Introduction – Dynamic Ad Insertion

Dynamic Ad Insertion (DAI) is an advanced technology provided by Google Ad Manager designed to help publishers seamlessly insert ads into live, linear, and on-demand video content. This system ensures a broadcast-quality, personalized ad experience across various devices such as connected TVs, mobile phones, tablets, and laptops. As the television industry evolves with over-the-top (OTT) technology, DAI becomes crucial in maintaining streaming quality and providing a reliable viewing experience. This comprehensive tutorial will guide you through the fundamentals of DAI, implementation steps, best practices for live events, and troubleshooting common challenges, all aimed at optimizing ad delivery and maximizing revenue.

Executive Summary

Television continues to be a popular medium for entertainment, offering the ultimate viewing experience with its big screens, enhanced sound, and high-quality pictures. However, the way people watch TV has significantly changed, with 80% of US households now using connected TV devices and subscribers having an average of four paid video streaming services. This shift to OTT technology allows people to stream TV content anytime and anywhere, whether on a big screen in the living room, on a mobile device on the go, or from a laptop in another room.

The growth of OTT has emphasized the importance of streaming quality, with viewers expecting the same broadcast-quality, reliable experience as traditional TV. Buffering, slow load times, and failed ads or content can lead to viewer abandonment. According to Conviva, nearly 20% of viewers abandon content when an ad has a 5-second delay. Therefore, streaming quality is paramount, and it continues to improve with faster internet speeds, new video distribution mechanisms, and reliable dynamic ad insertion technology.

Google Ad Manager’s Dynamic Ad Insertion (DAI) helps TV partners deliver a seamless, personalized ad experience across every screen. This server-side ad insertion (SSAI) technology allows partners to insert ads into live, linear, and on-demand TV programming, minimizing buffering and latency while ensuring ads are rendered in the appropriate format. With direct integration with Ad Manager 360, DAI offers added scale, precision, and flexibility, enabling TV partners to earn more revenue from their video inventory.

Part 1: Preparing to Implement DAI

Fundamental Technologies and Prerequisites

Before incorporating DAI into your video business, ensure the following systems and technologies are in place:

• Content Delivery Network (CDN): The origin server for all digital content.
• Content Management System (CMS): Maintains metadata for digital content and provides a media-rich site summary feed output. A CMS is optional for live/linear content but required for video-on-demand.
• Injector: (For live/linear content only) This technology takes the SCTE-104 information and cuts the content using cue-out and cue-in to make room for ad breaks. This ensures seamless transitions between content and ads.
• Encoder/Transcoder: This technology has two functions for partner content. The contribution encoder transforms analog-formatted content into digital format, while the distribution encoder converts it into multiple formats or variants. The distribution encoder also creates and sends SCTE-35 data with the variants, mapping out ad breaks.
• Digital Rights Management (DRM): Optional technology required if a partner needs to encrypt digital content to comply with syndication or business rules.
• Packager: Packages variant streams in adaptive streaming formats (HLS or DASH) with SCTE-35 metadata and DRM (if applicable), then places the transport content streams into the CDN.

Additional Prerequisites

To ensure premium quality ads are matched with your premium content, DAI requires the following:

• Transcoding: All video ads must be transcoded, converting one video format into another and creating different variants.
• VAST Compliance: All video ads must be compliant with the IAB’s Video Ad Serving Template (VAST) standards. Google Ad Manager supports VAST versions up to 4.2.
• Unique Ad Units for DAI Inventory: Create DAI-specific ad units to reduce trafficking errors, track and report DAI campaign delivery, and prevent noncompliant ads from targeting DAI inventory.
• Ingest Video Ad Content into DAI CDN: Ensure video ad content is ingested and transcoded into required variants before deploying DAI campaigns.

Implementing Adaptive Streaming

After ensuring all prerequisites are met, implement adaptive streaming to provide an optimal viewing experience. Ad Manager DAI can stitch ads into live linear streams, live event streams, and on-demand content using two adaptive bitrate video streaming standards:

• HTTP Live Streaming (HLS)
• Dynamic Adaptive Streaming over HTTP (DASH)

HTTP Live Streaming (HLS)

HLS is an adaptive bitrate streaming format that uses a manifest file to define a playlist of segments. The packager or encoder chops the video into small segments and uses SCTE-35 messages to indicate ad break opportunities. Best practices for HLS include:

• Playlists and Rendition Groups: Deliver playlists using GZIP content-encoding. Variants in master playlists and segments can use either absolute or relative URLs.
• Codecs and Resolution: Include the CODECS and RESOLUTION attributes in master playlists for live/linear streams and VOD assets to ensure ads match these encoding settings.
• Segment Duration: Use decimal-floating-point numbers for media segment durations to accurately determine ad break timings.
• Timestamp Alignment: Ensure Presentation Timestamp (PTS) aligns across segments for smooth transitions.
• Media Encryption: If required, encrypt media content with AES-128 or SAMPLE-AES.

