{"abstract":"Labels near each minute boundary skip too early.","category":"Broadcast timecode arithmetic","checks":9,"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":"Subtracting a single frame misplaces the skip at every minute boundary.","family":"w2-broadcast-timecode-arithmetic-frames-to-df29-in-block-minute-offset","id":"FA-78421","implementations":{"attempt":{"sha256":"0a858a1e93397e59d8bd44aa689e2b92d1a19ae8c24e600abca78ee0bdcc4efd","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-1)//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: in-block minute offset', [1799], '00:00:59;29'), ('regression variant: in-block minute offset', [17981], '00:09:59;29'), ('partial repair probe: in-block minute offset', [2589407], '23:59:59;29'), ('partial repair variant: in-block minute offset', [557441], '05:09:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [17982], '00:10:00;00'), ('normal control', [-1], None), ('normal control', [52594], '00:29:14;28')], [('regression: in-block minute offset', [107891], '00:59:59;29'), ('regression variant: in-block minute offset', [287711], '02:39:59;29'), ('partial repair probe: in-block minute offset', [683315], '06:19:59;29'), ('partial repair variant: in-block minute offset', [757043], '07:00:59;29'), ('boundary control', [17982], '00:10:00;00'), ('boundary control', [-1], None), ('normal control', [3372691], '07:15:35;17'), ('normal control', [2589408], '00:00:00;00'), ('normal control', [916013], '08:29:24;11')], [('regression: in-block minute offset', [2589407], '23:59:59;29'), ('regression variant: in-block minute offset', [3597], '00:01:59;29'), ('partial repair probe: in-block minute offset', [165435], '01:31:59;29'), ('partial repair variant: in-block minute offset', [125873], '01:09:59;29'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [2576030], '23:52:33;18'), ('normal control', [1346634], '12:28:52;22'), ('normal control', [3599], '00:02:00;03')], [('regression: in-block minute offset', [683315], '06:19:59;29'), ('regression variant: in-block minute offset', [451349], '04:10:59;29'), ('partial repair probe: in-block minute offset', [17981], '00:09:59;29'), ('partial repair variant: in-block minute offset', [793007], '07:20:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [17982], '00:10:00;00'), ('normal control', [3470210], '08:09:49;14'), ('normal control', [544816], '05:02:58;20'), ('normal control', [431569], '04:00:00;01')], [('regression: in-block minute offset', [165435], '01:31:59;29'), ('regression variant: in-block minute offset', [557441], '05:09:59;29'), ('partial repair probe: in-block minute offset', [287711], '02:39:59;29'), ('partial repair variant: in-block minute offset', [143855], '01:19:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [737264], '06:50:00;02'), ('normal control', [701299], '06:30:00;01'), ('normal control', [1874662], '17:22:31;08')]]\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":"7ce450168c99b475ebeb10238e037d2cc810026c828181c500b48af06058236b","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//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: in-block minute offset', [1799], '00:00:59;29'), ('regression variant: in-block minute offset', [17981], '00:09:59;29'), ('partial repair probe: in-block minute offset', [2589407], '23:59:59;29'), ('partial repair variant: in-block minute offset', [557441], '05:09:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [17982], '00:10:00;00'), ('normal control', [-1], None), ('normal control', [52594], '00:29:14;28')], [('regression: in-block minute offset', [107891], '00:59:59;29'), ('regression variant: in-block minute offset', [287711], '02:39:59;29'), ('partial repair probe: in-block minute offset', [683315], '06:19:59;29'), ('partial repair variant: in-block minute offset', [757043], '07:00:59;29'), ('boundary control', [17982], '00:10:00;00'), ('boundary control', [-1], None), ('normal control', [3372691], '07:15:35;17'), ('normal control', [2589408], '00:00:00;00'), ('normal control', [916013], '08:29:24;11')], [('regression: in-block minute offset', [2589407], '23:59:59;29'), ('regression variant: in-block minute offset', [3597], '00:01:59;29'), ('partial repair probe: in-block minute offset', [165435], '01:31:59;29'), ('partial repair variant: in-block minute offset', [125873], '01:09:59;29'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [2576030], '23:52:33;18'), ('normal control', [1346634], '12:28:52;22'), ('normal control', [3599], '00:02:00;03')], [('regression: in-block minute offset', [683315], '06:19:59;29'), ('regression variant: in-block minute