[pulseaudio-discuss] Seeking advice on use of padsp

[Sean Greenslade]

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On Tue, Feb 15, 2022 at 10:56:55AM +0000, Geoff Browne wrote:
> Great!  You cracked it Sean.
> 
> > What user is the C code running as?
> 
> Thank you Sean, I should have realised - it felt like something silly
> all along.  The current C code has to be run with root privileges at
> the moment due to the need to access various low-level control
> registers.  I'd assumed that with root privileges it would just work
> for any user, not realising that pulseaudio uses daemon sockets on a
> per-user basis.
> 
> All I really want to do is to play short sine wave bleeps of varying
> frequency to the bluetooth speaker that i've paired with the Pi, maybe
> I'm making a mountain out of a molehill?

There is a way to get root to use your user's pulseaudio session. You
just need to point it to pulse's socket and connection cookie. This can
be done via environment variables. For example, I ran the following on
my machine:

# PULSE_SERVER=/run/user/1000/pulse/native PULSE_COOKIE=/home/sean/.config/pulse/cookie pactl list

Of course, you will need to substitute your user's correct UID and home
directory path. You should be able to set environment variables with the
setenv() C function in stdlib.h.

--Sean