FFmpeg Video Calls

Posted September 18, 2023

If you have seen any of the videos I made on FFmpeg you would know that I absolutely love it and I think that it is the absolute BEST video/multimedia program ever made.¹ FFmpeg has so many features and it implements almost all of them extremely well. So it comes to no surprise, after I initially made my FFmpeg videos I found out that FFmpeg can actually be used to create video streams and send them over the internet. After I found out about this I wondered if it could be used as a sort of minimal way to create video calls. After experimenting for just a few minutes I found a way to stream video over the internet via FFmpeg.

ffmpeg -f alsa -i default \ # Get audio from mic
-i /dev/video0 \ # Get video from camera
-s 640x480 \ # Scale down to 640x480
-c:v libx264 -preset:v ultrafast \ # Encode fast!
-tune zerolatency -intra-refresh 1 \ # Reduce latency
-f mpegts \ # Put everything into mpegts stream
-b:v 1M udp://localhost:1313 # Send video over localhost:1313

In order to actually view this video you would need a video player that is able to read/receive from UDP. Luckily such a program exists: mpv.

mpv --profile=low-latency udp://localhost:1313

Now to actually send this over the internet and not just over LAN or localhost you would need to replace localhost:1313 with the IP address of the recipient for FFmpeg and the IP address of the sender for mpv. This is will let you be able to do peer-to-peer video calls using only FFmpeg and mpv (or any other UDP compatible video player). FFplay, a media player that comes with FFmpeg, can play UDP streams, so technically this can be done using only FFmpeg. If you replace -f /dev/video0 with -i x11grab you can also screencast to another computer as well, pretty neat.

Theoretically, you could do more than just one-on-one video calls, you could have 4, 7, or even 15 people using this method. It would definitely be tedious to set it up, but it would be possible. And of course if you don’t want to use video at all you can easily use this method for audio calls.

I think this example shows just how versatile FFmpeg can be. Not only that but the settings I used for this example are not actually optimal, it was just a test but it worked great. This is just the tip of the iceberg too, you can also use this to stream movies from another computer, video games, general live streaming, and much more. I personally find it crazy that you can basically do audio and video calls using only FFmpeg and this shows just how absolutely amazing it is.