# *** My "~/.asoundrc" for creating loopback devices (capture playback)
# Copy-paste to your home directory and uncomment, backup your own if you have one.
# Find your playback card index with $ aplay -l and set [your card] accordingly.
# You can record your playback sound on Loopback hw:0,1 (0,0=in, 0,1=out).
# For testing do $ arecord -f S16_LE -r 48000 -c 2 -D hw:0,1 test.wav

defaults.pcm.card 1         # [your card]
defaults.pcm.device 0       # [your card]
defaults.ctl.card 1         # [your card]

pcm.!default {
    type asym
    playback.pcm "LoopAndReal"
    capture.pcm "hw:1,0"    # [your card]
}

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:1,0"        # [Your card]
        rate 48000
        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
        periods 128
        period_time 0
        period_size 1024 # must be power of 2
        buffer_size 8192
    }
}