A VAST (Video Ad Serving Template) video advertising parser is a software component that processes and interprets VAST XML documents, which contain information about video ads. VAST is an IAB (Interactive Advertising Bureau) standard that enables the communication between video players and ad servers. The main goal of a VAST parser is to extract relevant information from the VAST document, such as video ad creatives, tracking events, and ad metadata, and provide this information to the video player for rendering and tracking.
Here’s a high-level overview of how a VAST video advertising parser works:
- Receive VAST XML document: The parser receives a VAST XML document, either by requesting it from an ad server or receiving it as a response from another component (e.g., a video ad request).
- Extract relevant information: The parser extracts relevant information from the VAST document, such as:
- Media files: These are the actual video ad creatives that can be played by the video player. The parser extracts information such as the URL, MIME type, bitrate, and dimensions of the media files.
- Tracking events: VAST documents may contain tracking URLs that should be called when specific events occur, such as the ad starting, pausing, or completing. The parser extracts these tracking URLs and associates them with the corresponding events.
- Ad metadata: Additional information about the ad, such as duration, ad title, ad description, click-through URL, and skip offset, may also be extracted by the parser.
- Handle VAST wrappers: VAST documents may contain “wrappers,” which are VAST documents that point to another VAST document from a different ad server. In this case, the parser must make a request to the secondary VAST document and repeat the parsing process until it reaches the final VAST document containing the actual video ad creatives.
- Pass information to the video player: Once the parser has extracted all the relevant information, it passes this information to the video player. The video player then renders the video ad creative, handles user interactions (e.g., clicking on the ad), and sends tracking events to the appropriate URLs as the events occur.
In summary, a VAST video advertising parser is responsible for processing and interpreting VAST XML documents to extract relevant information about video ads, handling VAST wrappers, and providing the extracted information to the video player for rendering and tracking.