# ----------------------------------------- #
# !!! CHANGE "hw:PCH,0" TO YOUR DEVICE  !!! #
# ----------------------------------------- #
#    in `pcm.playback` and `pcm.capture`    #
# ----------------------------------------- #


# set default resampler
defaults.pcm.rate_converter "speexrate"


# Playback
# --------

    pcm.playback {
        type dmix
        ipc_key 1111
        slave {
            pcm "hw:PCH,0"
            period_size 1024
            buffer_size 4096
            # firefox can't play AAC with buffer size lower than 2048
            #   ("failed to init cubeb")
            # defaults for dmix/dsnoop plugins:
            #   format S16_LE; rate 48000; channels 2
        }
    }

    pcm.loop_in {
        type dmix
        ipc_key 2222
        slave {
            pcm "hw:Loopback,0,7"
            period_size 1024
            buffer_size 4096
        }
    }

    pcm.duplicate {
        # this 4-channel pcm splits one stream into two
        # (e.g. output to speakers and to the loop device)

        # / if an app opens 4-channel device to write to,
        #   then channels 1 and 2 map to `slave a`
        #   and channels 3 and 4 map to `slave b`,
        #   which is not what this device is intended for;
        #   use `duplicate_stereo` in this case /

        type plug
        slave.pcm {
            type multi
            slaves {
                a { channels 2 pcm "playback" }
                b { channels 2 pcm "loop_in" }
            }
            bindings [
                { slave a channel 0 }
                { slave a channel 1 }
                { slave b channel 0 }
                { slave b channel 1 }
            ]
        }
        #~ route_policy "duplicate"
        # -- or --
        ttable [
            [ 1 0 1 0 ]   # left  -> a.left,  b.left
            [ 0 1 0 1 ]   # right -> a.right, b.right
        ]
    }

    pcm.duplicate_stereo {
        # this device may fail at some configurations
        # use 4-channel "duplicate" if it fails
        type plug
        slave.pcm "duplicate"
        slave.channels 2
    }


# Capture
# -------

    pcm.capture {
        type plug
        slave.pcm {
            type dsnoop
            ipc_key 3333
            slave {
                pcm "hw:PCH,0"
                period_size 1024
                buffer_size 4096
                # lingot fails with buffer size lower than 2048
                #   ("cannot set parameters")
            }
        }
    }

    pcm.loop_out {
        # system sounds capture device
        type plug
        slave.pcm {
            type dsnoop
            ipc_key 4444
            slave {
                pcm "hw:Loopback,1,7"
                period_size 1024
                buffer_size 4096
            }
        }
        #~ slave.channels 2
        hint {
            show on
            description "System sounds"
        }
    }


# The Default
# --------------------

    # Playback:
    #   [source] -> multi ---> /duplicate/ -> dmix -> hardware -> [output]
    #                      \-> /duplicate/ -> dmix -> *pcm.loop_in* -> (loopback)
    # Capture:
    #   [input] -> hardware -> dsnoop -> *pcm.capture* -> [sink]
    #   (loopback) -> dsnoop -> *pcm.loop_out* -> [sink]

    pcm.!default {
        type asym
        playback.pcm "duplicate_stereo"     # variants: "duplicate_stereo", "duplicate"
        capture.pcm "capture"
    }