Broadcast Signaling Causing Problems for Live Linear Streaming

By Alan Young  |  June 8, 2017


The SCTE 35 Standard has been used in the cable and broadcast industry to signal the start of local advertising breaks for more than two decades. It has evolved over the years through multiple revisions to also enable signaling for dynamic ad insertion, content replacement, start over, look back and DVR functionality for OTT distribution to multiple screens.  But, there are now so many ways to signal the same thing that no two providers use the same signaling markers! This makes it very difficult for providers to interpret the signaling and the situation has become so bad for one OTT player – Hulu – that they have actually taken the step of disabling processing of SCTE 35 altogether on some of the channels they carry.

Crystal’s Insight suite of products has been specifically designed to diagnose SCTE 35 problems and then provide solutions for the automated delivery and monitoring of consistent and reliable SCTE 35 for OTT distributors and their linear channel providers.

The Problem

The SCTE 35 Standard can be used to signal a) the precise timing details (i.e. start, end and duration) of each segment of a linear television channel b) the type of segment (program start, advert start, placement opportunity etc.) and c) an asset ID.

There is, however, no requirement to signal everything mentioned above and there are multiple different message and segment types available within SCTE 35 with no clear definition on when each should be used.

The result is that no two channel providers use the same SCTE 35 signaling format, which is a nightmare for the OTT Distributors.

The Impact

There are three main reasons why the metadata carried in SCTE 35 markers is so important to an OTT Distributor.

Dynamic Ad Insertion and Content Replacement – SCTE 35 provides the timing – i.e. when to insert – so that there is no peek through of the programming being replaced. Obviously, if this timing is off, either because of message timing errors or because the message itself is missing, the end user will see “peek through” programming, which is objectionable.

Start over, Look back and DVR – SCTE 35 provides the timing but can also provide the asset ID as well as some rights data, all of which are necessary to support (or enable) this sought after functionality. If some or all of this metadata is off or missing, workarounds at the OTT Distributor will be required. This almost always means resorting to the use of the EPG to source information about the asset and its timing plus spreadsheets to convey the rights. The EPG can never be frame accurate and often changes from when it was first distributed because of schedule changes, breaking news or non-deterministic live events.

Blackouts, Rights Enforcement and Content Replacement – This is perhaps the most critical. The first two are mostly an annoyance if they don’t work properly. If content is distributed when there is no right to do so, there can be legal and financial penalties which may be severe. Accurate SCTE 35 metadata – timing, asset IDs and rights (possibly in conjunction with SCTE 224) – is critical in order for OTT Distributors to reliably enforce content providers’ rights on the Internet (which are sometimes exceedingly complex). Without reliable SCTE 35, expensive workarounds and/or excessive content restrictions need to be applied.

The Solution

Crystal has developed a suite of products to better manage and monitor SCTE 35 for content providers and OTT Distributors:

Crystal’s Connect Metadata packager can integrate seamlessly with any broadcast automation system AND associated MAMs, scheduling and traffic systems to extract ALL required metadata and associated timing. Connect can format and frame accurately inject the metadata as required – in SCTE 104 format for “meet me room” encoders, directly in SCTE 35 format and/or using proprietary APIs (such as VDMS’s Live Slicer and AWS’s Elemental API). If different OTT Distributors require different formats, Connect can inject the same metadata into multiple formats simultaneously so that each distributor gets exactly the metadata they need for their business in exactly the right format.

Crystal’s Video Metadata Analyzer – VMA – can swiftly analyze the exact format, content and timing so all metadata can be validated. If there are problems they can quickly be diagnosed and fixed because the VMA’s intuitive visual display makes it easy to see what is wrong.

Crystal’s AdCheck system automates monitoring by the VMA so that metadata measurements can be taken at multiple points along the metadata’s path and compared to a set of configurable business rules (including the lack of metadata markers within a given window of time). If any rule is violated, an alarm – that can interface with any existing NMS – is raised, pinpointing exactly what has failed and when.

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