Add C++ runtime for vocos (#2014)

sherpa-onnx/csrc/vocoder.h

@@ -0,0 +1,35 @@
+// sherpa-onnx/csrc/vocoder.h
+//
+// Copyright (c)  2025  Xiaomi Corporation
+
+#ifndef SHERPA_ONNX_CSRC_VOCODER_H_
+#define SHERPA_ONNX_CSRC_VOCODER_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "onnxruntime_cxx_api.h"  // NOLINT
+#include "sherpa-onnx/csrc/offline-tts-model-config.h"
+
+namespace sherpa_onnx {
+
+class Vocoder {
+ public:
+  virtual ~Vocoder() = default;
+
+  static std::unique_ptr<Vocoder> Create(const OfflineTtsModelConfig &config);
+
+  template <typename Manager>
+  static std::unique_ptr<Vocoder> Create(Manager *mgr,
+                                         const OfflineTtsModelConfig &config);
+
+  /** @param mel A float32 tensor of shape (batch_size, feat_dim, num_frames).
+   *  @return Return a float32 vector containing audio samples..
+   */
+  virtual std::vector<float> Run(Ort::Value mel) const = 0;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_VOCODER_H_