ARArathorn·Mar 5, 2022
The competitive gap with Discord in terms of media quality is probably something like:
* Need a low-latency SFU. This should be very doable; not only are there a lot of good FOSS SFUs to build on top of these days, the history of the Matrix team is actually that we built VoIP stacks fulltime before we shifted focus to Matrix, and we've built MCUs and media servers of all flavours in the past. MSC3401 should also give us a competitive edge given latency will be automagically minimised by using the physically closest decentralised SFU, thus letting anyone bring their SFU to the party.
* Needs a SFU with good rate control (and/or FEC). This is probably the single most important thing to get right in terms of quality. Signal wrote up a good overview of why: https://signal.org/blog/how-to-build-encrypted-group-calls/
* Excellent noise canc
Read the rest
ellation (and background noise elimination, microphone scratch noise elimination etc). Ideally you need something like https://krisp.ai/ or https://workspaceupdates.googleblog.com/2021/06/background-n... in the mix - but doing this in an E2EE-friendly and privacy preserving manner is Hard. However, just like we solved E2EE full text search by doing it clientside and making the indexes gossipable between your clients (https://github.com/matrix-org/seshat), we'll have a go at doing something similar for this problem too.
* Excellent automatic gain control. The importance of normalising/compressing everyone's audio so they're equivalent loudness is really important.
We're also in the process of adding in spatial audio (unsure if Discord has that) which should help a tonne with distinguishing the different audio feeds.
We can probably also be more bullish about supporting new audio codecs like Lyra.
EDIT: oh, the other obvious thing is echo cancellation - but we're currently at the mercy of the browser's WebRTC stack for that. However, we could ship a tweaked WebRTC in Element Desktop (or other native Matrix clients) in future to do better than plain old WebRTC.