[pulseaudio-discuss] R: New equalizer module (module-eqpro-sink), some questions

Tanu Kaskinen tanuk at iki.fi
Fri Apr 5 11:29:01 UTC 2019

On Tue, 2019-04-02 at 20:28 +0200, Georg Chini wrote:
> On 06.11.18 22:14, Andrea A wrote:
> > Thanks a lot for the reply
> > 
> > > If the preset files are expected to be shared between users, then the
> > database.h stuff isn't good, because different users can have their
> > pulseaudio configured with different database formats. I like the "ini-
> > style" configuration file style that pulseaudio uses for .conf files.
> > There are no helpers for writing those files, though, but that's
> > probably not a big issue.
> > 
> > I can write a parser for ini-style file however since PA is 
> > multiplatform I need some information about how to store user and 
> > system settings. System settings can be hardcoded at least, but the 
> > directory of user config depends on the platform I think.
> > 
> > > Iwould love to have the equalizer as a LADSPA plugin
> > 
> > My fear is that a LADSPA plugin will be too hard to use for a lot of 
> > desktop users. I think that a GNU desktop user would like to have a 
> > fully working audio equalizer in his distribution and PA is default in 
> > almost all GNU distributions. Configuring a LADSPA plugin may be hard 
> > and boring for the average user and GNU will continue to don't have a 
> > standard equalizer. Beyond the issues you've already listed.
> > 
> > > It's not very uncommon that some core
> > change requires changes in all sinks, so even if the module is perfect
> > and doesn't require maintenance in form of bug fixes, there are other
> > kinds of real maintenance costs.
> > 
> > As far as I know the actual equalizer is deprecated so if this mine 
> > equalizer will be adequate I think that the actual can be substitute 
> > and the number of modules to maintain will not change.
> > 
> > Andrea993
> > 
> > 
> Hi Andrea,
> maybe there is a chance now to have your equalizer included as a module. 
> The messaging API patches
> should have their final form (at least I do not think the public 
> functions will change anymore) and today
> I submitted a patch series that consolidates the code of the current 
> virtual sinks and moves the common
> code to a separate file. Using the common code should significantly 
> reduce the maintenance cost of an
> additional sink.
> So if you are still interested to have it included, at least I would 
> welcome a new patch.
> Arun, Tanu, what do you think?

I think it would anyway make sense to make one or more LADSPA plugins
out of the equalizer code (I say one or more, because of the lack of
parametrization support in LADSPA). That way the equalizer would be
available also to other software than just PulseAudio (I'm thinking
PipeWire in particular).

If a suitable LADSPA plugin existed, we might or might not still need a
separate equalizer module, but in any case we wouldn't need to maintain
the DSP code in PulseAudio. If there's some reason why module-ladspa-
sink isn't (and can't become) suitable for implementing the integration
in PulseAudio, then a specialized module is fine.

I'm not saying that I'm dead against hosting the DSP code in
PulseAudio, but I'd certainly prefer not to.



More information about the pulseaudio-discuss mailing list