/* record.c
 *
 * Written by Tracy Harton (harton@owlnet.rice.edu)
 * December, 1995
 *
 * matlab mex function for recording audio on SGIs.
 *
 * Can specify bps, sampling rate, and duration
 * 
 * Waits for signal to cross THRESHOLD before beginning sample
 *
 */
#define THRESHOLD 10000 /* minimum signal amplitude to "start" recording... */
 
#include <dmedia/audio.h>     /* audio library header */
#include <malloc.h>
#include <memory.h>
#include <stdio.h>

#include "mex.h"


int record(int bits, long rate, int length, int verbose, short **data);

void mexFunction(int nlhs, Matrix *plhs[], int nrhs, Matrix *prhs[])
{
  int ma, mb, mc, md, na, nb, nc, nd;
  double *ap, *bp, *cp, *dp;
  double *ep;
  int length;
  int count;
  short *data;
  
  if ((nrhs != 4)||(nlhs != 1))
    {
      mexErrMsgTxt("Usage: data = record(bits, rate, length, verbose)");
    }
  
  ma = mxGetM(prhs[0]);
  mb = mxGetM(prhs[1]);
  mc = mxGetM(prhs[2]);
  md = mxGetM(prhs[3]);
  
  na = mxGetN(prhs[0]);
  nb = mxGetN(prhs[1]);
  nc = mxGetN(prhs[2]);
  nd = mxGetN(prhs[3]);
  
  ap = mxGetPr(prhs[0]);
  bp = mxGetPr(prhs[1]);
  cp = mxGetPr(prhs[2]);
  dp = mxGetPr(prhs[3]);
  
  
  length = record((int) *ap, (int) *bp, (int) *cp, (int) *dp, &data);
  
  plhs[0] = mxCreateFull(length, 1, REAL);
  ep = mxGetPr(plhs[0]);
  
  for(count = 0; count < length; count++)
    {
      ep[count] = (double) data[count];
    }
}


int record(int bits, long rate, int length, int verbose, short **data)
{
  short *buf_pos;
  short tmp_buff;
  int start;
  int time = 0;
  ALconfig config;              /* port configuration structure  */
  ALport inport;                /* audio port structure */
  long pvbuf[2];
  
  *data = (short *) malloc(length*rate*sizeof(short));
  if(data == NULL)
    {
      printf("Unable to allocate temporary buffer.\n");
      return(0);
    }
  buf_pos = *data;
  
  config = ALnewconfig();             /* create a config object   */
  
  pvbuf[0] = AL_INPUT_RATE;
  pvbuf[1] = (long) rate;
  ALsetparams(AL_DEFAULT_DEVICE, pvbuf, 2);
  ALgetparams(AL_DEFAULT_DEVICE, pvbuf, 2);
  rate = pvbuf[1];

  ALsetqueuesize(config, rate*2);  /* 2 sec of mono          */
  
  switch(bits)
    {
    case 8:	ALsetwidth(config, AL_SAMPLE_8);
      break;
    case 16:
    default:
      ALsetwidth(config, AL_SAMPLE_16); /* 16-bit signed samples  */
      break;
    }

  ALsetchannels(config, AL_MONO);  	/* mono port              */
  
  
  inport = ALopenport("inport", "r", config); 
  
  if(verbose)
    printf("Waiting for sound...");
  
  start = 0;
  while(start < 25)
    {
      ALreadsamps(inport, &tmp_buff, 1);
      if((tmp_buff > THRESHOLD) || (tmp_buff < -THRESHOLD))
	start++;
    }
  
  if(verbose)
    printf("\nStarting to record %d seconds at %d/%dbits\n", length, rate, bits);
  
  while (time < length)
    {  
      if(verbose)
	printf(".");
      ALreadsamps(inport, buf_pos, rate);     /* read 1 sec of sound */
      buf_pos += rate;
      time++;
      
    }
  
  if(verbose)
    printf("\nDone sampling.\n");
  
  ALfreeconfig(config);               /* free the config object    */
  ALcloseport(inport);                /* shut down the input port  */
  
  return(time*rate);
}