Bug Simulcast plainTransport -> webrtcTransport

[EtiennePestre]

Bug Report

Environment

• Operating system: debian or ubuntu
• docker image: node:18.17.1-alpine3.17
• npm version: 9.6.7
• gcc/clang version: gcc (Alpine 12.2.1_git20220924-r4) 12.2.1 20220924
• mediasoup version: seence 3.13.14
• mediasoup-client version: 3.7.2

Issue description

When simulcasting with FFmpeg, I can't get multiple clients to work at the same time. Only one works, and the others freeze.

In this schema MediasSoupClient2 dosen't receive the video. In chrome chrome://webrtc-internals/ I see a lot of lost package:

If I stop MediasSoupClient1, MediasSoupClient2 starts receiving packets and the video works fine. However, if I start a new client, MediasSoupClient2 stops receiving packets and the video stops running.

The workaround I found is to disable liburing in meson_options.txt

I found a workaround because everything works in an older version of Mediasoup. The bug appeared when updating to version 3.13.14, exactly at this commit https://github.com/versatica/mediasoup/commit/ad2d8146e21f6343fb8bcd189c2a9e1e5215925c

[jmillan]

I cannot get a glimpse of the reason why liburing could be related to such thing.

The given bug description is definitely not sufficient for making any diagnostic. @EtiennePestre, please expose as much detail as possible of what you are doing and what you are getting.

I can't get multiple clients to work at the same time. Only one works, and the others freeze

What does this mean exactly?

[EtiennePestre]

I have created this thread in the discourse that explains the problem: https://mediasoup.discourse.group/t/key-frame-not-receiv-by-client/5933

[EtiennePestre]

The problem is that the router distributes RTP packets to only one consumer.

[ibc]

I have created this thread in the discourse that explains the problem:

https://mediasoup.discourse.group/t/key-frame-not-receiv-by-client/5933

The thing about reporting an issue in GitHub is to properly describe the issue from scratch rather than referencing a thread in a forum and asking the developers to read it. So can you please edit the description of this issue with all the valid information about the issue?

[ibc]

@jmillan, the issue description has been properly updated now. I think we can test this issue by using the mediasoup-demo app (in Linux so liburing is enabled) by connecting many browsers to the same room and producing audio and video using the ffmpeg or gstreamer clients included in mediasoup-demo/app.