HLS More or Less

People expect video to just work. But how does it work? HTTP Live Streaming (HLS) is the most widely adopted protocol for providing high-quality, adaptive video streaming over the internet. Let’s summarize.

What is HTTP Live Streaming (HLS)?

HLS is an adaptive streaming protocol developed by Apple Inc. for delivering audio and video content over the internet. Unlike traditional streaming methods, where the entire video file must be downloaded before playback begins, HLS segments video files into smaller chunks, enabling seamless streaming, even under varying network conditions.At the time of introduction, online video was mostly done using Flash and its protocols. Thanks to the adoption of HLS in nearly every web browser, video producers were able to move away from the bloated, insecure world of Flash.

How HLS Works

The HLS workflow ensures a smooth and buffer-free video streaming experience for viewers. Here's a simplified explanation of the process:

1. Encoding: Video content is encoded into multiple quality renditions, each with varying bit rates and resolutions. These renditions are then divided into small segments, typically lasting a few seconds.

2. Manifest File: A manifest file, called the "M3U8" playlist, is generated. This file contains references to the individual video segments and provides information about the available renditions and their respective URLs.

3. Adaptive Streaming: When a user initiates video playback, the HLS player automatically selects the most suitable quality rendition based on the user's internet connection speed and device capabilities. It dynamically switches between renditions as network conditions change, ensuring smooth playback throughout the streaming session.

Advantages of HLS

HLS offers many benefits, making it an attractive choice for content providers and viewers alike:

1. Adaptive Bitrate Streaming: HLS adapts to the user's network conditions, adjusting the quality of video segments on the fly. This results in minimized buffering and improved playback, even in situations with fluctuating internet speeds.

2. Device and Platform Compatibility: HLS is supported by a wide range of devices, including smartphones, tablets, desktops, and smart TVs. It is compatible with major web browsers, iOS devices, Android devices, and various streaming media players.

3. Improved Viewer Experience: Viewers experience less buffering and smoother playback, leading to increased engagement and satisfaction.

4. Scalability and Redundancy: HLS leverages standard HTTP servers, making it easier to scale and distribute content globally. Moreover, its ability to recover from network interruptions enhances the reliability of video delivery.

Implementing HLS

To implement HLS, content creators and providers need a video encoding software that supports HLS, such as Apple's Media Encoder or open-source alternatives like FFMpeg. Additionally, a web server capable of delivering HTTP-based content is required to host the segmented video files and the M3U8 playlist.

HLS and Live Streaming

HLS is particularly well-suited for live streaming events due to its adaptive nature and low-latency capabilities. With the use of specialized encoders and streaming servers, content creators can deliver live events to a global audience with minimal delay, enhancing real-time engagement and interaction.

HLS Progression

HLS is well established, but the technology continues to be improved, indicating it will continue to be a dominant form of video streaming for years to come. Advances like CMAF file format allow storage of video files to be more efficient, while improvements like HLS Low Latency reduce the delay when live streaming to under a second.

At Four Rivers Consulting we use protocols like HLS every day. Contact us to find out how you can benefit from our experience. Or check out our course which uses HLS as part of a Live Streaming Pipeline.