Add C++ API for streaming zipformer ASR on RK NPU (#1908)

sherpa-onnx/csrc/rknn/online-stream-rknn.cc

@@ -0,0 +1,60 @@
+// sherpa-onnx/csrc/rknn/online-stream-rknn.cc
+//
+// Copyright (c)  2025  Xiaomi Corporation
+
+#include "sherpa-onnx/csrc/rknn/online-stream-rknn.h"
+
+#include <utility>
+#include <vector>
+
+namespace sherpa_onnx {
+
+class OnlineStreamRknn::Impl {
+ public:
+  void SetZipformerEncoderStates(std::vector<std::vector<uint8_t>> states) {
+    states_ = std::move(states);
+  }
+
+  std::vector<std::vector<uint8_t>> &GetZipformerEncoderStates() {
+    return states_;
+  }
+
+  void SetZipformerResult(OnlineTransducerDecoderResultRknn r) {
+    result_ = std::move(r);
+  }
+
+  OnlineTransducerDecoderResultRknn &GetZipformerResult() { return result_; }
+
+ private:
+  std::vector<std::vector<uint8_t>> states_;
+  OnlineTransducerDecoderResultRknn result_;
+};
+
+OnlineStreamRknn::OnlineStreamRknn(
+    const FeatureExtractorConfig &config /*= {}*/,
+    ContextGraphPtr context_graph /*= nullptr*/)
+    : OnlineStream(config, context_graph), impl_(std::make_unique<Impl>()) {}
+
+OnlineStreamRknn::~OnlineStreamRknn() = default;
+
+void OnlineStreamRknn::SetZipformerEncoderStates(
+    std::vector<std::vector<uint8_t>> states) const {
+  impl_->SetZipformerEncoderStates(std::move(states));
+}
+
+std::vector<std::vector<uint8_t>> &OnlineStreamRknn::GetZipformerEncoderStates()
+    const {
+  return impl_->GetZipformerEncoderStates();
+}
+
+void OnlineStreamRknn::SetZipformerResult(
+    OnlineTransducerDecoderResultRknn r) const {
+  impl_->SetZipformerResult(std::move(r));
+}
+
+OnlineTransducerDecoderResultRknn &OnlineStreamRknn::GetZipformerResult()
+    const {
+  return impl_->GetZipformerResult();
+}
+
+}  // namespace sherpa_onnx