PulseAudio Equalizer Script

[F!o]

Hi psyke83,

your script is totaly what I was searching for since PulseAudio integration.
Equalizer works fine, but it kinda behaves odd, when changing the master volume.

When I'm listening to a song in Rhythmbox and I turn on the equalizer, changing the volume behaves just normal, but as soon as I stop playback and start it again, there is a crackling noise (sounds like dropouts or lag or something), whenever I change the master volume.

Any idea?

Thanks,
Flo

[psyke83]

Originally Posted by F!o Hi psyke83, your script is totaly what I was searching for since PulseAudio integration. Equalizer works fine, but it kinda behaves odd, when changing the master volume. When I'm listening to a song in Rhythmbox and I turn on the equalizer, changing the volume behaves just normal, but as soon as I stop playback and start it again, there is a crackling noise (sounds like dropouts or lag or something), whenever I change the master volume. Any idea? Thanks, Flo

Unfortunately that seems to be an issue with the module-ladspa-sink in PulseAudio, and can't be fixed by me.

Just to confirm: the issue only happens at the moment that you change volume, and stops just after you stop changing the volume?

[F!o]

Originally Posted by psyke83 Unfortunately that seems to be an issue with the module-ladspa-sink in PulseAudio, and can't be fixed by me. Just to confirm: the issue only happens at the moment that you change volume, and stops just after you stop changing the volume?

Yup, it only occurs in the act of changing volume. It really sounds like lag.

Well, then I'm unfortunate. It doesn't really bother me, but it's just not the way it's supposed to be, is it?

Thanks,
Flo

[psyke83]

Originally Posted by F!o Yup, it only occurs in the act of changing volume. It really sounds like lag. Well, then I'm unfortunate. It doesn't really bother me, but it's just not the way it's supposed to be, is it? Thanks, Flo

It's a bug in Karmic's version of PulseAudio (0.9.19), and unlikely to be fixed in Karmic.

Coincidentally, I tested 0.9.20 (semi-official packages available from the Ubuntu Audio Dev PPA), and I no longer notice any unusual sounds when changing volume levels.

[tinivole]

Originally Posted by psyke83 It's a bug in Karmic's version of PulseAudio (0.9.19), and unlikely to be fixed in Karmic. Coincidentally, I tested 0.9.20 (semi-official packages available from the Ubuntu Audio Dev PPA), and I no longer notice any unusual sounds when changing volume levels.

So the odd pop, click or glitch in audio is limited to Karmic?
Actually, scratch that, it seems to occur every time an I/O operation occurs (ie: reading data from disk.)

update:
Just upgraded to the Ubuntu PPA Dev repository version and it has indeed gone!

update2:
The preamp is LOUD. And there is a noticeable distortion in Music. A limiter or compressor to keep the output audio tame would be nice. But having a quick look, seems to be outside the jurisdiction of your scripts.

One itch though, it would be nice to have it in realtime, rather than clicking "Apply".

Regards
Iain

[F!o]

Originally Posted by psyke83 It's a bug in Karmic's version of PulseAudio (0.9.19), and unlikely to be fixed in Karmic. Coincidentally, I tested 0.9.20 (semi-official packages available from the Ubuntu Audio Dev PPA), and I no longer notice any unusual sounds when changing volume levels.

I just updated to 0.9.20, but I still have the same situation as before.
Actually nothing changed, I think... Are you sure it's gone for you?

Thanks,
Flo

[psyke83]

Originally Posted by tinivole So the odd pop, click or glitch in audio is limited to Karmic? Actually, scratch that, it seems to occur every time an I/O operation occurs (ie: reading data from disk.)

I didn't notice pops happening due to I/O load, even with 0.9.19 - that's odd.

update: Just upgraded to the Ubuntu PPA Dev repository version and it has indeed gone!

Phew! Less work for me

update2: The preamp is LOUD. And there is a noticeable distortion in Music. A limiter or compressor to keep the output audio tame would be nice. But having a quick look, seems to be outside the jurisdiction of your scripts.

A limiter/compresser would mean chaining two LADSPA sinks together, which would increase CPU usage. A more reasonable alternative is to use more conservative values for the presets.

If you take a look at previous posts, sbersier and I discussed the issue of distortion in the presets. Reducing the values will resolve the issue - as an example, try the Laptop preset. It has less/no distortion because it uses smaller values compared to the other presets.

The Laptop preset is my own personal preset (which I had spent quite some time tuning), but the rest of the presets are a very quick port from the VLC's built-in list of equalizers, with little testing. I assume VLC has a built-in limiter, but the LADSPA plugin that the script uses does not.

I'll refine the presets in the next update, which should hopefully eliminate distortion in all cases.

One itch though, it would be nice to have it in realtime, rather than clicking "Apply".

Me too . Unfortunately, it's not possible. See this post from the Lucid forum.

[psyke83]

Originally Posted by F!o I just updated to 0.9.20, but I still have the same situation as before. Actually nothing changed, I think... Are you sure it's gone for you? Thanks, Flo

Maybe it's volume distortion? Reduce the pre-amp to 1x, and try with the EQ enabled but all bands set to 0.0. See if the distortion is gone.

[tinivole]

Originally Posted by psyke83 I didn't notice pops happening due to I/O load, even with 0.9.19 - that's odd.

I am on a Netbook, so my testimonial should be treated as a gauge for how well this runs on low-end machines.

Originally Posted by psyke83 A limiter/compresser would mean chaining two LADSPA sinks together, which would increase CPU usage. A more reasonable alternative is to use more conservative values for the presets.

Oh, you use a ladspa plugin to control it?
Fixing it should be easy then.

Rather than toolchaining plugins, write your own that has both in one.
I've never done LADSPA programming myself, but I am familiar with how sound processing works.

For everything else you've mentioned. Thanks!

Regards
Iain