Add C++ runtime for silero_vad with RKNN (#2078)

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

@@ -0,0 +1,53 @@
+// sherpa-onnx/csrc/rknn/silero-vad-model-rknn.h
+//
+// Copyright (c)  2025  Xiaomi Corporation
+#ifndef SHERPA_ONNX_CSRC_RKNN_SILERO_VAD_MODEL_RKNN_H_
+#define SHERPA_ONNX_CSRC_RKNN_SILERO_VAD_MODEL_RKNN_H_
+
+#include "rknn_api.h"  // NOLINT
+#include "sherpa-onnx/csrc/online-model-config.h"
+#include "sherpa-onnx/csrc/vad-model.h"
+
+namespace sherpa_onnx {
+
+class SileroVadModelRknn : public VadModel {
+ public:
+  explicit SileroVadModelRknn(const VadModelConfig &config);
+
+  template <typename Manager>
+  SileroVadModelRknn(Manager *mgr, const VadModelConfig &config);
+
+  ~SileroVadModelRknn() override;
+
+  // reset the internal model states
+  void Reset() override;
+
+  /**
+   * @param samples Pointer to a 1-d array containing audio samples.
+   *                Each sample should be normalized to the range [-1, 1].
+   * @param n Number of samples.
+   *
+   * @return Return true if speech is detected. Return false otherwise.
+   */
+  bool IsSpeech(const float *samples, int32_t n) override;
+
+  // For silero vad V4, it is WindowShift().
+  int32_t WindowSize() const override;
+
+  // 512
+  int32_t WindowShift() const override;
+
+  int32_t MinSilenceDurationSamples() const override;
+  int32_t MinSpeechDurationSamples() const override;
+
+  void SetMinSilenceDuration(float s) override;
+  void SetThreshold(float threshold) override;
+
+ private:
+  class Impl;
+  std::unique_ptr<Impl> impl_;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_RKNN_SILERO_VAD_MODEL_RKNN_H_