Add online LSTM transducer model (#25)

sherpa-onnx/csrc/onnx-utils.cc

@@ -0,0 +1,49 @@
+// sherpa/csrc/onnx-utils.cc
+//
+// Copyright (c)  2023  Xiaomi Corporation
+#include "sherpa-onnx/csrc/onnx-utils.h"
+
+#include <string>
+#include <vector>
+
+#include "onnxruntime_cxx_api.h"  // NOLINT
+
+namespace sherpa_onnx {
+
+void GetInputNames(Ort::Session *sess, std::vector<std::string> *input_names,
+                   std::vector<const char *> *input_names_ptr) {
+  Ort::AllocatorWithDefaultOptions allocator;
+  size_t node_count = sess->GetInputCount();
+  input_names->resize(node_count);
+  input_names_ptr->resize(node_count);
+  for (size_t i = 0; i != node_count; ++i) {
+    auto tmp = sess->GetInputNameAllocated(i, allocator);
+    (*input_names)[i] = tmp.get();
+    (*input_names_ptr)[i] = (*input_names)[i].c_str();
+  }
+}
+
+void GetOutputNames(Ort::Session *sess, std::vector<std::string> *output_names,
+                    std::vector<const char *> *output_names_ptr) {
+  Ort::AllocatorWithDefaultOptions allocator;
+  size_t node_count = sess->GetOutputCount();
+  output_names->resize(node_count);
+  output_names_ptr->resize(node_count);
+  for (size_t i = 0; i != node_count; ++i) {
+    auto tmp = sess->GetOutputNameAllocated(i, allocator);
+    (*output_names)[i] = tmp.get();
+    (*output_names_ptr)[i] = (*output_names)[i].c_str();
+  }
+}
+
+void PrintModelMetadata(std::ostream &os, const Ort::ModelMetadata &meta_data) {
+  Ort::AllocatorWithDefaultOptions allocator;
+  std::vector<Ort::AllocatedStringPtr> v =
+      meta_data.GetCustomMetadataMapKeysAllocated(allocator);
+  for (const auto &key : v) {
+    auto p = meta_data.LookupCustomMetadataMapAllocated(key.get(), allocator);
+    os << key.get() << "=" << p.get() << "\n";
+  }
+}
+
+}  // namespace sherpa_onnx