offset', [451349], '04:10:59;29'), ('partial repair probe: in-block minute offset', [17981], '00:09:59;29'), ('partial repair variant: in-block minute offset', [793007], '07:20:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [17982], '00:10:00;00'), ('normal control', [3470210], '08:09:49;14'), ('normal control', [544816], '05:02:58;20'), ('normal control', [431569], '04:00:00;01')], [('regression: in-block minute offset', [165435], '01:31:59;29'), ('regression variant: in-block minute offset', [557441], '05:09:59;29'), ('partial repair probe: in-block minute offset', [287711], '02:39:59;29'), ('partial repair variant: in-block minute offset', [143855], '01:19:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [737264], '06:50:00;02'), ('normal control', [701299], '06:30:00;01'), ('normal control', [1874662], '17:22:31;08')]]\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":"d34b65f7950eeb9c2590fa08e260109da38ea25685707602ba4232ffda8c539a","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: in-block minute offset', [1799], '00:00:59;29'), ('regression variant: in-block minute offset', [17981], '00:09:59;29'), ('partial repair probe: in-block minute offset', [2589407], '23:59:59;29'), ('partial repair variant: in-block minute offset', [557441], '05:09:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [17982], '00:10:00;00'), ('normal control', [-1], None), ('normal control', [52594], '00:29:14;28')], [('regression: in-block minute offset', [107891], '00:59:59;29'), ('regression variant: in-block minute offset', [287711], '02:39:59;29'), ('partial repair probe: in-block minute offset', [683315], '06:19:59;29'), ('partial repair variant: in-block minute offset', [757043], '07:00:59;29'), ('boundary control', [17982], '00:10:00;00'), ('boundary control', [-1], None), ('normal control', [3372691], '07:15:35;17'), ('normal control', [2589408], '00:00:00;00'), ('normal control', [916013], '08:29:24;11')], [('regression: in-block minute offset', [2589407], '23:59:59;29'), ('regression variant: in-block minute offset', [3597], '00:01:59;29'), ('partial repair probe: in-block minute offset', [165435], '01:31:59;29'), ('partial repair variant: in-block minute offset', [125873], '01:09:59;29'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [2576030], '23:52:33;18'), ('normal control', [1346634], '12:28:52;22'), ('normal control', [3599], '00:02:00;03')], [('regression: in-block minute offset', [683315], '06:19:59;29'), ('regression variant: in-block minute offset', [451349], '04:10:59;29'), ('partial repair probe: in-block minute offset', [17981], '00:09:59;29'), ('partial repair variant: in-block minute offset', [793007], '07:20:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [17982], '00:10:00;00'), ('normal control', [3470210], '08:09:49;14'), ('normal control', [544816], '05:02:58;20'), ('normal control', [431569], '04:00:00;01')], [('regression: in-block minute offset', [165435], '01:31:59;29'), ('regression variant: in-block minute offset', [557441], '05:09:59;29'), ('partial repair probe: in-block minute offset', [287711], '02:39:59;29'), ('partial repair variant: in-block minute offset', [143855], '01:19:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [737264], '06:50:00;02'), ('normal control', [701299], '06:30:00;01'), ('normal control', [1874662], '17:22:31;08')]]\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-in-block-minute-offset","generated_at":"2026-09-29T14:49:35.279071+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":"Subtract the first two frames before dividing by 1798.","root_cause":"The in-block minute count ignores the two frames of the undropped first minute.","sha256":"9d6d50a6367af835bc2eaeea45004e148c97e9d6467641270404790da0095f98","title":"Frame count to drop-frame 29.97 label: in-block minute offset · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":47.556,"exit_code":1,"observations":[{"actual":"00:01:00;01","check":"regression: in-block minute offset","expected":"00:00:59;29","passed":false},{"actual":"00:10:00;01","check":"regression variant: in-block minute offset","expected":"00:09:59;29","passed":false},{"actual":"24:00:00;01","check":"partial repair probe: in-block minute offset","expected":"23:59:59;29","passed":false},{"actual":"05:10:00;01","check":"partial repair variant: in-block minute offset","expected":"05:09:59;29","passed":false},{"actual":"00:01:00;02","check":"boundary control","expected":"00:01:00;02","passed":true},{"actual":"00:00:00;00","check":"boundary control","expected":"00:00:00;00","passed":true},{"actual":"00:10:00;00","check":"normal