DVRIP stream opening delay

[maksz42]

On Android, the official XMeye app and IP Cam Viewer can open the camera's stream almost instantly. However, when I open the RTSP restream of that camera with ffplay, I need to wait a few seconds to see the video (connection is already established by another ffplay instance). Why is that? Does DVRIP do something clever, or is it an inherent RTSP drawback? Maybe there's a trick to avoid opening delay with ffplay? Just curious
Thanks

[AlexxIT]

I don't see a question about go2rtc here.

[maksz42]

Well, it's restreamed with go2rtc. I thought you or someone else maybe had figured it out. Sorry if this is off-topic.

[AlexxIT]

This is the decision of the camera's developer. Do they give each new client an independent stream. Or do they give them all one stream.

Go2rtc gives all clients a single stream.

A good camera starts its first stream with a keyframe. If it gives this stream to a second client - it will be from an random time. And the client will see the picture only at the moment of the next keyframe.

A good camera gives away keyframes every second. But there are cameras with keyframes every 5 and 10 seconds (very rare).

Sometime in the future go2rtc will try to start a stream for each client with a keyframe. But this is a very complicated development task at the moment - #96