{
  "frames": [
    {
      "requested_t": 5.4,
      "actual_t": 5.394799925965547
    },
    {
      "requested_t": 5.7,
      "actual_t": 5.694799925965546
    },
    {
      "requested_t": 6.0,
      "actual_t": 5.9947999259655464
    },
    {
      "requested_t": 6.5,
      "actual_t": 6.4947999259655464
    },
    {
      "requested_t": 7.0,
      "actual_t": 6.9947999259655464
    },
    {
      "requested_t": 7.5,
      "actual_t": 7.4947999259655464
    },
    {
      "requested_t": 8.0,
      "actual_t": 7.9947999259655464
    },
    {
      "requested_t": 8.5,
      "actual_t": 8.494799925965546
    },
    {
      "requested_t": 9.0,
      "actual_t": 8.994799925965546
    }
  ],
  "purpose": "核对日志后5.7秒已静止与画面仍接近斑马线的跨模态时间差，不移动原锚点",
  "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。"
}