Playback open error on device 'default': No such file or directory

[SATURDAY Mr.]

Hi all:
when I porting gstreamer and some plugins to arm-linux platform, I come across a trouble,
 
when I use commandline "gst-launch playbin2 uri=file:///......", result is:
    the autoaudiosink  is not working
 
when I use commandline "gst-launch filesrc location=music.ogg ! oggdemux ! vorbisdec ! audioconvert ! audioresample ! alsasink", result is:
    ERROR: from element /GstPipeline:pipeline0/GstAlsaSink:alsasink0: Could not open audio device for playback.
    Playback open error on device 'default': No such file or directory
 
before do those, I've add some device node below /dev/snd/....(timer、controlC0 、pcmC0D0c 、pcmC0D0p)；
and the plugins necessary have be cross-compiled and installed.
and the kernel I used is Android's kernel(some driver necessary have included in kernel), I just make a file system,
I think it maybe due to alsa driver can not find correct audio device to playback audio file, 
is there someone have come across this problem and can help me? thx a lot in advance.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.freedesktop.org/archives/gstreamer-embedded/attachments/20111219/ed7382e6/attachment.htm>