Dynamic Adaptive Streaming over HTTP (DASH)

DASH is an adaptive bitrate video streaming standard that supports high-quality streaming and DRM technology like Widevine. Key requirements for DASH include:

• MPD Requirements: Use HTTPS for DASH content and declare VOD content as type=”static”. Each period in the MPD must specify a duration attribute.
• Media Requirements: Adhere to the ISO-BMFF on-demand profile and DASH-IF Interoperability Points.
• Media Encryption and DRM: Include the <ContentProtection> element in the MPD for DRM-enabled content, with the PSSH box content present in the manifest.

Part 2: Implementing DAI

Generating Ad Tags

Generating ad tags for DAI involves creating tags that are compatible with either live/linear streams or video-on-demand content. Best practices for generating ad tags include:

• Live Linear: Use HTTPS URLs, set appropriate parameters (sz, iu, impl=s, env=vp, gdfp_req=1, unviewed_position_start=1, ad_rule=0), and optionally control creative eligibility with the pp parameter.
• Video on Demand: Use HTTPS URLs, set parameters (sz, iu, impl=s, env=vp, gdfp_req=1, unviewed_position_start=1, ad_rule=1), and add cmsid and vid parameters for content-specific targeting.

Platform Support

DAI supports various platforms through three main options:

• IMA SDK: The recommended approach, enabling players to make client-side video ad requests and parse VAST responses. The IMA SDK adds methods for requesting VOD or live streams and ensures accurate reporting and event tracking.
• DAI API: Suitable for devices like Smart TVs that lack IMA SDK support, this API allows the player to make direct HTTP requests to the DAI system and handle metrics reporting.
• Server-Side Beaconing (SSB): Enables the player to make direct HTTP requests to DAI, with limitations such as lack of programmatic support.

Optimal Player Development

Developing applications with the following features can enhance user experience and maximize revenue:

• Total Ads Countdown and Per Ad Countdown: Displays the remaining time for total ads and individual ads.
• Closed Captions/Subtitles: Supports Timed Text Markup Language (TTML) and WebVTT formats for subtitles.
• Bookmarking: Saves and returns to a specific point in the content stream for a seamless viewing experience.
• Snapback: Takes the user back to the start of the ad break they skipped and then returns them to their seek location after the ad break.
• Scrubbing: Shows the first frame of each piece of content as the user scrolls through the content bar.

Part 3: Best Practices for Managing Live Events with DAI

Planning for Live Events

Live events require meticulous planning to ensure smooth content and ad delivery. Key considerations include:

• Historical Data: Use past event data to estimate concurrent users, considering changes in implementation, stream authentication, player distribution, and event type.
• Regionality: Account for regional-specific live events to ensure sufficient resources are provisioned.
• DVR Window: Optimize the DVR window to balance serving and storage capacity.
• Ad Inventory: Ensure sufficient ad inventory for popular live events by coordinating with the Ad Operations team.
• DAI Prefetch: Prefetch ads to distribute ad requests evenly and accommodate longer ad decisioning times.
• Early Break Notification API (EBN): Use real-time ad break data to monetize live events effectively.

Building for Failure

Prepare for potential failures by implementing fault tolerance strategies:

• Encoder Failover: Set up primary and backup encoders and address potential ingest or playback issues.
• Stream Request Failure: Use HTTP errors detection and specify backup streams to handle stream request failures.
• Ad Request Failure: Configure appropriate ad-tag settings and handle scenarios where ad break durations do not match returned ads.

Leveraging Data and Standards

Use analytics and VAST reporting to optimize DAI setup:

• Bitrate Profiles: Review and adjust bitrate profiles based on audience usage to save transcoding and hosting costs.
• Bandwidth: Analyze user bandwidth to optimize stream variant parameters.
• Latency: Measure and address latency issues to improve user experience.
• VAST Error Codes: Report and address VAST error codes to debug ad serving issues.
• Mezzanine File: Use mezzanine files for high-quality ad generation across different platforms.
• Universal Ad ID: Implement Universal Ad ID for consistent creative identification.

Part 4: Troubleshooting Common Challenges with DAI

Locating a DAI Session ID or Debug Key

To troubleshoot video streams, find the session ID using IMA SDK or inspect HTTP traffic. Log session IDs for stream troubleshooting and implement methods to display the DAI Session ID easily.

Stream Activity Monitor (SAM)

Use SAM to monitor and debug live stream videos, viewing details about ad breaks, fill and served durations, and troubleshooting issues in real time.

Live Stream Monitor (LSM)

Monitor and troubleshoot live stream videos to view performance snapshots or historical logs of stream activities. LSM provides details about variant statuses, master playlist information, and errors.

Conclusion

Implementing Google Ad Manager’s Dynamic Ad Insertion (DAI) can significantly enhance your ad delivery, ensuring a seamless viewing experience across various devices and content types. By following the guidelines and best practices outlined in this tutorial, you can optimize your ad experience, manage live events effectively, and troubleshoot common challenges. For further assistance, contact your Google Ad Manager Account Manager or visit the Dynamic Ad Insertion help center.

References

• Google Ad Manager Help Center