Certain live video streaming use cases require that end user viewers are able to watch video as close to real-time as possible, and importantly, that there is consistency on stream latency across different viewing devices. This low-latency streaming requirement is present in a number of industries, particularly in gambling, gaming, and sports broadcasts. The importance of low and consistent latency manifests in online gambling and betting where users are in different locations wagering on the same game.
Streaming over HTTP to deliver via HLS, DASH, HDS, or Smooth Streaming, has typically resulted in latencies of 30 seconds or more, compared to older formats like RTMP (Flash) streaming with 2-6 second latency. That’s because these are HTTP-based protocols which stream chunks of data. Because each video chunk is generated and viewed in real time, the chunk size plays a big part in latency. For example, the default Apple HLS chunk size is 10 seconds, leading to latency of up to 45 seconds, when CDN ingesting, transcoding time, and delivery are factored in.
A common technique in lowering the latency of HTTP streaming is to reduce the chunk size. Some implementations lower the chunk size to 1 second, allowing HLS and DASH to achieve latencies near RTMP. The problem facing these implementations is how to deliver these smaller chunks to their end users across the globe, while losing little time in reaching them and without risking high rebuffering rates. Traditional CDN delivery has the reach, but can introduce unwanted additional latency just to move bytes from ingest to edge.
To help you achieve successful delivery of your low-latency streams, limelight has introduced Video Acceleration, a specific set of configuration options in the Content Delivery Service designed to accelerate the delivery of dynamic manifest files and very small video chunks. Video Acceleration is targeted at organizations delivering HLS and DASH live streams from their own infrastructure as an origin for the CDN to cache fill from, and will typically be deploying a video platform to produce the Master Manifest, individual bitrate manifests, and the video chunks.
Organizations benefiting from Video Acceleration will typically have one of the following use cases:
Ensuring consistent reduced latency experience for end users on a range of devices.
Scale the delivery of low-latency live video to large audiences.
Reduce the latency difference between broadcast TV and online OTT streaming delivery.
Consistent end-user experience across multi-devices for non-simulcast delivery.
Use the Limelight Content Delivery Service to offload and accelerate delivery of small live video chunks.
Accelerating delivery of live streams ensures lower latency without compromising the efficiency of your infrastructure.