AMWA, the Advanced Media Workflow Association has been working on for many years now.

Jed Deame from Nextera introduces the main specifications that have been developed to work hand-in-hand with uncompressed workflows. All prefixed with IS- which stands for ‘Interface Specificaion’, they are IS-04, IS-05, IS-08, IS-09 and IS-10. Between them they allow you to discover new devices, create connections between then, manage the association of audio with video as well as manage system-wide information. Each of these, Jed goes through in turn. The only relevant ones which are skipped are IS-06 which allows devices to communicate northbound to an SDN controller and IS-07 which manages GPI and tally information.

Jed sets the scene by describing an example ST-2110 setup with devices able to join a network, register their presence and be quickly involved in routing events. He then looks at the first specification in today’s talk, NMOS IS-04. IS-04’s job is to provide an API for nodes (cameras, monitors etc.) to use when they start up to talk to a central registry and lodge some details for further communication. The registry contains a GUID for every resource which covers nodes, devices, sources, flows, senders and receivers. IS-04 also provides a query API for controllers (for instance a control panel).

While IS-04 started off very basic, as it’s moved to version 1.4, it’s added HTTPS transport, paged queries and support for connection management with IS-05 and IS-06. IS-04 is a foundational part of the system allowing each element to have an identity, track when entities are changes and update clients accordingly.

IS-05 manages connections between senders and receivers allowing changes to be immediate or set for the future. It allows, for example, querying of a sender to get the multicast settings and provides for sending that to a receiver. Naturally, when a change has been made, it will update the IS-04 registry.

IS-08 helps manage the complexity which is wrought by allowing all audios to flow separately from the video. Whilst this is a boon for flexibility and reduces much unnecessary processing (in extracting and recombining audio) it also adds a burden of tracking which audios should be used where. IS-08 is the answer from AMWA on how to manage this complexity. This can be used in association with BCP-002 (Best Current Practice) which allows for essences in the IS-04 registry to be tagged showing how they were grouped when they were created.

Jed looks next at IS-09 which he explains provides a way for global facts of the system to be distributed to all devices. Examples of this would be whether HTTPS is in use in the facility, syslog servers, the registration server address and NMOS versions supported.

Security is the topic of the last part of talk. As we’ve seen, IS-04 already allows for encrypted API traffic, and this is mandated in the EBU’s TR-1001. However BCP 003 and IS-10 have also been created to improve this further. IS-10 deals with authorisation to make sure that only intended controllers, senders and receivers are allowed access to the system. And it’s the difference between encryption (confidentiality) and authorisation which Jed looks at next.

It’s no accident that security implementations in AMWA specifications shares a lot in common with widely deployed security practices already in use elsewhere. In fact, in security, if you can at all avoid developing your own system, you should avoid it. In use here is the PKI system and TLS encryption we use on every secure website. Jed steppes through how this works and the importance of the cipher suite which lives under TLS.

The final part of this talk is a case study where a customer required encrypted control, an authorisation server, 4K video over 1GbE, essence encryption, unified routing interface and KVM capabilities. Jed explains how this can all be achieved with the existing specifications or an extension non top of them. Extending the encryption methods for the API to essences allowed them to meet the encryption requirements and adding some other calls on top of the existing NMOS provided a unified routing interface which allowed setting modes on equipment.

Watch now!
For more information, download these slides from a SMPTE UK Section meeting on NMOS
Speakers

Jed Deame Jed Deame
CEO,
Nextera Video

Video: The Basics of SMPTE ST 2110 in 60 Minutes

SMPTE ST 2110 is a growing suite of standards detailing uncompressed media transport over networks. Now at 8 documents, it’s far more than just ‘video over IP’. This talk looks at the new ways that video can be transported, dealing with PTP timing, creating ‘SDPs’ and is a thorough look at all the documents.

Building on this talk from Ed Calverly which explains how we can use networks to carry uncompressed video, Wes Simpson goes through all the parts of the ST 2110 suite explaining how they work and interoperate as part of the IP Showcase at NAB 2019.

Wes starts by highlighting the new parts of 2110, namely the overview document which gives a high level overview of all the standard docs, the addition of compressed bit-rate video carriage and the recommended practice document for splitting a single video and sending it over multiple links; both of which are detailed later in the talk.

SMPTE ST 2110 is fundamentally different, as highlighted next, in that it splits up all the separate parts of the signal (i.e. video, audio and metadata) so they can be transferred and processed separately. This is a great advantage in terms of reading metadata without having to ingest large amounts of video meaning that the networking and processing requirements are much lighter than they would otherwise be. However, when essences are separated, putting them back together without any synchronisation issues is tricky.

