[pulseaudio-discuss] ubuntu flash pulseaudio multiuser

duportail poort at telenet.be
Thu Dec 23 05:59:19 PST 2010

Op 23-12-2010 0:05, Colin Guthrie schreef:
> 'Twas brillig, and duportail at 22/12/10 22:08 did gyre and gimble:
>> Op 22-12-2010 21:12, Colin Guthrie schreef:
>>> 'Twas brillig, and duportail at 22/12/10 19:51 did gyre and gimble:
>>>> Op 22-12-2010 20:37, Colin Guthrie schreef:
>>>>> 'Twas brillig, and duportail at 22/12/10 19:26 did gyre and gimble:
>>>>>> I have a multi-user system with four usb soundcards.I use
>>>>>> pulseaudio per
>>>>>> user.
>>>>>> I set default soundcard per user.However flash uses always the
>>>>>> first usb
>>>>>> soundcard.Other applications use the user's default soundcard.
>>>>>> Is there a solution or is it a flash issue?
>>>>> Do you use system-wide PA or a separate PA process for each user
>>>>> (recommended).
>>>>> If the latter, then all you need to do is setup the ACLs correctly
>>>>> (probably via some custom udev trickery) so that a given user is *only*
>>>>> allowed to use the one USB card.
>>>>> This setup will mean each user can only use one sound card by
>>>>> virtual of
>>>>> file-system permissions and PA is designed to respect these
>>>>> permissions.
>>>>> Col
>>>>    I use a separate PA process for each user.
>>> So can each user see multiple sinks or just the one? (in e.g.
>>> pavucontrol)
>>>> With padevchooser I set the default sink for that user.
>>> padevchooser is rubbish and unsupported and obsolete. I strongly
>>> recommend not using it at all.
>>> Ideally each users PA process will only have one sink and thus there is
>>> really no option for any apps in the first place.
>>>> Al program's,such as mediaplayers sends the
>>>> sound to the correct usb device that is set as default for this user.
>>>> Only flash player in firefox or opera sends the sound to the first
>>>> soundcard.And not to the default soundcard for this user.
>>> Well I'm confused as if there is only one sink listed for each user in
>>> their own private PA daemon, this suggests that these applications are
>>> bypassing PA and accessing ALSA directly. Not sure why they would do
>>> that, but flash does have a habbit of being rubbish with such things.
>>> Still if the ACLs on the sound devices themselves are restricted then
>>> even if it does bypass PA each user should still only have access to one
>>> sound device each.
>>> Col
>> Well, it worked in ubuntu 10.04, but not in 10.10 anymore.
>> With padevchooser you can see all sinks, and the user has to set the
>> default.
> I really cannot see how padevchooser should be able to see all the sinks
> if the users are not allowed to access them, so I'm guessing your setup
> technically allows users to use any sink they want.
> This isn't really the best setup. Like I say, setting the ACLs is by far
> and away the most appropriate way to achieve the right setup.
>> However, on my multi-user systems i have a script (with password) to set
>> the default sink .So the users cannot change this
> Hmm, padevchoser does not set the default sink. It operates in a
> completely different way to any concept of "default" sinks in the PA
> daemon (which is not really a 'default' anyway - more of a 'fallback').
> To explain, padevchooser sets properties on the X11 root window (see
> xprop -root | grep PULSE). The libpulse client will look at these
> properties when connecting to PA or initiating streams.
> In PA itself, there is a concept of a "default" or "fallback" sink. This
> is often used but PA will also remember which device a given program
> prefers (e.g. if it was moved via pavucontrol in the past, it will
> remember that device).
> Over all, as I said, the most stable and secure setup will be to only
> include one sink in each user's PA daemon. Using the ACLs via udev rules
> is likely to be the best way to achieve this, but a custom default.pa
> for each user that does not use udev-detect and instead hard codes
> module-alsa-card loads (with differetn device_id= arguments) would also
> work fine.
>> Again all is working weel, except flash.
>> It's kde 4.5, maybe it is phonon?
> Well Phonon routing (when done correctly as I believe it is with the
> latest Kubuntu 10.10) is quite different to a simple default and it may
> indeed work differently. Each user will have a priority list of devices.
> See http://pulseaudio.org/wiki/KDE for some screenshots.
> I really can't stress enough however that the best setup would be to
> only give each user access to the sink they should be using.
> Also, please drop padevchooser. it's deprecated and unsupported.
> Hope this helps.
> Col
I do not use padevchooser.I run a little script to set the default sink 
for each user.
I can confirm that kde's phonon is the cause of this .If I set up a 
multi-users system with pulseaudio and several usb-audio devices and the 
users only use xfce4 desktop the sound stays ok for flash an other 
player. If they login the kde4.5 desktop,the flash sound goes to the 
first audio device.If the logout of the kde desktop and login the xfce4 
desktop, the flash sound stays on the first sound device.If I remove 
some cache in .mozilla, .adobe and .macromedia, I can set the sound for 
this user and xfce4 back in order.
Is there a way to disable this phonon?

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