{
  "frames": [
    {
      "requested_t": -3.9,
      "actual_t": -3.9052000740344535
    },
    {
      "requested_t": -2.5,
      "actual_t": -2.5052000740344536
    },
    {
      "requested_t": -1.5,
      "actual_t": -1.5052000740344536
    },
    {
      "requested_t": -0.1,
      "actual_t": -0.1052000740344532
    },
    {
      "requested_t": 1.0,
      "actual_t": 0.9947999259655464
    },
    {
      "requested_t": 3.0,
      "actual_t": 2.9947999259655464
    },
    {
      "requested_t": 5.7,
      "actual_t": 5.694799925965546
    },
    {
      "requested_t": 8.2,
      "actual_t": 8.194799925965546
    },
    {
      "requested_t": 9.5,
      "actual_t": 9.494799925965546
    }
  ],
  "purpose": "核对夜间红灯接近、短时开启辅助及停车，避免把日志初始零速误判为起步",
  "video_anchor_s": 4.2552000740344536,
  "note": "使用元数据锚点，不按主观场景判断移动视频；不从未标定画面测算距离或推断路权。"
}