Video: An Introduction to fibre optic cabling

Many of us take fibre optics for granted but how much about the basics do we actually know…or remember? You may be lucky enough to work in a company that only uses one type of fibre and connector, but in an job interview, it pays to know what happens in the wider world. Fortunately, Phil Crawley is here to explain fibre optics from scratch.

This introduction to fibre looks at the uses for fibre in broadcast. Simply put, we can consider that they’re used in high-speed networking and long-distance cabling of baseband signals such as SDI, audio or RF. The meat of the topic is that there are two types of fibre, multimode and single mode. It’s really important to know which one you’re going to be using; Phil explains why showing the two ways they manage to get light to keep moving down the glass and get to the other end.

The talk looks at the history of mulit-mode fibres which have continued to improve over the years which is recognised by the ‘OM’ number which currently stretches to OM5 (this is an advance on the OM4 which that talk considers.) Since multi-mode has some different versions, it’s possible to have mismatches if you send from one fibre to another. Phil visits these scenarios explaining how differences of the launch (laser vs. LED) and core diameter all affect the efficiency of moving light from one side of the junction to the other.

On that note, connectors are of key importance as there’s nothing worse than turning up with a fibre patch lead with the wrong connectors on the end. Phil explains the differences then looks at how to splice fibres together and the issues that need to be taken care of to do it well along with easy ways to fault find. Phil finishes the talk explaining how single-mode differs and offers some resources to learn more.

This video was recorded at a Jigsaw24 Tech Breakfast while Phil Crawley was their Chief Engineer. Download the slides

Watch now!

Phil Crawley Phil Crawley
Lead Engineer, Media Engineers Ltd.
Former Chief Engineer, Jigsaw24

Video: The 7th Circle of Hell; Making Facility-Wide Audio-over-IP Work


When it comes to IP, audio has always been ahead of video. Whilst audio often makes up for it in scale, its relatively low bandwidth requirements meant computing was up to the task of audio-over-IP long before uncompressed video-over-IP. Despite the early lead, audio-over-IP isn’t necessarily trivial. However, this talk aims to give you a heads up to the main hurdles so you can address them right from the beginning.

Matt Ward, Head of Video for UK-based Jigsaw24, starts this talk revising the reasons to go audio over IP (AoIP). The benefits vary for each company. For some, reducing cabling is a benefit, many are hoping it will be cheaper, for others achievable scale is key. Matt’s quick to point out the drawbacks we should be cautious of, not least of which are complexity and skill gaps.

Matt fast-tracks us to better installations by hitting a list of easy wins some of which are basic, but a disproportionately important as the project continues i.e. naming paths and devices and having IP addresses in logical groups. Others are more nuanced like ensuring cable performance. For CAT6 cabling, it’s easy to get companies to test each of your cables to ensure the cable and all terminations are still working at peak performance.

Planning your timing system is highlighted as next on the road to success with smaller facilities more susceptible to problems if they only have one clock. But any facility has to be carefully considered and Matt points out that the Best Master Clock Algorithm (BMCA).

Network considerations are the final stop on the tour, underlining that audio doesn’t have to run in its own network as long as QoS is used to maintain performance. Matt details his reasons to keep Spanning Tree Protocol off, unless you explicitly know that you need it on. The talk finishes by discussing multicast distribution and IGMP snooping.

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Matt Ward Matt Ward
Head of Audio,

[Video]: Video Compression 101

Jigsaw24’s Chief Engineer, Phil Crawley, explains video codecs from the fundamentals up. Codecs touch every part of the broadcast chain and are a vital part of the industry as much as of day to day life. So it’s worth brushing up or learning the basics to help you to fully understand what’s happening with today’s codecs, whether that be HEVC, AV1, JPEG XS or trusty MPEG4.

Phil covers:

  • Compressed and Uncompressed video & codecs
  • DCT Principles
  • Intra/Inter-frame compression
  • Acquisition Vs Editing Vs. Transmission codecs
  • Measuring compression effects
  • Codecs Vs File Formats & wrappers
  • Compression concatenation
  • MPEG4, H.264(AVC) & H.265(HEVC)

Watch now!

Want to take things further? Check out Harmonic’s Next-Gen Compression Techniques


Phil Crawley Phil Crawley
Chief Engineer,

Meeting: Post with the Pros – Intelligent Adobe Workflows

Date: Thursday 19th July, 17:30 BST
Location: 8 Golden Square, Soho W1F 9HY

Join Jigsaw24 for an evening of Adobe and Workflows!

The Post with the Pros team 19th July looks at intelligent Adobe workflows for post, and how you can adapt your workflow for maximum efficiency and creativity.

Come along to find out about the cutting edge Premiere Pro editing system being used in Russia for the World Cup from Adobe Master Trainer Alex Macleod. There’ll be discussion panels with users from media and corporate companies, presentations from manufacturers including FlavourSys, Adobe and Qumulo on the power of shared storage and asset management.

En evening of discussion, demos and the obligatory free beer! Sign up now!