Live video streaming has expanded beyond watching live sports and catching up on news, to permeate multiple industries and bring about business transformation. Live streaming is evolving business models in areas like in-event sports betting, online auctions, casinos, gaming, and sports streaming apps that enable groups of fans to watch live sports together and interact via text or chat. The addition of social interactivity capabilities made possible by ultra-low latency streaming in conjunction with methods to share data and video is among the primary drivers for increased live video consumption. In this paper, we’ll explore recent trends and explain the role latency plays in various use cases for live streaming.
Consumption of online video is growing rapidly. Bolstered by the growth of OTT (over the top) streaming, online video will account for 82% of all internet traffic by 2022. And live streaming is no exception to this trend, growing more than 90% in 2021 as live video streaming increasingly touches many areas of our lives beyond entertainment.
Significant latencies are inherent in the majority of online streaming video formats, causing live streams to lag live events by 30 seconds or more. One of the primary complaints with watching live events online is the delay of the stream. Beyond viewer annoyance, streaming latency is an inhibitor to making online video a more engaging experience. Video latency is defined as the amount of time it takes for video streams to travel from the live source acquisition to a viewer's screen. There are several streaming technologies that can provide a range of reduced latencies to deliver new and better viewer experiences. It's important to understand the various online video applications, and each of their latency requirements, to choose the most appropriate streaming technology for your application.
There are many live online streaming applications, each with specific latency requirements. For reference, the diagram below shows the typical latency of traditional chunked HTTP streaming formats and traditional TV broadcast via cable, along with the low latency delivered by other streaming technologies. Not every low latency application requires the sub-second streaming provided by newer technologies such as Web Real-Time Communications (WebRTC). The addition of audience interactivity pushes an application into the sub-second latency domain.
As live events continue to move to OTT platforms, latency and live interaction remain clear challenges to the viewing format. There have been advances in the two most standardized approaches to reducing latency: WebRTC and Low Latency HLS and DASH.
WebRTC is an open-source project to provide realtime communication and is supported by Google, Apple, Microsoft, and others. WebRTC technology can be used to deliver streams with less than a second of latency worldwide and is well suited to interactive applications. With the appropriate design and implementation, WebRTC solutions can deliver reliable, broadcast-quality, realtime video streaming at scale. These dimensions have been a focus for Limelight’s next-generation Realtime Streaming solution that is integrated with one of the world’s largest Content Delivery Networks (CDNs). While enabling subsecond latency, Realtime Streaming also incorporates data sharing that can be used to create interactive services. Shared data capability is becoming important in new applications for live video streaming including in-event sports betting, online casinos, auctions, gaming, and learning. WebRTC is emerging as the leading option for scaling the delivery of live content that is incorporated into the social, audience experience.
DASH and HLS media formats deliver most live events today and are compatible with the majority of modern consumer devices between them. Without low-latency options for delivery, these formats are generally incurring at least 10 seconds of latency and in some cases up to a minute of latency. Both have options for low-latency delivery, which are at different stages of development and use. For HLS, the LL-HLS specification is being produced by Apple for use on iOS devices and is just beginning to be seen in production solutions, and Low-Latency mode for DASH, produced by the DASH Industry Forum, is already in use today to reduce stream latency. Both of these formats promise to be able to deliver streams to supporting devices with latencies as low as 3 seconds. This low latency delivery provides enough time to include server-side ad insertion, Digital Right Management (DRM), forensic watermarking, and other stream enhancements and still match broadcast delivery latency, making these formats ideal for streaming popular live sports and other major live events to large audiences.
The applications for Realtime Streaming are expanding rapidly as the combination of sub-second latency and interactivity enable innovations in how live streams can be experienced by viewers. The following are some examples of use cases that are expanding audiences and participation with online access. There are many more use cases.
Live betting is a more recent technological advancement in legal sports wagering and one that impacts the overall betting experience. Live betting allows fans to bet on in-game outcomes while the game is being played. The keys to betting success are advanced analytics algorithms that allow sportsbooks to monitor games and recalculate odds in realtime. Fans can bet through sportsbook websites that show a live stream of the game and offer bets in realtime based on action on the field.
The higher latency associated with traditional live streaming shortens betting windows for providers, resulting in less revenue. It also means that online fans are at a significant disadvantage compared with those attending the game in person.
Realtime Streaming solves these challenges. The combination of sub-second latency and data sharing along with the video means increased betting, and it allows online fans to wager on in-game action on a level playing field with those in attendance.
Online casinos are growing in popularity, catering to people preferring to play online from anywhere and expanding the potential player market globally. Online casinos typically set up table games with live dealers and video cameras. Online players access the table games via a website on their mobile devices or computers. Casino-developed applications or third-party platforms provide an interface to deposit funds, signal table action, withdraw winnings, and more.
The key challenges are how to enable remote players who can be located anywhere in the world to participate in the same online game, providing a way to include shared data between the online casino and players, accepting bets, and paying off winning bets. To ensure fairness and to maintain pace of play, all players must see the turn of a card or roll of dice at the same time.
To solve these challenges, Realtime Streaming can be used to stream live game action videos to online players. For online players, it's not only realtime latency that’s important but consistent latency among them no matter where they are located.
Live auctions with remote participation are common practice. With Realtime Streaming a live video stream from the auction venue enables remote bidders to participate as if they were present. The realtime stream complements the auction online bidding application, allowing online bidders to participate in realtime.
The latency of typical HLS and DASH chunked streaming results in delays of up to 30 seconds or more between the online video feed and the live auction action. This prevents online participants from bidding in realtime. Sub-second latency in the live video feed is critical to ensure a level playing field in the bidding process.
To solve these challenges, Limelight's Realtime Streaming has the capabilities required to stream live auction video and level the playing field between online and in-person participants. The sub-second latency ensures online participants can signal bids with confidence, knowing that they are viewing the action at the same time as those on-site.
Live trivia contests are played via an app that displays a video stream of game hosts and has a data field where trivia questions are shown. Players respond on the app. Some trivia games attract large numbers of players.
Online players must receive the live host streams and questions with the shortest possible latency, and consistent latency, so all players have the same opportunity to respond.
Realtime Streaming has the combination of sub-second and consistent latency, and data sharing along with the video, allowing all online players to receive trivia questions at the same time, and respond in realtime. Some trivia games create their apps, or use third-party platforms, and only need realtime streaming for the video stream distribution.
The largest live sports events draw huge streaming audiences. Major broadcasters and large social media companies owning the streaming rights for these matches monetize their streams through advertisements and subscriptions. To ensure enough streaming capacity to reach audiences, and reliability of the stream delivery, multi-CDN delivery is deployed.
HLS and DASH media formats are the current standard to deliver streams, but the latency is much longer than typical broadcast delivery. With online viewers demanding lower latency, and to provide new ways to experience live sports online, a streaming format that provides latency close to broadcast and also support enhancements such as ad insertion for monetization is required.
Low-Latency HLS and DASH can deliver streams with as low as 3 seconds of latency, leverage the massive global CDN delivery capacity, and allow stream enhancements such as dynamic ad insertion, DRM, watermarking, and others while matching broadcast latency.
Reducing the latency of your live streams is an important way to drive viewers to your live content. Beyond reducing delay, lowering latency makes it possible to offer new interactive online experiences such as in-event sports betting, online gambling, online auctions, and many other new business opportunities. To do this effectively, at scale, you need a CDN that offers a range of low latency stream delivery options.