[pulseaudio-discuss] No volume control for audio from java applet in browser (pulseaudio-discuss Digest, Vol 26, Issue 61)

[Andrew Skretvedt]

On Tue, Jul 2, 2013 at 6:34 PM, Andrew Skretvedt
<andrew.skretvedt at gmail.com> wrote:
> On Fri, Jun 28, 2013 at 6:52 AM, Alexander E. Patrakov
> <patrakov at gmail.com> wrote:
>> 2013/6/28 Andrew Skretvedt <andrew.skretvedt at gmail.com>:
>
>> Note: because my IcedTea plugin does not use PulseAudio directly
>> (probably due to some misconfiguration) and instead goes through the
>> default ALSA device (apparently, with software attenuation), I cannot
>> reproduce the bug on my Gentoo system on http://radman.no-ip.com:8901/
>> .
>
> Apparently, in my system, the Adobe Flash plugin seems to try to use
> ALSA too, but I think my configuration wants to catch such an attempt
> and redirect that access through some kind of wrapper (?) so it can
> then be handled by PulseAudio like any other stream. The attached
> screenshot demonstrates what happens when I start a YouTube video
> playing. If that's what's happening, I think that's great! So...I will
> investigate if it's possible to reconfigure icedtea java to use alsa
> instead of Pulse, and see if I would get the same behavior I'm getting
> for Flash. That would solve my primary concern, and would seem to
> demonstrate either a bug in Pulse, or a bug in java's use of Pulse. Do
> you have any thoughts on that?
>

(note: I got a moderation bounce due to the image I attached to my
last post, I won't do that again, but this might be received to the
list out-of-order as a result)

I just completed a test: I edited /etc/java-6-openjdk/sound.properties
to switch off the default PulseAudio configuration (referenced in my
first post), to the DirectAudioDeviceProvider (i.e. lines like:

javax.sound.sampled.Clip=org.classpath.icedtea.pulseaudio.PulseAudioMixerProvider

became

javax.sound.sampled.Clip=com.sun.media.sound.DirectAudioDeviceProvider

.)

This worked out for me as I hoped. In pavucontrol, a playback slider
for java now appeared, as had done for the Flash plugin I mentioned
above. Flash comes in as "ALSA plug-in [plugin-container] : ALSA
Playback", and java comes in as "ALSA plug-in [java] : ALSA Playback".

Plugin-container makes sense as that's what firefox forks to run
flash, and it's my understanding that java isn't sent to a
plugin-container process due to some compatibility issues.

So, it appears my system is configured as I guessed above, with a
wrapper plugin for ALSA to redirect attempts to access the hardware
directly and feed them back into PulseAudio instead. A great setup!

I think we can also conclude that something is broken with the way
IcedTea 1.3.2 accesses PulseAudio...at least as configured for
debian/Crunchbang (I don't know how such things work).

Reaction?

Thanks people! -Andrew