What is in this article?:
- Content replacement: New protocols enable flexibility in simulcast services.
- Stream conditioning and ESAM
- User-centric ad insertion at the edge
User-centric ad insertion at the edge
On the output side of the encoding workflow, video chunks are placed onto the CDN, and a cloud-based service responsible for performing dynamic content replacement receives the manifest file. This means that the actual replacement of content — whether it is ad insertion or content occlusion for rights purposes — is performed, in network topology terms, close to the client device.
The mechanism, as described earlier, relies on the relatively lightweight manipulation of the part of the video delivery protocol that tells the client where to fetch the video chunks. This can be performed efficiently on such a scale as to permit decisions to be made for each individual user accessing the live stream. By performing the content replacement in the network, the client simply follows the video segments laid out to it by the content replacement service, and the transitions between live and replacement content are completely seamless. That makes it a broadcast experience — a seamless succession of content, advertising, promos and so on, with no freezes, blacks or buffering — but with the potential for user-centric addressability.
Of course, the content replacement policy and user tracking through the integration of this content replacement service lies with the broadcaster’s choice of ad servers and rights management servers. SCTE-130 defines a series of interfaces which include the necessary interface between a content replacement service and an Ad Decision Service (ADS). In the Web world, Video Ad Serving Template (VAST) and Video Player Ad Interface Definition (VPAID) have emerged as generally analogous specifications.
The ability to tailor content down to the individual, by replacing material in stream, in simulcast, while retaining the broadcast-quality experience of seamless content, is a totally new concept. The commercial ecosystem that generates the need for focused ad targeting must now catch up with the technology that supports it. (See Figure 2.) And broadcasters should be prepared to turn the diagram the other way round.
—David Springall is CTO of Yospace.