wavsample.cc

#include <stdio.h>
#include <math.h>

typedef unsigned char BYTE;
typedef unsigned short WORD;
typedef unsigned int DWORD;

const int WAVE_FORMAT_PCM = 1;
typedef struct { 
  WORD  wFormatTag; 
  WORD  nChannels; 
  DWORD nSamplesPerSec; 
  DWORD nAvgBytesPerSec; 
  WORD  nBlockAlign; 
  WORD  wBitsPerSample; 
  WORD  cbSize; 
} WAVEFORMATEX; 

//---------------------------------------------------------------------------
void SaveWavFile(const char *filename){

  const DWORD SRATE = 11025; //Sampling Rate (11025Hz)
  const int totalsec = 2;  //Length of Data [sec]
  const DWORD dwFmtSize = 16;
  const DWORD dwWaveSize = SRATE*totalsec;  //Size of Data
  const DWORD dwFileSize = dwWaveSize + 36; //Size of File

  WAVEFORMATEX wfe;

  FILE *fp = fopen(filename,"wb");
  if(fp == NULL){
    printf("Failed to open %s.",filename);
    return;
  }

  fwrite("RIFF",sizeof(BYTE),4,fp);
  fwrite(&dwFileSize,sizeof(DWORD),1,fp);
  fwrite("WAVE",sizeof(BYTE),4,fp);

  wfe.wFormatTag = WAVE_FORMAT_PCM;  //Fileformat (PCM)
  wfe.nChannels = 1;
  wfe.nSamplesPerSec = SRATE;
  wfe.nAvgBytesPerSec = SRATE;
  wfe.wBitsPerSample = 8;
  wfe.nBlockAlign = wfe.nChannels * wfe.wBitsPerSample / 8;

  unsigned char *bWave = new unsigned char[dwWaveSize];

  const double Pi = M_PI;
  double f = (double)440.0/(double)SRATE; //(440.0Hz)
  for(int i=0;i<dwWaveSize;i++){
    double phase = (double)i*f*Pi*2.0;
    bWave[i] = (unsigned char)(sin(phase)*128+128);
  }

  fwrite("fmt ",sizeof(BYTE),4,fp);
  fwrite(&dwFmtSize,sizeof(DWORD),1,fp);
  fwrite(&wfe,1,16,fp);
  fwrite("data",sizeof(BYTE),4,fp);
  fwrite(&dwWaveSize,sizeof(DWORD),1,fp);
  fwrite(bWave,sizeof(BYTE),dwWaveSize,fp);

  delete bWave;
  fclose(fp);
}
//---------------------------------------------------------------------------
int main(void){
  SaveWavFile("test.wav");
}
//---------------------------------------------------------------------------