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HTTP Live Streaming vs WebRTC

Low-latency streams are needed by all. However, not all protocols have the ability to deliver the same quality. The question is how to decide which protocol to use for your use case? You don’t want a video conferencing solution that is full of glitches and won’t stop buffering. Another factor is cost — some protocols cost more than others. There are many heads where protocols can be examined.

Let’s look at HLS and WebRTC, the top two protocols with low latency to find out which one is right and which one to choose. 

• Latency

Which protocol wins the battle of the low-latency? 

Before the Apple Worldwide Developer Conference (WWDC) of 2019,  Apple’s HTTP Live Streaming (HLS) protocol did not have low latency as one of the attributes. In the past, 10- to 45-second latency was expected with HLS — far too high for interactive streaming. WebRTC, although able to stream in real-time, came with its own set of difficulties.

Low-Latency HLS (LL-HLS) was announced during WWDC 2019. LL-HLS was an extension of the HLS specification. With these announcements, Apple has joined the big game. The new HLS protocol has a latency of 3 seconds. This is very fast and can work for low-latency use cases. However, the fastest option for real-time streaming is still WebRTC. Low latency is crucial — a few seconds of delay means all the difference in the world. Offering sub–500 milliseconds of latency, WebRTC is the fastest protocol there and a clear winner. 

• Flexibility and Compatibility

Which protocol has better flexibility? LL-HLS is certainly standing in muddy waters. As a widely used protocol for streaming, HLS is supported by a wide range of devices and has adequate compatibility. Closed captions and subtitling, Digital Rights Management (DRM), ad insertions, and metadata are some other perks offered by HLS. However, LL-HLS isn’t there yet. 

Browser support for LL-HLS protocol is par for the course. Player compatibility is an issue. Except for Apple’s native player, compatibility isn’t there. Not even for open-source native players such as Android’s ExoPlayer. 

Here, one remarkable WebRTC strength is that no additional plug-ins or software are required for functioning within the browser. WebRTC’s adoption had a slow start, but all major desktop browsers support it now, except for Safari for obvious reasons. 

All said and done, there is no straight answer to which protocol is the most flexible and compatible. You need to look closely at what you’re trying to build and the level of flexibility you need, then opt for the protocol.

• Quality

High-quality media can’t be delivered without adaptive bitrate (ABR) capabilities. It’s the secret ingredient of streaming., having the best video quality and viewer experience possible. Both HLS and WebRTC support ABR. Read more on media quality here. 

• Security

Privacy issues were and are a big issue in the industry. Content protection can range from encryption of incoming and outcoming streams and token authentication to digital rights management (DRM).  LL-HLS spec has been merged into the HLS spec and LL-HLS spec supports everything that the HLS spec does. But, it’ll take time for providers to catch up. However, LL-HLS is not completely unprotected. HLS 1.3 is part of the spec and it prevents hackers from intercepting data in transit.

WebRTC also supports delivery over TLS and ensures the security of content. The traffic between the clients is end-to-end encrypted to enhance security. More on WebRTC end-to-end encryption here. 

• Cost

WebRTC is a free, open-source protocol. WebRTC is very cost-effective if you aren’t streaming hundreds of people. When engaging a mass audience, you’ll need to employ additional servers to reduce the load from the browser, which increases the cost. LL-HLS is the cheaper option for scaling, probably the most cost-effective way of delivering video to a larger audience. 

Summing up… 

In the last couple of years, LL-HLS and WebRTC both have come a long way. Both are cutting-edge technologies and are driving the industry forward. Ultimately, the best protocol depends on the project specifics and use cases of your project. The device, the size of the audience, etc are things that you should keep in mind when building your low-latency solution. RTCWeb.in is here to help you in taking the right decision. We have experience of several years in the business of making video conferencing solutions and all your needs for such a solution ends here.