[MPlayer-users] Can't open audio device /dev/dsp: No such file or directory

[Malte Schünemann]

I am running Ubuntu 11.10. Chasing some problem with mencoder, I tried 
the most recent vanilla version of mplayer / mencoder (MPlayer 
SVN-r34509-4.6.1 (C) 2000-2012 MPlayer Team). When running mplayer, I 
get the following output

Error opening/initializing the selected video_out (-vo) device.
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
libavcodec version 53.54.100 (internal)
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
[AO OSS] audio_setup: Can't open audio device /dev/dsp: No such file or 
directory
ao_nas: init(): Can't open nas audio server -> nosound
DVB card number must be between 1 and 4
AO: [null] 48000Hz 2ch s16le (2 bytes per sample)
Video: no video

Of course, I get nothing visible, or audible. The version coming with 
the distribution tells me

MPlayer SVN-r33713-4.6.1 (C) 2000-2011 MPlayer Team
...
Cannot load subtitles './96 Hours.txt'.
==========================================================================
Opening video decoder: [ffmpeg] FFmpeg's libavcodec codec family
Selected video codec: [ffmpeg2] vfm: ffmpeg (FFmpeg MPEG-2)
==========================================================================
==========================================================================
Opening audio decoder: [ffmpeg] FFmpeg/libavcodec audio decoders
AUDIO: 48000 Hz, 2 ch, s16le, 192.0 kbit/12.50% (ratio: 24000->192000)
Selected audio codec: [ffac3] afm: ffmpeg (FFmpeg AC-3)
==========================================================================
AO: [pulse] 48000Hz 2ch s16le (2 bytes per sample)
Starting playback...

What can I do to overcome the sound, and video problems ?

Malte