Matrox Archives – Page 2 of 2 – The Broadcast Knowledge

What can ST 2110 do for you? What problems can it solve? These questions and more are tackled in this video from BBright and Matrox.

Guillaume Arthuis from BBright kicks off the video by highlighting that SMPTE ST 2110 sends all media as separate streams. Called essences, all aspects of a signal are delivered separately such as metadata, audio and video. For a device which looks at subtitling, this saves having to receive a 3Gb/s stream just to get a few Kbps of data. Sending of the video has also been improved as no blanking data is sent which can see bandwidth savings of up to 30% depending on the video format. It shouldn’t be forgotten that network cables are bi-directional and typically can carry many streams. This means the number of cables in a facility can be greatly reduced.

Marwan al-Habbal from Matrox compares the pros and cons of SDI against ST 2110. SDI has incredible interoperability, has good reliability and ‘discovery’ is not really a problem since everything is point-to-point connected with uni-directional cabling. These latter two points are, of course, downsides compared to ST 2110. Marwan looks at whether we can be confident in 2110’s reliability, discovery and connectivity. Within the standard, ‘narrow’ and ‘wide’ senders are specified. Marwan makes the point that using narrow senders everywhere will give better determinism and can avoid momentary ‘blips’ in the network. Any problems on the network can be mitigated by using ST 2022-7 seamless switching whereby two feeds are sent over the network(s) and a single stream is reassembled from the received packets. Testing is the key to interoperability. JT-NM’s testing programme is, by another name, a ‘plugfest’ whereas many vendors as possible connect to other vendors’ equipment in order to test compatibility. This is leading to confidence in terms of inter-vendor workflows being generally accessible.

Another major benefit of ST 2110 is density. Guillaume takes us through calculations showing that you can implement a 512×512 router using just a 1U switch at an approximate cost of $80. He also looks at future scaling approaches. One approach outlined is to use 25G interfaces today to leave room for expansion but the other is to implement JPEG XS running ST 2110-22. This is a relatively new standard which brings in the ability to use compressed video in 2110 for the first time. This would allow ‘HD’ bitrates for low-latency UHD streams.

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Speakers

	Guillaume Arthuis President, BBright
	Marwan Al-Habbal OEM Product Manager. Matrox

IPMX is an IP specification for interoperating Pro AV equipment. As the broadcast industry is moving towards increasing IP deployments based on SMPTE 2110 and AMWA’s NMOS protocols, there’s been a recognition that the Pro AV market needs to do many of the same things Broadcast wants to do. Moreover, there is not an open standard in Pro AV to achieve this transformation. Whilst there are a number of proprietary alliances, which enable wide-spread use of a single chip or software core, this interoperability comes at a cost and ultimately is underpinned by one, or a group of companies.

Dave Chiappini from Matrox discusses the work of the AIMS Pro AV working group with Wes Simpson from the VSF. Dave underlines the fact that this is a pull to unify the Pro AV industry to help people avoid investing over and over again in reinventing protocols or reworking their products to interoperate. He feels that ‘open standards help propel markets forward’ adding energy and avoiding vendor lock-in. This is one reason for the inclusion of NMOS, allowing any vendor to make a control system by working to the same open specification, opening up the market to both small and large companies.

Dave is the first to acknowledge that the Pro AV market’s needs are different to broadcast’s, and explains that they have calibrated settings, added some and ‘carefully relaxed’ parts of the standards. The aim is to have a specification which allows one piece of equipment, should the vendor wish to design it this way, that can be used in either an IPMX or ST 2110 system. He explains that the idea of relaxing some aspects of the ST 2110 ecosystem helps simplify implementation which therefore reduces cost.

One key relaxation has been in PTP. A lot of time and effort goes into making the PTP infrastructure work properly within SMPTE 2110 infrastructure. Having to do this at an event whilst setting up in a short timespan is not helpful to anyone and, elaborates Dave, a point to point video link simply doesn’t need high precision timing. IPMX, therefore, is lenient in the need for PTP. It will use it when it can, but will gracefully reduce accuracy and, when there is no grandmaster, will still continue to function.

Another difference in the Pro AV market is the need for compression. Whilst there are times when zero compression is needed in both AV and Broadcast, Pro AV needs the ability to throw some preview video out to an iPad or similar. This isn’t going to work with JPEG XS, the preferred ‘minimal compression’ codec for IPMX, so a system for including H264 or H265 is being investigated which could have knock-on benefits for Broadcast.

HDMI is essential for a Pro AV solution and needs its own treatment. Different from SDI, it has lots of resolutions and frame rates. It also has HDCP so AIMS is now working with the DCP on creating a method of carrying HDCP over 2110. It’s thus hoped that this work will help broadcast use cases. TVs are already replacing SDI monitors, such interoperability with HDMI should bring down the costs of monitoring for non-picture critical environments.

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Speakers

	David Chiappini Chair, Pro AV Working Group, AIMS Executive Vice President, Research & Development, Matrox Graphics Inc.
	Wes Simpson RIST AG Co-Chair, VSF President & Founder, LearnIPvideo.com

When you’ve chosen to go IP in your facility using ST 2110, you’ll need to know how to verify it’s working correctly, how to diagnose problems and have the right tools available. Vendors participate in several interop tests a year, so we can learn from how they set up their tests and the best practices they develop.

In this talk, Jean Lapierre explains what to test for and the types of things that typically go wrong in ST 2110 systems with PTP. Jean starts by talking about the parts of 2110 which are tested and the network and timing infrastructure which forms the basis of the testing. He then starts to go through problems to look for in deployments.

Jean talks about testing that IGMPv3 multicasts can be joined and then looks at checking the validity of SDP files which can be done by visual inspection and also SDPoker. A visual inspection is still important because whilst SDPoker checks the syntax, there can be basic issues in the content. 2022-7 testing is next. The simplest test is to turn one path off and check for disturbances, but this should be followed up by using a network emulator to deliver a variety of different types of errors of varying magnitudes to ensure there are no edge cases.

ST 2110 uses PTP for timing so, naturally, the timing system also needs to be tested. PTP is a bi-directional system for providing time to all parts of the network instead of a simple waterfall distribution of a centrally created time signal like black and burst. Whilst this system needs monitoring during normal operation, it’s important to check for proper grandmaster failover of your equipment.

PTP is also important when doing 2110 PCAPs in order to have accurate timing and to enable analysis with the EBU’s LIST project. Jean gives some guidelines on using and installing LIST and finishes his talk outlining some of the difficulties he has faced, providing tips on what to look out for.

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Speakers