[pulseaudio-discuss] No volume control for audio from java applet in browser

[Tanu Kaskinen]

On Tue, 2013-06-25 at 03:58 -0500, Andrew Skretvedt wrote:
> Hello list, I have a playback volume control question:
> I'm running Crunchbang Linux, Firefox 21, and icedtea for Java...
> 
> I like to listen to WebSDR sites, which mostly use java applets for
> their audio delivery. These play fine in my browser, but I get no
> volume slider in pavucontrol's playback tab. So, the only control over
> the volume of the java audio coming at me is by the slider for my
> output device under that tab, which is suboptimal as it's controlling
> volume of all audio globally on my machine. What I'd like is to just
> be able to adjust the volume coming from the java applet, which
> doesn't always provide its own volume control in the browser for users
> of the WebSDR receiver to twiddle.
> 
> Anyone know why the java applet's audio output is not causing a volume
> slider to appear in the playback tab? Other applications (all that
> I've ever used, anyway: vlc, deadbeef, etc.) do cause sliders to pop
> on as soon as they start emitting audio.

The likely reason is that the java applet uses alsa directly. I would
expect that if you have the java applet playing, nothing else can play
simultaneously.

> I checked /etc/java-6-openjdk/sound.properties, and I see that it's
> setup to use org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider.
> 
> So, it would appear my icedtea setup is configured to use
> pulseaudio...but, no volume control for it.
> 
> Any ideas?

I'm not familiar with java audio at all, but "PulseAudioMixerProvider"
might refer to volume control type of stuff only, since "mixer" usually
means that sort of stuff. Audio streaming might still use something
else.

> Thanks... next I will be exploring the possibility of using pulseaudio
> on my Windows Vista box as a way of making up for the lack of a Stereo
> Mix record output by the audio hardware's driver there (one of these
> software-defined low-cost integrated SB Audigy devices...Creative
> abandoned development for it just after Vista released and couldn't be
> bothered to fully support it). I've been using a commercial product
> called Virtual Audio Cable, which works well enough, but has some
> shortcomings I'd like to get away from, like cronic buffer
> under/overflow problems that glitch any audio flowing thru.

According to some recent mails on the list, there are problems with
running recent versions of PulseAudio on Windows. I know nothing about
that stuff, though...

-- 
Tanu