[pulseaudio-discuss] location of pa-equalizer default config and presets

Bernhard Landauer oberon at manjaro.org
Sat Jul 29 08:41:14 UTC 2017

Am 29. Juli 2017 05:46:19 MESZ schrieb Jason Newton <nevion at gmail.com>:
>Hi Bernhard,
>Sorry for the lag in getting back to you, I've got many things I'm
>these days and for some reason my alerts for PA don't work all the
>Anyway - Tanu gave you an accurate reply.  Your confusion is due to the
>ecosystem of the equalizers coming into popularity in the same
>and at some point the ladspa one became more popular - but then many
>conflated the two and propagated based on the names, especially across
>A couple of points:
>- qpaeq does not store any profiles, although I think it should have
>   feature to upload CSVs/ lists of tie points.
>   - The database the equalizer uses to store profiles is whatever the
>database format pulse decides at build time, but ultimately binary
>store like bdb.  It uses pulse's api to get and put stuff to that
>- You can, like qpaeq does, speak to the sink over dbus to add or
>profiles, including specifying control points in binary.  Have a look
>the equalizer_handle_seed_filter function which receives and processes
>dbus messages, for any or all channels.  This is how you should do what
>   you're asking to do.
>   - The dbus routines/callbacks (currently under line 1328 in
>module-equalizer-sink.c) would be helpful to review to see the
>methods available for manipulating the equalizer through either
>   qpaeq or having a separate utility for importing profiles.
>- Be aware that the filter rate and sample rate are different, with the
>filter sampling rate being higher (next power of 2) and renormalize
>control points as such before handing it over to the server and that
>profile is expected to be this filter rate size big. I should have had
>optional boolean to do this on the server, but I didn't need it at the
>It shouldn't be too much work (like 50-100 lines of python) to hack
>together a dbus based upload/import script for such profiles.
>On Wed, Jul 26, 2017 at 12:03 PM, Bernhard Landauer
><oberon at manjaro.org>
>> On 26.07.2017 20:58, Tanu Kaskinen wrote:
>> My answer was based on reading the source code, and it seemed like
>>> module-equalizer-sink stores some database in
>>> ~/.config/pulse/equalizer-presets, and based on the file name, that
>>> seemed like the place where the presets live.
>>> I now looked at the contents of the files in
>>> https://github.com/rsommerard/pulse-presets and it's clear that
>>> preset files aren't used with qpaeq/module-equalizer-sink. The
>>> that module-equalizer-sink uses is not in text format, but the
>>> rsommerard presets are text files. The files contain the string
>>> "mbeq_1197", which is an identifier for a ladspa eq plugin.
>>> the presets are meant to be used with some program that sets up
>>> ladspa-sink in pulseaudio. I don't know what program that is.
>> Right. My actual question is still not answered.
>> I need to preconfigure qpaeq and the files in ~/.config/pulse are in
>> not doing the job. Deleting them does not remove an existing config
>> providing them does not supply them ... So how does it really work?
>> _______________________________________________
>> pulseaudio-discuss mailing list
>> pulseaudio-discuss at lists.freedesktop.org
>> https://lists.freedesktop.org/mailman/listinfo/pulseaudio-discuss

Thank you very much for your detailed reply, Jason! 
I'm not at my development computer for a few days and will look into all that again next week.

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