wave file export is corrupted - c++

Question

I wrote two functions which should export an audio-float buffer into a .wav-file, but I have problems with playing the exported file. Audacity plays it like it should be (sounds exactly like within my application), however, Ableton (DAW-software) seems to misinterprets some part of the wav so it sounds realy distorted. (like a distortion-effekt)
I guess that ableton somehow assumes a wrong sample-depth (smaller) so the actuall samples blow the limits.
I have two functions, the one creates an int32_t buffer from two float-buffers (mixing left and right into one buffer), the other function writes the .wav-file, including the format chunk etc. I guess that somewhere there is the problem.
class members / structs
// static I use in the export function
static const int FORMAT_PCM = 1;
static const int CHANNEL_COUNT = 2; // fix stereo
static const int BYTES_PER_SAMPLE = 4; // fix bytes per sample, 32bit audio
// a function I found in the internet, helps writting the bytes to the file
template <typename T>
static void write(std::ofstream& stream, const T& t) {
stream.write((const char*)&t, sizeof(T));
};
// used "structure" to store the buffer
class StereoAudioBuffer {
public:
StereoAudioBuffer(int length) : sizeInSamples(2*length){
samples = new int32_t[2*length];
};
~StereoAudioBuffer() {delete samples;};
int32_t *samples;
const int sizeInSamples;
};
converting function
StereoAudioBuffer* WaveExport::convertTo32BitStereo(
float *leftSamples,
float*rightSamples,
int length)
{
StereoAudioBuffer *buffer = new StereoAudioBuffer(length);
float max = 0;
// find max sample
for(int i = 0; i < length; i++) {
if(abs(leftSamples[i]) > max) {
max = abs(leftSamples[i]);
}
if(abs(rightSamples[i]) > max) {
max = abs(rightSamples[i]);
}
}
// normalise and scale to size(int32_t)
float factor = 2147483000.0f / max;
for(int i = 0; i < length; i++) {
buffer->samples[2*i] = leftSamples[i] * factor ;
buffer->samples[2*i+1] = rightSamples[i] * factor;
}
return buffer;
}
the exporting function (part of this code comes from the internet, sadly, I can't find the source anymore
void WaveExport::writeStereoWave(
const char *path,
StereoAudioBuffer* buffer,
int sampleRate)
{
std::ofstream stream(path, std::ios::binary);
// RIFF
stream.write("RIFF", 4);
// FILE SIZE
write<int>(stream, 36 + buffer->sizeInSamples * BYTES_PER_SAMPLE); // 32 bits -> 4 bytes
// WAVE
stream.write("WAVE", 4);
// FORMAT CHUNK
stream.write("fmt ", 4);
write<int>(stream, 16);
write<short>(stream, FORMAT_PCM); // Format
write<short>(stream, CHANNEL_COUNT); // Channels
write<int>(stream, sampleRate); // Sample Rate
write<int>(stream, sampleRate * CHANNEL_COUNT * BYTES_PER_SAMPLE); // Byterate
write<short>(stream, CHANNEL_COUNT * BYTES_PER_SAMPLE); // Frame size
write<short>(stream, 8 * BYTES_PER_SAMPLE); // Bits per sample
int dataChunkSize = buffer->sizeInSamples * BYTES_PER_SAMPLE;
// SAMPLES
stream.write("data", 4);
stream.write((const char*)&dataChunkSize, 4);
stream.write((const char*)buffer->samples, BYTES_PER_SAMPLE*buffer->sizeInSamples);
}
Does anybody know how to write .wav files and maybe can tell me what I did wrong or missed?
Thanks!

Answer 1

There was no problem. I used 32bit .wav which just wasn't supported in the application, I used for playback.
I changed the export functions to use int16_t, 16bit depth, and it works fine.