wavfile.hpp

#ifndef WAVFILE_H_
#define WAVFILE_H_

#include <iostream>

struct WavHeader {
  uint8_t RIFF[4] = {'R', 'I', 'F', 'F'};
  uint32_t chunkSize;
  uint8_t WAVE[4] = {'W', 'A', 'V', 'E'};

  // fmt
  uint8_t fmt[4] = {'f', 'm', 't', ' '};
  uint32_t fmtSize = 16;    // bytes
  uint16_t audioFormat = 1; // PCM
  uint16_t numChannels;     // mono
  uint32_t sampleRate;      // Hertz
  uint32_t bytesPerSec;     // sampleRate * sampleWidth
  uint16_t blockAlign = 2;  // 16-bit mono
  uint16_t bitsPerSample = 16;

  // data
  uint8_t data[4] = {'d', 'a', 't', 'a'};
  uint32_t dataSize;
};

// Write WAV file header only
void writeWavHeader(int sampleRate, int sampleWidth, int channels,
                    uint32_t numSamples, std::ostream &audioFile) {
  WavHeader header;
  header.dataSize = numSamples * sampleWidth * channels;
  header.chunkSize = header.dataSize + sizeof(WavHeader) - 8;
  header.sampleRate = sampleRate;
  header.numChannels = channels;
  header.bytesPerSec = sampleRate * sampleWidth * channels;
  header.blockAlign = sampleWidth * channels;
  audioFile.write(reinterpret_cast<const char *>(&header), sizeof(header));

} /* writeWavHeader */

#endif // WAVFILE_H_