{
  "frames": [
    {
      "requested_t": -3.0,
      "actual_t": -3.0
    },
    {
      "requested_t": -1.5,
      "actual_t": -1.5
    },
    {
      "requested_t": -0.6,
      "actual_t": -0.5999999999999996
    },
    {
      "requested_t": -0.3,
      "actual_t": -0.3000000000000007
    },
    {
      "requested_t": 0.3,
      "actual_t": 0.3000000000000007
    },
    {
      "requested_t": 2.2,
      "actual_t": 2.1999999999999993
    },
    {
      "requested_t": 5.5,
      "actual_t": 5.5
    },
    {
      "requested_t": 7.8,
      "actual_t": 7.800000000000001
    },
    {
      "requested_t": 9.85,
      "actual_t": 9.850000000000001
    }
  ],
  "purpose": "核对货车沿主路前行、本车出口右转、横向未退出及后段减速",
  "video_anchor_s": 10.0,
  "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。"
}