[ffmpeg] What steps are needed to stream RTSP from FFmpeg?

What steps are needed to stream RTSP from FFmpeg?

Streaming UDP is not a problem, but as I want to stream to mobile devices which can natively read RTSP streams, I couldn't find any setup which tells what exactly is needed. Do I need an RTSP streaming server like LIVE555 or can I use FFmpeg only?

My Command:

ffmpeg -i space.mp4 -vcodec libx264 -tune zerolatency -crf 18 -f rtsp -muxdelay 0.1 rtsp://192.168.1.200:1234

I get an Input/Output error.

Do I need a SDP description to use RTSP? And if yes where do I have to put it?

FWIW, I was able to setup a local RTSP server for testing purposes using simple-rtsp-server and ffmpeg following these steps:

1. Create a configuration file for the RTSP server called rtsp-simple-server.yml with this single line:

   protocols: [tcp]
   

2. Start the RTSP server as a Docker container:

   $ docker run --rm -it -v $PWD/rtsp-simple-server.yml:/rtsp-simple-server.yml -p 8554:8554 aler9/rtsp-simple-server
   

3. Use ffmpeg to stream a video file (looping forever) to the server:

   $ ffmpeg -re -stream_loop -1 -i test.mp4 -f rtsp -rtsp_transport tcp rtsp://localhost:8554/live.stream
   

Once you have that running you can use ffplay to view the stream:

$ ffplay -rtsp_transport tcp rtsp://localhost:8554/live.stream

Note that simple-rtsp-server can also handle UDP streams (i.s.o. TCP) but that's tricky running the server as a Docker container.

An alternative that I used instead of FFServer was Red5 Pro, on Ubuntu, I used this line: ffmpeg -f pulse -i default -f video4linux2 -thread_queue_size 64 -framerate 25 -video_size 640x480 -i /dev/video0 -pix_fmt yuv420p -bsf:v h264_mp4toannexb -profile:v baseline -level:v 3.2 -c:v libx264 -x264-params keyint=120:scenecut=0 -c:a aac -b:a 128k -ar 44100 -f rtsp -muxdelay 0.1 rtsp://localhost:8554/live/paul

Another streaming command I've had good results with is piping the ffmpeg output to vlc to create a stream. If you don't have these installed, you can add them:

sudo apt install vlc ffmpeg

In the example I use an mpeg transport stream (ts) over http, instead of rtsp. I've tried both, but the http ts stream seems to work glitch-free on my playback devices.

I'm using a video capture HDMI>USB device that sets itself up on the video4linux2 driver as input. Piping through vlc must be CPU-friendly, because my old dual-core Pentium CPU is able to do the real-time encoding with no dropped frames. I've also had audio-sync issues with some of the other methods, where this method always has perfect audio-sync.

You will have to adjust the command for your device or file. If you're using a file as input, you won't need all that v4l2 and alsa stuff. Here's the ffmpeg|vlc command:

ffmpeg -thread_queue_size 1024 -f video4linux2 -input_format mjpeg -i /dev/video0 -r 30 -f alsa -ac 1 -thread_queue_size 1024 -i hw:1,0 -acodec aac -vcodec libx264 -preset ultrafast -crf 18 -s hd720 -vf format=yuv420p -profile:v main -threads 0 -f mpegts -|vlc -I dummy - --sout='#std{access=http,mux=ts,dst=:8554}'

For example, lets say your server PC IP is 192.168.0.10, then the stream can be played by this command:

ffplay http://192.168.0.10:8554
#or
vlc http://192.168.0.10:8554