Chromium and Opera play sound.
Firefox does not. (Nor does SeaMonkey.)

I have a System76 Gazelle Pro, which has an HDMI output as card0 and PCH as card1.


Things I have tried so far:

- I have created an ~/.asoundrc file defining the default sound card. This worked for Chromium and Opera but has no effect on Firefox.

- I have reset Firefox to default settings.

- I have created an /etc/asound.conf file

- I have set default sound device in KDE through System Settings


Nothing seems to be getting Firefox to give me sound!

What web pages have you tried and failed to get sound when using Firefox? I don't really understand what you're trying to do without seeing some examples.
jdk

Any webpage. It is not a site-specific issue. Sites I've tried: youtube.com, revision3.com, tuxradar.com, lots more; anything that I play in Firefox renders no sound.

There is sound from all sites when browsing in Chromium or Opera.


I am attempting to configure either my system or Firefox so that I get sound from Firefox, as it is my preferred browser.

This is still very vague. Can you post a url involving sound which fails to play. And what makes you think that it's not a flash issue? Is the flash plugin installed and functioning properly?
jdk

http://www.youtube.com/watch?v=FN6Q--zqroM
http://tuxradar.com/content/podcast-season-6-episode-1
https://archive.org/details/UNIX1985

All of these play both video and sound in Chromium and Opera.
All of these play video ONLY, with no sound, in Firefox and SeaMonkey.

Flash is definitely not involved, as I do not have Flash installed on my computer. I don't use Flash for philosophical reasons. (I stated in the topic that it was not a Flash issue only because every internet search I've done in an attempt to remedy this problem seems to always assume it's Flash-related.)

Your second link, http://tuxradar.com/content/podcast-season-6-episode-1, doesn't appear to involve video and the audio uses the ogg format which FireFox can handle unless you have a very old version (older than 3.5) of Firefox. Some youtube videos use the htlm5 player which is included with recent versions of Firefox. What version of Firefox are you using?
jdk

Firefox 24.3 ESR

It works fine on my other computers, just not on this one.

I am pretty sure it's a soundcard config thing. I have ~/.asoundrc

# Setting default device
defaults.ctl.card 1
defaults.pcm.card 1
defaults.timer.card 1

pcm.!default {
type hw
card 1
device 0
}

ctl.!default {
type hw
card 1
device 0
}

# Enable mixing
pcm.dsp {
type plug
slave.pcm "dmix"


and if I do `aplay -l`
card 0: MID [HDA Intel MID], device 3: HDMI 0 [HDMI 0]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: MID [HDA Intel MID], device 7: HDMI 1 [HDMI 1]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 0: MID [HDA Intel MID], device 8: HDMI 2 [HDMI 2]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 0: VT1802 Analog [VT1802 Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0
card 1: PCH [HDA Intel PCH], device 2: VT1802 Alt Analog [VT1802 Alt Analog]
Subdevices: 1/1
Subdevice #0: subdevice #0

I don't have ~/.asoundrc on my system so I can't help there. What sound system are you using? alsa? pulseaudio? oss? something else? Have you checked that nothing is muted?
jdk

Alsa, no pulse. Nothing is muted in alsamixer. Besides, I know of no Firefox-specific sound output that I could mute that would render Firefox sound-less but Opera and Chromium with sound.

It's a puzzle!

I figured it out.

Using the kernel argument:

snd-hda-intel.index=1,0

I was able to override the way the sound card was getting mapped, so my analog output is now being mapped to card0 and the HDMI to card1

I removed .asoundrc so now I am no longer remapping sound in userland.

And now everything works, including the HTML5 video and audio in Firefox.

I'm not running Gentoo, but this was my references, and it was correct:
http://wiki.gentoo.org/wiki/ALSA#HTM...irefox_browser

None of this explains why Firefox and other Mozilla applications are ignoring the user's preferences of which sound card to prefer, but I guess that's an issue for Mozilla's bug reporting.