28 Apr, 2023

Understanding HTTP Live Streaming (HLS): The Future of Online Video Delivery

Penetration Testing as a service (PTaaS)

Tests security measures and simulates attacks to identify weaknesses.

HTTP Live Streaming (HLS) is a protocol used to deliver live and on-demand video content over the internet. With the growth of online video platforms, the demand for efficient and reliable video delivery has never been higher. HLS has emerged as the leading technology in this area, offering a standardized approach for delivering high-quality video content to a global audience. In this blog, we’ll take a deep dive into the world of HTTP Live Streaming, exploring how it works, its benefits and limitations, and its role in the future of online video delivery. Whether you’re a content creator, a developer, or simply someone interested in the latest trends in online video, this blog will provide you with a comprehensive understanding of HLS and its importance in the digital landscape. 

Overview of HLS Protocol 

HTTP Live Streaming (HLS) is a protocol used for delivering video content over the internet. It was first developed by Apple in 2009 as a proprietary technology, but it has since been standardized by the Internet Engineering Task Force (IETF) as RFC 8216. HLS enables the streaming of live and on-demand video content by breaking it into small, manageable chunks that are delivered over standard HTTP connections. This means that HLS can be delivered over any standard web server and is compatible with a wide range of devices and platforms, including iOS, Android, Windows, and macOS. 

One of the key advantages of HLS is its ability to adapt to varying network conditions, including changes in bandwidth and latency. This is achieved through the use of adaptive bitrate streaming, which enables the server to detect the available bandwidth and deliver the appropriate quality of video for the viewer’s device and network conditions. Additionally, HLS supports encryption and digital rights management (DRM) to protect content from unauthorized access and piracy. 

HLS has become increasingly popular in recent years due to the growth of online video platforms, which require a reliable and efficient means of delivering high-quality video content to a global audience. Its standardization by the IETF has also contributed to its widespread adoption, as it has enabled developers and content providers to implement HLS more easily and reliably. As a result, HLS has become a critical technology for online video delivery, and its importance is likely to continue growing in the future. 

History of HLS  

The history of HTTP Live Streaming (HLS) dates back to 2009 when it was first introduced by Apple. At the time, the technology was proprietary and was only supported on Apple’s devices and platforms. The primary motivation behind the development of HLS was to provide a standardized approach for delivering video content to iOS devices, which were rapidly gaining popularity at the time. 

HLS was initially designed to work with Apple’s QuickTime media player and the Safari web browser. It relied on the MPEG-2 Transport Stream (TS) format for delivering video content over the internet. The technology enabled video content to be delivered in small, discrete chunks, each of which could be cached locally to improve performance and reduce buffering. Additionally, HLS supported adaptive bitrate streaming, which enabled the server to adjust the quality of the video based on the available bandwidth and network conditions. 

In 2011, Apple submitted a proposal to the Internet Engineering Task Force (IETF) to standardize the HLS protocol. The proposal was accepted, and HLS was officially standardized as RFC 8216 in August 2017. This move enabled other platforms and devices to support HLS, making it more widely accessible and compatible. 

Since then, HLS has become the leading protocol for delivering live and on-demand video content over the internet. It is widely used by major online video platforms such as YouTube, Netflix, and Amazon Prime Video. Additionally, HLS has been adopted by many broadcasters and content providers for delivering their content to viewers over the internet. 

In recent years, HLS has continued to evolve and improve. For example, the protocol now supports a range of video codecs, including H.264, H.265, and VP9, as well as audio codecs such as AAC and MP3. Additionally, HLS has become more efficient, with the ability to deliver high-quality video content over lower bandwidth connections. 

Overall, the history of HLS reflects the growing demand for high-quality online video content and the need for standardized, reliable protocols for delivering it to viewers around the world. 

Key features of HLS 

It offers several key features that make it a reliable and efficient solution for online video delivery. Some of the key features of HLS include: 

Adaptive Bitrate Streaming: HLS supports adaptive bitrate streaming, which means that the server can adjust the quality of the video based on the available bandwidth and network conditions. This ensures that viewers can enjoy high-quality video content, regardless of their internet connection speed. 

Wide Compatibility: HLS is supported by a wide range of devices and platforms, including iOS, Android, Windows, macOS, and Linux. This makes it a versatile solution for delivering video content to viewers across a variety of devices. 

Segment-Based Delivery: HLS breaks video content into small, manageable segments, typically ranging from 2 to 10 seconds in length. This enables faster and more efficient delivery of video content, as segments can be cached and delivered independently of one another. 

