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Similar to How can I apply a LADSPA plugin to a PulseAudio stream?, but I'm trying to apply the plugins to my source, not a sink. Basically, I want other people to hear my voice with plugins applied to it.

Let's say I have a input: INPUT='alsa_input.usb-mic-00-mic.analog-stereo'

And a filter:

pacmd load-module module-ladspa-sink sink_name=ladspa_low_pass master=$INPUT plugin=cmt label=lpf control=200

Doesn't really work. I'm able to select the filter on pavucontrol but only for my output.

I don't want to install JACK, it caused me a few problems on VOIP clients.

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braindamage
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1 Answers1

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To apply a LADSPA filter on our microphone input we need to combine the following:

  1. Load a LADSPA plugin to a newly created sink (see this question)

    pacmd load-module module-ladspa-sink sink_name=<yourname> master=<sinkname> plugin=<plugin> label=<label> control=<option1>,<option2>,[...]

  2. Loopback the microphone input to this sink (see this question)

    pacmd load-module module-loopback latency_msec=1

To record this filtered output we choose <name_of_ladspa_sink>.monitor as a recording source.

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Takkat
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  • I can't get this to work. I can hear myself with the plugins enabled if I change to the monitor on the "Playback" tab, but when I'm trying to do this on Skype and I select the monitor on the "Recording" => "All Streams" => I get no sound. I've tried to change to every possible combination of loopback/stream and I can't hear anything on Skype (made a call to another computer on my network), no matter what. – braindamage Nov 22 '14 at 20:55
  • @braindamage The name you need for recording is nameofsink.monitor but there may be issues with Skype. – Takkat Nov 22 '14 at 22:01
  • yes that's what I'm using, I tried both from the terminal and also from pavucontrol – braindamage Nov 23 '14 at 19:11