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
A VAST call is a plain HTTPS exchange. 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.
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>