add csharp example

examples/csharp/Program.cs

@@ -0,0 +1,35 @@
+using System.Text;
+
+namespace VadDotNet;
+
+
+class Program
+{
+    private const string MODEL_PATH = "./resources/silero_vad.onnx";
+    private const string EXAMPLE_WAV_FILE = "./resources/example.wav";
+    private const int SAMPLE_RATE = 16000;
+    private const float THRESHOLD = 0.5f;
+    private const int MIN_SPEECH_DURATION_MS = 250;
+    private const float MAX_SPEECH_DURATION_SECONDS = float.PositiveInfinity;
+    private const int MIN_SILENCE_DURATION_MS = 100;
+    private const int SPEECH_PAD_MS = 30;
+
+    public static void Main(string[] args)
+    {
+
+            var vadDetector = new SileroVadDetector(MODEL_PATH, THRESHOLD, SAMPLE_RATE,
+                MIN_SPEECH_DURATION_MS, MAX_SPEECH_DURATION_SECONDS, MIN_SILENCE_DURATION_MS, SPEECH_PAD_MS);
+            List<SileroSpeechSegment> speechTimeList = vadDetector.GetSpeechSegmentList(new FileInfo(EXAMPLE_WAV_FILE));
+            //Console.WriteLine(speechTimeList.ToJson());
+            StringBuilder sb = new StringBuilder();
+            foreach (var speechSegment in speechTimeList)
+            {
+                sb.Append($"start second: {speechSegment.StartSecond}, end second: {speechSegment.EndSecond}\n");
+
+            }
+            Console.WriteLine(sb.ToString());
+
+    }
+
+
+}

examples/csharp/SileroSpeechSegment.cs

@@ -0,0 +1,21 @@
+namespace VadDotNet;
+
+public class SileroSpeechSegment
+{
+    public int? StartOffset { get; set; }
+    public int? EndOffset { get; set; }
+    public float? StartSecond { get; set; }
+    public float? EndSecond { get; set; }
+
+    public SileroSpeechSegment()
+    {
+    }
+
+    public SileroSpeechSegment(int startOffset, int? endOffset, float? startSecond, float? endSecond)
+    {
+        StartOffset = startOffset;
+        EndOffset = endOffset;
+        StartSecond = startSecond;
+        EndSecond = endSecond;
+    }
+}

