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Server-Side Ad Insertion

Published Date: 15 March 2023

What is Server-Side Ad Insertion(SSAI)?

Server-Side Ad Insertion, or SSAI, is an ad deployment technique in which the advertisements are stitched directly into the video being streamed. The advertisement will reach the server without the client having to request it from an external ad source. As the client will not make any server calls, ad-blocking technologies normally don’t work when SSAI is in play.

How does SSAI work?

Before The Video Plays:

  1. The video stream is adorned with baseband markers which are also known as SCTE-10 markers.
  2. After the video is sent for transcoders and compression takes place, the SCTE-104 markers are converted to reveal the position of ad breaks in the video.
  3. Manifest locations are revealed further to CMS and made accessible to Video Players during playback.

After The Video Plays:

  1. After the video plays, the Video Player can access the HLS/DASH manifest.
  2. The Video Player will then ask for the manifest.
  3. In response, the Player will also receive viewers’ personal information to deliver personalized advertisements.
  4. When an Ad-Marker approaches the stream, the Ad-Insertion service contacts the Ad Decisioning server, which further supplies the advertisement.
  5. The Ad Decisioning Server uses multiple bits of information to pull a personalized ad out of its repository for playback.
  6. The server is then responsible for transcoding the personalized ad to match the bitrate requirement of the original video.
  7. The Video Player then receives the refreshed manifest for seamless ad delivery.
  8. After playing the ad, the video resumes without any lag or buffer time.

Advantages of Using SSAI

  • SSAI eliminates the need to conduct API calls, providing broadcast-like ad experiences.
  • Because there are no server calls from the client’s side, ad-blocking technologies are obsolete against SSAI.
  • The client is under less pressure as the ad is stitched directly into the streaming video.

Disadvantages of SSAI

  • There is no method to verify that relevant advertisements are being stitched into videos that users are streaming.
  • SSAI is prone to spoofing to mislead advertisers into thinking that millions of users are playing their ads.
  • Ad personalization is not as effective in the case of SSAI.
  • Server-Side Ad Insertion operations through a complex backend infrastructure.

Related Terms


SD—or Standard Definition represents the standard resolution level for streaming.

Stream Key

A stream key is a code that analyzes the source of an audio/video streaming request before allowing the stream to play on the respective website or application.

SVOD - Subscription Video On Demand

SVOD, or Subscription Video on Demand, is a content delivery and monetization model where users are charged a month-to-month or annual subscription fee for uninterrupted access to an extensive entire library of content.

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