Support for Multiple Codecs: HLS supports a range of video and audio codecs, including H.264, H.265, and VP9 for video, and AAC and MP3 for audio. This ensures that content providers can deliver high-quality video content that is compatible with a wide range of devices and platforms. 

Encryption and DRM Support: HLS supports encryption and digital rights management (DRM) to protect content from unauthorized access and piracy. This ensures that content providers can securely deliver their content to viewers without the risk of piracy or copyright infringement. 

Low Latency: HLS supports low-latency streaming, which means that live video content can be delivered with minimal delay. This makes it a suitable solution for delivering real-time events, such as sports or news broadcasts. 

Improved Viewer Experience: The combination of adaptive bitrate streaming, segment-based delivery, and low-latency streaming ensures that viewers can enjoy a smooth and uninterrupted viewing experience, with minimal buffering or interruptions. 

How Does HLS Work? 

HTTP Live Streaming (HLS) works by breaking video content into small, manageable chunks, which are delivered over standard HTTP connections. The technology relies on a server-client architecture, where the server stores the video content and serves it to the client device, which plays the content using a compatible media player. 

The process of delivering video content via HLS typically involves the following steps: 

Encoding: The video content is first encoded into multiple versions at different quality levels, each of which is stored in a separate file. These files are known as “variants.” 

Segmentation: Each variant is then broken down into smaller segments, typically ranging from 2 to 10 seconds in length. These segments are stored as individual files on the server. 

Manifest creation: A “manifest” file is created, which provides the client device with information about the available video variants and the URLs for each segment of each variant. The manifest file is typically in the form of an M3U8 playlist, which is a text-based file that contains a list of URLs for each segment of each variant. 

Delivery: When the client device requests the video content, the server delivers the manifest file, which the client device then uses to request and download the individual video segments. The client device selects the appropriate quality level based on the available bandwidth and network conditions. 

Playback: The client device assembles the downloaded video segments and plays them using a compatible media player. 

One of the key features of HLS is its support for adaptive bitrate streaming, which enables the server to adjust the quality of the video based on the available bandwidth and network conditions. This means that HLS can deliver high-quality video content over lower bandwidth connections, without buffering or interruptions. Additionally, HLS supports encryption and digital rights management (DRM) to protect content from unauthorized access and piracy. 

Overall, HLS is a reliable and efficient protocol for delivering high-quality video content over the internet, and its widespread adoption by major online video platforms and broadcasters has solidified its position as the leading technology for online video delivery. 

HLS Streaming vs. Other Video Streaming Protocols 

There are several video streaming protocols available today, each with its own advantages and disadvantages. Two of the most popular protocols, other than HLS, are MPEG-DASH and RTMP. Let’s compare HLS to these protocols in terms of their features and capabilities. 

Adaptive Bitrate Streaming: All three protocols support adaptive bitrate streaming, which adjusts the video quality based on the available bandwidth and network conditions. However, HLS and MPEG-DASH use HTTP-based adaptive streaming, which allows for better compatibility with firewalls and content delivery networks. 

Support for Multiple Codecs: All three protocols support a wide range of video and audio codecs. HLS supports H.264, H.265, and VP9 for video, and AAC and MP3 for audio. MPEG-DASH supports similar codecs as HLS, but also includes support for WebM and Opus. RTMP, on the other hand, only supports H.264 and AAC. 

Encryption and DRM Support: All three protocols support encryption and digital rights management (DRM) to protect content from unauthorized access and piracy. However, HLS and MPEG-DASH support more advanced DRM solutions, such as Apple’s FairPlay DRM for HLS and Google’s Widevine DRM for MPEG-DASH. 

Segment-Based Delivery: All three protocols use segment-based delivery to break video content into small, manageable segments. However, HLS and MPEG-DASH use a manifest file to organize and deliver these segments, while RTMP streams the video content in real-time. 

Latency: HLS and MPEG-DASH support low-latency streaming, which makes them suitable for delivering real-time events, such as sports or news broadcasts. RTMP, on the other hand, has higher latency, making it less suitable for real-time events. 

Device Compatibility: HLS is natively supported on iOS devices, while MPEG-DASH is supported on Android devices. However, both protocols are supported on most web browsers, smart TVs, streaming devices, and desktop computers. RTMP, on the other hand, is less widely supported on modern devices and platforms. 

