Optimized HLS Streaming
Are you tired of buffering issues while streaming your favorite content online? Do you experience delays or interruptions while watching live events? If yes, then optimized HLS streaming can be the solution to your problem.
KeyCDN has added a new feature for better HTTP Live Streaming (HLS) with a regular Pull Zone. Optimized HLS streaming comes for free and is available for everyone. It's now even easier to accelerate HLS streams from your origin server.
In this comprehensive guide, we will discuss what HLS streaming is, how it works, and the techniques to optimize it for a better streaming experience.
What is HLS Streaming?
HTTP Live Streaming is an adaptive bitrate streaming protocol developed by Apple Inc. It is designed to deliver media content, such as videos and live events, over the internet. HLS divides the video into small chunks of segments, usually between 6 to 10 seconds, and delivers them to the viewer's device via an HTTP server.
How does HLS Streaming work?
HLS Streaming works in a simple yet efficient way. It divides the video content into small segments and creates multiple versions of each segment with different bitrates. These versions are then served to the viewer's device based on its available bandwidth and screen resolution. The viewer's device then selects the most suitable version based on its internet connection speed and displays the video content.
HLS Streaming also provides a mechanism to switch between different bitrate versions during playback. This helps to ensure uninterrupted playback by adjusting the video quality based on available bandwidth.
Optimizing HLS streaming
Optimizing HLS streaming involves various techniques that can help to improve the user's streaming experience. Let's take a look at some of the most effective ways to optimize HLS Streaming.
Encode video content with optimal settings
The quality of video encoding plays a crucial role in HLS Streaming. Encoding the video content with optimal settings can help to reduce buffering and improve overall video quality. Some of the essential settings to consider while encoding video content are:
Bitrate: The bitrate of the video determines the amount of data required to display one second of video. Higher bitrate results in better video quality, but it also requires more data to be transferred over the internet.
Resolution: The resolution of the video determines the number of pixels used to display the video content. Higher resolution results in better video quality, but it also requires more bandwidth to transfer the video data.
Frame rate: The frame rate of the video determines the number of frames displayed per second. Higher frame rate results in smoother video playback but also requires more data to be transferred over the internet.
Use a content delivery network (CDN)
Using a content delivery network (CDN) can help to optimize HLS streaming by reducing the latency and improving the overall video quality. A CDN is a network of servers located around the world that are designed to deliver content to users from the nearest server. By using a CDN, the video content can be delivered to the viewer's device from the nearest server, reducing the latency and improving the overall video quality.
Use adaptive bitrate streaming
Adaptive bitrate streaming is a technique that adjusts the video quality based on the viewer's available bandwidth. It works by creating multiple versions of each video segment with different bitrates and switching between them during playback based on the viewer's internet speed. This helps to ensure that the viewer experiences uninterrupted playback, even if their internet connection speed changes.
Use chunked encoding
Chunked encoding is a technique that divides the video content into small chunks and encodes each chunk separately. This helps to optimize HLS streaming by reducing the latency and improving the overall video quality. Chunked encoding also provides a mechanism to switch between different bitrate versions during playback, which helps to ensure uninterrupted playback by adjusting the video quality based on available bandwidth.
Use a reliable streaming platform
Using a reliable streaming platform is essential for optimizing HLS streaming. A good streaming platform should be designed to deliver high-quality video content with minimal buffering and interruptions. It should also provide a user-friendly interface for easy management of the video content and customization of the player. Some of the popular streaming platforms that support HLS Streaming include Wowza, Vimeo, and Livestream.
Optimize the server configuration
Optimizing the server configuration can also help to improve HLS streaming performance. Some of the essential server configuration optimizations to consider are:
Compression: Compressing the video content before delivering it to the viewer's device can help to reduce the data transfer size and improve the overall streaming performance.
Caching: Caching the video content can help to reduce the server load and improve the overall streaming performance by serving the content from the cache instead of generating it every time a request is received.
Load balancing: Load balancing is a technique that distributes the traffic load among multiple servers, reducing the server load and improving the overall streaming performance.
Monitor and analyze performance
Monitoring and analyzing the performance of HLS streaming can help to identify and fix issues that may affect the viewer's streaming experience. Some of the essential metrics to monitor and analyze are:
Buffering ratio: The buffering ratio indicates the percentage of time the viewer's device is buffering while streaming the video content. High buffering ratio can indicate network or server issues that need to be fixed.
Bitrate switching: Bitrate switching indicates how often the viewer's device switches between different bitrate versions during playback. High bitrate switching frequency can indicate network issues that need to be addressed.
Playback failure rate: The playback failure rate indicates the percentage of time the video content fails to play on the viewer's device. High playback failure rate can indicate issues with the video content or server that need to be fixed.
What are the advantages of HLS?
HLS has several advantages that make it a popular choice for video streaming:
1. Adaptive Bitrate Streaming
HLS uses Adaptive Bitrate Streaming (ABR) technology to dynamically adjust the video quality based on the viewer's internet connection. This means that the video quality can be adjusted in real-time, which results in a smoother playback experience with less buffering and stuttering.
2. Cross-platform support
HLS is supported by a wide range of devices and platforms, including iOS, Android, Windows, and macOS. This means that viewers can access HLS streams on a variety of devices, making it a versatile and flexible streaming protocol.
3. Scalability
HLS is highly scalable, making it an ideal choice for delivering video content to a large audience. This is because the video content is split into small chunks, which can be delivered over a Content Delivery Network (CDN) to multiple viewers simultaneously.
4. Security
HLS supports encryption and digital rights management (DRM) to protect video content from unauthorized access and distribution. This makes it a secure choice for delivering premium video content over the internet.
5. Low latency
HLS has low latency, which means that the delay between the video being captured and the viewer seeing it is minimal. This makes it an ideal choice for delivering live video content, such as sports events and news broadcasts.
6. Accessibility
HLS supports closed captioning and multiple audio tracks, which makes it accessible to a wider audience, including people with disabilities.
7. Additional advantages
- Any firewall or proxy that allows HTTP traffic, can handle HLS as well.
- iOS devices can't handle RTMP but can handle HLS streaming very well.
- Most web players such as JW Player or Flowplayer require the Flash-based version to play RTMP streams, which is not so common anymore.
How does live streaming work with KeyCDN?
The feature can be enabled for any Pull Zone by going to the Zone settings and updating the Optimize for HLS feature to enabled. Like all other Zone features, it will be globally enabled within just a few minutes.
The index file (.m3u8) will not be cached at all. The .ts files will only be cached for 5 minutes. If the origin server sends other Cache-Control headers, it will be ignored by the CDN.
In most cases live streaming based on HLS is better suited and, therefore, recommended from our side as well over RTMP. KeyCDN's support is deprecated for RTMP.
This feature should be enabled for HLS live events but not for prerecorded HLS videos.