MacOS Big Sur | Other person doesn't see me in video call

[dropik]

Steps to reproduce

I am experiencing a very strange behaviour in video calls in TG desktop for mac. It appears that when I have a video call with someone with telegram on a smartphone, the other person does not see my video (or screen sharing). So how the issue first occured:

1. Installed TG 5.9 on macOS Big Sur.
2. Made a video call.
3. Other person accepted the video call in TG on a smartphone.
4. The other person reported that he doesn't see my video.

Expected behaviour

Video recorded from telegram desktop should be visible on other person's smartphone.

Actual behaviour

Currently on my mac with macOS Big Sur and telegram desktop no video is transmitted to others. Later I've figured out this does not depend on camera device. Both external camera and integrated camera do not work. I've figured out also, that screen sharing is not transmitted either.

I suspect this is not an issue with smartphone's version of telegram. I've tried receiving a call on an Android device and on an iOS device. Both do not receive any video from tg desktop.

But here comes the strange part. When doing a call from tg desktop to another tg desktop, video works without issues on both devices, with any camera, as well as screen sharing. The other tg desktop was on Windows. And when tested with the same tg desktop version 5.9, but on a different mac running on macOS Catalina (10.15.6) instead I had no issues with video at all, i.e. it worked fine when calling smartphones as well as when calling other tg desktop.

So it seems like it must be something in the integration of Telegram desktop (or probably the WebRTC dependency it is built on) and the macOS version that causes this behaviour.

I was trying to figure out any evidence of the issue in logs. I've enabled debug mode in tg desktop to see a bit more. And this is what I've got:

• log.txt and last_call_log.txt of tg desktop on macOS Big Sur when calling an Android device.
• log.txt and last_call_log.txt of same tg desktop but receiving a call on another tg desktop on Windows.
• log.txt and last_call_log.txt of same version of tg desktop 5.9 but on a mac with macOS Catalina (10.15.6) and receiving a call on an Android device without any video issue.

By just quickly grepping through all this logs by error, what all them have in common, is some error due to probably networking issues with connecting to TURN server or whatever. Even though 2 of 3 scenarios seems to work fine even with this error in place. But only in the scenario of a call from macOS Big Sur to Android device you can notice this kind of log (h265_bitstream_parser.cc:364): Failed to parse bitstream. Error: 1.

I see tg uses its own fork of WebRTC repo, so my first guess is that it might be something to do with its integration with big sur. But this is just what I've noticed so far from logs.

Operating system

MacOS Big Sur (11.7.10)

Version of Telegram Desktop

5.9.0

Installation source

Static binary from official website

Crash ID

No response

Logs

No response

[dropik]

P.S.: Tested with older builds and experienced the same issue.