examples/csharp/SileroVadDetector.cs

@@ -0,0 +1,250 @@
+using NAudio.Wave;
+using VADdotnet;
+
+namespace VadDotNet;
+
+public class SileroVadDetector
+{
+    private readonly SileroVadOnnxModel _model;
+    private readonly float _threshold;
+    private readonly float _negThreshold;
+    private readonly int _samplingRate;
+    private readonly int _windowSizeSample;
+    private readonly float _minSpeechSamples;
+    private readonly float _speechPadSamples;
+    private readonly float _maxSpeechSamples;
+    private readonly float _minSilenceSamples;
+    private readonly float _minSilenceSamplesAtMaxSpeech;
+    private int _audioLengthSamples;
+    private const float THRESHOLD_GAP = 0.15f;
+    // ReSharper disable once InconsistentNaming
+    private const int SAMPLING_RATE_8K = 8000;
+    // ReSharper disable once InconsistentNaming
+    private const int SAMPLING_RATE_16K = 16000;
+
+    public SileroVadDetector(string onnxModelPath, float threshold, int samplingRate,
+        int minSpeechDurationMs, float maxSpeechDurationSeconds,
+        int minSilenceDurationMs, int speechPadMs)
+    {
+        if (samplingRate != SAMPLING_RATE_8K && samplingRate != SAMPLING_RATE_16K)
+        {
+            throw new ArgumentException("Sampling rate not support, only available for [8000, 16000]");
+        }
+
+        this._model = new SileroVadOnnxModel(onnxModelPath);
+        this._samplingRate = samplingRate;
+        this._threshold = threshold;
+        this._negThreshold = threshold - THRESHOLD_GAP;
+        this._windowSizeSample = samplingRate == SAMPLING_RATE_16K ? 512 : 256;
+        this._minSpeechSamples = samplingRate * minSpeechDurationMs / 1000f;
+        this._speechPadSamples = samplingRate * speechPadMs / 1000f;
+        this._maxSpeechSamples = samplingRate * maxSpeechDurationSeconds - _windowSizeSample - 2 * _speechPadSamples;
+        this._minSilenceSamples = samplingRate * minSilenceDurationMs / 1000f;
+        this._minSilenceSamplesAtMaxSpeech = samplingRate * 98 / 1000f;
+        this.Reset();
+    }
+
+    public void Reset()
+    {
+        _model.ResetStates();
+    }
+
+    public List<SileroSpeechSegment> GetSpeechSegmentList(FileInfo wavFile)
+    {
+        Reset();
+
+        using (var audioFile = new AudioFileReader(wavFile.FullName))
+        {
+            List<float> speechProbList = new List<float>();
+            this._audioLengthSamples = (int)(audioFile.Length / 2);
+            float[] buffer = new float[this._windowSizeSample];
+
+            while (audioFile.Read(buffer, 0, buffer.Length) > 0)
+            {
+                float speechProb = _model.Call(new[] { buffer }, _samplingRate)[0];
+                speechProbList.Add(speechProb);
+            }
+
+            return CalculateProb(speechProbList);
+        }
+    }
+
+    private List<SileroSpeechSegment> CalculateProb(List<float> speechProbList)
+    {
+        List<SileroSpeechSegment> result = new List<SileroSpeechSegment>();
+        bool triggered = false;
+        int tempEnd = 0, prevEnd = 0, nextStart = 0;
+        SileroSpeechSegment segment = new SileroSpeechSegment();
+
+        for (int i = 0; i < speechProbList.Count; i++)
+        {
+            float speechProb = speechProbList[i];
+            if (speechProb >= _threshold && (tempEnd != 0))
+            {
+                tempEnd = 0;
+                if (nextStart < prevEnd)
+                {
+                    nextStart = _windowSizeSample * i;
+                }
+            }
+
+            if (speechProb >= _threshold && !triggered)
+            {
+                triggered = true;
+                segment.StartOffset = _windowSizeSample * i;
+                continue;
+            }
+
+            if (triggered && (_windowSizeSample * i) - segment.StartOffset > _maxSpeechSamples)
+            {
+                if (prevEnd != 0)
+                {
+                    segment.EndOffset = prevEnd;
+                    result.Add(segment);
+                    segment = new SileroSpeechSegment();
+                    if (nextStart < prevEnd)
+                    {
+                        triggered = false;
+                    }
+                    else
+                    {
+                        segment.StartOffset = nextStart;
+                    }
+
+                    prevEnd = 0;
+                    nextStart = 0;
+                    tempEnd = 0;
+                }
+                else
+                {
+                    segment.EndOffset = _windowSizeSample * i;
+                    result.Add(segment);
+                    segment = new SileroSpeechSegment();
+                    prevEnd = 0;
+                    nextStart = 0;
+                    tempEnd = 0;
+                    triggered = false;
+                    continue;
+                }
+            }
+
+            if (speechProb < _negThreshold && triggered)
+            {
+                if (tempEnd == 0)
+                {
+                    tempEnd = _windowSizeSample * i;
+                }
+
+                if (((_windowSizeSample * i) - tempEnd) > _minSilenceSamplesAtMaxSpeech)
+                {
+                    prevEnd = tempEnd;
+                }
+
+                if ((_windowSizeSample * i) - tempEnd < _minSilenceSamples)
+                {
+                    continue;
+                }
+                else
+                {
+                    segment.EndOffset = tempEnd;
+                    if ((segment.EndOffset - segment.StartOffset) > _minSpeechSamples)
+                    {
+                        result.Add(segment);
+                    }
+
+                    segment = new SileroSpeechSegment();
+                    prevEnd = 0;
+                    nextStart = 0;
+                    tempEnd = 0;
+                    triggered = false;
+                    continue;
+                }
+            }
+        }
+
+        if (segment.StartOffset != null && (_audioLengthSamples - segment.StartOffset) > _minSpeechSamples)
+        {
+            segment.EndOffset = _audioLengthSamples;
+            result.Add(segment);
+        }
+
+        for (int i = 0; i < result.Count; i++)
+        {
+            SileroSpeechSegment item = result[i];
+            if (i == 0)
+            {
+                item.StartOffset = (int)Math.Max(0, item.StartOffset.Value - _speechPadSamples);
+            }
+
+            if (i != result.Count - 1)
+            {
+                SileroSpeechSegment nextItem = result[i + 1];
+                int silenceDuration = nextItem.StartOffset.Value - item.EndOffset.Value;
+                if (silenceDuration < 2 * _speechPadSamples)
+                {
+                    item.EndOffset = item.EndOffset + (silenceDuration / 2);
+                    nextItem.StartOffset = Math.Max(0, nextItem.StartOffset.Value - (silenceDuration / 2));
+                }
+                else
+                {
+                    item.EndOffset = (int)Math.Min(_audioLengthSamples, item.EndOffset.Value + _speechPadSamples);
+                    nextItem.StartOffset = (int)Math.Max(0, nextItem.StartOffset.Value - _speechPadSamples);
+                }
+            }
+            else
+            {
+                item.EndOffset = (int)Math.Min(_audioLengthSamples, item.EndOffset.Value + _speechPadSamples);
+            }
+        }
+
+        return MergeListAndCalculateSecond(result, _samplingRate);
+    }
+
+    private List<SileroSpeechSegment> MergeListAndCalculateSecond(List<SileroSpeechSegment> original, int samplingRate)
+    {
+        List<SileroSpeechSegment> result = new List<SileroSpeechSegment>();
+        if (original == null || original.Count == 0)
+        {
+            return result;
+        }
+
+        int left = original[0].StartOffset.Value;
+        int right = original[0].EndOffset.Value;
+        if (original.Count > 1)
+        {
+            original.Sort((a, b) => a.StartOffset.Value.CompareTo(b.StartOffset.Value));
+            for (int i = 1; i < original.Count; i++)
+            {
+                SileroSpeechSegment segment = original[i];
+
+                if (segment.StartOffset > right)
+                {
+                    result.Add(new SileroSpeechSegment(left, right,
+                        CalculateSecondByOffset(left, samplingRate), CalculateSecondByOffset(right, samplingRate)));
+                    left = segment.StartOffset.Value;
+                    right = segment.EndOffset.Value;
+                }
+                else
+                {
+                    right = Math.Max(right, segment.EndOffset.Value);
+                }
+            }
+
+            result.Add(new SileroSpeechSegment(left, right,
+                CalculateSecondByOffset(left, samplingRate), CalculateSecondByOffset(right, samplingRate)));
+        }
+        else
+        {
+            result.Add(new SileroSpeechSegment(left, right,
+                CalculateSecondByOffset(left, samplingRate), CalculateSecondByOffset(right, samplingRate)));
+        }
+
+        return result;
+    }
+
+    private float CalculateSecondByOffset(int offset, int samplingRate)
+    {
+        float secondValue = offset * 1.0f / samplingRate;
+        return (float)Math.Floor(secondValue * 1000.0f) / 1000.0f;
+    }
+}