public static unsafe double CrossCorrelationOffset(byte[] x, byte[] y)
{
if (x.Length != y.Length)
{
throw new ArgumentException("interval lengths do not match");
}
fixed(byte *xB = &x[0], yB = &y[0])
{
float *xF = (float *)xB;
float *yF = (float *)yB;
int n = x.Length / sizeof(float);
CrossCorrelation.Result ccr;
return((1 - Math.Abs(CrossCorrelation.Calculate(xF, yF, n, out ccr)) / (n / 2d)) * ccr.AbsoluteMaxValue);
}
}
public void Execute()
{
Debug.WriteLine("window length: {0}s, interval length: {1}s, sample rate: {2}",
windowLength.TotalSeconds, intervalLength.TotalSeconds, sampleRate);
IProgressReporter reporter = progressMonitor.BeginTask("Analyzing alignment...", true);
List <IAudioStream> streams = new List <IAudioStream>(audioTracks.Count);
TimeSpan start = audioTracks.Start;
TimeSpan end = audioTracks.End;
foreach (AudioTrack audioTrack in audioTracks)
{
streams.Add(CrossCorrelation.PrepareStream(audioTrack.CreateAudioStream(), sampleRate));
}
long[] streamOffsets = new long[audioTracks.Count];
for (int i = 0; i < audioTracks.Count; i++)
{
streamOffsets[i] = TimeUtil.TimeSpanToBytes(audioTracks[i].Offset - start, streams[0].Properties);
}
int windowLengthInBytes = (int)TimeUtil.TimeSpanToBytes(windowLength, streams[0].Properties);
int windowLengthInSamples = windowLengthInBytes / streams[0].Properties.SampleBlockByteSize;
long intervalLengthInBytes = TimeUtil.TimeSpanToBytes(intervalLength, streams[0].Properties);
long analysisIntervalLength = TimeUtil.TimeSpanToBytes(end - start, streams[0].Properties);
OnStarted();
byte[] x = new byte[windowLengthInBytes];
byte[] y = new byte[windowLengthInBytes];
long positionX;
long positionY;
double sumNegative = 0;
double sumPositive = 0;
int countNegative = 0;
int countPositive = 0;
double min = 0;
double max = 0;
for (long position = 0; position < analysisIntervalLength; position += intervalLengthInBytes)
{
double windowSumNegative = 0;
double windowSumPositive = 0;
int windowCountNegative = 0;
int windowCountPositive = 0;
double windowMin = 0;
double windowMax = 0;
Debug.WriteLine("Analyzing {0} @ {1} / {2}", intervalLengthInBytes, position, analysisIntervalLength);
// at each position in the analysis interval, compare each stream with each other
for (int i = 0; i < streams.Count; i++)
{
positionX = position - streamOffsets[i];
if (positionX >= 0 && positionX < streams[i].Length)
{
streams[i].Position = positionX;
StreamUtil.ForceRead(streams[i], x, 0, windowLengthInBytes);
for (int j = i + 1; j < streams.Count; j++)
{
positionY = position - streamOffsets[j];
if (positionY >= 0 && positionY < streams[j].Length)
{
streams[j].Position = positionY;
StreamUtil.ForceRead(streams[j], y, 0, windowLengthInBytes);
double val = analyzeSection(x, y);
if (val > 0)
{
windowSumPositive += val;
windowCountPositive++;
}
else
{
windowSumNegative += val;
windowCountNegative++;
}
if (windowMin > val)
{
windowMin = val;
}
if (windowMax < val)
{
windowMax = val;
}
Debug.WriteLine("{0,2}->{1,2}: {2}", i, j, val);
}
}
}
}
sumPositive += windowSumPositive;
countPositive += windowCountPositive;
sumNegative += windowSumNegative;
countNegative += windowCountNegative;
if (min > windowMin)
{
min = windowMin;
}
if (max < windowMax)
{
max = windowMax;
}
reporter.ReportProgress((double)position / analysisIntervalLength * 100);
OnWindowAnalyzed(start + TimeUtil.BytesToTimeSpan(position, streams[0].Properties),
windowCountPositive, windowCountNegative,
windowMin, windowMax,
windowSumPositive, windowSumNegative);
}
reporter.Finish();
Debug.WriteLine("Finished. sum: {0}, sum+: {1}, sum-: {2}, sumAbs: {3}, avg: {4}, avg+: {5}, avg-: {6}, avgAbs: {7}, min: {8}, max: {9}, points: {10}",
sumPositive + sumNegative, sumPositive, sumNegative, sumPositive + (sumNegative * -1),
(sumPositive + sumNegative) / (countPositive + countNegative), sumPositive / countPositive,
sumNegative / countNegative, (sumPositive + (sumNegative * -1)) / (countPositive + countNegative),
min, max, countPositive + countNegative);
double score = (sumPositive + (sumNegative * -1)) / (countPositive + countNegative);
Debug.WriteLine("Score: {0} => {1}%", score, Math.Round(score * 100));
OnFinished(countPositive, countNegative, min, max, sumPositive, sumNegative);
streams.ForEach(s => s.Close());
}