Add Silero VAD (#313)

sherpa-onnx/csrc/silero-vad-model-config.h

@@ -0,0 +1,41 @@
+// sherpa-onnx/csrc/silero-vad-model-config.h
+//
+// Copyright (c)  2023  Xiaomi Corporation
+#ifndef SHERPA_ONNX_CSRC_SILERO_VAD_MODEL_CONFIG_H_
+#define SHERPA_ONNX_CSRC_SILERO_VAD_MODEL_CONFIG_H_
+
+#include <string>
+
+#include "sherpa-onnx/csrc/parse-options.h"
+
+namespace sherpa_onnx {
+
+struct SileroVadModelConfig {
+  std::string model;
+
+  // threshold to classify a segment as speech
+  //
+  // The predicted probability of a segment is larger than this
+  // value, then it is classified as speech.
+  float threshold = 0.5;
+
+  float min_silence_duration = 0.5;  // in seconds
+
+  float min_speech_duration = 0.25;  // in seconds
+
+  // 512, 1024, 1536 samples for 16000 Hz
+  // 256, 512, 768 samples for 800 Hz
+  int window_size = 512;  // in samples
+
+  SileroVadModelConfig() = default;
+
+  void Register(ParseOptions *po);
+
+  bool Validate() const;
+
+  std::string ToString() const;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_SILERO_VAD_MODEL_CONFIG_H_