Symmetric dmix and dnsoop for applications that process input/output synchronous (WebRTC, Chromium)

setsound.sh

#!/bin/sh

if [ -z "$1" ]; then
    aplay -L | grep -v "^    " | cut -d ':' -f 2 | uniq | sort | uniq
    exit 1
fi

cat <<EOF > "$HOME/.asoundrc"
pcm.!default {
        type asym
        playback.pcm "dmixer"
        capture.pcm "dsnooper"
}

pcm.dmixer  {
        type dmix
        ipc_key 1024
        slave {
                pcm "hw:$1"
                period_time 0
                period_size 1024
                buffer_size 5120
                rate 48000
        }
        bindings {
                0 0
                1 1
        }
}

pcm.dsnooper  {
        type dsnoop
        ipc_key 1025
        slave {
                pcm "hw:$1"
                period_time 0
                period_size 1024
                buffer_size 5120
                rate 48000
        }
        bindings {
                0 0
                1 1
        }
}

ctl.dmixer {
        type hw
        card $1
}

ctl.dsnooper {
        type hw
        card $1
}
EOF