{
  "event": "2026 Chinese Grand Prix Sprint",
  "session": "Sprint",
  "source_video": "Supplied Sky Sports F1 Sprint program",
  "source_sha256": "fd39b6c26130ef5c20959013d628c16df5a155cdd5d2d3eccb52cf707937f069",
  "source_video_format": {
    "stored_resolution": "3840x2160",
    "display_aspect_ratio": "16:9",
    "frame_rate": 50.0
  },
  "source_offset_seconds": 1984.4,
  "race_start_s": 1984.4,
  "race_end_s": 4009.7,
  "race_start_timecode": "00:33:04.400",
  "race_end_timecode": "01:06:49.700",
  "proxy_start_s": 0.0,
  "proxy_end_s": 2025.3,
  "race_seconds": 2025.3,
  "race_time": "33:45.300",
  "official_winner_elapsed_seconds": 2018.998,
  "difference_from_official_seconds": 6.302,
  "decode_gap": {
    "undecodable_proxy_span_seconds": [
      72.38,
      72.9
    ],
    "undecodable_frame_count_at_50_fps": 26,
    "forced_safe_boundary_seconds": 72.92,
    "post_gap_pts_offset_seconds": -0.008,
    "post_gap_pts_regime_verified_through_asset_seconds": 2045.792,
    "post_gap_pts_regime_packet_count": 97891,
    "policy": "The cut immediately following the unavailable span is placed at the first fully decodable adjacent post-gap comparison; no unavailable frame-level boundary is inferred."
  },
  "caveats": [
    "This audit measures the Sprint only, not the Chinese Grand Prix race.",
    "The source program clock spans 6.302 seconds more than the official winner elapsed time between the observed lights-out and finish-confirmation boundaries; no portion of the observed race window was removed.",
    "Editorial-focus time is exclusive and split equally among co-primary drivers.",
    "Visible-presence time is non-exclusive and intentionally conservative.",
    "Timing-tower text alone never establishes visible physical car presence.",
    "Replays within the race window are included and itemized.",
    "The low-resolution detector proxy is approximate and is never used as the authority for 50 fps cut boundaries.",
    "Exact cut refinement and manual review frames are linked to the lossless remux at a 14.980-second asset offset.",
    "One 0.520-second HEVC span at race-relative 72.380\u201372.900 could not be decoded from the source or remux. Valid packets then resume on a stable source-PTS grid 0.008 seconds before the nominal 50 fps grid; every recovered frame records that real PTS. Both detectors placed a cut immediately after the gap, so the authoritative boundary is conservatively fixed at the first safe adjacent post-gap comparison, 72.920 seconds; results retain this interval with an explicit uncertainty caveat.",
    "UNKNOWN records unresolved car subjects; NO_CAR records shots without an identifiable physical car subject."
  ],
  "shot_count": 421,
  "authoritative_exact_set": true,
  "frame_alignment_ms": 20.0,
  "analysis_segment_count": 489,
  "refined_parent_shots": 39,
  "replay_segment_count": 26,
  "replay_seconds": 138.18,
  "replay_time": "2:18.180",
  "replay_pct_race": 6.822693,
  "focus_reconciliation_seconds": 2025.3,
  "special_focus_seconds": {
    "NO_CAR": 9.98,
    "UNKNOWN": 150.422333
  },
  "special_visible_seconds": {
    "NO_CAR": 9.98,
    "UNKNOWN": 462.48
  },
  "mode_seconds": {
    "crowd_team": 4.2,
    "garage": 7.64,
    "graphic": 4.38,
    "live_external": 911.66,
    "onboard": 188.06,
    "other": 0.4,
    "pit": 53.32,
    "split_screen": 855.64
  },
  "confidence_seconds": {
    "high": 1274.8,
    "low": 104.84,
    "medium": 645.66
  },
  "unknown_or_low_confidence_shots": 79,
  "zero_focus_driver_codes": [
    "ALB",
    "ALO",
    "BOR",
    "BOT",
    "COL",
    "PER",
    "STR"
  ],
  "zero_visible_driver_codes": [
    "ALB",
    "ALO",
    "BOR",
    "BOT",
    "COL",
    "PER",
    "STR"
  ],
  "method": {
    "headline": "editorial-focus time; co-primary shots split equally",
    "secondary": "identifiable visible-presence time; non-exclusive, shot-level",
    "window": "first fully extinguished starting-light frame through the first broadcast winner-confirmation frame after the winner crossed",
    "timing": "review annotations use proxy-relative timestamps; published segments use absolute source timestamps",
    "replays": "included in headline and separately itemized"
  }
}