chrome listed twice in pavucontrol causing echo for others in zoom meeting.
Ubuntu 21.04 pipewire 3.27 1 sound card : built in : alc887v motherboard: f2a68hm-h apu: a4-7300 (richland + aruba)
Note:after writing this I recall noticing rampant dual routes in carla patch bay. It may still be my own mistake but I will watch for it now.
On a zoom (zoom web client) call, others complained of an echo of their own voice. When I checked pavucontrol, I see that chrome is listed twice under playback. Carla patchbay shows two sets of connections from two chrome sessions even though there is only one instance of chrome running .( https://drive.google.com/file/d/1rZjpbWw8CRdOtAqUn4Ol68-cVoftURdT/view?usp=sharing)
I purged pulseeffects via apt. I deleted .asoundrc. I tried various chrome extensions including "dictation for gmail", "voice in voice typing" and "google voice search". Only gv search resulted in a single connection in carla patchbay and pavucontrol. I also tried the discrete zoom app. It showed a single connection as well. I also tried "single client mode" in the engine settings for carla.
the work around is to turn the volume down in pavucontrol on the second stream. I notice that there is only one stream when I open the meeting until I click join with computer audio.
If I close the tab for zoom and open a tab for pandora then there is only one stream for chrome in pavucontrol. If I open zooom by itself there are two streams.
cross ref from carla to the output of pw-cli shows one stream is an output node and one is an input node.
$ pactl list short sinks 41 alsa_output.pci-0000_00_14.2.analog-stereo PipeWire s32le 2ch 48000Hz RUNNING $ pactl list short sources 65577 alsa_output.pci-0000_00_14.2.analog-stereo.monitor PipeWire s32le 2ch 48000Hz RUNNING 42 alsa_input.pci-0000_00_14.2.analog-stereo PipeWire s32le 2ch 48000Hz RUNNING
After reboot I can still duplicate the issue with "Dictation for gmail" and "zoom web interface" but not the others.
It appears sound is being routed from the mic via two paths in both cases.
Is this only in Ubuntu? Can you duplicate this in Redhat? Is this a flaw or a feature? At least it showed up in pavucontrol and left a trail I could follow. If I could automagically set a different route or set the volume to zero for the second device as it is created then it would qualify as a feature.
peace, Ifishtoo