Generate WAV header

generate_wav_header.c

Bit8u hdr[44];
#define WAV_WRITE_LE16(b,v) { (b)[0] = (unsigned char)((unsigned short)(v) & 0xFF); (b)[1] = (unsigned char)((unsigned short)(v) >> 8); }
#define WAV_WRITE_LE32(b,v) { (b)[0] = (unsigned char)((unsigned int)(v) & 0xFF); (b)[1] = (unsigned char)(((unsigned int)(v) >> 8) & 0xFF); (b)[2] = (unsigned char)(((unsigned int)(v) >> 16) & 0xFF); (b)[3] = (unsigned char)((unsigned int)(v) >> 24); }
WAV_WRITE_LE32(hdr +  0, 0x46464952U);                            //"RIFF"
WAV_WRITE_LE32(hdr +  4, 36 + pcm_data_size);                     //chunk size
WAV_WRITE_LE32(hdr +  8, 0x45564157U);                            //"WAVE"
WAV_WRITE_LE32(hdr + 12, 0x20746d66U);                            //subchunk 1 id "fmt "
WAV_WRITE_LE32(hdr + 16, 16);                                     //subchunk 1 size
WAV_WRITE_LE16(hdr + 20, 1);                                      //audio format
WAV_WRITE_LE16(hdr + 22, channels);                               //num of chan
WAV_WRITE_LE32(hdr + 24, sample_rate);                            //samples per sec
WAV_WRITE_LE32(hdr + 28, sample_rate * channels * sizeof(short)); //bytes per sec
WAV_WRITE_LE16(hdr + 32, channels * sizeof(short));               //block align
WAV_WRITE_LE16(hdr + 34, sizeof(short) * 8);                      //bits per sample
WAV_WRITE_LE32(hdr + 36, 0x61746164U);                            //subchunk 2 id "data"
WAV_WRITE_LE32(hdr + 40, pcm_data_size);                          //subchunk 2 size
#undef WAV_WRITE_LE16
#undef WAV_WRITE_LE32