{"abstract":"Drop-frame labels are indistinguishable from non-drop labels downstream.","category":"Broadcast timecode arithmetic","checks":8,"contract":"Convert a non-negative frame count (negative counts return None; counts wrap to the 2589408-frame drop-frame day) to an HH:MM:SS;FF 29.97 drop-frame label: 18 labels are skipped per 10-minute block of 17982 frames, and labels ;00/;01 are skipped at each minute not divisible by ten.","evaluation_group":"w2-broadcast-timecode-arithmetic-frames-to-df29","failed_approach":"The period spelling is not the separator the contract requires.","family":"w2-broadcast-timecode-arithmetic-frames-to-df29-drop-separator","id":"FA-78436","implementations":{"attempt":{"sha256":"e2e846b8767238830522106e8298a86c77a10430a1bc6d7277064d19a270753d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames):\n    if frames<0:\n        return None\n    frames%=2589408\n    d,mrem=divmod(frames,17982)\n    add=18*d\n    if mrem>=2:\n        add+=2*((mrem-2)//1798)\n    n=frames+add\n    ff=n%30\n    ss=n//30%60\n    mm=n//1800%60\n    hh=n//108000\n    return '%02d:%02d:%02d.%02d'%(hh,mm,ss,ff)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: drop separator', [1800], '00:01:00;02'), ('regression variant: drop separator', [107891], '00:59:59;29'), ('partial repair probe: drop separator', [1799], '00:00:59;29'), ('partial repair variant: drop separator', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: drop separator', [17982], '00:10:00;00'), ('regression variant: drop separator', [2589407], '23:59:59;29'), ('partial repair probe: drop separator', [107892], '01:00:00;00'), ('partial repair variant: drop separator', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: drop separator', [1799], '00:00:59;29'), ('regression variant: drop separator', [52594], '00:29:14;28'), ('partial repair probe: drop separator', [0], '00:00:00;00'), ('partial repair variant: drop separator', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: drop separator', [107892], '01:00:00;00'), ('regression variant: drop separator', [3372691], '07:15:35;17'), ('partial repair probe: drop separator', [107891], '00:59:59;29'), ('partial repair variant: drop separator', [703099], '06:31:00;03'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: drop separator', [0], '00:00:00;00'), ('regression variant: drop separator', [683315], '06:19:59;29'), ('partial repair probe: drop separator', [2589407], '23:59:59;29'), ('partial repair variant: drop separator', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-745831], None), ('normal control', [-1976708], None)]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"broken":{"sha256":"1e4161d2fba9b581e66efdad727a2627051c7a9fd14151326e6e7238a787cd36","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames):\n    if frames<0:\n        return None\n    frames%=2589408\n    d,mrem=divmod(frames,17982)\n    add=18*d\n    if mrem>=2:\n        add+=2*((mrem-2)//1798)\n    n=frames+add\n    ff=n%30\n    ss=n//30%60\n    mm=n//1800%60\n    hh=n//108000\n    return '%02d:%02d:%02d:%02d'%(hh,mm,ss,ff)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: drop separator', [1800], '00:01:00;02'), ('regression variant: drop separator', [107891], '00:59:59;29'), ('partial repair probe: drop separator', [1799], '00:00:59;29'), ('partial repair variant: drop separator', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: drop separator', [17982], '00:10:00;00'), ('regression variant: drop separator', [2589407], '23:59:59;29'), ('partial repair probe: drop separator', [107892], '01:00:00;00'), ('partial repair variant: drop separator', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: drop separator', [1799], '00:00:59;29'), ('regression variant: drop separator', [52594], '00:29:14;28'), ('partial repair probe: drop separator', [0], '00:00:00;00'), ('partial repair variant: drop separator', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: drop separator', [107892], '01:00:00;00'), ('regression variant: drop separator', [3372691], '07:15:35;17'), ('partial repair probe: drop separator', [107891], '00:59:59;29'), ('partial repair variant: drop separator', [703099], '06:31:00;03'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: drop separator', [0], '00:00:00;00'), ('regression variant: drop separator', [683315], '06:19:59;29'), ('partial repair probe: drop separator', [2589407], '23:59:59;29'), ('partial repair variant: drop separator', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-745831], None), ('normal control', [-1976708], None)]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"},"fixed":{"sha256":"94c89b1b86189dde7cb556474b2925935b9d08d37a2b9552cc18a7d5bd700b1d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames):\n    if frames<0:\n        return None\n    frames%=2589408\n    d,mrem=divmod(frames,17982)\n    add=18*d\n    if mrem>=2:\n        add+=2*((mrem-2)//1798)\n    n=frames+add\n    ff=n%30\n    ss=n//30%60\n    mm=n//1800%60\n    hh=n//108000\n    return '%02d:%02d:%02d;%02d'%(hh,mm,ss,ff)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: drop separator', [1800], '00:01:00;02'), ('regression variant: drop separator', [107891], '00:59:59;29'), ('partial repair probe: drop separator', [1799], '00:00:59;29'), ('partial repair variant: drop separator', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: drop separator', [17982], '00:10:00;00'), ('regression variant: drop separator', [2589407], '23:59:59;29'), ('partial repair probe: drop separator', [107892], '01:00:00;00'), ('partial repair variant: drop separator', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: drop separator', [1799], '00:00:59;29'), ('regression variant: drop