{
  "title": "Infrastructure activity",
  "status": "Illustrative annotation draft",
  "authoring": "Agent-authored editorial example; not human-approved training labels, a validated track or backend output.",
  "source": {
    "reference": "d71cgwlxocvg1",
    "window_seconds": [
      25,
      29
    ],
    "timestamp_origin": "Elapsed time in the local source recording; absolute capture date and location unverified.",
    "poster_source_seconds": 27,
    "display_dimensions": [
      720,
      1058
    ]
  },
  "presentation": {
    "type": "Continuous source excerpt with editorial boxes",
    "duration_seconds": 4.0,
    "frames_per_second": 12,
    "full_frame": true,
    "audio": false
  },
  "method": {
    "geometry": "Coarse rectangular regions authored by visual inspection of displayed source frames.",
    "keyframe_spacing_seconds": 0.5,
    "interpolation": "Linear interpolation of rectangle edges between listed keyframes; no automated tracking or segmentation.",
    "coordinates": "Normalized xyxy in full displayed frame after applying source rotation; origin top left.",
    "timing": "Keyframes target elapsed source times. Source decoding and conversion to 12 fps introduce frame-sampling tolerance; source frame indices are not claimed.",
    "review": "Agent visual review only; requires project-specific human review before dataset use."
  },
  "selected_coverage": "Selected drone and pylon crossarm throughout the clip; one clearly separated bird during the first 0.5 seconds. Other birds, wires and structural parts are visible context, not fully annotated.",
  "physical_output": {
    "selected_annotations": [
      {
        "id": "selected-drone",
        "label": "Drone",
        "role": "object",
        "keyframes": [
          {
            "clip_time_seconds": 0.0,
            "box_xyxy_normalized": [
              0.468531,
              0.102381,
              0.587413,
              0.17619
            ]
          },
          {
            "clip_time_seconds": 0.5,
            "box_xyxy_normalized": [
              0.5,
              0.116667,
              0.611888,
              0.185714
            ]
          },
          {
            "clip_time_seconds": 1.0,
            "box_xyxy_normalized": [
              0.573427,
              0.171429,
              0.688811,
              0.257143
            ]
          },
          {
            "clip_time_seconds": 1.5,
            "box_xyxy_normalized": [
              0.559441,
              0.207143,
              0.688811,
              0.285714
            ]
          },
          {
            "clip_time_seconds": 2.0,
            "box_xyxy_normalized": [
              0.548951,
              0.238095,
              0.681818,
              0.32619
            ]
          },
          {
            "clip_time_seconds": 2.5,
            "box_xyxy_normalized": [
              0.552448,
              0.264286,
              0.681818,
              0.342857
            ]
          },
          {
            "clip_time_seconds": 3.0,
            "box_xyxy_normalized": [
              0.552448,
              0.285714,
              0.681818,
              0.369048
            ]
          },
          {
            "clip_time_seconds": 3.5,
            "box_xyxy_normalized": [
              0.541958,
              0.3,
              0.674825,
              0.383333
            ]
          },
          {
            "clip_time_seconds": 4.0,
            "box_xyxy_normalized": [
              0.541958,
              0.307143,
              0.674825,
              0.390476
            ]
          }
        ]
      },
      {
        "id": "crossarm",
        "label": "Pylon crossarm",
        "role": "scene feature",
        "keyframes": [
          {
            "clip_time_seconds": 0.0,
            "box_xyxy_normalized": [
              0.0,
              0.32381,
              1.0,
              0.52381
            ]
          },
          {
            "clip_time_seconds": 0.5,
            "box_xyxy_normalized": [
              0.0,
              0.359524,
              1.0,
              0.566667
            ]
          },
          {
            "clip_time_seconds": 1.0,
            "box_xyxy_normalized": [
              0.0,
              0.435714,
              1.0,
              0.640476
            ]
          },
          {
            "clip_time_seconds": 1.5,
            "box_xyxy_normalized": [
              0.0,
              0.47381,
              1.0,
              0.680952
            ]
          },
          {
            "clip_time_seconds": 2.0,
            "box_xyxy_normalized": [
              0.0,
              0.5,
              1.0,
              0.702381
            ]
          },
          {
            "clip_time_seconds": 2.5,
            "box_xyxy_normalized": [
              0.0,
              0.533333,
              1.0,
              0.738095
            ]
          },
          {
            "clip_time_seconds": 3.0,
            "box_xyxy_normalized": [
              0.0,
              0.547619,
              1.0,
              0.752381
            ]
          },
          {
            "clip_time_seconds": 3.5,
            "box_xyxy_normalized": [
              0.0,
              0.561905,
              1.0,
              0.761905
            ]
          },
          {
            "clip_time_seconds": 4.0,
            "box_xyxy_normalized": [
              0.0,
              0.566667,
              1.0,
              0.764286
            ]
          }
        ]
      },
      {
        "id": "selected-bird",
        "label": "Bird",
        "role": "object",
        "visible_clip_interval_seconds": [
          0,
          0.5
        ],
        "identity_note": "Selected visible bird for this short interval only; no cross-interval identity claim.",
        "keyframes": [
          {
            "clip_time_seconds": 0,
            "box_xyxy_normalized": [
              0.608392,
              0.130952,
              0.695804,
              0.207143
            ]
          },
          {
            "clip_time_seconds": 0.5,
            "box_xyxy_normalized": [
              0.608392,
              0.128571,
              0.681818,
              0.195238
            ]
          }
        ]
      }
    ]
  },
  "situational_output": {
    "observed": [
      "A drone and birds are visible above a transmission-pylon crossarm.",
      "Their image positions change during the selected source window."
    ],
    "unknown": [
      "Purpose of the flight or whether any inspection is occurring.",
      "Physical clearance, electrical safety and structural condition."
    ]
  },
  "limitations": [
    "Editorial example of proposed project outputs; does not establish production schema support.",
    "Sparse sampled rectangles may be coarse between keyframes and do not measure precision, clearance, severity or identity.",
    "No segmentation masks, exhaustive labels or confirmed object identities."
  ]
}