Digital Samba English Blog

Choosing the Right Streaming Protocol: RTMP vs. RTSP

Written by Digital Samba | September 21, 2023

In recent years, livestreaming has become a norm among content creators, with many viewers opting for it over pre-recorded media. As such, choosing the right streaming protocol or the right video streaming platform is becoming more crucial among content creators. While most people consider how relevant, creative or engaging content is, they often overlook content delivery, which is vital for the success of live streaming. 

For viewers to have an enjoyable viewer experience, it is important for the content delivery to be seamless. While there are numerous delivery protocols RTMP and RTSP are among the most common protocols.  But which one do you choose among the two?

In this article, we delve into what is RTMP and RTSP and what sets them apart.

Table of Contents

  1. What are streaming protocols?
  2. What is RTMP streaming protocol?
  3. What is RTSP streaming protocol?
  4. RTSP vs RTMP?
  5. Additional RTMP vs RTSP comparison
  6. How does RTMP integrate with Digital Samba?
  7. Final thought

What are Streaming Protocols? 

Streaming protocols help in defining the procedure that will be taken to break down your large video file into small chunks or data packets, using which they can be transmitted over the internet more easily. In simple terms, these protocols are just a written set of rules that govern how multimedia sharing or transmission will take place between two communication systems.

Among the most popular ones, you've got RTMP, RTSP, HLS, and WebRTC. Each has its strengths and quirks, which we'll delve into. But for now, just remember: they're the backbone of any video transmission.

What is RTMP streaming protocol?

RTMP protocol is a TCP-based protocol that allows for real-time communication between a server and a client. Originally, RTMP was developed by Macromedia but it’s now under the ownership of Adobe. It was initially developed to establish stability between servers and Flash players, but with time, as Flash players became less popular, it has grown to become the best protocol for achieving low latency on VOD or live streaming platforms such as YouTube Live, Facebook live and Twitch streaming.

How does RTMP work for streaming?

The RTMP protocol of three main components: the RTMP client, the encoder and the RTMP server. The RTMP client is responsible for capturing media files and other data from the source device and then passing it to the encoder which converts (encodes) the data into steamtable formats.

As the intermediary, the RTMP server is responsible for distributing content to the connected viewer. When a viewer wants to view the live stream or VOD, the media player will make a request to the streaming server, which establishes a direct connection with the media player through the RTMP protocol.

When you're streaming video content using RTMP, the video is broken down into small chunks called "packets" and sent from the server to the client in real-time. This means that the video plays simultaneously as it's being downloaded, resulting in a low-latency streaming experience.

Pros and Cons of RTMP

Benefits of RTMP:

Drawbacks of RTMP:

What is RTSP streaming protocol?

RTSP transport protocol, or Real-Time Streaming Protocol is a lesser-known streaming protocol. The primary aim of the RTSP is to control the streaming servers used in both communication and entertainment systems. Basically, RTSP servers sit between the viewer and the live stream and are responsible for handling the ‘pause’ ‘play’ and ‘record’ commands between the systems.

RTSP streaming relies on TCP to transmit the control commands and UDP to transfer video, audio and other data formats. This setup allows RTSP streams to run smoothly even when downloading videos.

How does RTSP work for streaming?

When a viewer wants to transmit a video signal, their device will send an RTSP request to a dedicated server which will determine the possible playback options. The server responds with a list of requests capable of receiving via RTSP. When the viewer’s device receives the set of commands and the process for requesting the server, it sends a request for the video description.

When the server responds with the video description, the viewer’s device sends a download request and the server responds will the data pertaining to the transport mechanism, which is when the video streaming process is initiated on the user’s device.

Pros and Cons of RTSP

What are the pros of RTSP?

There are two main advantages to using RTSP for streaming:

What are the cons of RTSP?

While RTSP has its strengths, there are also some limitations to consider:

RTSP vs RTMP comparison: Which one is right for you?

RTMP and RTSP - Performance comparison

Both streaming protocols were built and designed for seamless low-latency video streaming. 

  • When it comes to performance, RTMP is widely used for broadcasting, whereas RTSP is often used for localised video streaming such as CCTV, IP cameras or video-on-demand.
  • When it comes to data transfer, RTMP is considered more efficient since it can compress data during transmission RTSP minimising data usage and transfer time - which RTSP cannot. 

