Add C++ runtime for spleeter about source separation (#2242)

sherpa-onnx/csrc/offline-source-separation.h

@@ -0,0 +1,77 @@
+// sherpa-onnx/csrc/offline-source-separation.h
+//
+// Copyright (c)  2025  Xiaomi Corporation
+
+#ifndef SHERPA_ONNX_CSRC_OFFLINE_SOURCE_SEPARATION_H_
+#define SHERPA_ONNX_CSRC_OFFLINE_SOURCE_SEPARATION_H_
+
+#include <memory>
+#include <string>
+#include <vector>
+
+#include "sherpa-onnx/csrc/offline-source-separation-model-config.h"
+#include "sherpa-onnx/csrc/parse-options.h"
+
+namespace sherpa_onnx {
+
+struct OfflineSourceSeparationConfig {
+  OfflineSourceSeparationModelConfig model;
+
+  OfflineSourceSeparationConfig() = default;
+
+  OfflineSourceSeparationConfig(const OfflineSourceSeparationModelConfig &model)
+      : model(model) {}
+
+  void Register(ParseOptions *po);
+
+  bool Validate() const;
+
+  std::string ToString() const;
+};
+
+struct MultiChannelSamples {
+  // data[i] is for the i-th channel
+  //
+  // each sample is in the range [-1, 1]
+  std::vector<std::vector<float>> data;
+};
+
+struct OfflineSourceSeparationInput {
+  MultiChannelSamples samples;
+
+  int32_t sample_rate;
+};
+
+struct OfflineSourceSeparationOutput {
+  std::vector<MultiChannelSamples> stems;
+
+  int32_t sample_rate;
+};
+
+class OfflineSourceSeparationImpl;
+
+class OfflineSourceSeparation {
+ public:
+  ~OfflineSourceSeparation();
+
+  OfflineSourceSeparation(const OfflineSourceSeparationConfig &config);
+
+  template <typename Manager>
+  OfflineSourceSeparation(Manager *mgr,
+                          const OfflineSourceSeparationConfig &config);
+
+  OfflineSourceSeparationOutput Process(
+      const OfflineSourceSeparationInput &input) const;
+
+  int32_t GetOutputSampleRate() const;
+
+  // e.g., it is 2 for 2stems from spleeter
+  int32_t GetNumberOfStems() const;
+
+ private:
+  std::unique_ptr<OfflineSourceSeparationImpl> impl_;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_OFFLINE_SOURCE_SEPARATION_H_