Info required on attaching two Multimedia plugins

GENERAL Help
1

Hi,

I am trying to attach two multimedia filters(i.e.,"ogg decoder"with “udio writer” filter which come as part of sample filters in QNX 6.3.2.)

but MmAttachChannels is failing.

below is the code snippet…

#include <stdio.h>
#include <mmedia/mmedia.h>
#include <mmedia/mmconvenience.h>
#include <aoi/aoi.h>

int main(int argc,char *argv[])
{
MmGraph_t *graph;
MmFilter_t *rf,*mpf,*xf,*af, *mdf;
MmChannel_t *rc,*mpic,*mpoc,*xic,*xoc,*ac,*mdic,*mdoc;
int ret;

MmInitialize(NULL);
printf(" MM lib is initialized\n");
graph=MmCreateGraph("mp3 player");


printf(" Finding ogg decoder\n");
if (!(mdf=MmFindFilter(graph,"ogg_decoder")))
{
 printf("Couldn't grab the ogg decoder.\n");
 MmDestroyGraph(graph);
 exit(-5);
}

// grab the mp3_decoder filter output channel
if (!(mdoc=MmAcquireOutputChannel(mdf,MEDIA_TYPE_AUDIO)))
{
 printf("Couldn't get a audio output channel from ogg_dec
 MmDestroyGraph(graph);
 exit(-10);
 }

  printf("Finding Audio writer \n");

 // grab the audio_writer filter
 if (!(af=MmFindFilter(graph,"audio_writer")))
{
 printf("Couldn't grab the audio_writer filter.\n");
 MmDestroyGraph(graph);
 exit(-11);
}
printf("Audio writer found\n");
printf("Acquiring Writer's I/P channel\n");
// grab the audio input channel
if (!(ac=MmAcquireInputChannel(af,MEDIA_TYPE_AUDIO)))
{
  printf("Couldn't get an audio input channel from audio_writer.\n");
  MmDestroyGraph(graph);
  exit(-12);
}
printf("Writer's I/P channel acquired\n");

printf("Attaching channels : (Decoder->Writer)\n");
if (MmAttachChannels(mdoc,ac)!=0)

{
printf(“Couldn’t attach ogg_decoder and audio_writer channels.\n”);
MmDestroyGraph(graph);
exit(-13);
}
printf(“Attaching channels Done : (Decoder->Writer)\n”);
return 0;
}

Please help me understand where I am doing wrong.

Thanks in advance,

Satish