ST 2110-10 deals with timing and knowing which packets of one essence are associated with packets of another essence at any particular point in time. It does this with PTP, which is detailed in IEEE 1588 and also in SMPTE ST 2059-2. Two standards are needed to make this work because the IEEE defined how to derive and carry timing over the network, SMPTE then detailed how to match the PTP times to phases of media. Wes highlights that care needs to be used when using PTP and AES67 as the audio standard requires specific timing parameters.

The next section moves into the video portion of 2110 dealing with video encapsulation on the networks pixel grouping and the headers needed for the packets. Wes then spends some time walking us through calculating the bitrate of a stream. Whilst for most people using a look-up table of standard formats would suffice, understanding how to calculate the throughput helps develop a very good understanding of the way 2110 is carried on the wire as you have to take note not only of the video itself (4:2:2 10 bit, for instance) but also the pixel groupings, UDP, RTP and IP headers.

Timing of packets on the wire isn’t anything new as it is also important for compressed applications, but it is of similar importance to ensure that packets are sent properly paced on wire. This is to say that if you need to send 10 packets, you send them one at a time with equal time between them, not all at once right next to each other. Such ‘micro bursting’ can cause problems not only for the receiver which then needs to use more buffers, but also when mixed with other streams on the network it can affect the efficiency of the routers and switches leading to jitter and possibly dropped packets. 2110-21 sets standards to govern the timing of network pacing for all of the 2110 suite.

Referring back to his warning earlier regarding timing and AES67, Wes now goes into detail on the 2110-30 standard which describes the use of audio for these uncompressed workflows. He explains how the sample rates and packet times relate to the ability to carry multiple audios with some configurations allowing 64 audios in one stream rather than the typical 8.

‘Essences’, rather than media, is a word often heard when talking about 2110. This is an acknowledgement that metadata is just as important as the media described in 2110. It’s sent separately as described by 2110-40. Wes explains the way captions/subtitles, ad triggers, timecode and more can be encapsulated in the stream as ancillary ‘ANC’ packets.

2110-22 is an exciting new addition as this enables the use of compressed video such as VC-2 and JPEG-XS which are ultra low latency codecs allowing the video stream to be reduced by half, a quarter or more. As described in this talk the ability to create workflows on a single IP infrastructure seamlessly moving into and out of compressed video is allowing remote production across countries allowing for equipment to be centralised with people and control surfaces elsewhere.

Noted as ‘forthcoming’ by Wes, but having since been published, is RP 2110-23 which adds back in a feature that was lost when migrating from 2022-6 into 2110 – the ability to send a UHD feed as 4x HD feeds. This can be useful to allow for UHD to be used as a production format but for multiviewers to only need to work in HD mode for monitoring. Wes explains the different modes available. The talk finishes by looking at RTP timestamps and SDPs.

Watch now!
The slides for this talk are available here
Speakers

Wes Simpson Wes Simpson
President,
Telecom Product Consulting

Webinar: IP for Media Part 4 – Audio

Date: Thursday 21st March 2019
Time: 2PM EDT / 18:00 GMT

The fourth in the series of IP in broadcasting, Wes Simpson, NewTek and TV Technology are back, this time, to discuss using Audio over IP – specifically uncompressed audio over IP.

There are a number of proprietary systems like Dante, RAVENNA and others, but this webinar focusses on the standardised AES67 and the closely linked SMPTE ST 2110-30 standards.

Register here for this webinar and the previous IP ones which cover Security, Remote Production and the first ‘101’ session covering the basics of compressed and uncompressed IP for broadcasting.

Speakers

Wes Simpson Wes Simpson
President,
Telecom Product Consulting
Will Waters Will Waters
Vice President of Customer Success,
NewTek
Tom Butts Tom Butts
Content Director,
TV Technology

Video: IP For Media Webcast Part II

Following on from last week’s post part II is here. Wes Simpson looks at use of IP in Remote Production/Remote Integration (REMI) and finished with a panel discussion including Newtek and Grass Valley, a Belden brand.

This video talks about:

  • Why Broadcasters need networking?
  • Typical Live remote sports broadcast roles
  • Overview of video & audio Signal types
  • HDR & Wide Colour Gamut (WCG)
  • Data (metadata, scripts etc)
  • REMI – Remote Integration, AKA ‘Remote Production’ in Europe.
  • Overview of what tasks can be done at base, what still needs to be done ‘on-site’
  • Uncompressed formats summary (SDI, 2022-6, 2110)
  • Slice-based compression
  • Mezzanine compression
  • TR-01 for carrying JPEG 2000 & audio
  • Bonded Cellular
  • Packetloss & FEC (Forward Error Correction)
  • 2022-7 – route diversity
  • Typical delays
  • Plus a panel discussion

 
Watch now!

Speakers

Wes Simpson Wes Simpson
President,
Telecom Product Consulting
Tom Butts Tom Butts
Content Director,
TV Technology