separator', [52594], '00:29:14;28'), ('partial repair probe: drop separator', [0], '00:00:00;00'), ('partial repair variant: drop separator', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: drop separator', [107892], '01:00:00;00'), ('regression variant: drop separator', [3372691], '07:15:35;17'), ('partial repair probe: drop separator', [107891], '00:59:59;29'), ('partial repair variant: drop separator', [703099], '06:31:00;03'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: drop separator', [0], '00:00:00;00'), ('regression variant: drop separator', [683315], '06:19:59;29'), ('partial repair probe: drop separator', [2589407], '23:59:59;29'), ('partial repair variant: drop separator', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-745831], None), ('normal control', [-1976708], None)]]\nfor label, args, expected in fixtures[N-1]:\n    check(label, solve(*args), expected)\nprint(json.dumps({\"observations\": observations, \"passed\": all(x[\"passed\"] for x in observations)}, ensure_ascii=False))\nraise SystemExit(0 if all(x[\"passed\"] for x in observations) else 1)\n"}},"limitations":"A deterministic bounded teaching model with a stipulated toy contract; it does not claim conformance to SMPTE or any broadcast standard. This reproducer isolates one failure mechanism. Results cover the supplied fixtures. Variants within a family share a test contract and should remain grouped when constructing evaluation splits. Related mechanisms with a shared evaluation_group must also remain together; these controlled models are not independent production incidents.","method":"Deterministic executable model with adversarial boundary fixtures.","provenance":{"created_by":"Failure Map","dependencies":"Python standard library","family":"w2-broadcast-timecode-arithmetic-frames-to-df29-drop-separator","generated_at":"2026-09-29T14:49:35.318858+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Timecode arithmetic errors misplace edits, commercial breaks and captions against the broadcast clock.","repair":"Write the drop-frame semicolon before the frame field.","root_cause":"The label is written with a colon before the frame field.","sha256":"0092b95f227e1129d1582fdc4fa63294e19ec80c27f227651857ba2fd13b3acc","title":"Frame count to drop-frame 29.97 label: drop separator · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.731,"exit_code":1,"observations":[{"actual":"00:01:00.02","check":"regression: drop separator","expected":"00:01:00;02","passed":false},{"actual":"00:59:59.29","check":"regression variant: drop separator","expected":"00:59:59;29","passed":false},{"actual":"00:00:59.29","check":"partial repair probe: drop separator","expected":"00:00:59;29","passed":false},{"actual":"06:19:59.29","check":"partial repair variant: drop separator","expected":"06:19:59;29","passed":false},{"actual":null,"check":"boundary control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: drop separator\", \"actual\": \"00:01:00.02\", \"expected\": \"00:01:00;02\", \"passed\": false}, {\"check\": \"regression variant: drop separator\", \"actual\": \"00:59:59.29\", \"expected\": \"00:59:59;29\", \"passed\": false}, {\"check\": \"partial repair probe: drop separator\", \"actual\": \"00:00:59.29\", \"expected\": \"00:00:59;29\", \"passed\": false}, {\"check\": \"partial repair variant: drop separator\", \"actual\": \"06:19:59.29\", \"expected\": \"06:19:59;29\", \"passed\": false}, {\"check\": \"boundary control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":48.316,"exit_code":1,"observations":[{"actual":"00:01:00:02","check":"regression: drop separator","expected":"00:01:00;02","passed":false},{"actual":"00:59:59:29","check":"regression variant: drop separator","expected":"00:59:59;29","passed":false},{"actual":"00:00:59:29","check":"partial repair probe: drop separator","expected":"00:00:59;29","passed":false},{"actual":"06:19:59:29","check":"partial repair variant: drop separator","expected":"06:19:59;29","passed":false},{"actual":null,"check":"boundary control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: drop separator\", \"actual\": \"00:01:00:02\", \"expected\": \"00:01:00;02\", \"passed\": false}, {\"check\": \"regression variant: drop separator\", \"actual\": \"00:59:59:29\", \"expected\": \"00:59:59;29\", \"passed\": false}, {\"check\": \"partial repair probe: drop separator\", \"actual\": \"00:00:59:29\", \"expected\": \"00:00:59;29\", \"passed\": false}, {\"check\": \"partial repair variant: drop separator\", \"actual\": \"06:19:59:29\", \"expected\": \"06:19:59;29\", \"passed\": false}, {\"check\": \"boundary control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.925,"exit_code":0,"observations":[{"actual":"00:01:00;02","check":"regression: drop separator","expected":"00:01:00;02","passed":true},{"actual":"00:59:59;29","check":"regression variant: drop separator","expected":"00:59:59;29","passed":true},{"actual":"00:00:59;29","check":"partial repair probe: drop separator","expected":"00:00:59;29","passed":true},{"actual":"06:19:59;29","check":"partial repair variant: drop separator","expected":"06:19:59;29","passed":true},{"actual":null,"check":"boundary control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: drop separator\", \"actual\": \"00:01:00;02\", \"expected\": \"00:01:00;02\", \"passed\": true}, {\"check\": \"regression variant: drop separator\", \"actual\": \"00:59:59;29\", \"expected\": \"00:59:59;29\", \"passed\": true}, {\"check\": \"partial repair probe: drop separator\", \"actual\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"partial repair variant: drop separator\", \"actual\": \"06:19:59;29\", \"expected\": \"06:19:59;29\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}