HLS (HTTP Live Streaming)

What is HLS?

HLS (HTTP Live Streaming) is a streaming protocol developed by Apple. It enables the transmission of audio and video files over the Internet. HLS is particularly suitable for streaming live events and on-demand streaming of videos on various devices such as computers, smartphones, tablets, and smart TVs. However, this does not change the fact that HLS also works excellently for pure audio content.

How does HLS work?

The main mechanism of HLS is to divide the video or audio data stream into small segments and then transfer these segments to the client via HTTP protocol. Each segment has a fixed duration, typically between 2 and 10 seconds.

When a user opens an HLS stream URL, the client downloads the playlist file (M3U8), which contains information about the available video and audio streams. The playlist also contains the URLs of the segment files. The client selects the appropriate stream and begins downloading and playing the segment files.

Advantages of HLS

HLS offers several advantages over other streaming protocols:

  • Adaptive streaming: HLS dynamically adjusts the quality of the stream to the user’s network conditions. If the internet connection is weak, HLS can reduce the bitrate to avoid interruptions and buffering.
  • Compatibility: HLS is supported by most modern web browsers and operating systems, including iOS and Android. This makes it accessible to a broad user base.
  • Scalability: By dividing the stream into segments and using HTTP, HLS can efficiently deliver content via content delivery networks (CDNs). This enables high scalability to serve a large number of users.
  • Reusability: HLS enables segment files to be stored and archived so that users can retrieve content at a later date.

Note on using HLS in SPCast

HLS should be used with caution. There are scenarios that cannot yet be implemented with HLS.

  • Fallback functions are not available.
  • A seamless transition between AutoDJ and live source does not work when broadcasting via SPCast presenter accounts.
  • When broadcasting via AutoDJ, the transitions also function, as the mount is not changed. Changing the mount point is the actual issue that HLS currently still has.

In any case, we strongly recommend that you do not use HLS links as standard links for external radio directories, but instead specifically inform your users when they should use HLS links.

Note: The HLS limitations mentioned are due to the technology itself. Should HLS continue to develop in this direction in the future, we will let you know.

All in all, however, HLS is too useful for us to do without.