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ALSAequal on microphone

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ant!
Posts: 3
Joined: 2018-07-06 00:55

ALSAequal on microphone

#1 Post by ant! »

Hi,

I am building right now a baby monitor using a Raspberry Pi (based on https://ivadim.github.io/2017-08-21-fruitnanny/, with some changes). This isn't exactly Debian, but Raspbian is close enough in this case, as ALSA commands would work the same, so I try my luck here as I couldn't get any in the RP forum. Hope this is ok...

To cancel out some microphone noise, I was thinking a simple EQ might help already. So it should go mic -> EQ -> GStreamer. I installed ALSAequal, but something isn't working. I use only ALSA, no jack, Pulseaudio etc., just a headless setup via SSH.

For the EQ, I followed basically this: https://scribles.net/enabling-equalizer ... al-plugin/

snd-aloop is loaded and my .asoundrc looks the same:

Code: Select all

ctl.equal { 

  type equal
}
 
pcm.plugequal {
  type equal
  slave.pcm "plughw:Loopback,0,0"
}
 
pcm.equal {
  type plug
  slave.pcm plugequal
}
For the GStreamer configuration, I replaced "device=hw:1" with "device=equal". Shouldn't this do the job, or am I missing something?

My soundcards with the aloop:

Code: Select all

~ $ cat /proc/asound/cards 
 0 [Loopback       ]: Loopback - Loopback
                      Loopback 1
 1 [ALSA           ]: bcm2835_alsa - bcm2835 ALSA
                      bcm2835 ALSA
 2 [Device         ]: USB-Audio - USB PnP Sound Device
                      C-Media Electronics Inc. USB PnP Sound Device at usb-3f980000.usb-1.1.3, full s
The last one is the USB microphone...

User avatar
debiman
Posts: 3063
Joined: 2013-03-12 07:18

Re: ALSAequal on microphone

#2 Post by debiman »

ant! wrote:I am building right now a baby monitor using a Raspberry Pi (based on https://ivadim.github.io/2017-08-21-fruitnanny/, with some changes). This isn't exactly Debian, but Raspbian is close enough in this case
i'm sure many people here would disagree.
also, raspbian isn't even always debian-based.
but let's put that aside for now.
To cancel out some microphone noise, I was thinking a simple EQ might help already. So it should go mic -> EQ -> GStreamer. I installed ALSAequal, but something isn't working. I use only ALSA, no jack, Pulseaudio etc., just a headless setup via SSH.

For the EQ, I followed basically this: https://scribles.net/enabling-equalizer ... al-plugin/
...yet this guide clearly states that it uses pulseaudio?!
if you diverted from it, you're going to have to walk us through it.

fwiw, i'm currently thinking of using an equaliser on my record player's sound input, and i think i will use jackaudio for it.
Last edited by debiman on 2018-07-08 22:10, edited 1 time in total.

ant!
Posts: 3
Joined: 2018-07-06 00:55

Re: ALSAequal on microphone

#3 Post by ant! »

Thanks for your answer! Yes, you are right, there are differences in between Raspbian and Debian (e.g. the binary blob for the graphic card etc...), but ALSA should work the same, that's why I thought trying it here makes still sense.

I haven't used Jack yet (on the RP just ALSA, on Kubuntu Pulseaudio), so I would need to look into it. Want to avoid Pulseaudio to keep things simple and controllable per terminal/SSH. Do you have a suggestion of a Jack equalizer? I just found JackEQ, but not sure if this needs a GUI (or if jack in general needs a GUI?). Probably worth to look into it if I don't get it running with pure ALSA.

For ALSA, I found ALSAequal only applied to outputs, not input, that's why I though the loopback makes sense. Will have to check my settings again...

User avatar
debiman
Posts: 3063
Joined: 2013-03-12 07:18

Re: ALSAequal on microphone

#4 Post by debiman »

neither jack- nor pulseaudio require a gui.

not sure about available comamnd line equaliser tools though.

a word of warning for messing with alsa: it got much better nerds than i am frantic to the point of kicking their machines.

ant!
Posts: 3
Joined: 2018-07-06 00:55

Re: ALSAequal on microphone

#5 Post by ant! »

Haha, thanks for this advice! Will look therefore as well in these directions if I find some times in the next days, and will post if I get it running somehow.

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