[pulseaudio-discuss] Make pulseaudio the default alsa device

[Felipe Sateler]

On 18 October 2016 at 06:50, Tanu Kaskinen <tanuk at iki.fi> wrote:
> On Fri, 2016-10-14 at 14:49 -0300, Felipe Sateler wrote:
>> On 14 October 2016 at 13:12, Felipe Sateler <fsateler at debian.org> wrote:
>> > On 14 October 2016 at 12:13, Tanu Kaskinen <tanuk at iki.fi> wrote:
>> > > The relevant configuration snippet is already shipped in alsa-plugins
>> > > upstream. The file in the source tree is
>> > >
>> > >     pulse/99-pulseaudio-default.conf.example
>> > >
>> > > and it gets installed to
>> > >
>> > >     $datadir/alsa/alsa.conf.d/99-pulseaudio-default.conf.example
>> >
>> > Yes, but that is not enabled by default. In debian we use the
>> > following file to load that config automatically:
>> >
>> > https://sources.debian.net/src/pulseaudio/9.0-4/debian/pulse.conf/
>>
>> I realized that link may die in the future, so I'm copying the contents:
>>
>> # PulseAudio alsa plugin configuration file to set the pulseaudio plugin as
>> # default output for applications using alsa when pulseaudio is running.
>> hook_func.pulse_load_if_running {
>>     lib "libasound_module_conf_pulse.so"
>>     func "conf_pulse_hook_load_if_running"
>> }
>>
>> @hooks [
>>     {
>>         func pulse_load_if_running
>>         files [
>>             "/usr/share/alsa/pulse-alsa.conf"
>>         ]
>>         errors false
>>     }
>> ]
>
> If the system is configured to use pulseaudio, then I would prefer alsa
> applications to fail if pulseaudio isn't running, rather than falling
> back to whatever the default is if pulse-alsa.conf isn't loaded. It
> makes debugging easier.

I'm not sure if it makes sense to ask if "the system is configured to
use pulseaudio", because individual users on a system might
disable/enable it.

> But if the Debian alsa maintainers prefer to
> fall back to non-pulseaudio configuration even when pulseaudio is
> installed, then it seems reasonable to propose this to alsa upstream.

This file is being shipped by pulseaudio, not alsa.

> Maybe it could be an alternate "example" side-by-side with the current
> pulseaudio-default.conf.example. Distributions could then easily choose
> between the two approaches.

I'd like to avoid having to force users into doing stuff as root to
disable/enable this. The current solution achieves this by simply
disabling autospawn in the user config. A file that is loaded
unconditionally must be removed by the user.

> As a sidenote, I think it would be good to add much more commenting to
> that file. The alsa configuration syntax is very hard to understand, so
> it would be good to explain pretty much everything that is happening in
> that file, line by line. I understand what the file does in general,
> but I can't confidently explain almost any of the individual lines.

Neither do I, FWIW. This file is part of the pulseaudio debian package
since before I got involved, and I have never touched it yet, mostly
for that reason[1].


[1] There is a request to be able to disable the pulse default via an envvar.

-- 

Saludos,
Felipe Sateler