I have been using this VU meter program http://laugeo.free.fr/ameter.html to show the output from media players.
with vlc "vlc --alsa-audio-device=ameter sound.wav"
or with aplay "aplay -D ameter sound.wav"
or with mplayer "mplayer -ao alsa:device=ameter sound.wav"
ameter works fine on an external usb sound card, but when I try to use ameter on the "HiFiBerry DAC+ Pro" it simply doesn't want to work.
Here is a pre-complied version of ameter, compiled on "raspbian wheezy"
Create the /home/pi/.asoundrc file as follows,
slave.pcm 'hw:0,0' #can be hw or hw:0,1 etc...
This works fine on an external usb sound card, just not the "HiFiBerry DAC+ Pro"
It could be possible there is a conflict between the "/etc/asound.conf" and the "/home/pi/.asoundrc" file.
Does anyone know how to write/modify the ".asoundrc" file so that ameter works on the "HiFiBerry DAC+ Pro"?
PS, on another subject: if you are have trouble playing MP3s with VLC using the "HiFiBerry DAC+ Pro"
Run VLC with: "vlc --aout alsa --alsa-audio-device=hw:0,0" and it will play MP3s.
Make a script
exec /usr/bin/vlc --aout alsa --alsa-audio-device=hw:0,0 "$@"