how to record audio output from browser

inkscape · 12-09-2021, 09:22 AM

I listen to music through my browser, it adds reverberation and other effects to it from the browser add-on.
And now how to record other changed music to mp3 / ogg with my favorite settings.
How to record "what comes out of the browser when it comes to audio"

teckk · 12-09-2021, 09:48 AM

You can dump what is coming through the sound card to file. Some sound hardware will allow that. ffmpeg will do that for example.

Other sound devices will need you to make a virtual sound loopback device in alsa or pulse, and dump that steam to file.

Better solution is to find the source/url/rtsp/HLS playlist/mp3 of the sound stream and dump that to file.

Look at:
ffmpeg
ffplay
mplayer
mpv
aucadicy
vlc
etc.

Do you have a particular stream the you wish to dump?

inkscape · 12-09-2021, 10:23 AM

How to do this virtual loopback for alsa?
I don't have a specific stream.
I just listen to music, or via YouTube or bandcamp, turn on the browser plug
https://chrome.google.com/webstore/d...jbpfpiepjdpnpp
and now I need to rip it to disk to be able to listen to such effects and settings on another device, i.e. what comes out of the browser + plugin.

I have tried various players for the desktop or phone, but in my opinion none of them has such a nice sound that suits me.
So I'm looking for help on the forum

teckk · 12-09-2021, 10:39 AM

Quote:

Features:
- Volume control (up to 400% boost).
- Bass boost level
- Audio Limiter / Compressor.
- Equalizer 32hz-16khz
- Stereo / Mono toggle.
- Stereo / Mono Pan.
- Save your own presets

ffmpeg, ffplay. mplayer, mpv will do all of that.

Quote:

How to do this virtual loopback for alsa?

Do a search for alsa virtual loopback device.

Examples:
https://unix.stackexchange.com/quest...sa-loop-device
https://stackoverflow.com/questions/...card-with-alsa
https://linux.die.net/man/1/alsaloop
https://sysplay.in/blog/linux/2019/0...pback-devices/
https://bbs.archlinux.org/viewtopic.php?id=181922

I never do that. I find the source of the audio and download that.

inkscape · 12-09-2021, 01:29 PM

I can't apply it. I would need step by step instructions.

computersavvy · 12-09-2021, 03:23 PM

Quote:

Originally Posted by inkscape

I can't apply it. I would need step by step instructions.

Try a little bit of experimentation, and reading the man or info pages as well as searching for tutorials. You may learn something.
This is how I learn to do everything I do as an admin.

frankbell · 12-09-2021, 08:42 PM

You might want to take a look at jack.

ondoho · 12-10-2021, 06:28 AM

Quote:

Originally Posted by inkscape

I listen to music through my browser, it adds reverberation and other effects to it from the browser add-on.
(...)
How to record "what comes out of the browser when it comes to audio"

This should be possible with pulseaudio:
https://askubuntu.com/questions/6083...ith-pulseaudio

With ALSA only it is going to be very painful.

Let me just add my personal opinion: I think this is a bad idea. The audio quality won't be very good, you won't be able to change the effects you applied later etc. Much better to actually download the audio stream (check out yt-dlp), and apply effects during playback.

inkscape · 12-13-2021, 11:09 AM

.asoundrc

Code:

pcm.!default {
  type asym
  playback.pcm "LoopAndReal"
  capture.pcm "hw:0,0"
}
pcm.LoopAndReal {
  type plug
  slave.pcm mdev
  route_policy "duplicate"
}
pcm.mdev {
  type multi
  slaves.a.pcm pcm.MixReale
  slaves.a.channels 2
  slaves.b.pcm pcm.MixLoopback
  slaves.b.channels 2
  bindings.0.slave a
  bindings.0.channel 0
  bindings.1.slave a
  bindings.1.channel 1
  bindings.2.slave b
  bindings.2.channel 0
  bindings.3.slave b
  bindings.3.channel 1
}
pcm.MixReale {
  type dmix
  ipc_key 1024
  slave {
    pcm "hw:0,0"
    rate 48000
    #rate 44100
    periods 128
    period_time 0
    period_size 1024 # must be power of 2
    buffer_size 8192
  }
}
pcm.MixLoopback {
  type dmix
  ipc_key 1025
  slave {
    pcm "hw:Loopback,0,0"
    rate 48000
    #rate 44100
    periods 128
    period_time 0
    period_size 1024 # must be power of 2
    buffer_size 8192
  }
}

reboot

Code:

sudo modprobe snd-aloop

and works

rec via terminal or audacity

thanks for guidance pointers