RTMP Streaming using FFmpeg Tutorial – Step-By-Step

In this article, we will go through the process of RTMP streaming using FFmpeg. For more details about the RTMP streaming protocol, please refer to this article on the basics of RTMP and other low-latency streaming protocols.

What is The RTMP Streaming protocol?

Real-Time Messaging Protocol (RTMP) is a TCP-based communication protocol. It provides a bidirectional message multiplex service and mainly carries streams of videos, audio, and messages. Adobe Systems created the RTMP (Real-Time Messaging Protocol) protocol to effectively stream audio, video, and data over the internet. 

Note: go here to learn more about other low-latency streaming protocols as well.

RTMP is perfect for live broadcasts of events like sporting events, concerts, or breaking news since it maintains persistent connections and permits communication with minimal latencies. 

RTMP divides streams into pieces and sends them across TCP, assuring data transfer security. 

Due to its low latency advantages, RTMP is still frequently used in the initial capture and transmission of live streams despite the development of more contemporary protocols like HLS and MPEG-DASH. Go here to learn more about HLS and MPEG-DASH streaming protocols.

Hence, knowing how to learn RTMP streaming using FFmpeg is pretty helpful. If you are interested in other applications of FFmpeg, please check out our Recipes in FFmpeg page.

Steps Involved in RTMP Streaming using FFmpeg

To have a better understanding of the complete process of video streaming using RTMP, we can represent the steps involved using the following diagram :

Let’s discuss each of the steps in detail.

Step 1: Encoding

The encoder encodes the audio/video using any supported codecs (what is a video codec?) and transfers the data to the RTMP server using the RTMP protocol.

We would be using FFmpeg to encode and send data to the server. Following is the FFmpeg command to encode and transfer the video to the server.

ffmpeg -re -i crowdrun.mp4 -c:v libx264 -c:a aac -f flv rtmp://localhost/show/stream

Let’s review the meaning of the parameters used in the above command.

-re	It is an input parameter that instructs FFmpeg to read the same number of frames per second as the framerate of the input video. It is most used for live streaming or with a camera input.
-i crowdrun.mp4	It is the input video that we are using for the discussion and can be downloaded from here
-c:v libx264	Here we are specifying the encoder to be used for the video as H.264/AVC
-c:a aac	This is the target RTMP destination for the video. The URL is based on the configuration of the streaming server.
-f flv	This is the target RTMP destination for the video. The URL is based on the configuration of the streaming server.
rtmp://localhost/show/stream	This is the target RTMP destination for the video. The url is based on the configuration of the streaming server.

Running the above command on the terminal after the streaming server is configured, would look like this:

You will see an output like this on your terminal that should confirm that the video is being encoded using H.264/AVC and being transferred to the server.

Let’s move to the next step.

Step 2: Serving 

The RTMP server receives the feed and is responsible for scaling and delivering the content to many audiences online. 

We have used the Nginx server and the RTMP module for our test. The server application is installed and configured locally; hence, the localhost is being used as the URL. It is configured to serve the content using the same RTMP protocol to the end user. 

Step 3: Consuming 

The last step of the process is to receive the content and consume it on the end user’s device. Since the server is configured to use the RTMP protocol for serving, we will again use the same to demonstrate this process. However, many other alternate HTTP-based protocols, such as HLS, are being used for this due to their other advantages (cost, scalability, ease of use, etc.)

As discussed in the previous sections, the target address we used to publish the video stream was : rtmp://localhost/show/stream 

We can use the VLC player, which supports RTMP, to demonstrate the playback of the video.

Use the network stream option in VLC and add the RTMP URL. Now, you can see that the stream is being played back in the VLC Player. This confirms that you have a working RTMP streaming setup on your local machine.

Conclusion

In this article, we learned about RTMP streaming using FFmpeg. This opens up a world of opportunities as one can now stream to different video streaming platforms like Facebook and YouTube.

I hope you found this helpful, and do come back and read the rest of the articles on OTTVerse.