#include <stdio.h>
#include <stdlib.h>
#include <math.h>
#include "segy.h"
#include "defs.h"
#include "larsemod.h"

main()
{
	int n,i,nt;
	int ngather=0;
	int splast=-1;  
	char x[64004];  /* x= input - original data (segy data);   */
	char y[65000]; 		/* y=sis header + data */
	struct segy *segyhead;
	struct traceinfo *sishead;
	struct LarseHead *larsehead;
	float *segydata;
	float *sisdata;
	double cos();
	
	nt= 15001;
	
	segyhead=(struct segy*)(x);
	larsehead=(struct LarseHead*)(x);
	segydata= (float *)(&x[240 + 2000]);

	sishead=(struct traceinfo*)(y);
	sisdata= (float *)(&y[TRSIZE]);
	
	while ((n=read(0,x,64000)) >=0)
            {
		if(n==400) continue;
		if(n==3200) continue;		
		if(n==0) break;
	
		ngather++;
	
		for (i=0;i<240;i++) y[i]=x[i];	
		if((segyhead->sp != splast) && (splast >=0))
			{
			   writeeof(1);      
			   ngather=1;
			}
		if ((larsehead->component)==1) 
		{
	    	splast=segyhead->sp;
		/* source x coordinate UTM scale */
		sishead->xs=larsehead->utmSrcX;  	

		/* source y coordinate UTM */
		sishead->ys=larsehead->utmSrcY;  	
		sishead->zs=segyhead->szsurf; 	/* surface elevation at source */

		/* x receiver group coordinate UTM scale */
		sishead->xr=larsehead->utmRecX;	

		/* y receiver group coordinate UTM scale */
	        sishead->yr=larsehead->utmRecY; 
		sishead->zr=segyhead->gz;	/* elevation at receiver group */
                sishead->t0=0.0;
		sishead->samplerate=0.004;
		sishead->srcflagnum=segyhead->sp; /* shotpoint */
		sishead->recflagnum=larsehead->fieldStakeNum; /*receiver*/
		sishead->status=INIT;
		sishead->gain=1.0;
		sishead->dtstatic=0.0;
		sishead->nt=(7600);  /*30 seconds for larse shot gathers */

		for(i=0;i<NUSER;i++) sishead->user[i]=0;
		ibm2ieee(segydata,&nt);   /*data IEEE float */

		for (i=0;i<sishead->nt;i++)
			sisdata[i]=(segydata[i]);
	        write(1,y,TRSIZE+4*sishead->nt); 
		}
  	   }	
   }