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VAST: video & audio

VAST - the Video Ad Serving Template - is the standard the IAB introduced to make video and audio ad serving work across players from different vendors. It uses an XML schema to carry an ad's metadata from the ad server to the video or audio player.

More information on VAST can be found here: https://www.iab.com/guidelines/vast/

How does it work?

The player requests an ad from the ad server using a simple URL, and Adhese answers with a VAST XML document the player knows how to read. That document is assembled from two building blocks: advar templates, which supply the VAST markup, and creatives, where you provide the media itself. Such media can be provived in three ways:

  1. By uploading the material in Adhese
  2. By providing a link to material hosted on a different domain
  3. By providing a link to an external VAST tag. Adhese will in that case redirect to the external tag while maintaining the ability to track events

Because a template holds static VAST markup, each type / version of video or audio you want to serveserve, needswill require its own template.

Simplified response example

<VAST version="4.0">
  <Ad id="19787">
    <InLine>
      <AdSystem>Adhese</AdSystem>
      <AdTitle>Your creative</AdTitle>
      <Impression><![CDATA[ …/impression ]]></Impression>
      <Creatives>
        <Creative>
          <Linear>
            <Duration>00:00:15</Duration>     
            <TrackingEvents>              
              <Tracking event="start"> … </Tracking>
              <Tracking event="firstQuartile"> … </Tracking>
              <Tracking event="complete"> … </Tracking>
            </TrackingEvents>
            <VideoClicks>
              <ClickThrough><![CDATA[ …/click ]]></ClickThrough>
            </VideoClicks>
            <MediaFiles>                  
              <MediaFile type="video/mp4" width="640" height="360">
                <![CDATA[ …/creative.mp4 ]]>
              </MediaFile>
            </MediaFiles>
          </Linear>
        </Creative>
      </Creatives>
    </InLine>
  </Ad>
</VAST>

Video

Linear

In-stream video ads that interrupt the main video content. They include Pre-rolls (playing before the video), Mid-rolls (playing during), and Post-rolls (playing after). These usually include skippable or non-skippable formats (introduced in VAST 3.0). 

Companion ads

A companion ad is a display ad shown alongside a linear video ad, usually displayed on top of the player or on its side. It is displayed at the same time as the video ad and can continue to be displayed after the video has finished playing. 

Outstream

The video ad appears in non-video environments, typically embedded in text-based content such as articles or news feeds. An outstream video could for example be shown in typical display placements such as a 'medium rectangle'. 

Non-linear

The ad runs alongside the content, typically as an overlay, without interrupting playback.

Ad pods

The IAB VAST 3.0 template introduced the concept of Ad Pods. Ad Pods are a way to specify multiple <ad> elements, which are to be sequenced together and played back-to-back within a single ad break. 

Audio

Audio creatives are audio ads that play in a vendor's digital audio player. They are handled similarly to video creatives, except they only have audio and no video component.

Native audio arrived in VAST 4.1, when the separate audio spec (DAAST) was folded back into VAST - before that, audio was served through DAAST as its own template.

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