Adaptive Bitrate Streaming

How does it work ?

Both live and on-demand streams are delivered in multiple resolutions using the HTTP Live Streaming (HLS) protocol, in order to guarantee smooth streaming in the best possible quality on any device at any time.

• For live streams, the broadcasted stream is transcoded in real time by our streaming servers into a separate stream for each available resolution (e.g. 1080p, 720p, 480p, 360p, 240p).
• For Video on-Demand, this is done when you upload a video. Clevercast automatically transcodes it to multiple resolutions and places these on our Content Delivery Network (CDN).

All streams are available to Clevercast player, which is able to switch dynamically between the different streams and choose the most suitable one for the playback device (depending on screen size and available bandwidth, memory, available CPU and GPU resources). If a viewer’s device has sufficient bandwidth and GPU/CPU resources, this means playing the best possible resolution for the size of the player.

For example, if the embedded size of Clevercast player is 480p, it will start by playing the 480p stream. When the viewer continues to watch fullscreen on a full HD screen, Clevercast player will automatically switch to the 720p or 1080p resolution (depending on the size of the screen).

This way, adaptive streaming allows for Full HD streaming, while also delivering smooth streams to viewers with smaller screens or insufficient bandwidth. As a Clevercast administrator, you can decide which resolutions are being used (both live and on-demand).

Global CDN Delivery

Clevercast uses the Akamai Content Delivery Network (CDN) to deliver the streams as close to the viewers as possible. The Akamai CDN has unparalleled capacity and scale, with edge servers in all possible regions of the world. When a viewer starts to watch a stream, Clevercast player requests the required resolution from the closest edge server. This way, speed and scalability is guaranteed, both for live and on-demand streams (the closer the video content is to the viewer, the faster it will load and play).

Through the CDN backbone, all resolutions of a live stream – via real-time transcoding on our streaming servers – or an on-demand video are immediately transferred to edge servers all over the world, cut into segments. When someone presses play, the closest CDN server starts to deliver the requested segments. By using the HTTP Live Streaming (HLS) protocol, edge servers are able to cache these segments and allow our player to switch to a different resolution without any delay.

By connecting servers across the globe, the Akamai CDN severely limits the time it takes to deliver video streams to end user. Because of the scale of the CDN and the ability of edge servers to cache the different video segments, the number of simultaneous viewers is unlimited. It also makes the video delivery process fully redundant; if an access point is temporarily unavailable, the CDN will simply failover to another one.

Thanks to the real time transcoding on our streaming servers, the adaptive bitrate streaming used by Clevercast player and the scale of the Akamai CDN, all viewers will get the best possible viewing experience on any device, browser or platform.