fmod getWaveData() export to WAVE file help (C++)
- by eddietree
I am trying to export the current sound that is being played by the FMOD::System into a WAVE file by calling getWaveData(). I have the header of the wave file correct, and currently trying to write to the wave file each frame like so:
const unsigned int samplesPerSec = 48000;
const unsigned int fps = 60;
const int numSamples = samplesPerSec / fps;
float data[2][numSamples];
short conversion[numSamples*2];
m_fmodsys->getWaveData( &data[0][0], numSamples, 0 ); // left channel
m_fmodsys->getWaveData( &data[1][0], numSamples, 1 ); // right channel
int littleEndian = IsLittleEndian();
for ( int i = 0; i < numSamples; ++i )
{
// left channel
float coeff_left = data[0][i];
short val_left = (short)(coeff_left * 0x7FFF);
// right channel
float coeff_right = data[1][i];
short val_right = (short)(coeff_right * 0x7FFF);
// handle endianness
if ( !littleEndian )
{
val_left = ((val_left & 0xff) << 8) | (val_left >> 8);
val_right = ((val_right & 0xff) << 8) | (val_right >> 8);
}
conversion[i*2+0] = val_left;
conversion[i*2+1] = val_right;
}
fwrite((void*)&conversion[0], sizeof(conversion[0]), numSamples*2, m_fh);
m_dataLength += sizeof(conversion);
Currently, the timing of the sound is correct, but the sample seems clipped way harshly. More specifically, I am outputting four beats in time. When I playback the wave-file, the beats timing is correct but it just sounds way fuzzy and clipped. Am I doing something wrong with my calculation?
I am exporting in 16-bits, two channels.
Thanks in advance! :)
Reference (WAVE file format): http://www.sonicspot.com/guide/wavefiles.html
