{
  "frames": [
    {
      "requested_t": -6.58,
      "actual_t": -6.6
    },
    {
      "requested_t": -2.48,
      "actual_t": -2.5
    },
    {
      "requested_t": -0.17,
      "actual_t": -0.15000000000000036
    },
    {
      "requested_t": 0.96,
      "actual_t": 0.9499999999999993
    },
    {
      "requested_t": 1.26,
      "actual_t": 1.25
    },
    {
      "requested_t": 3.49,
      "actual_t": 3.5
    },
    {
      "requested_t": 5.85,
      "actual_t": 5.85
    },
    {
      "requested_t": 6.7,
      "actual_t": 6.699999999999999
    },
    {
      "requested_t": 9.8,
      "actual_t": 9.8
    }
  ],
  "purpose": "核实环岛排队与脚刹后低TTC，区分事前线索和介入后风险指标，并核查近停再蠕行",
  "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。"
}