SoundStack, which supports streaming audio and podcast providers, has been talking up HLS Interstitial as a solution for issues around ad content delivery.
Jon Stephenson is CEO.
Radio World: What is HLS Interstitial?
Jon Stephenson: In the context of audio, HLS Interstitial is an easier and more efficient way to insert an advertisement into a live audio stream, separate from the main streaming content.
It eliminates the need for using systems that weren’t really built to do everything ad insertion needs to do — streaming servers that support server-side ad insertion, where ad insertion was bolted onto an existing product, and listening destinations where the player does not support client-side inserted ads, limiting a publisher’s ability to make money.
With HLS Interstitial, the logic of handling the “triggering” of ads is guided by the server, and the complex logic of handling reporting, personalization and more is no longer on the streaming server, but on an SSP (supply side platform) or ad server instead — systems that were built for ad insertion.
RW: What role does it play in how radio broadcasters and others manage their audio streams?
Stephenson: Radio broadcasters can leverage HLS Interstitial to manage their monetization strategies more efficiently and reduce overhead. It allows stations to broadcast the same content for all listeners while the HLS protocol handles personalization for each listener.
RW: Haven’t most CDNs and streaming stations been doing this for quite a while?
Stephenson: Streaming stations are now investing a lot of money in the infrastructure in order to deliver personalized streams. With HLS Interstitial, streaming stations no longer need specialized CDNs that handle server-side ad insertion, but instead can manage this on their own.
RW: SoundStack’s CTO has written that proponents of server-side and client-side audio ad insertion “battle” over which method is better, but he says both are inefficient. Can you expand on that?
Stephenson: Yes. It’s not that server-side and client-side insertion are necessarily inefficient, and each method has its proponents. But they do add extra complexity to the streaming server and players, while this simple protocol solves the ad insertion puzzle in a much easier way. Currently, streaming servers manipulate the original stream and build offsets to attempt to make the transition seamless for each user. In addition, client-side integrations typically require an SDK implementation that requires continuous updates as time goes on.
RW: So your pitch is that a streaming server shouldn’t have to address server-side ad insertion and replacement, and that the client player doesn’t have to implement VAST. Is that correct?
Stephenson: Yes, both should just support HLS Interstitial and this will work.
RW: What else should we know about this process?
Stephenson: We should be aware that HLS Interstitial is a new feature in the HLS protocol and player adoption is not complete. In the same way HLS was slowly adopted in audio to replace ICY — which was developed by Nullsoft in 1998 and stands for “I Can Yell” — we will see players upgrading to the latest versions of the HLS protocol. Right now, it’s fully supported by Apple’s AVFoundation, and gaining more traction with third-party players.
RW: What should radio managers take away from this discussion?
Stephenson: We’re still in the infancy stages of HLS Interstitial adoption on the player side and more usage by radio broadcasters. But, in addition to just making ads more efficient, the possibilities are endless, including using separate content for specific listeners to create the ultimate customized live streaming experiences. Think about it —creating customized weather, promos, news updates, and more, while still fostering a broad listening community around your station connected in real time.
