Handle audio files less than 10s for speaker diarization.

sherpa-onnx/csrc/offline-speaker-diarization-pyannote-impl.h

@@ -99,6 +99,14 @@ class OfflineSpeakerDiarizationPyannoteImpl
 
     segmentations.clear();
 
+    if (labels.size() == 1) {
+      if (callback) {
+        callback(1, 1, callback_arg);
+      }
+
+      return HandleOneChunkSpecialCase(labels[0], n);
+    }
+
     // labels[i] is a 0-1 matrix of shape (num_frames, num_speakers)
 
     // speaker count per frame
@@ -201,7 +209,7 @@ class OfflineSpeakerDiarizationPyannoteImpl
     }
 
     int32_t num_chunks = (n - window_size) / window_shift + 1;
-    bool has_last_chunk = (n - window_size) % window_shift > 0;
+    bool has_last_chunk = ((n - window_size) % window_shift) > 0;
 
     ans.reserve(num_chunks + has_last_chunk);
 
@@ -524,9 +532,9 @@ class OfflineSpeakerDiarizationPyannoteImpl
       count(seq, Eigen::all).array() += labels[i].array();
     }
 
-    bool has_last_chunk = (num_samples - window_size) % window_shift > 0;
+    bool has_last_chunk = ((num_samples - window_size) % window_shift) > 0;
 
-    if (has_last_chunk) {
+    if (!has_last_chunk) {
       return count;
     }
 
@@ -622,6 +630,27 @@ class OfflineSpeakerDiarizationPyannoteImpl
     return ans;
   }
 
+  OfflineSpeakerDiarizationResult HandleOneChunkSpecialCase(
+      const Matrix2DInt32 &final_labels, int32_t num_samples) const {
+    const auto &meta_data = segmentation_model_.GetModelMetaData();
+    int32_t window_size = meta_data.window_size;
+    int32_t window_shift = meta_data.window_shift;
+    int32_t receptive_field_shift = meta_data.receptive_field_shift;
+
+    bool has_last_chunk = (num_samples - window_size) % window_shift > 0;
+    if (!has_last_chunk) {
+      return ComputeResult(final_labels);
+    }
+
+    int32_t num_frames = final_labels.rows();
+
+    int32_t new_num_frames = num_samples / receptive_field_shift;
+
+    num_frames = (new_num_frames <= num_frames) ? new_num_frames : num_frames;
+
+    return ComputeResult(final_labels(Eigen::seq(0, num_frames), Eigen::all));
+  }
+
   void MergeSegments(
       std::vector<OfflineSpeakerDiarizationSegment> *segments) const {
     float min_duration_off = config_.min_duration_off;