RTMP vs HLS: When to Use Each Streaming Protocol

Today, HLS has solidified its position as one of the most important protocols in any video streaming service, alongside options like RTMP. According to data from Gravedad Cero, 80% of a brand's followers prefer watching live content over reading a blog, and this percentage increases to 82% when comparing live streaming to social media posts.

Given this premise, understanding how HLS and RTMP function is crucial for optimizing any video workflow.

What Are Streaming Protocols?

Live streaming protocols fall under the family of Internet protocols, defined as a set of rules that transmit data between computers.

The expansion of broadband and the internet made it possible to watch live content without downloading files, which spurred the creation and standardization of protocols like HLS and RTMP.

What Are RTMP and HLS?

To understand what HLS is and how it compares to RTMP, it's important to start with the fact that both are ingest protocols that transport audio and video data from a source (e.g., an encoder) to an RTMP server or a Content Delivery Network (CDN).

RTMP

The Real Time Messaging Protocol (RTMP) was created by Adobe to connect Flash Player and Adobe Air, and it's still widely used as an RTMP server for CDNs and streaming.

It uses TCP, one of the basic Internet protocols, to ensure the correct delivery of data. Although it originally relied on Adobe Flash, today it's combined with HTML5 to extend its compatibility.

• Uses TCP to ensure stable data transmission.
• Does not automatically adjust transmission quality; this task depends on the platform.
• Playback requires Adobe Flash for most internet browsers.

HLS

HLS (HTTP Live Streaming) is a protocol developed by Apple that transmits audio and video over HTTP and allows for adaptive bitrate streaming.

This means that the image quality automatically adjusts based on the user's broadband connection. This makes it ideal for both live streaming and video-on-demand (VOD) content.

• Transmits audio and video via HTTP, the foundation of the World Wide Web.
• Supports adaptive bitrate, adjusting image quality to each user's broadband connection.
• Content can be delivered from an HTTP (Hypertext Transfer Protocol) server.
• Video encoding is done in short segments (usually 10 seconds).
• An index file organizes the segments so that the player downloads each fragment in order.
• Content can be encrypted to protect copyrights and ensure secure delivery.

RTMP vs. HLS: Which One to Choose?

Choosing between RTMP and HLS depends on factors such as desired latency, target device, browser compatibility, and available resources.

RTMP stands out for its very low latency, making it ideal when combined with an RTMP server for low-delay transmissions. However, it requires Flash for older browsers, which is now obsolete.

On the other hand, HLS has slightly higher latency, but it is currently the most widely adopted standard because it works natively in modern browsers, Smart TVs, Android, and Apple devices. Its support for adaptive bitrate makes it a flexible choice for any video streaming service.

Compatibility at Mediastream

At Mediastream, our content delivery network is compatible with both protocols. RTMP remains the most robust protocol for ingest, while HLS is the recommended option for playback due to its flexibility and HTML5 compatibility.

Thanks to HLS's segmented delivery, we can guarantee stable, scalable, and high-quality transmissions for over a million simultaneous users.