F5OEO-rpitx/fm/pifm.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include <stdarg.h>
#include <stdint.h>
#include <math.h>
#include <time.h>
#include <signal.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <sys/mman.h>


#include <sndfile.h>

#define		BUFFER_LEN	1024*8
int FileFreqTiming;
// Test program using SNDFILE
// see http://www.mega-nerd.com/libsndfile/api.html for API
void WriteTone(double Frequency,uint32_t Timing)
{
typedef struct {
		double Frequency;
		uint32_t WaitForThisSample;
	} samplerf_t;
	samplerf_t RfSample;


	RfSample.Frequency=Frequency;
	RfSample.WaitForThisSample=Timing; //en 100 de nanosecond
	//printf("Freq =%f Timing=%d\n",RfSample.Frequency,RfSample.WaitForThisSample);
	if (write(FileFreqTiming,&RfSample,sizeof(samplerf_t)) != sizeof(samplerf_t)) {
		fprintf(stderr, "Unable to write sample\n");
	}

}

int main(int argc, char **argv) {
	float data [2*BUFFER_LEN] ;
	float data_filtered[2*BUFFER_LEN] ; // we generate complex I/Q samples
	SNDFILE      *infile, *outfile ;
	SF_INFO		sfinfo ;

    int			readcount, nb_samples ;
    char	*infilename  ;
    char	*outfilename  ;
	int k   ;
	float x ;

	if( argc < 2 ) {
		printf("Usage : %s in.wav [out.wav]\n", argv[0]);
		return(1);
	}
	infilename = argv[1] ;
	if( argc == 3 ) {
		outfilename = argv[2] ;
	} else {
		outfilename = (char *)malloc( 128 );
		sprintf( outfilename, "%s", "out.ft");
	}
    if (! (infile = sf_open (infilename, SFM_READ, &sfinfo)))
    {   /* Open failed so print an error message. */
        printf ("Not able to open input file %s.\n", infilename) ;
        /* Print the error message from libsndfile. */
        puts (sf_strerror (NULL)) ;
        return  1 ;
    } ;

	if( sfinfo.samplerate != 48000 ) {
		printf("Input rate must be 48K.\n");
		return 1 ;
	}

	FileFreqTiming = open(outfilename, O_WRONLY|O_CREAT, 0644);


	/** **/
	printf ("Reading file : %s\n", infilename ) ;
	printf ("Sample Rate : %d\n", sfinfo.samplerate) ;
	printf ("Channels    : %d\n", sfinfo.channels) ;
	printf ("----------------------------------------\n") ;
	printf ("Writing file : %s\n", outfilename ) ;



    /* While there are.frames in the input file, read them, process
    ** them and write them to the output file.
    */
	int Excursion=6000;
    while ((readcount = sf_readf_float(infile, data, BUFFER_LEN)))
    {
		nb_samples = readcount / sfinfo.channels ;
		for( k=0 ; k < nb_samples ; k++ ) {
			x = data[k*sfinfo.channels] ;
			if( sfinfo.channels == 2 ) {
				// stereo file, avg left + right
				x += data[k*sfinfo.channels+1] ;
				x /= 2 ;
			}
			//printf("%f \n",x);
			WriteTone(x*Excursion*2.0,1e9/48000.0);

		}

    } ;

    /* Close input and output files. */
    sf_close (infile) ;
close(FileFreqTiming);



    return 0;
}