In summary, while all three protocols offer adaptive bitrate streaming, support for multiple codecs, and encryption/DRM, HLS and MPEG-DASH have more advanced features and wider compatibility with modern devices and platforms. Additionally, HLS and MPEG-DASH support low-latency streaming, making them suitable for real-time events. RTMP, on the other hand, has higher latency and is less widely supported on modern devices and platforms. Ultimately, the choice of video streaming protocol depends on the specific requirements and needs of the content provider and the audience. 

HLS Supported Devices 

HTTP Live Streaming (HLS) is a widely adopted protocol for delivering live and on-demand video content over the internet. It is supported by a wide range of devices and platforms, making it a versatile solution for delivering video content to viewers across multiple devices. 

Some of the devices that support HLS include: 

iOS Devices: HLS is natively supported on all iOS devices, including iPhone, iPad, and iPod touch. This includes support for adaptive bitrate streaming, low-latency streaming, and digital rights management (DRM). 

Android Devices: Many Android devices also support HLS, including those running Android 3.0 and higher. This includes support for adaptive bitrate streaming and low-latency streaming. 

Web Browsers: Most modern web browsers, including Google Chrome, Mozilla Firefox, and Microsoft Edge, support HLS playback using HTML5 video. This includes support for adaptive bitrate streaming, low-latency streaming, and digital rights management (DRM). 

Smart TVs: Many smart TVs support HLS playback, including those from Samsung, LG, and Sony. This includes support for adaptive bitrate streaming and low-latency streaming. 

Streaming Devices: Streaming devices such as Roku, Apple TV, Amazon Fire TV, and Google Chromecast also support HLS playback. This includes support for adaptive bitrate streaming, low-latency streaming, and digital rights management (DRM). 

Gaming Consoles: Gaming consoles such as Xbox One and PlayStation 4 also support HLS playback. This includes support for adaptive bitrate streaming and low-latency streaming. 

Desktop Computers: Most desktop computers support HLS playback using compatible media players, such as VLC media player and QuickTime player. This includes support for adaptive bitrate streaming, low-latency streaming, and digital rights management (DRM). 

Security Issues and Remediation 

As with any online technology, there are potential security risks associated with HTTP Live Streaming (HLS) that content providers should be aware of. Here are some common security issues and remediation techniques for HLS: 

Content Piracy: One of the biggest security risks associated with HLS is content piracy. Attackers may attempt to capture and redistribute copyrighted content by intercepting HLS traffic and copying the content. To prevent this, content providers can use encryption and digital rights management (DRM) technologies to protect their content from unauthorized access and copying. 

Man-in-the-Middle Attacks: Another security risk is man-in-the-middle (MITM) attacks, where attackers intercept and modify HLS traffic to steal sensitive information or inject malware into the system. To prevent MITM attacks, content providers can use encryption and secure communication protocols, such as HTTPS, to protect their content and communications. 

Malicious Code Injection: Attackers may also attempt to inject malicious code into the HLS stream, either through the manifest file or the media segments themselves. To prevent this, content providers should validate and verify the HLS stream before delivering it to viewers. 

Denial-of-Service Attacks: Denial-of-service (DoS) attacks may also be launched against HLS servers, either by overwhelming them with traffic or by targeting specific vulnerabilities in the HLS protocol. To prevent DoS attacks, content providers should implement proper security measures, such as firewalls, load balancers, and content delivery networks. 

Cross-Site Scripting (XSS) Attacks: Cross-site scripting (XSS) attacks may also be launched against HLS-enabled websites, where attackers inject malicious scripts into the web page to steal sensitive information or execute arbitrary code. To prevent XSS attacks, content providers should sanitize and validate all user inputs and use secure communication protocols, such as HTTPS. 

Conclusion 

In conclusion, HTTP Live Streaming (HLS) is a popular video streaming protocol that offers several advantages over other protocols, including adaptive bitrate streaming, support for multiple codecs, encryption and DRM support, and low-latency streaming. HLS is widely supported on modern devices and platforms, making it a popular choice for content providers. However, there are also potential security risks associated with HLS, such as content piracy, man-in-the-middle attacks, malicious code injection, denial-of-service attacks, and cross-site scripting attacks. To mitigate these risks, content providers should implement appropriate security measures, such as encryption, DRM, secure communication protocols, validation and verification of the HLS stream, and proper network security measures. Overall, HLS is a robust and reliable video streaming protocol that offers a high-quality viewing experience for audiences worldwide, while also providing security and protection for content providers. 

Other Services

Ready to secure?

Let's get in touch