{
  "requested_second": 91,
  "exact_baseline_frame": {
    "id": "f2730",
    "source_frame_index": 2730,
    "timestamp_seconds": 91.0,
    "source_pts_seconds": 91.0,
    "timestamp": "91.000000",
    "reasons": [
      "baseline_1fps"
    ],
    "image": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002730.webp",
    "width": 405,
    "height": 720,
    "selection_reasons": [
      "baseline_1fps_or_last"
    ],
    "source_width": 720,
    "source_height": 1280,
    "image_url": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002730.webp"
  },
  "nearby_frames": [
    {
      "id": "f2700",
      "source_frame_index": 2700,
      "timestamp_seconds": 90.0,
      "source_pts_seconds": 90.0,
      "timestamp": "90.000000",
      "reasons": [
        "baseline_1fps"
      ],
      "image": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002700.webp",
      "width": 405,
      "height": 720,
      "selection_reasons": [
        "baseline_1fps_or_last"
      ],
      "source_width": 720,
      "source_height": 1280,
      "image_url": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002700.webp"
    },
    {
      "id": "f2730",
      "source_frame_index": 2730,
      "timestamp_seconds": 91.0,
      "source_pts_seconds": 91.0,
      "timestamp": "91.000000",
      "reasons": [
        "baseline_1fps"
      ],
      "image": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002730.webp",
      "width": 405,
      "height": 720,
      "selection_reasons": [
        "baseline_1fps_or_last"
      ],
      "source_width": 720,
      "source_height": 1280,
      "image_url": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002730.webp"
    },
    {
      "id": "f2760",
      "source_frame_index": 2760,
      "timestamp_seconds": 92.0,
      "source_pts_seconds": 92.0,
      "timestamp": "92.000000",
      "reasons": [
        "baseline_1fps"
      ],
      "image": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002760.webp",
      "width": 405,
      "height": 720,
      "selection_reasons": [
        "baseline_1fps_or_last"
      ],
      "source_width": 720,
      "source_height": 1280,
      "image_url": "https://ai-video-relay-check-20261027.pages.dev/frames/frame-00002760.webp"
    }
  ],
  "screen_observation": {
    "time": 91.0,
    "source_frame_index": 2730,
    "raw_ocr": "",
    "raw_caption": "",
    "raw_title": "",
    "screen_caption": "",
    "screen_title": "",
    "reviewed_changes": [],
    "verification": "automatic OCR; not independently verified",
    "timing": "observed frame time; onset/offset not known to subsecond precision",
    "is_confirmed_speech": false
  },
  "raw_ASR_at_estimated_time": [],
  "content_section": {
    "index": 4,
    "start": 81.433333,
    "end": 93.366667,
    "title": "黑T恤盖头演示",
    "visual_observation": "人物换为黑色T恤；后段把黑衣向上拉到头面部，眼周留出开口，白色背心露出。",
    "camera": "人物主要在固定机位前抬手、拉衣，末段动作较快。",
    "uncertainty": "不推断人物身份或把衣服英文当讲话。",
    "provenance": "assistant visual review of source-frame sheets; not an independent human or automatic semantic-model benchmark"
  },
  "unknowns": [
    "ASR not a verified listening transcript",
    "Caption display time can differ from speech time",
    "Assistant observation must be cross-checked by actually opening image"
  ]
}