As a remark, to simultaneously listen to mpds music and the sound of a
youtube video in Firefox (running under your user), you have to copy
your cookie to /var/empty/ (_mpds home dir).
$ doas ls -l .aucat_cookie /var/empty/.aucat_cookie
-rw------- 1 nils nils 16 May 29 2015 .aucat_cookie
-rw------- 1 _mpd _mpd 16 May 29 2015 /var/empty/.aucat_cookie
$ doas sha1 -r .aucat_cookie /var/empty/.aucat_cookie
e8d33a71594c0ba7816e075d17afa81e0ba220ce .aucat_cookie
e8d33a71594c0ba7816e075d17afa81e0ba220ce /var/empty/.aucat_cookie
