void BwDoWork(object sender, DoWorkEventArgs e)
{
var args = e.Argument as BackgroundWorkerArgs;
e.Result = args;
short nCh = 1;
int sampleFreq = 44100;
int sineFreq = sampleFreq / 4;
long nPeriod = (long)(args.durationSec * sineFreq);
long nFrames = nPeriod * 4;
long nFrameBytes = nFrames * nCh * 4; // 8==sizeof float
if (0x7fff0000 < nFrameBytes)
{
args.errMsg = "Error: Sound Duration is too long!";
}
try {
using (var bw = new BinaryWriter(File.Open(args.path, FileMode.Create))) {
var wwl = new WavWriterLowLevel();
int dataChunkSize = (int)(nFrameBytes);
int riffChunkSize = 4 /* RIFF */
+ 26 /* fmt */
+ 8 /* DATA */
+ dataChunkSize;
wwl.RiffChunkWrite(bw, riffChunkSize);
wwl.FmtChunkWriteEx(bw, nCh, sampleFreq, 32, WavWriterLowLevel.WAVE_FORMAT_IEEE_FLOAT, 0);
wwl.DataChunkHeaderWrite(bw, dataChunkSize);
for (int i = 0; i < nPeriod; ++i)
{
var signal = new float[] {
0.0f,
+(float)Math.Pow(10, args.magnitude / 20.0),
0.0f,
-(float)Math.Pow(10, args.magnitude / 20.0),
};
bw.Write(signal[0]);
bw.Write(signal[1]);
bw.Write(signal[2]);
bw.Write(signal[3]);
}
}
} catch (System.Exception ex) {
args.errMsg = ex.ToString();
}
args.errMsg = "";
}
