asound.conf

###################### /etc/asound.conf ##################################
pcm.!default {
       type plug
       slave.pcm "asymed"
}

pcm.asymed {
       type asym
       playback.pcm "swmixer"
       capture.pcm "mixin"
}

pcm.dsp0 {
       type plug
       slave.pcm "asymed"
}

pcm.swmixer {
       type dmix
       ipc_key 1234
       slowptr yes
       slave {
               pcm "hw:0,0"
               period_time 0
               period_size 1024
               buffer_size 4096
               rate 48000
       }
}

ctl.dmixer {
       type hw
       card 0
}

pcm.mixin {
       type dsnoop
       ipc_key 5978293 # must be unique for all dmix plugins!!!!
       ipc_key_add_uid yes
       slave {
               pcm "hw:0,0"
               channels 2
               period_size 1024
               buffer_size 4096
               rate 48000
               periods 0
               period_time 0
       }
       bindings {
               0 0
               0 1
       }
}