C++ API for speaker diarization (#1396)

sherpa-onnx/csrc/offline-speaker-diarization-result.h

@@ -0,0 +1,65 @@
+// sherpa-onnx/csrc/offline-speaker-diarization-result.h
+//
+// Copyright (c)  2024  Xiaomi Corporation
+
+#ifndef SHERPA_ONNX_CSRC_OFFLINE_SPEAKER_DIARIZATION_RESULT_H_
+#define SHERPA_ONNX_CSRC_OFFLINE_SPEAKER_DIARIZATION_RESULT_H_
+
+#include <cstdint>
+#include <optional>
+#include <string>
+#include <vector>
+
+namespace sherpa_onnx {
+
+class OfflineSpeakerDiarizationSegment {
+ public:
+  OfflineSpeakerDiarizationSegment(float start, float end, int32_t speaker,
+                                   const std::string &text = {});
+
+  // If the gap between the two segments is less than the given gap, then we
+  // merge them and return a new segment. Otherwise, it returns null.
+  std::optional<OfflineSpeakerDiarizationSegment> Merge(
+      const OfflineSpeakerDiarizationSegment &other, float gap) const;
+
+  float Start() const { return start_; }
+  float End() const { return end_; }
+  int32_t Speaker() const { return speaker_; }
+  const std::string &Text() const { return text_; }
+  float Duration() const { return end_ - start_; }
+
+  std::string ToString() const;
+
+ private:
+  float start_;       // in seconds
+  float end_;         // in seconds
+  int32_t speaker_;   // ID of the speaker, starting from 0
+  std::string text_;  // If not empty, it contains the speech recognition result
+                      // of this segment
+};
+
+class OfflineSpeakerDiarizationResult {
+ public:
+  // Add a new segment
+  void Add(const OfflineSpeakerDiarizationSegment &segment);
+
+  // Number of distinct speakers contained in this object at this point
+  int32_t NumSpeakers() const;
+
+  int32_t NumSegments() const;
+
+  // Return a list of segments sorted by segment.start time
+  std::vector<OfflineSpeakerDiarizationSegment> SortByStartTime() const;
+
+  // ans.size() == NumSpeakers().
+  // ans[i] is for speaker_i and is sorted by start time
+  std::vector<std::vector<OfflineSpeakerDiarizationSegment>> SortBySpeaker()
+      const;
+
+ public:
+  std::vector<OfflineSpeakerDiarizationSegment> segments_;
+};
+
+}  // namespace sherpa_onnx
+
+#endif  // SHERPA_ONNX_CSRC_OFFLINE_SPEAKER_DIARIZATION_RESULT_H_