Telegram in general

[Kevin Kofler]

I think the main limiting factor is going to be not the camera hardware (that can actually deliver video data quite reasonably), but the encoding speed. It depends on what codec at what resolution Telegram is going to try to use. VP9 at the camera's full resolution is really slow to encode, at least with libvpx, so the video is going to be more of a slideshow if it attempts to use that (and if it does it in the same thread as the audio encoding and/or the decoding, it is going to make the entire call suck). A faster codec at a lower resolution has more chances to succeed. A faster codec typically means worse compression and hence higher bandwidth requirements, but the lower resolution reduces the bandwidth requirements and at the same time speeds up the process.