cpu load without client stream

[int2018]

Question

Hallo,

I have a little pi zero 1 running bookworm and there is also a pi cam attached. I used rpicam-vid for stream testing an then tested mediamtx and a little webrtc webpage. I works quite well and I think I run it as a service but then I discovered that even without any clients it takes a good amount of cpu load. top jumps from 13% to 65% after starting mediamtx.
And this is my question: Why?
I would understand that there is lot to do when some client requests a stream, either vlc rtsp or browser page webtrc. But why is the idle load so high an how can I reduce that?
Thanks for a hint... :-)

[aler9]

Hello, load is due to the fact that the camera video stream is being encoded even when there are no connected readers. You can disable encoding when there are no connected readers by using sourceOnDemand:

paths:
  rpi:
    source: rpiCamera
    sourceOnDemand: true

[int2018]

Thanks, I had that but as
sourceOnDemand: yes
which seems to work too.

However, after closing the connection the "load" stays high for some time until it says:
[RPI Camera source] stopped: not needed by anyone

Seems I just was a little impatient...