Choosing the right protocol for video delivering: a guide to HLS, MPEG-DASH, WebRTC, and SRT

Imagine you’re settling in for a night of binge-watching on your Smart TV. You expect the show to start instantly, play in high definition, and never buffer, even if your child is playing online games in the next room. What makes this seamless experience possible? Behind the scenes, it’s all about the streaming protocol that delivers video to your TV.

In this article, we’ll explore the key streaming protocols—HLS, MPEG-DASH, WebRTC, and SRT—that power the content you watch every day. Understanding these protocols is crucial for anyone in the business of delivering video to large audiences, particularly on IPTV, TV and OTT services. At Flussonic, we help build reliable infrastructure for these tasks: we assist in choosing the right protocols, offer flexible tools, and ensure high-quality video delivery to your audience. Contact us if you have challenges we can help with.

In this article, let’s take a closer look at popular video delivery protocols and their application in the industry.

Understanding Streaming Protocols for IPTV and OTT

When you click “play” on your TV remote, a sophisticated process begins to deliver that video content to your screen. The protocol used determines how quickly the video loads, how smoothly it plays, and how well it adapts to network conditions.

Let’s take a closer look at the main players in this field.

HLS (HTTP Live Streaming): The go-to protocol for Apple TV and many other devices, ensuring your shows stream smoothly, whether you’re on a high-speed fiber connection or barely managing with your neighbor’s Wi-Fi.

MPEG-DASH (Dynamic Adaptive Streaming over HTTP): The backbone of global streaming giants like YouTube and Netflix, MPEG-DASH ensures that millions of users can stream content simultaneously without a hitch.

WebRTC (Web Real-Time Communication): While not your typical streaming protocol, WebRTC is what makes interactive TV apps, like those used for live sports commentary or video chats, possible.

SRT (Secure Reliable Transport): The hero in live broadcasts, SRT ensures that even when your network is struggling, the live concert you’re watching doesn’t miss a beat.

HLS (HTTP Live Streaming): The Reliable Workhorse

Developed by Apple, HLS has become a standard in the streaming world, particularly for devices like Apple TV. Imagine you’re streaming the latest blockbuster on your TV. HLS ensures that as your network conditions change—maybe your roommate starts a download in the next room—your video quality adjusts seamlessly, without interruption.

How HLS Works for IPTV and OTT

HLS operates by breaking the video into smaller segments and delivering these segments over HTTP. The streaming process is orchestrated using an m3u8 playlist file, which indexes and orders the segments of the video. This m3u8 file is crucial as it tells the player which segment to download next, allowing the video to adapt on the fly, shifting between different quality levels depending on your network speed. It’s like a well-trained athlete, constantly adjusting its pace to stay in the race without dropping out.

However, one challenge with HLS has been its relatively higher latency compared to other protocols. This latency arises because HLS typically buffers several segments of video before playback begins, which can cause a delay. To address this, Apple introduced a newer HLS version known as Low-Latency HLS (LL-HLS). LL-HLS significantly reduces latency by shortening segment durations and enabling faster delivery of HLS content. This makes HLS even more suitable for live events and real-time interactions where every second counts.

HLS Media Benefits for TV Use Cases

• Universal compatibility: Almost every smart device out there can handle HLS content, making it the most reliable choice for reaching a broad audience. Whether you’re streaming on a smart TV, a tablet, or a smartphone, HLS ensures a consistent experience.

• Smooth streaming: Whether you’re on a fast fiber connection or dealing with spotty Wi-Fi, HLS media adapts dynamically to provide the best possible viewing quality. With the introduction of LL-HLS, you also get the advantage of lower latency, making HLS even more versatile.

MPEG-DASH (Dynamic Adaptive Streaming over HTTP): The Global Standard

Imagine the massive data centers at YouTube or Netflix, streaming thousands of videos to millions of users worldwide. MPEG-DASH is what keeps everything running smoothly. This open standard protocol doesn’t belong to any single company, making it the preferred choice for many global streaming platforms. However, it competes closely with HLS in popularity, especially given that HLS streams are widely supported across various devices.

How MPEG-DASH Works for TV Devices

Like HLS, MPEG-DASH breaks the video into chunks and delivers them over HTTP. The difference lies in its flexibility and openness. Because MPEG-DASH is an open standard, it allows different devices and platforms to stream content without being tied to any specific ecosystem.

Benefits for TV Use Cases

• Interoperability: Whether you’re streaming on a gaming console, a smart TV, or your old laptop, MPEG-DASH ensures everything works together, similar to how an HLS stream would but with the added benefit of broader platform support.

• Scalability: From a small indie film site to a global giant like Netflix, MPEG-DASH can handle it all.

WebRTC (Web Real-Time Communication): The Real-Time Connector

WebRTC might not be the first protocol that comes to mind when you think of TV streaming, but it’s what powers real-time interactions on your screen. Picture this: you’re watching a live debate, and you want to jump into a video chat to discuss it with friends. WebRTC makes this possible, ensuring your conversation happens with minimal delay.

How WebRTC Works for TV Interactions

WebRTC establishes a direct peer-to-peer connection, bypassing the usual server route. This means that your video call or interactive TV app responds in real-time, creating a seamless experience for live interactions. While WebRTC is less common in traditional TV streaming where HLS streams are more prevalent, it excels in scenarios requiring real-time communication, such as interactive TV apps, live polling, or video chats.

Benefits for TV Use Cases

• Instant interaction: For apps that require real-time communication, such as video chats or live polls, WebRTC is the go-to choice. Its ability to create instant connections makes it invaluable for live, interactive TV experiences, complementing the on-demand nature of HLS content.

• Low latency: In situations where even a second of delay can ruin the experience, WebRTC shines. Its peer-to-peer architecture ensures that latency is minimized, making interactions feel immediate and natural—an important feature that differentiates it from protocols like HLS, which are more suited to content delivery than live interaction.

SRT (Secure Reliable Transport): The Live Broadcast Guardian

Imagine you’re watching a live concert being streamed from the other side of the world. The network might be unpredictable, but you don’t notice a thing—no buffering, no interruptions. This is where SRT comes into play, ensuring that even under the most challenging network conditions, the stream remains smooth and secure.

How SRT Works for Live TV Broadcasting

SRT uses advanced error correction and encryption to deliver your video stream securely and reliably. It’s like a security detail for your video, making sure it reaches you unscathed, even when the network gets rough.

• Security: When broadcasting sensitive or high-value content, SRT’s encryption keeps the stream safe from prying eyes.
• Reliability: For live broadcasts, especially in environments where the network is less than perfect, SRT ensures that the show goes on without a hitch.

Comparison of HLS, MPEG-DASH, WebRTC, and SRT for TV

Choosing the Right Protocol for Your TV Streaming Needs

The right protocol for TV streaming depends on several factors:

• Compatibility with TV devices: Make sure the protocol works across all the platforms and devices your audience uses.

• Quality and latency: Consider what kind of viewing experience you want to deliver. HLS and MPEG-DASH are excellent for general streaming, while SRT is perfect for transmitting live events.

• Security: If your content needs to be protected, SRT offers strong encryption that makes it the best choice for secure live streaming.

To unlock the full benefits of each streaming protocol—whether it’s the adaptability of HLS, the scalability of MPEG-DASH, the real-time interaction of WebRTC, or the reliability of SRT—and to easily transcode video to meet your professional needs, try Flussonic Media Server. Share your challenges with us, and our experts will build an ideal workflow for you.