Microphone not working in Firefox

[Kamila Součková]

Hello,

I recently installed FreeBSD on my laptop (X1 Carbon 4th gen). The hardware
support is not terrible, but I am having issues higher up in the stack. One
of the problems I've encountered is that I cannot get my microphone working
in Firefox, even though it works in native applications and in Chromium.

"Doesn't work" means that:
- Firefox thinks I have a "default" microphone and asks for permission when
I try to use it.
- Websites that test microphone by recording and playing it back either get
silence or complain about being unable to find the microphone.
- https://test.webrtc.org/ reports:
  Audio capture
  [ OK ] Audio track created using device=default
  [ FAILED ] No active input channels detected. Microphone is most likely
muted or broken, please check if muted in the sound settings or physically
on the device. Then rerun the test.
- It works in Chromium: I can hear myself when I record and re-play on a
mic testing website.
- I do not have PulseAudio installed and I believe my Firefox is using Alsa
emulation.
- As Chromium seems to be compiled without PulseAudio, I tried recompiling
Firefox with PULSEAUDIO: off. No change.
- This is probably useless, but: My webcam works in Firefox.

pkg info firefox:

firefox-65.0_2,1
Name           : firefox
Version        : 65.0_2,1
Installed on   : Tue Feb 12 19:23:52 2019 CET
Origin         : www/firefox
Architecture   : FreeBSD:12:amd64
Prefix         : /usr/local
Categories     : ipv6 www
Licenses       :
Maintainer     : gecko at FreeBSD.org
WWW            : http://www.mozilla.com/firefox
Comment        : Web browser based on the browser portion of Mozilla
Options        :
    ALSA           : on
    CANBERRA       : off
    DBUS           : on
    DEBUG          : off
    FFMPEG         : on
    GCONF          : on
    JACK           : off
    LIBPROXY       : off
    OPTIMIZED_CFLAGS: on
    PROFILE        : on
    PULSEAUDIO     : off
    SNDIO          : off
    TEST           : off
Shared Libs required:
    libdbus-glib-1.so.2
    libgtk-x11-2.0.so.0
    libXext.so.6
    libpango-1.0.so.0
    libjpeg.so.8
    libpixman-1.so.0
    libsqlite3.so.0
    libcairo.so.2
    libgtk-3.so.0
    libffi.so.6
    libxcb-shm.so.0
    libX11-xcb.so.1
    libfreetype.so.6
    libwebp.so.7
    libcairo-gobject.so.2
    libatk-1.0.so.0
    libevent-2.1.so.6
    libXt.so.6
    libplc4.so
    libXcomposite.so.1
    libxcb.so.1
    libgdk_pixbuf-2.0.so.0
    libgio-2.0.so.0
    libssl3.so
    libXfixes.so.3
    libwebpdemux.so.2
    libnss3.so
    libnssutil3.so
    libnspr4.so
    libgobject-2.0.so.0
    libicuuc.so.63
    libharfbuzz.so.0
    libstartup-notification-1.so.0
    libX11.so.6
    libdbus-1.so.3
    libXdamage.so.1
    libglib-2.0.so.0
    libgraphite2.so.3
    libasound.so.2
    libgdk-x11-2.0.so.0
    libpng16.so.16
    libXrender.so.1
    libicui18n.so.63
    libfontconfig.so.1
    libsmime3.so
    libgdk-3.so.0
Annotations    :
    FreeBSD_version: 1200086
    cpe            : cpe:2.3:a:mozilla:firefox:65.0:::::freebsd12:x64:2
    no_provide_shlib: yes
    repo_type      : binary
    repository     : poudriere-local

Where can I go from here?

Thank you!

Best,
Kamila