I wonder if maybe audio_writer is having some trouble finding a shared 
library that is required.  You can try starting io-media with the 
environment variable DL_DEBUG set.  ie, from the shell:
   DL_DEBUG=1 io-media-generic

Here's the list of shared libraries that it should require:
$ ntoarm-readelf -d 
./lib/mmedia/filters/writers/audio_writer/nto/arm/dll.le/audio_writer.so

Dynamic section at offset 0x6020 contains 23 entries:
   Tag        Type                         Name/Value
  0x00000001 (NEEDED)                     Shared library: [libasound.so.2]
  0x00000001 (NEEDED)                     Shared library: [libmmfilter.so.1]
  0x00000001 (NEEDED)                     Shared library: [libaoi.so.1]
  0x00000001 (NEEDED)                     Shared library: [libmmedia.so.1]
  0x00000001 (NEEDED)                     Shared library: [libc.so.3]
  0x0000000e (SONAME)                     Library soname: [audio_writer.so]


-- 
Ryan J. Allen
QNX Software Systems

Hi Lakshmi,

Here are a few simple things I recommend trying when it seems that a filter can't be loaded or doesn't work:

* Run pidin mem.  It will tell you whether the filter DLL is successfully loaded or not.  Make sure that the keepdlls 
option in your configuration file is set to "all" -- otherwise it may be normal for some filters to be absent from the 
output of pidin mem even if io-media has no trouble loading them:

  keepdlls = "all"

* Find or add a "keepdll" element in the config file that mentions the filter.  Make sure that the filter is not listed 
as optional -- this way if io-media fails to load it at startup, it will complain and exit:

  keepdll {
      name = "audio_writer"
  }

* Run io-media with stderr pointing to somewhere readable like a file or a terminal.  Some error messages go to stderr 
even if you don't use the -S option.  This includes the dynamic linker's complaints about missing symbols or libraries.

* If it turns out that the DLL indeed fails to load, try exporting an environmant variable named DL_DEBUG before you run
 io-media.  This will produce detailed information about all the shared objects that it's trying to load, and about any 
failures.  This information also goes to stderr.

  DL_DEBUG=1 io-media-generic ...

* If it turns out that the filter does load but seems to reject inputs that you beileve it should accept, run io-media 
with two -D options.  That will make it send more detailed debug information to the system log (or to stderr, if you 
also use the -S option).

In the particular case of audio_writer, it's possible that it fails to load because you don't have the requred version 
of libasound.  There is a patch that contains an updated libasound, and any recent audio_writer will not work without 
that patch unless you have QNX 6.5.

I hope this helps -- if not, you know where to find me.  :)