vid_writer = cv2.VideoWriter("result.mp4", cv2.VideoWriter_fourcc(*"mp4v"), fps, (int(1920), int(1080)))

导出视频仅1K，原因是我在目标识别过程中把图片宽高改成960x540，所以导出时也要保持一致！

改成：

vid_writer = cv2.VideoWriter("result.mp4", cv2.VideoWriter_fourcc(*"mp4v"), fps, (int(960), int(540)))