Read AU sound file
Keywords: main

Subsections

- Library
- Description
- Dialog Box
- Default properties
- Interfacing function
- Computational function (type 2)

##
Read AU sound file

### Library

Sources

### Description

Read from an audio file in .au format.

### Dialog Box

Set READAU block parameters |
Input file name | test.au
Buffer size | 20
Swap mode 0/1 | 0

- Input file name: the name of the .au file
- Buffer size: how much buffer to use.
- Swap mode 0/1: whether or not to swap

### Default properties

- always active: no
- direct-feedthrough: no
- zero-crossing: no
- mode: no
- number/sizes of inputs: 0 /
- number/sizes of outputs: 1 / 1
- number/sizes of activation inputs: 1 / 1
- number/sizes of activation outputs: 0 /
- continuous-time state: no
- discrete-time state: yes
- name of computational function: readau

### Interfacing function

`scilab/macros/scicos_blocks/sources/READAU_f.sci`

### Computational function (type 2)

    #include <stdio.h>
    #include <math.h>
    #include <string.h>
    #include "../machine.h"
    extern  int C2F(cvstr)  __PARAMS((integer *,integer *,char *,integer *,unsigned long int));
    extern void sciprint __PARAMS((char *fmt,...));
    extern void mget2 __PARAMS((FILE *fa, integer swap, double *res, integer n, char *type, integer *ierr));
    void
    readau(flag,nevprt,t,xd,x,nx,z,nz,tvec,ntvec,rpar,nrpar,
    	       ipar,nipar,inptr,insz,nin,outptr,outsz,nout)
         /*
         ipar[1]   = lfil : file name length
         ipar[2:4] = fmt  : numbers type ascii code
         ipar[5]   = void
         ipar[6]   = n : buffer length in number of records
         ipar[7]   = maxvoie : record size
         ipar[8]   = swap
         ipar[9]   = first : first record to read
         ipar[10:9+lfil] = character codes for file name
         */
    integer *flag,*nevprt,*nx,*nz,*ntvec,*nrpar,ipar[],*nipar;
    integer insz[],*nin,outsz[],*nout;
    double x[],xd[],z[],tvec[],rpar[];
    double *inptr[],*outptr[],*t;

    {
      char str[100],type[4];
      int job = 1,three=3;
      FILE *fd;
      int n, k, kmax, /*no, lfil,*/ m, i, irep,/* nm,*/ ierr;
      double *buffer,*record;
      long offset;
      double y;
      /*  div_t divt;*/int quot, rem;
      double SCALE=0.000030517578125;
      /*  int ETAB[8]={0, 132, 396, 924, 1980, 4092, 8316, 16764}; */
      int ETAB[8];
      int mu;
      int sig;
      int e;
      int f;
    /*  double ff;*/

      ETAB[0]=0; ETAB[1]=132; ETAB[2]= 396; ETAB[3]=924; ETAB[4]=1980;
      ETAB[5]=4092; ETAB[6]=8316; ETAB[7]=16764;

      --ipar;
      --z;
      fd=(FILE *)(long)z[3];
      buffer = (z+4);

      /*
        k    : record counter within the buffer
        kmax :  number of records in the buffer
      */

      if (*flag==1) {
        n    = ipar[6];
        k    = (int)z[1];
        /* copy current record to output */
        record=buffer+(k-1)*ipar[7];

        for (i=0;i<*nout;i++)
          {
    	mu=(int) record[i];

    	mu=255-mu;
    	if(mu>127)
    	  sig=1;
    	else
    	  sig=0;
    	/* comment out for SUNOS SS 8/10/99
    	divt=div(mu,16);
    	e=divt.quot-8*sig+1;
    	f=divt.rem;
    	*/
    	quot=mu/16;rem=mu-16*quot;
    	e=quot-8*sig+1;
    	f=rem;

    	y=ldexp((double)(f),(e+2));
    	/* ff=(double)(e+2);
    	   y=((double) f) * pow(two, ff); */

    	e=ETAB[e-1];

    	y=SCALE*(1-2*sig)*(e+y);

    	*outptr[i]=y;
          }
        if (*nevprt>0) {
          /*     discrete state */
          kmax =(int) z[2];
          if (k>=kmax&&kmax==n) {
    	/*     read a new buffer */
    	m=ipar[6]*ipar[7];
    	F2C(cvstr)(&three,&(ipar[2]),type,&job,strlen(type));
    	for (i=2;i>=0;i--)
    	  if (type[i]!=' ') { type[i+1]='\0';break;}
    	ierr=0;
    	mget2(fd,ipar[8],buffer,m,type,&ierr);
    	if (ierr>0) {
    	  sciprint("Read error!\n");
    	  fclose(fd);
    	  z[3] = 0.0;
    	  *flag = -1;
    	  return;
    	}
    	else if (ierr<0) { /* EOF reached */
    	  kmax=-(ierr+1)/ipar[7];
    	}
    	else
    	  kmax=ipar[6];

    	z[1] = 1.0;
    	z[2] = kmax;
          }
          else if (k<kmax)
    	z[1] = z[1]+1.0;
        }
      }
      else if (*flag==4) {
        F2C(cvstr)(&(ipar[1]),&(ipar[10]),str,&job,strlen(str));
        str[ipar[1]] = '\0';
        fd = fopen(str,"rb");
        if (!fd ) {
          sciprint("Could not open the file!\n");
          *flag = -1;
          return;
        }
        z[3]=(long)fd;
        /* skip first records */
        if (ipar[9]>1) {
          F2C(cvstr)(&three,&(ipar[2]),type,&job,strlen(type));
          for (i=2;i>=0;i--)
    	  if (type[i]!=' ') { type[i+1]='\0';break;}
          offset=(ipar[9]-1)*ipar[7]*sizeof(char);
          irep = fseek(fd,offset,0) ;
          if ( irep != 0 )
    	{
    	  sciprint("Read error\r\n");
    	  *flag = -1;
    	  fclose(fd);
    	  z[3] = 0.0;
    	  return;
    	}
        }
        /* read first buffer */
        m=ipar[6]*ipar[7];
        F2C(cvstr)(&three,&(ipar[2]),type,&job,strlen(type));
        for (i=2;i>=0;i--)
    	  if (type[i]!=' ') { type[i+1]='\0';break;}
        mget2(fd,ipar[8],buffer,m,type,&ierr);
        if (ierr>0) {
          sciprint("Read error!\n");
          *flag = -1;
          fclose(fd);
          z[3] = 0.0;
          return;
        }
        else if (ierr<0) { /* EOF reached */
          kmax=-(ierr+1)/ipar[7];
        }
        else
          kmax=ipar[6];

        z[1] = 1.0;
        z[2] = kmax;
      }
      else if (*flag==5) {
        if(z[3]==0) return;
        fclose(fd);
        z[3] = 0.0;
      }
      return;
    }