It’s no secret that SDI is still the way to go for some new installations. For all the valid interest in SMPTE’s ST 2110, the cost savings are only realised either on a large scale or in the case that a system needs continuous flexibility (such as an OB truck) or scalability in the future. Those installations which have gone IP still have some SDI lying around somewhere. Currently, there are few situations where there is an absolute ‘no SDI’ policy because there are few business cases which can afford it.
Looking at the current deployments of broadcast 2110, we have large, often public, broadcasters who are undergoing a tech refresh for a building and can’t justify such as massive investment in SDI or they are aiming to achieve specific savings such as Discovery’s Eurosport Transformation Project which is an inspirational, international project to do remote production for whole buildings. We also have OB trucks who benefit significantly from reduced cabling, higher density routing and flexibility. For a more detailed view on 2110 in trucks, watch this video from NEP. In these scenarios, there is nearly always SDI still involved. Some equipment doesn’t yet work fully in 2110, some doesn’t yet work at all and while there are IP versions of some products, the freelance community still needs to learn how to use the new products or work in the new workflows. If you have a big enough project, you’ll hit the ‘vendor not yet ready’ problem, if you have an OB-truck or similar, you are likely to have to deal with the freelance experience issue. Both are reducing, but are still real and need to be dealt with.
Kevin Salvidge from Leader joins the VSF’s Wes Simpson to share his experience of these SDI/IP mixed workflows, many of which are in OB trucks so also include mixed HDR workflows. He starts by talking about PTP and GPS discussing how timing needs to be synced between locations. He then takes a closer look at the job of the camera shaders who make sure all the cameras have the same colour, exposure etc. Kevin talks about how live production in HDR and SDR work touching on the problem of ‘immediacy’. Shaders need to swap between cameras quickly and are used to the immediate switch that SDI can provide. IP can’t offer quite the same immediacy, Kevin says that some providers have added delays into the SDI switches to match the IP switch times within the same truck. This helps set expectations and stop operators pressing two or more times to get a switch made.
Kevin finishes his talk on the topic of synchronising analogue timing signals with PTP. Kevin shows us the different tools you can use to monitor these signals such as a display of PTP timing against B&B timing, a BMCA data readout of data from the PTP grandmasters to check if the BMCA algorithm is working correctly, PTP delay time, packet inter-arrival time, path delay, traffic shaping monitoring. He then closes with a Q&A talking about the continued prevalence of SDI, what ‘eye patterns’ are in the IP world and increasing HDR roll-outs.
As the transition to IP-based transport for video, audio, and data continues. The early adopters have already demonstrated the operational and commercial benefits of COTS IP infrastructure and SMPTE ST 2110 video-over-IP standard suite becomes mature now. However, configuration and troubleshooting of IP systems requires a completely new skillset. Broadcast engineers need to gain an understanding of the technology and the new techniques required to monitor these signals.
In this video Kevin Salvidge from Leader shows what test and measurement tools you need to ensure you continue to deliver the same quality of service that can be achieved with SDI systems.
Kevin looks at the main differences between traditional and IP systems which stem as much from a move from synchronous to asynchronous infrastructure as the way you measure how well the system is working.
This IP Showcase super session consists of six presentation from six different vendors which focus on specific aspects of test or measurement that is unique for ST 2110 environment. It is worth noting that these are technology presentations, not product presentations.
The session is led by Willem Vermost from EBU. He describes what kind of issues we need to solve in a SMPTE ST 2110 environment in terms of testing and monitoring. He speaks about PTP accuracy, traffic shaping (SMPTE ST 2110-21) and SMPTE ST 2022-7 redundancy.
Next, Michael Waidson from Tektronix focuses on Precision Time Protocol (PTP) which is a cornerstone of synchronisation of IP media networks. He walks us through Best Master Clock algorithm, boundary and transparent clocks plus PTP fault finding. (You might also want to watch the Monitoring and Measuring IP Media Networks presentation by Michael which we recently published on The Broadcast Knowledge.)
Furthermore, Jack Douglass from PacketStorm talks about ST 2110-21 traffic shaping measurements. He also shows how to use network emulation tools for testing ST 2022-7 link redundancy (the same data is sent through two separate paths of network emulation that are synchronised together, then burst loss are generated using RTP sequence number, with the least important bit different on both paths).
The next speaker is Ståle Kristoffersen from Bridge Technologies. He focuses on live performance monitoring in a ST 2110 network – does the signal make sense? (IP headers, RTP headers, ST 2110-20/30/40 essences), do all of the signals arrive? (packet loss, monitoring packet loss on 2022-7 links), does the signal arrive on time? (late can be just as bad as a packet loss) amongst others.
Moreover, Kevin Salvidge from Leader shows the differences in monitoring in an SDI and an all-IP facility. He compares single essence per BNC with multiple essences per fibre, synchronous and asynchronous transport and causes for errors (cable loss and impedance mismatch vs error packet loss and network overload). He also emphasises the need for accuracy of PTP and explains how to measure it.
Last but not least, Adam Schadle from Video Clarity walk us through video / audio performance and quality methods. He shows how to use picture and sound quality objective tests to understand network behaviour.
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