HLS

HLS is an modern streaming protocol available for all AAC and MP3 streams on the Radio Mast Streaming Network, providing enhanced stability for mobile listeners and improved battery life.

HLS on Radio Mast is the easiest way to get started with HLS audio streaming, requiring no manual configuration or changes to your encoder. Your stream will be available in both HLS and traditional HTTP streaming simultaneously, so you choose to use HLS on mobile devices without affecting existing listeners.

Listener statistics for HLS are seamlessly integrated into Analytics.

Getting Started

  • Create a stream on your Radio Mast account.
  • Connect your encoder using the provided credentials. We recommend using an AAC codec (AAC, HE-AAC v1, or HE-AAC v2 / AAC+).
  • Under the Overview tab of your stream, look for the "HLS link" for your stream. This can be used to listen to your stream via HLS.

HLS Advantages and Limitations

HLS offers a number of key advantages, making it our recommended protocol for streaming live audio to mobile listeners.

Resilience: HLS streams are downloaded in "segments", which allows players to intelligently retry a download if it is interrupted. Network interruptions on mobile devices happen more often than wired devices due to cellular network dead zones, excessive Wifi interference, or switching between Wifi and cellular networks. HLS allows players to seamlessly recover from network interruptions by re-downloading audio segments and stitching them together without any audible interruption for listeners. Simply put, HLS is more resilient to network disruptions, allowing for smooth playback over longer periods of time on mobile devices.

Battery life: HLS reduces battery consumption on mobile devices by allowing the RF transceiver (baseband) to spend less time active. When a new HLS segment is available, it can be downloaded in a shorter time, allowing the baseband to spend more time sleeping. This power savings results in improved battery life while listening to HLS streams.

Limitations: HLS comes at a cost of much larger audio delay, which is typically about 30 seconds. This delay is mandated by the protocol and provides players with a larger buffer to weather longer network disruptions without stalling playback.

Compatibility

HLS is available for MP3 and AAC streams (AAC-LC, HE-AAC v1, and HE-AAC v2). Any Icecast-compatible streaming encoder can be used, including Rocket Broadcaster Pro and Barix Instreamer.

HLS has excellent playback compatibility on mobile devices, but limited native browser support on desktops. As a result, HLS URL cannot be played directly on desktop browsers, but will play on mobile browsers. A player widget that supports HLS must be used on desktop browsers. The Radio Mast Player Widget will soon automatically serve HLS to mobile listeners if HLS playback is supported.

Mobile apps: HLS is widely supported by mobile audio APIs and SDKs including Google exoPlayer and Apple AvPlayer. Due to the benefits of HLS over traditional HTTP streams for mobile listeners, we recommend using HLS in mobile radio apps.

The following compatibility table provides guidance about where HLS streams can be expected to play:

Platform / Player HLS Notes for Implementers
AAC MP3
iOS apps Yes Yes HLS is well-supported in Apple's AvPlayer component.
iOS Safari / Chrome Yes Yes iOS Safari can natively play AAC and MP3 HLS streams. However, HLS.js does not work out-of-the-box to lack of support for MediaSource Extensions, but can be configured to fallback on native HLS playback.
Android apps Yes Yes Most Android audio apps use Google exoPlayer, which supports HLS.
Android Chrome Yes No Native MP3 playback not supported by Chrome on Android. However, MP3 playback will work in HLS.js.
Desktop Browsers (Windows, macOS) Limited Limited Desktop Google Chrome and Microsoft Edge do not support native HLS playback. In-browser playback is possible using 3rd party Javascript libraries such as HLS.js. Safari on macOS is the only desktop browser to support native HLS playback.
VLC Yes Limited MP3 HLS playback requires VLC 3.0.17.4 or newer. Works on both desktop and mobile VLC.
Roku Streaming Stick+ Yes No
Bluesound Node 2i Yes No

Analytics

Statistics for HLS streams are seamlessly integrated into Radio Mast Analytics.

Due to the design of the HLS protocol, HLS listener session durations are only accurate to within 30 seconds.

Feature Support

Certain Radio Mast Streaming Network features are not yet supported on HLS streams. The status of these features is summarized below:

Feature HLS Supported Notes
Analytics Yes
Geoblocking Yes
Custom Listener Authentication Yes
Backup Streams No
Custom Ads No Preroll and post-roll Custom Ads are currently not supported with HLS.
Promotion N/A HLS not supported by Icecast and Shoutcast streaming directories.

FAQ

Where can I find the HLS link for my stream?

You can add /hls.m3u8 to the end of your direct stream link to get your HLS link. Alternatively, look in the Overview tab of the stream in your account and scroll down until you see "HLS Link".

Will my stream still be available as a regular HTTP stream? Can I have both?

All MP3 and AAC streams on Radio Mast are available as both traditional HTTP streams and HLS streams simultaneously, at no extra charge. You can choose to let your listeners use either protocol depending on their device.