public static TimeSpan Calculate(IAudioStream s1, Interval i1, IAudioStream s2, Interval i2, ProgressMonitor progressMonitor, out Result result)
{
if (i1.Length != i2.Length)
{
throw new ArgumentException("interval lengths do not match");
}
s1 = PrepareStream(s1, 11050);
s2 = PrepareStream(s2, 11050);
IProgressReporter progress = progressMonitor.BeginTask("calculating cross-correlation", true);
float seconds = (float)(i1.Length / 10d / 1000 / 1000);
int sampleRate = s1.Properties.SampleRate;
int n = (int)(seconds * sampleRate);
float[] x = new float[n];
float[] y = new float[n];
int maxdelay = (int)(sampleRate * seconds / 4);
if (maxdelay * 2 > n)
{
throw new Exception("maximum delay must be <= half of the interval to be analyzed");
}
Debug.WriteLine("CC window: " + seconds + " secs = " + n + " samples");
float[] r = new float[maxdelay * 2];
StreamUtil.ForceReadIntervalSamples(s1, i1, x);
StreamUtil.ForceReadIntervalSamples(s2, i2, y);
int indexOffset = Calculate(x, y, progress, out result);
TimeSpan offset = new TimeSpan((long)(indexOffset / (float)sampleRate * TimeUtil.SECS_TO_TICKS));
Debug.WriteLine("peak offset @ " + offset);
progress.Finish();
return(offset);
}