I want to use the output of mplayer as an input to ecasound. With a fifo I can play it with aplay but have no idea how to get it to play in ecasound. Anybody can tell me what I am doing wrong here. This works:

mkfifo /tmp/audio
mplayer  -vc null -vo null -af format=s16le -srate 44100 -ao pcm:nowaveheader:file=/tmp/audio http://icecast.omroep.nl/radio1-bb-aac
aplay -t raw -c 2 -f S16_LE -r 44100 /tmp/audio

but replacing aplay with ecasound gives me this error:

$ ecasound -D -z:nodb -f 16,2,44100 -i:sndfile,/tmp/audio,wav -o alsahw,0,0
*        ecasound v2.9.1 (C) 1997-2014 Kai Vehmanen and others   
(eca-chainsetup-parser) Double-buffering disabled.
(eca-chainsetup) Chainsetup "untitled-chainsetup"
(eca-chainsetup) NOTE: Real-time configuration, but insufficient privileges to utilize real-time scheduling (SCHED_FIFO). With small buffersizes, this may cause audible glitches during processing.
(eca-chainsetup) "rt" buffering mode selected.
(audioio_sndfile) Using libsndfile to open file "/tmp/audio" for reading.
ERROR:  Connecting chainsetup failed: "Enabling chainsetup: AUDIOIO-SNDFILE: Can't open file "/tmp/audio" for reading