def get_person_box_at_frame(tracking_results, target_frame_idx):
  """Get all the box from the tracking result at frameIdx."""
  data = []
  for frame_idx, track_id, left, top, width, height in tracking_results:
    if frame_idx == target_frame_idx:
      data.append({
          "track_id": track_id,
          "bbox": [left, top, width, height]
      })
  return data