control","expected":"00:10:00;00","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:29:14;28","check":"normal control","expected":"00:29:14;28","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: in-block minute offset\", \"actual\": \"00:01:00;01\", \"expected\": \"00:00:59;29\", \"passed\": false}, {\"check\": \"regression variant: in-block minute offset\", \"actual\": \"00:10:00;01\", \"expected\": \"00:09:59;29\", \"passed\": false}, {\"check\": \"partial repair probe: in-block minute offset\", \"actual\": \"24:00:00;01\", \"expected\": \"23:59:59;29\", \"passed\": false}, {\"check\": \"partial repair variant: in-block minute offset\", \"actual\": \"05:10:00;01\", \"expected\": \"05:09:59;29\", \"passed\": false}, {\"check\": \"boundary control\", \"actual\": \"00:01:00;02\", \"expected\": \"00:01:00;02\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": \"00:00:00;00\", \"expected\": \"00:00:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:29:14;28\", \"expected\": \"00:29:14;28\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.667,"exit_code":1,"observations":[{"actual":"00:01:00;01","check":"regression: in-block minute offset","expected":"00:00:59;29","passed":false},{"actual":"00:10:00;01","check":"regression variant: in-block minute offset","expected":"00:09:59;29","passed":false},{"actual":"24:00:00;01","check":"partial repair probe: in-block minute offset","expected":"23:59:59;29","passed":false},{"actual":"05:10:00;01","check":"partial repair variant: in-block minute offset","expected":"05:09:59;29","passed":false},{"actual":"00:01:00;02","check":"boundary control","expected":"00:01:00;02","passed":true},{"actual":"00:00:00;00","check":"boundary control","expected":"00:00:00;00","passed":true},{"actual":"00:10:00;00","check":"normal control","expected":"00:10:00;00","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:29:14;28","check":"normal control","expected":"00:29:14;28","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: in-block minute offset\", \"actual\": \"00:01:00;01\", \"expected\": \"00:00:59;29\", \"passed\": false}, {\"check\": \"regression variant: in-block minute offset\", \"actual\": \"00:10:00;01\", \"expected\": \"00:09:59;29\", \"passed\": false}, {\"check\": \"partial repair probe: in-block minute offset\", \"actual\": \"24:00:00;01\", \"expected\": \"23:59:59;29\", \"passed\": false}, {\"check\": \"partial repair variant: in-block minute offset\", \"actual\": \"05:10:00;01\", \"expected\": \"05:09:59;29\", \"passed\": false}, {\"check\": \"boundary control\", \"actual\": \"00:01:00;02\", \"expected\": \"00:01:00;02\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": \"00:00:00;00\", \"expected\": \"00:00:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:29:14;28\", \"expected\": \"00:29:14;28\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":40.363,"exit_code":0,"observations":[{"actual":"00:00:59;29","check":"regression: in-block minute offset","expected":"00:00:59;29","passed":true},{"actual":"00:09:59;29","check":"regression variant: in-block minute offset","expected":"00:09:59;29","passed":true},{"actual":"23:59:59;29","check":"partial repair probe: in-block minute offset","expected":"23:59:59;29","passed":true},{"actual":"05:09:59;29","check":"partial repair variant: in-block minute offset","expected":"05:09:59;29","passed":true},{"actual":"00:01:00;02","check":"boundary control","expected":"00:01:00;02","passed":true},{"actual":"00:00:00;00","check":"boundary control","expected":"00:00:00;00","passed":true},{"actual":"00:10:00;00","check":"normal control","expected":"00:10:00;00","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:29:14;28","check":"normal control","expected":"00:29:14;28","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: in-block minute offset\", \"actual\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"regression variant: in-block minute offset\", \"actual\": \"00:09:59;29\", \"expected\": \"00:09:59;29\", \"passed\": true}, {\"check\": \"partial repair probe: in-block minute offset\", \"actual\": \"23:59:59;29\", \"expected\": \"23:59:59;29\", \"passed\": true}, {\"check\": \"partial repair variant: in-block minute offset\", \"actual\": \"05:09:59;29\", \"expected\": \"05:09:59;29\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": \"00:01:00;02\", \"expected\": \"00:01:00;02\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": \"00:00:00;00\", \"expected\": \"00:00:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:29:14;28\", \"expected\": \"00:29:14;28\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}