kopia lustrzana https://github.com/F5OEO/rpitx
122 wiersze
3.1 KiB
C
122 wiersze
3.1 KiB
C
#include <stdio.h>
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#include <stdlib.h>
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#include <unistd.h>
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#include <string.h>
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#include <errno.h>
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#include <stdarg.h>
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#include <stdint.h>
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#include <math.h>
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#include <time.h>
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#include <signal.h>
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#include <sys/types.h>
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#include <sys/stat.h>
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#include <fcntl.h>
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#include <sys/mman.h>
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#include <math.h>
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#include <sndfile.h>
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#define ln(x) (log(x)/log(2.718281828459045235f))
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#define BUFFER_LEN 1024*8
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int FileFreqTiming;
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// Test program using SNDFILE
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// see http://www.mega-nerd.com/libsndfile/api.html for API
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void WriteTone(double Frequency,uint32_t Timing)
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{
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typedef struct {
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double Frequency;
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uint32_t WaitForThisSample;
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} samplerf_t;
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samplerf_t RfSample;
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RfSample.Frequency=Frequency;
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RfSample.WaitForThisSample=Timing; //en 100 de nanosecond
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//printf("Freq =%f Timing=%d\n",RfSample.Frequency,RfSample.WaitForThisSample);
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if (write(FileFreqTiming,&RfSample,sizeof(samplerf_t)) != sizeof(samplerf_t)) {
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fprintf(stderr, "Unable to write sample\n");
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}
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}
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int main(int argc, char **argv) {
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float data [2*BUFFER_LEN] ;
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float data_filtered[2*BUFFER_LEN] ; // we generate complex I/Q samples
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SNDFILE *infile, *outfile ;
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SF_INFO sfinfo ;
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int readcount, nb_samples ;
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char *infilename ;
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char *outfilename ;
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int k ;
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float x ;
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if( argc < 2 ) {
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printf("Usage : %s in.wav [out.wav]\n", argv[0]);
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return(1);
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}
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infilename = argv[1];
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if( argc == 3 ) {
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outfilename = argv[2];
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} else {
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outfilename = (char *)malloc( 128 );
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sprintf( outfilename, "%s", "out.ft");
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}
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if (! (infile = sf_open (infilename, SFM_READ, &sfinfo)))
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{ /* Open failed so print an error message. */
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printf ("Not able to open input file %s.\n", infilename);
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/* Print the error message from libsndfile. */
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puts (sf_strerror (NULL));
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return 1;
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}
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if( sfinfo.samplerate != 48000 ) {
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printf("Input rate must be 48K.\n");
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return 1;
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}
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FileFreqTiming = open(outfilename, O_WRONLY|O_CREAT, 0644);
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/** **/
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printf ("Reading file : %s\n", infilename );
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printf ("Sample Rate : %d\n", sfinfo.samplerate);
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printf ("Channels : %d\n", sfinfo.channels);
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printf ("----------------------------------------\n");
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printf ("Writing file : %s\n", outfilename );
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/* While there are.frames in the input file, read them, process
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** them and write them to the output file.
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*/
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while ((readcount = sf_readf_float(infile, data, BUFFER_LEN)))
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{
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nb_samples = readcount / sfinfo.channels;
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for( k=0 ; k < nb_samples ; k++ ) {
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x = data[k*sfinfo.channels];
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if( sfinfo.channels == 2 ) {
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// stereo file, avg left + right
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x += data[k*sfinfo.channels+1];
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x /= 2;
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}
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//printf("%f \n",x);
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float FactAmplitude=2.0; // To be analyzed more deeply !
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/*
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double A = 87.7f; // compression parameter
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double ampf=x/32767.0;
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ampf = (fabs(ampf) < 1.0f/A) ? A*fabs(ampf)/(1.0f+ln(A)) : (1.0f+ln(A*fabs(ampf)))/(1.0f+ln(A)); //compand
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x= (int)(round(ampf * 32767.0f));
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*/
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WriteTone(x*32767*FactAmplitude,1e9/48000.0);
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}
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}
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/* Close input and output files. */
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sf_close (infile) ;
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close(FileFreqTiming);
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return 0;
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}
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