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Understanding SCTE 35 Ad Insertion/Marker: A Technical Guide

  • Updated

Introduction

In the realm of digital television broadcasting, dynamic ad insertion (DAI) is a cornerstone for content monetization. SCTE 35 (Society of Cable Telecommunications Engineers) is a standard that provides a robust framework for signaling ad insertion and other events in video streams. This technical guide delves into the intricacies of SCTE 35, explaining the necessary components to trigger and utilize SCTE 35 markers effectively, and integrates concepts like Origin Server, Content Delivery Network (CDN), and Server-Side Ad Insertion (SSAI).

Table of Contents

  1. What is SCTE 35?
  2. Key Components of SCTE 35
    • Splice Insert Command
    • Time Signal Command
    • Segmentation Descriptors
  3. Triggering SCTE 35 Markers
    • Encoder Configuration
    • Splice Information Table (SIT)
  4. Utilizing SCTE 35 Markers for Ad Insertion
    • Ad Decision Service (ADS)
    • Server-Side Ad Insertion (SSAI)
    • Origin Server and CDN
  5. Conclusion

1. What is SCTE 35?

SCTE 35 is a standard protocol used to signal the insertion of ads, program segments, or other events in video streams. It facilitates the delivery of targeted advertisements to viewers, thereby enhancing monetization potential for broadcasters and content providers. The SCTE 35 message is embedded in the MPEG transport stream, allowing real-time control over ad insertion points.

2. Key Components of SCTE 35

Understanding the key components of SCTE 35 is essential for effectively leveraging this standard. Here are the primary elements:

Splice Insert Command

The Splice Insert Command is a fundamental part of SCTE 35, indicating a point in the video stream where an ad or another segment should be inserted. It includes:

  • Splice Event ID: A unique identifier for the splice event.
  • Splice Time: The exact time when the splice should occur.
  • Break Duration: The duration of the break (optional).

Time Signal Command

The Time Signal Command is used to indicate an absolute time for an event. It is particularly useful for synchronizing ad insertions across multiple streams.

  • PTS Time: Presentation Time Stamp indicating the exact moment for the event.

Segmentation Descriptors

Segmentation Descriptors provide additional information about the content being inserted, such as the type of event (e.g., advertisement, program start/end) and its duration.

  • Segmentation Event ID: Unique identifier for the segmentation event.
  • Segmentation Type ID: Specifies the type of segment (e.g., ad break, program start).

3. Triggering SCTE 35 Markers

To trigger SCTE 35 markers, several steps and components are required:

Encoder Configuration

The video encoder must be configured to recognize and insert SCTE 35 markers into the transport stream. This involves setting up the encoder to listen for splice commands and embedding the SCTE 35 messages at the appropriate points.

Splice Information Table (SIT)

The Splice Information Table (SIT) contains the SCTE 35 messages and is transmitted in the MPEG transport stream. It includes details about the splice events and is used by downstream equipment to execute the ad insertions.

4. Utilizing SCTE 35 Markers for Ad Insertion

Once you have triggered an ad break, LiveU Studio will send the marker downstream to pass through to a playout system*.

Depending on your configuration, these playout platforms will recognize the ad trigger, then either serve a pre-loaded advert or, more commonly, deliver a server-side ad from a 3rd party ad server (SSAI).

This workflow allows you to personalize ad breaks depending on the viewer identity, geography or platform your stream is being viewed on, whether linear broadcast, OTT or FAST channels.

Ad Decision Service (ADS)

The Ad Decision Service (ADS) is responsible for selecting the appropriate ads to insert based on the SCTE 35 markers. It considers factors such as viewer demographics, ad inventory, and campaign goals.

  • Ad Selection: The ADS chooses the best ad for the insertion point.
  • Ad Delivery: The selected ad is delivered to the video playout system.

Server-Side Ad Insertion (SSAI)

SSAI is a technique where ad insertion occurs on the server side, allowing for seamless ad stitching directly into the video stream before delivery to the viewer. It leverages SCTE 35 markers to ensure precise ad placement.

  • Ad Stitching: The SSAI system stitches the ad into the stream at the exact moment indicated by the SCTE 35 marker.
  • Seamless Experience: Ensures a seamless viewing experience without noticeable transitions between content and ads.

Origin Server and CDN

The Origin Server is the primary source of the video stream, including the SCTE 35 markers, while the Content Delivery Network (CDN) distributes the video content to end-users.

  • Origin Server: Hosts the original video content and SCTE 35 markers.
  • CDN (Akamai, Dacast, Brightcove,...): Distributes the content globally, ensuring low latency and high availability. The CDN must support the transmission of SCTE 35 markers to maintain the integrity of ad insertion points.

5. Conclusion

SCTE 35 is a powerful standard for enabling dynamic ad insertion in digital television broadcasting. By understanding and leveraging its key components—such as Splice Insert Commands, Time Signal Commands, and Segmentation Descriptors—broadcasters and content providers can enhance their monetization strategies. Proper configuration of encoders, use of the Splice Information Table, and integration with Ad Decision Services, Server-Side Ad Insertion, Origin Servers, and CDNs are crucial for the effective use of SCTE 35 markers.

As the demand for targeted advertising continues to grow, mastering SCTE 35 will become increasingly important for staying competitive in the broadcasting industry.

 

* Playout system supporting Ads insertion example:

1. Harmonic Spectrum X

  • Overview: Harmonic Spectrum X is a highly reliable, scalable, and flexible media server that supports advanced broadcast and OTT workflows.

2. Imagine Communications Versio

  • Overview: Versio is a cloud-native playout and master control solution from Imagine Communications, designed to simplify complex broadcast workflows.

3. Evertz OvertureRT

  • Overview: Evertz OvertureRT is a comprehensive playout solution known for its reliability and rich feature set, suitable for both traditional and IP-based workflows.

4. Grass Valley iTX

  • Overview: iTX from Grass Valley is a highly versatile and scalable playout system that caters to both linear and nonlinear broadcast operations.

5. BroadStream OASYS

  • Overview: OASYS by BroadStream is a software-based playout solution that offers flexible and efficient playout capabilities for broadcasters.

6. Vanguard Video VidiPlay

  • Overview: VidiPlay by Vanguard Video is an advanced playout system designed to handle complex broadcast workflows, including live and recorded content.

7. Pebble Beach Systems Marina

  • Overview: Marina by Pebble Beach Systems is a powerful automation and playout solution that delivers reliable and flexible broadcasting capabilities.