RTMP and RTSP - Specification

Streaming protocol feature

RTSP

RTMP

Latency

2 seconds

2 – 5 seconds

Audio codecs

AAC, AAC-LC, HE-AAC + v1 and v2, MP3, Speex, Opus, Vorbis

AAC, AAC-LC, HE-AAC + v1 and v2, MP3, Speex, Opus, Vorbis

Video codecs

H.264, VP6, VP8, Sorenson Spark, Screen Video V1 and V2

H.265 (preview), H.264, VP9, VP8

Playback compatibility

Flash Player, Adobe AIR, RTMP-compatible players

Quicktime Player, RTSP/RTP-compatible players

Transfer encoding

None

Chunked

Streaming type

Segmented

Continuous

Compatibility

Requires specific players or applications

Not natively supported by HTML5

Bandwidth usage

Adaptable to network conditions

Can be high

 

Additional RTMP vs RTSP comparison

RTSP vs WebRT 

Streaming protocol features

RTSP (Real-Time Streaming Protocol)

WebRTC (Web Real-Time Communication)

Purpose

Primarily designed for streaming multimedia content from servers to clients

Designed for real-time, peer-to-peer communications like video and audio calls in web browsers

Latency

Usually has a higher latency (can be several seconds)

Ultra-low latency, typically under 500 milliseconds and often as low as ~100 milliseconds

Media Control

Offers control mechanisms like play, pause, and seek

Lacks such specific media controls. Communication is continuous once established

Protocol Base

Built on top of CSeq numbers and session IDs

Built on top of DTLS (a derivative of SSL) and RTP

Interactivity

Low. Mainly one-way streaming (e.g., from security cameras)

High. Bi-directional audio and video designed for interactive communications

NAT/Firewall Traversal

Needs additional mechanisms like STUN or TURN servers, or port-forwarding for traversal

Built-in NAT/Firewall traversal capabilities using ICE, STUN, and TURN

Security

RTSPS is the secure version (using TLS), but not commonly used. Usually relies on external measures for security

Inherently secure. Uses DTLS for encryption and data integrity, and SRTP for media streams

Ecosystem

Used mainly in surveillance, IPTV systems, and certain broadcast applications

Web-focused, used heavily in web-based video calls, online conferencing tools, and certain gaming applications

Codec Flexibility

Often used with a variety of codecs, such as H.264, but depends on the specific implementation

Primarily VP8, VP9, and H.264 for video. Opus and G.711 for audio. However, more can be supported depending on the implementation

Scalability

Suitable for unicast and multicast. Multicast can be useful for large-scale broadcasts

Designed for peer-to-peer but can be scaled up with additional infrastructure (e.g., Selective Forwarding Units) for group calls or broadcasts

Browser Support

Not natively supported by browsers. Requires external players or plugins

Natively supported by modern web browsers like Chrome, Firefox, Safari, and Edge

 

HSL vs RTMP vs RTSP

Streaming protocol feature

HLS

RTMP

RTSP

Latency

Moderate to high

Low

Moderate to low

Streaming type

Adaptive

Continuous

Segmented

Customisability

Low

Moderate

High

Bandwidth usage

Adaptable to network conditions

Can be high

Adaptable to network conditions

HTTP compatibility

Compatible

Incompatible

Incompatible

Protocol type

HTTP-based

TCP-based

Typically, RTP over UDP or over TCP

Encryption

AES-128 standard encryption

RTMPE

Can use RTSPS

Content delivery

Uses HTTP, split into chunks

Push model, continuous stream

Pull model, client-server interaction

Adaptive bitrate streaming

Yes

Possible with third-party solutions

Not inherent, but can be implemented

Error recovery

Recovers by switching to a lower bitrate

TCP-based recovery

Depends on underlying transport protocol (RTP/UDP)

Use case

VOD, live streaming with some delay

Live streaming video conferencing

Surveillance, on-demand content

 

How does RTMP integrate with Digital Samba?

Digital Samba allows users to stream a Digital Samba session to an external RTMP endpoint. The Digital Samba API allows users to define an RTMP endpoint, which then tells the live streamer to send an RTMP stream to that endpoint. 

Additionally, Vimeo Premium can also be used to stream from an RTMP source into a Digital Samba session. This is a great way to stream from an RTMP source while keeping Digital Samba features. 

Final thought

As we have seen above, both RTMP and RTSP protocols have their strengths and drawbacks and also serve unique purposes in broadcasting live streams and previously streamed media files online. While RTMP is well suited for streaming pre-recorded media RTSP is suited for localised and live streaming and data transfer.

Ultimately, the decision between RTMP and RTSP depends on the type of content you are streaming.

But, if you’re looking for an easy-to-use, robust video conferencing platform with broad streaming capabilities, try Digital Samba today. Simply create a free account and enjoy 10,000 free participant minutes of HD-quality video calls and a smooth video streaming experience.