RTP packet is too big to be read with UDP

Tabarane commented 3 months ago

Which version are you using?

v16.0.0

Which operating system are you using?

[X] Linux amd64 standard
[ ] Linux amd64 Docker
[ ] Linux arm64 standard
[ ] Linux arm64 Docker
[X] Linux arm7 standard
[ ] Linux arm7 Docker
[ ] Linux arm6 standard
[ ] Linux arm6 Docker
[X] Windows amd64 standard
[X] Windows amd64 Docker (WSL backend)
[ ] macOS amd64 standard
[ ] macOS amd64 Docker
[ ] Other (please describe)

Describe the issue

Trying to get video feed from camera with proxy and get the error

2022/09/15 23:06:42 WAR [path glass] [rtsp source] RTP packet is too big to be read with UDP
2022/09/15 23:06:42 WAR [path glass] [rtsp source] RTP packet is too big to be read with UDP
2022/09/15 23:06:42 WAR [path glass] [rtsp source] 66 RTP packet(s) lost
2022/09/15 23:06:42 WAR [path glass] [rtsp source] RTP packet is too big to be read with UDP

Describe how to replicate the issue

start the server
publish with ...
read with vlc

Did you attach the server logs?

no

Did you attach a network dump?

no

yelodevopsi commented 2 months ago

Just a longshot since I just read this thread..

Check with Wireshark and with the filter udp. What are the sized of the of the incoming RTSP packages? Over MTU? (1500)
Check MTU value in router
What are the package size from the RTSP-source? Check the camera-configuration/web-interface.

aler9 commented 2 months ago

Hello, as clearly mentioned in the error, the server explicitly discards RTP packets that are bigger than the UDP MTU. These packets are sent fragmented, therefore in a really inefficient way, and furthermore it's impossible to detect whether they have been truncated by any NAT / gateway in between, resulting in a corrupted stream. Decrease the MTU of your camera in order for it to be less than the UDP MTU, otherwise switch to TCP.

bluenviron / mediamtx