I have a videoconference app that uses SimpleWebRTC and Adapter, both latest versions. When I have multiple users connected, one in Safari and others in Chrome, the Safari user can hear the others but other can't hear the sound input from the Safari user. Video works fine. The mic used is connected to the Mac with USB and Camera and Microphone permissions in Safari are set as "allow". If I use Chrome in the same Mac, it works fine.
Can you try with mock sources (Developer menu -> WebRTC sub menu)?
Which audio codec is being used? Is it Opus?
Is there a possibility for a repro case somewhere?
With mock sources it works. I suspect that Safari just cant access my microphone connected with USB. If I go to Sound Preferences, the audio input works fine, the same for Chrome in Mac. I can't use internal microphone because I'm using Mac Mini, which does not have one. https://www.webrtc-experiment.com/RecordRTC/simple-demos/audio-recording.html does not work either with USB mic.
Can you confirm that https://webrtc.github.io/samples/src/content/getusermedia/volume/ is not working with your USB microphone?
Yes, I confirm that it does not work with USB mic. The little red mic icon appears but nothing is captured. It does work with mock sources though.