Help needed for installing, configuring and using ladspa-dsp plugin

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1

Hello, I’ve been trying to install and configure this ALSA plugin here: GitHub - bmc0/dsp: An audio processing program with an interactive mode.

Recently, I’ve started to use and test some Linux distros after being a Windows-only user for a long time — And I’m findind its learning curve very satisfactory, but sometimes (this guide, for example) it’s not very intuitive for me to follow instrunctions cited in Linux guides.

I’ve succesfully cloned the repo and browsed to dsp directory though terminal, but couldn’t quite figure out how to follow the next steps for generating configuration files and applying the DSP effects. What I managed to do, was convert an Equalizer APO .txt file into an effects chain value through scripts/rew_to_dsp.sh

My goal with this plugin is to use it for a few programs — Mostly games, considering that I already use a player that have direct access to hardware and DSP, and, in my opinion, ALSA audio sounds better than PulseAudio and Windows ASAPI Realtek drivers.

Additionaly, will this plugin apply DSP to Lutris games when selecting ALSA option in game configs?

3

The repo that you have cloned provides the files that need to be build before use. So you first have to understand how to build programs.

dsp is available in the Official Repositories, so there is no need to build it yourself. See Add/Remove Software.

5

Oops, maybe I’ve not expressed myself correctly. Yes, I got it installed through repos, but the part I got stuck is the generation of a config file to apply presets.

Well, I’ve figured it out how to properly configurate it through some other topics.

After following these steps, I managed to route PulseAudio through ladspa-dsp plugin and apply the effects.

However, in the instructions contained in the GitHub repo, it says to put inside

~/.asoundrc

the following text:

pcm.dsp {
type plug
slave {
format FLOAT
rate unchanged
channels unchanged
pcm {
type ladspa
path “/usr/lib/ladspa”
playback_plugins [{
label “ladspa_dsp”
}]
slave.pcm {
type plug
slave {
pcm “<hw_device>”
rate unchanged
channels unchanged
}
}
}
}
}

I did set the following string:

pcm “hw_device”

as:

pcm “hw:0”

When I opened VLC Player and selected ALSA output, then browsed the list, I found an option called “dsp”, but then the player displayed an error that says the file or directory doesn’t exist.

6

Try with hw:0.0 or hw:0,0 (whichever works)

arecord -l displays all soundcards and digital audio devices available. hw:0,0 specifies the default device, on the default sound card. To access your second soundcard’s first device, you would specify hw:1,0.

8

It displayed the same error.

That’s the latest configs I’ve used at the moment:

pcm.dsp {
type plug
slave {
format FLOAT
rate unchanged
channels 2
pcm {
type ladspa
path “/usr/lib/ladspa”
playback_plugins [{
label “ladspa_dsp”
}]
slave.pcm {
type plug
slave {
pcm “hw:0.0”
rate unchanged
channels unchanged
}
}
}
}
}

9

Can you try with this:

10

Tried it, but it didn’t work.

11

Install ladspa package:

sudo pacman -S ladspa

and use this config:

pcm.dsp {
	type plug
	slave {
		format FLOAT
		rate unchanged
		pcm {
			type ladspa
			channels 2
			path "/usr/lib/ladspa"
			playback_plugins [{
				label "ladspa_dsp"
			}]
			slave.pcm {
				type plug
				slave {
					pcm "hw:0,0"
					rate unchanged
					channels unchanged
				}
			}
		}
	}
}
12

Odd, the error message didn’t show up as before, but there wasn’t audio. Tried another player with built-in DSP and it played through the plugin, but when I turned the player’s DSP off, the audio was unaltered, as if the plugin didn’t have any effects applied.

13