How to write mic data to .wav file ?

Souldrift

Good morning, I have trouble creating a wave file from the data stream I got from the microphone input. The recording seems to go quite well but know I´m stuck at the task of converting that data into a wave file. I recorded the mic data into a WAVEHDR structure like this ...

const int NUMPTS = 44100 * 10; // 10 seconds
int sampleRate = 44100;
short int waveIn[NUMPTS]; // 'short int' is a 16-bit type; I request 16-bit samples below
// for 8-bit capture, you'd use 'unsigned char' or 'BYTE' 8-bit types

HWAVEIN hWaveIn;
WAVEHDR WaveInHdr;
MMRESULT result;

int main( int argc, char *argv[] )
{
// Specify recording parameters
WAVEFORMATEX pFormat;
pFormat.wFormatTag=WAVE_FORMAT_PCM; // simple, uncompressed format
pFormat.nChannels=1; // 1=mono, 2=stereo
pFormat.nSamplesPerSec=sampleRate; // 44100
pFormat.nAvgBytesPerSec=sampleRate*2; // = nSamplesPerSec * n.Channels * wBitsPerSample/8
pFormat.nBlockAlign=2; // = n.Channels * wBitsPerSample/8
pFormat.wBitsPerSample=16; // 16 for high quality, 8 for telephone-grade
pFormat.cbSize=0;

result = waveInOpen(&hWaveIn, WAVE\_MAPPER,&pFormat, 0L, 0L, WAVE\_FORMAT\_DIRECT);
if (result)
{
	char fault\[256\];
	waveInGetErrorText(result, fault, 256);

	return 1;
}

// Set up and prepare header for input
WaveInHdr.lpData = (LPSTR)waveIn;
WaveInHdr.dwBufferLength = NUMPTS\*2;
WaveInHdr.dwBytesRecorded=0;
WaveInHdr.dwUser = 0L;
WaveInHdr.dwFlags = 0L;
WaveInHdr.dwLoops = 0L;
waveInPrepareHeader(hWaveIn, &WaveInHdr, sizeof(WAVEHDR));

// Insert a wave input buffer
result = waveInAddBuffer(hWaveIn, &WaveInHdr, sizeof(WAVEHDR));
if (result)
{
	return 1;
}


// Commence sampling input
result = waveInStart(hWaveIn);
if (result)
{
	return 1;
}


// Wait until finished recording
do
{
	// record for 10 seconds
} 
while (waveInUnprepareHeader(hWaveIn, &WaveInHdr, sizeof(WAVEHDR))==WAVERR\_STILLPLAYING);

waveInClose(hWaveIn);

save();

std::cin.get();
return 0;

}

... and now I am trying to store the data to a wave file like this:

bool save()
{
int subchunk2size = WaveInHdr.dwBufferLength*1*2;

fstream myFile ("test.wav", ios::out | ios::binary);

// write the wav file per the wav file format
myFile.seekp (0, ios::beg); 
myFile.write ("RIFF", 4);					// chunk id
myFile.write ((char\*) 36+subchunk2size, 4);			// chunk size (36 + SubChunk2Size)

Souldrift

Well, nevermind. I just fixed it :). Modified the save function like this:

bool save()
{
int bitsPerSample = 16;
int subchunk1size = 16;
int numChannels = 1;
int subchunk2size = WaveInHdr.dwBufferLength*numChannels;
int chunksize = 36+subchunk2size;
int audioFormat = 1;
int byteRate = sampleRate*numChannels*bitsPerSample/8;
int blockAlign = numChannels*bitsPerSample/8;

fstream myFile ("test.wav", ios::out | ios::binary);

// write the wav file per the wav file format
myFile.seekp (0, ios::beg); 
myFile.write ("RIFF", 4);					// chunk id
myFile.write ((char\*) &chunksize, 4);	        	// chunk size (36 + SubChunk2Size))
myFile.write ("WAVE", 4);					// format
myFile.write ("fmt ", 4);					// subchunk1ID
myFile.write ((char\*) &subchunk1size, 4);			// subchunk1size (16 for PCM)
myFile.write ((char\*) &audioFormat, 2);			// AudioFormat (1 for PCM)
myFile.write ((char\*) &numChannels, 2);			// NumChannels
myFile.write ((char\*) &sampleRate, 4);			// sample rate
myFile.write ((char\*) &byteRate, 4);			// byte rate (SampleRate \* NumChannels \* BitsPerSample/8)
myFile.write ((char\*) &blockAlign, 2);			// block align (NumChannels \* BitsPerSample/8)
myFile.write ((char\*) &bitsPerSample, 2);			// bits per sample
myFile.write ("data", 4);					// subchunk2ID
myFile.write ((char\*) &subchunk2size, 4);			// subchunk2size (NumSamples \* NumChannels \* BitsPerSample/8)
	
myFile.write (WaveInHdr.lpData, WaveInHdr.dwBufferLength);	// data

return true;

}

Cheers Souldrift