{"abstract":"Labels after the first ten minutes are two frames late per block.","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":"Adding a fixed two frames still shifts every label in the first block.","family":"w2-broadcast-timecode-arithmetic-frames-to-df29-block-label-skip","id":"FA-78426","implementations":{"attempt":{"sha256":"d930cf4be6dd8e50278808254f69f7ef5377edc576b0802a53b167622a77a388","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+2\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: block label skip', [17982], '00:10:00;00'), ('regression variant: block label skip', [3372691], '07:15:35;17'), ('partial repair probe: block label skip', [1799], '00:00:59;29'), ('partial repair variant: block label skip', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: block label skip', [107892], '01:00:00;00'), ('regression variant: block label skip', [683315], '06:19:59;29'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: block label skip', [107891], '00:59:59;29'), ('regression variant: block label skip', [5138128], '23:37:22;12'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: block label skip', [2589407], '23:59:59;29'), ('regression variant: block label skip', [703099], '06:31:00;03'), ('partial repair probe: block label skip', [107891], '00:59:59;29'), ('partial repair variant: block label skip', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: block label skip', [52594], '00:29:14;28'), ('regression variant: block label skip', [916013], '08:29:24;11'), ('partial repair probe: block label skip', [2589407], '23:59:59;29'), ('partial repair variant: block label skip', [1183387], '10:58:05;23'), ('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":"2ce532bdc9d1a6ed49e5f6e541afe805c69d12bd4f84c3b0cfbb7e0ea74bb5a0","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=20*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: block label skip', [17982], '00:10:00;00'), ('regression variant: block label skip', [3372691], '07:15:35;17'), ('partial repair probe: block label skip', [1799], '00:00:59;29'), ('partial repair variant: block label skip', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: block label skip', [107892], '01:00:00;00'), ('regression variant: block label skip', [683315], '06:19:59;29'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: block label skip', [107891], '00:59:59;29'), ('regression variant: block label skip', [5138128], '23:37:22;12'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: block label skip', [2589407], '23:59:59;29'), ('regression variant: block label skip', [703099], '06:31:00;03'), ('partial repair probe: block label skip', [107891], '00:59:59;29'), ('partial repair variant: block label skip', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: block label skip', [52594], '00:29:14;28'), ('regression variant: block label skip', [916013], '08:29:24;11'), ('partial repair probe: block label skip', [2589407], '23:59:59;29'), ('partial repair variant: block label skip', [1183387], '10:58:05;23'), ('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":"533cbc33098076b5d0bc9f1ea94d658b3fe38892efd20c0f00748e30cdab2166","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: block label skip', [17982], '00:10:00;00'), ('regression variant: block label skip', [3372691], '07:15:35;17'), ('partial repair probe: block label skip', [1799], '00:00:59;29'), ('partial repair variant: block label skip', [683315], '06:19:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [-464827], None), ('normal control', [-1153089], None)], [('regression: block label skip', [107892], '01:00:00;00'), ('regression variant: block label skip', [683315], '06:19:59;29'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [5138128], '23:37:22;12'), ('boundary control', [-1], None), ('normal control', [-180902], None), ('normal control', [-1007831], None), ('normal control', [-2704966], None)], [('regression: block label skip', [107891], '00:59:59;29'), ('regression variant: block label skip', [5138128], '23:37:22;12'), ('partial repair probe: block label skip', [0], '00:00:00;00'), ('partial repair variant: block label skip', [2589408], '00:00:00;00'), ('boundary control', [-1], None), ('normal control', [-1440574], None), ('normal control', [-2414851], None), ('normal control', [-1406281], None)], [('regression: block label skip', [2589407], '23:59:59;29'), ('regression variant: block label skip', [703099], '06:31:00;03'), ('partial repair probe: block label skip', [107891], '00:59:59;29'), ('partial repair variant: block label skip', [916013], '08:29:24;11'), ('boundary control', [-1], None), ('normal control', [-1130649], None), ('normal control', [-2542944], None), ('normal control', [-1108369], None)], [('regression: block label skip', [52594], '00:29:14;28'), ('regression variant: block label skip', [916013], '08:29:24;11'), ('partial repair probe: block label skip', [2589407], '23:59:59;29'), ('partial repair variant: block label skip', [1183387], '10:58:05;23'), ('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-block-label-skip","generated_at":"2026-09-29T14:49:35.279527+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":"Skip 18 labels per complete ten-minute block.","root_cause":"Twenty labels per block are skipped, including the tenth minute that keeps its labels.","sha256":"0e3df6ccb9b13a24fe86a02d7cdba0f8042552060e2af8e40752f42061e6d73f","title":"Frame count to drop-frame 29.97 label: block label skip · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":48.435,"exit_code":1,"observations":[{"actual":"00:10:00;02","check":"regression: block label skip","expected":"00:10:00;00","passed":false},{"actual":"07:15:35;19","check":"regression variant: block label skip","expected":"07:15:35;17","passed":false},{"actual":"00:01:00;01","check":"partial repair probe: block label skip","expected":"00:00:59;29","passed":false},{"actual":"06:20:00;01","check":"partial repair variant: block label skip","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: block label skip\", \"actual\": \"00:10:00;02\", \"expected\": \"00:10:00;00\", \"passed\": false}, {\"check\": \"regression variant: block label skip\", \"actual\": \"07:15:35;19\", \"expected\": \"07:15:35;17\", \"passed\": false}, {\"check\": \"partial repair probe: block label skip\", \"actual\": \"00:01:00;01\", \"expected\": \"00:00:59;29\", \"passed\": false}, {\"check\": \"partial repair variant: block label skip\", \"actual\": \"06:20:00;01\", \"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":38.046,"exit_code":1,"observations":[{"actual":"00:10:00;02","check":"regression: block label skip","expected":"00:10:00;00","passed":false},{"actual":"07:15:38;13","check":"regression variant: block label skip","expected":"07:15:35;17","passed":false},{"actual":"00:00:59;29","check":"partial repair probe: block label skip","expected":"00:00:59;29","passed":true},{"actual":"06:20:02;13","check":"partial repair variant: block label skip","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: block label skip\", \"actual\": \"00:10:00;02\", \"expected\": \"00:10:00;00\", \"passed\": false}, {\"check\": \"regression variant: block label skip\", \"actual\": \"07:15:38;13\", \"expected\": \"07:15:35;17\", \"passed\": false}, {\"check\": \"partial repair probe: block label skip\", \"actual\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"partial repair variant: block label skip\", \"actual\": \"06:20:02;13\", \"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":39.081,"exit_code":0,"observations":[{"actual":"00:10:00;00","check":"regression: block label skip","expected":"00:10:00;00","passed":true},{"actual":"07:15:35;17","check":"regression variant: block label skip","expected":"07:15:35;17","passed":true},{"actual":"00:00:59;29","check":"partial repair probe: block label skip","expected":"00:00:59;29","passed":true},{"actual":"06:19:59;29","check":"partial repair variant: block label skip","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: block label skip\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"regression variant: block label skip\", \"actual\": \"07:15:35;17\", \"expected\": \"07:15:35;17\", \"passed\": true}, {\"check\": \"partial repair probe: block label skip\", \"actual\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"partial repair variant: block label skip\", \"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"}