A Simple Ogg Vorbis Player using libvorbisplay and OpenAL

vorbisplay.c

#include <stdlib.h>
#include <stdio.h>
#include <AL/alut.h>
#include <vorbis/codec.h>
#include <vorbis/vorbisfile.h>

char pcmout[16*1024];

void check_error()
{
   ALenum error = alGetError();
   switch(error)
   {
   case AL_INVALID_NAME: fprintf(stderr,"invalid name\n"); return;
   case AL_INVALID_ENUM: fprintf(stderr,"invalid enum\n"); return;
   case AL_INVALID_VALUE: fprintf(stderr,"invalid value\n"); return;
   case AL_INVALID_OPERATION: fprintf(stderr,"invalid operation\n"); return;
   case AL_OUT_OF_MEMORY: fprintf(stderr,"out of memory\n"); return;
   default: return;
   }
}

int main (int argc, char **argv)
{
   OggVorbis_File vf;
   int current_section;
   int eof = 0;
   FILE *fp = fopen(argv[1], "rb");
   if(fp == NULL)
   {
      fprintf(stderr, "could not open file %s", argv[1]);
      exit(1);
   }

   if(ov_open_callbacks(fp, &vf, NULL, 0, OV_CALLBACKS_DEFAULT)<0)
   {
      fprintf(stderr, "input does not appear to be in an ogg bitstream");
      exit(1);
   }

   vorbis_info *vi = ov_info(&vf, -1);

   printf("rate %d channels: %d\n",vi->rate, vi->channels);

   


   ALuint source;
   alutInit (&argc, argv);
   
   ALuint buffers[16];
   alGenBuffers(16, buffers);

   alGenSources (1, &source);
   

   for(int i = 0;i<16;++i)
   {
      long pos = 0;

      while(pos < sizeof(pcmout))
      {
	 long ret = ov_read(&vf, pcmout+pos, sizeof(pcmout)-pos, 0, 2, 1, &current_section);
	 pos+=ret;
	 if(ret == 0)
	 {
	    eof = 1;
	    break;
	 }
      }
   
      alBufferData(buffers[i], AL_FORMAT_STEREO16, pcmout, pos, vi->rate);
   
   }
   alSourceQueueBuffers(source, 16, buffers);
   
   alSourcePlay(source);

   check_error();

   while(!eof)
   {
      ALuint released[16];
      ALint count;
      alGetSourcei(source, AL_BUFFERS_PROCESSED, &count);
      alSourceUnqueueBuffers(source, count, released);
    
      for(int i = 0;i<count;++i)
      {
	 long pos = 0;

	 while(pos < sizeof(pcmout))
	 {
	    long ret = ov_read(&vf, pcmout+pos, sizeof(pcmout)-pos, 0, 2, 1, &current_section);
	    pos+=ret;
	    if(ret == 0)
	    {
	       eof = 1;
	       break;
	    }
	 }
 
	 alBufferData(released[i], AL_FORMAT_STEREO16, pcmout, pos, vi->rate);
   
      }
      alSourceQueueBuffers(source, count, released);
      alutSleep(1/20.);
   }

   alutExit ();
   return EXIT_SUCCESS;
}