{
  "id": "C05-N01",
  "title": "手机拍的视频放久了声音不同步，怎样先核对 VFR 与 CFR",
  "schema_version": "1.0",
  "evidence_kind": "合成输入与协议；非现场测试结果",
  "tool_versions": {
    "generator": "Python 3.12.4",
    "ffmpeg": "8.0.1（仅实际媒体生成与解码）"
  },
  "required_delivery": "ffprobe 元数据、帧时间样本和固定位置口型对照记录",
  "input": {
    "pts_seconds": [
      0,
      0.033,
      0.083,
      0.116
    ],
    "events": [
      {
        "position": "start",
        "offset_seconds": 0.12
      },
      {
        "position": "middle",
        "offset_seconds": 0.12
      },
      {
        "position": "end",
        "offset_seconds": 0.12
      }
    ]
  },
  "expected": {
    "intervals_seconds": [
      0.033,
      0.05,
      0.033
    ],
    "conclusion": "合成间隔不恒定；固定音画偏移不是漂移证据"
  },
  "measurement": null,
  "unmeasured": [
    "实体播放硬件",
    "显示刷新相位",
    "现场拍摄",
    "实际Windows目标机配置"
  ],
  "record_fields": [
    "frame_index",
    "pts_seconds",
    "audio_event_seconds",
    "video_event_seconds",
    "offset_seconds",
    "observation"
  ]
}