Add Silero VAD (#313)

sherpa-onnx/csrc/voice-activity-detector.h

@@ -0,0 +1,41 @@
+// sherpa-onnx/csrc/voice-activity-detector.h
+//
+// Copyright (c)  2023  Xiaomi Corporation
+#ifndef SHERPA_ONNX_CSRC_VOICE_ACTIVITY_DETECTOR_H_
+#define SHERPA_ONNX_CSRC_VOICE_ACTIVITY_DETECTOR_H_
+
+#include <memory>
+#include <vector>
+
+#include "sherpa-onnx/csrc/vad-model-config.h"
+
+namespace sherpa_onnx {
+
+struct SpeechSegment {
+  int32_t start;  // in samples
+  std::vector<float> samples;
+};
+
+class VoiceActivityDetector {
+ public:
+  explicit VoiceActivityDetector(const VadModelConfig &config,
+                                 float buffer_size_in_seconds = 60);
+  ~VoiceActivityDetector();
+
+  void AcceptWaveform(const float *samples, int32_t n);
+  bool Empty() const;
+  void Pop();
+  const SpeechSegment &Front() const;
+
+  bool IsSpeechDetected() const;
+
+  void Reset();
+
+ private:
+  class Impl;
+  std::unique_ptr<Impl> impl_;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_VOICE_ACTIVITY_DETECTOR_H_