asoundrc

#https://bbs.archlinux.org/viewtopic.php?id=147852

pcm.!default {
    type asym
        playback.pcm "loop_and_hw"  # default to playing to loopback and hw
        capture.pcm "looprec"       # default to capture from loopback
        #capture.pcm "hw:0,0"       # uncomment to capture from hw
}

pcm.looprec {
    type hw
        card "Loopback"
        device 1
        subdevice 0
}


pcm.loop_and_hw {
    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
        }
}