[Bug]: Video calls: Conversations doesn't show Monal's video feed

[lissine0]

What Monal Release channel are you using?

Alpha

iOS system version

16.7

iOS Monal version

Alpha 8669792 (Feb 15 2024 22:14:54 UTC)

macOS system version

No response

macOS Monal version

No response

Used XMPP server (domain)

Personal

Which XMPP-Server software are you using?

Prosody

XMPP Server Software Version

No response

How many accounts are you using in Monal?

1

What happened?

When doing video calls between Monal and Conversations (no matter who initiates them),
sometimes in Conversations, no video feed is received from my Monal contact.
Tested with Conversations 2.13.1+free

Anything else?

• The bug happens about 50% of the time.
• The logs from Monal and from Conversations were not taken at the same time.
• I sent the logs through email.
• The issue doesn't exist with Dino. I didn't test with other clients (yet).

FAQ

• I have checked the FAQ for my issue

Considerations for XMPP users

• I have checked if my issue can be solved with Considerations for XMPP users and Considerations for XMPP server admins

Related Issues

• I have cross-checked this overview Overview: Tasks and Issues #322 as well as filtered for related labels https://github.com/monal-im/Monal/labels

XEP-Check

• I have checked that at least XEP-198, XEP-0280, XEP-0352, XEP-0357, XEP-0313 and XEP-0163 are activated on my server and shown as 'green' under Settings --> Account--> (i) in advanced settings

Notifications-Menu

• I have checked that all checkmarks are present under Settings --> Notifications

[lissine0]

Update: this bug also happens with Beagle IM.
So it's more likely the issue is on Monal's side.

[madfoss]

This bug also happens between Monal users.

[tmolitor-stud-tu]

If I check the log on a Monal device only seeing black (e.g. Monal-to-Monal videocall), I get the following logged by webrtc.
The SSRC mentioned is one of the 2 SSRCs the webrtc implementation negotiated as SSRC-group: <ssrc-group><source ssrc='3411384671'/><source ssrc='2730024798'/></ssrc-group>
I don't have any clue why and I don't know how to fix that either :(
Comparing the jingle negotiation with Conversations (which uses webrtc, too) gives no visible difference (both negotiate a SSRC-group containing 2 SSRCs).

(webrtc_video_engine.cc:3182): Creating default receive stream for SSRC=3411384671.
(webrtc_video_engine.cc:2846): AddRecvStream (default stream): {ssrcs:[3411384671];ssrc_groups:;stream_ids:;}
(webrtc_video_engine.cc:2823): Receive stream with SSRC '3411384671' already exists.
(webrtc_video_engine.cc:3185): Could not create default receive stream.
(webrtc_video_engine.cc:3240): No stream found to set base minimum playout delay
(webrtc_video_engine.cc:3003): SetSink: ssrc:3411384671 nullptr
(call.cc:1405): Failed to demux packet 3411384671
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.
(webrtc_video_engine.cc:3152): Another unsignalled ssrc packet arrived shortly after the creation of an unsignalled ssrc stream. Dropping packet.

The last message gets repeated several times, then a whole cycle is starting over again (e.g. the first message cited here).

[jpggithub]

I have the same bug using Monocles (Android) with a person who use Monal 6.2.0 : can't see his video feed 50% of the time