Make the rtsp server only "read" the stream being broadcast to it on demand (i.e if someone is trying to fetch the stream from the server)

[Mohamedemad4]

Which version are you using?

v0.13.2
OS: Linux (Ubuntu 20.04)

Question

• Make the rtsp Server only "read" the stream being broadcasted to it if someone is requesting to read that stream from the server
• does sourceOnDemand work if rtsp-simple-server is deployed in server mode? and if not what's an alternative?

Description

I have a raspberry pi streaming a webcam to an RTSP server running rtsp-simple-server with ffmpeg

• the RPI is using this ffmpeg cmd
  • ffmpeg -f v4l2 -i /dev/video0 -maxrate 4M -b 2M -f rtsp rtsp://user:[email protected]:8554/stream
• What i would like to do is to have the server tell ffmpeg to "stop streaming" if no one is reading the rtsp stream from the server (to save on bandwidth between the rpi and the server)
• since this setup should be running 24/7 and an rtsp client should only be requesting the rtsp stream throughout the day and not 24/7.
• i have tried setting sourceOnDemand to yes in all paths. but the server is sill receiving the same bandwidth weather somone is reading the rtsp stream or not

Also if i am going about this the wrong way. please do tell me how this can be achieved/where to look. Or if i can make a PR or something and contribute this functionality (idk a lot about rtsp if that wasn't obvious lol)

@aler9

[aler9]

Hello, this can be solved in a lot ot ways, these are the two that come in mind

way 1

Start a second instance of rtsp-simple-server on the Raspberry Pi with this configuration

paths:
  cam:
    runOnInit: ffmpeg -f v4l2 -i /dev/video0 -maxrate 4M -b 2M -f rtsp rtsp://localhost:8554/cam

Edit the configuration of the main instance running on the server in this way

paths:
  cam:
    source: rtsp://raspberry-url/cam
    sourceOnDemand: yes

The setup is now this
camera --> first rtsp server (running locally) --> 2nd rtsp server (running on the remote server)

In this way, the stream will be pulled only when requested, saving bandwidth.

way 2

edit the configuration on the server in this way

paths:
  stream:
    runOnDemand: /script.sh

create a script with this content:

#!/bin/sh

trap 'echo sending ssh command to the raspberry pi to stop the stream' INT

echo sending ssh command to the raspberry pi to start the stream

sleep 86400

and edit the two parts to do exactly what they are supposed to do :)

[Mohamedemad4]

in my setup the rapsberry pi is behind a NAT so ways 1 and 2 aren't really an option.
I thought about writing a simple bash script that polls a REST server to ask for permission to stream. But that just seems inefficient and a bad solution overall.
Surely there has to be a way to implement this over the RTSP protocol. Right? even if it means i will have to open a PR.

[dlueth]

@Mohamedemad4 no idea if it's works in this Szenario but you could try RabbitMQ. OnDemand command would be a shell script on the rtsp-simple server host that produces one message on start and another (different) one on trap INT. You would need to consume these on your RPI and act accordingly.

[Mohamedemad4]

thanks for the suggestion @dlueth. what we ended up doing was quiet similar. Just using redis Pub/Sub instead. I thought since RTSP can be used for controlling remote media (from my understanding at least) then something like that should have been trivial to implement inside RTSP. I am closing this issue but, if anyone has any ideas to do this inside RTSP feel free to re-open.

[aler9]

RTSP can be used only for unidirectional communication from client to server, not the opposite - a MQTT-based solution is the best approach in this case.