{"abstract":"Labels drift by several frames per hour relative to the frame count.","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":"A 17980-frame block over-corrects and still drifts.","family":"w2-broadcast-timecode-arithmetic-frames-to-df29-ten-minute-block-size","id":"FA-78416","implementations":{"attempt":{"sha256":"1e6438eb94d694078426ebb741856b0a98528f3884a6e45eecba0356ea0b1c98","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,17980)\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: ten-minute block size', [17982], '00:10:00;00'), ('regression variant: ten-minute block size', [1183387], '10:58:05;23'), ('partial repair probe: ten-minute block size', [985344], '09:07:57;20'), ('partial repair variant: ten-minute block size', [793007], '07:20:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [1799], '00:00:59;29'), ('normal control', [-1], None), ('normal control', [107891], '00:59:59;29')], [('regression: ten-minute block size', [2589407], '23:59:59;29'), ('regression variant: ten-minute block size', [2576030], '23:52:33;18'), ('partial repair probe: ten-minute block size', [1190345], '11:01:57;25'), ('partial repair variant: ten-minute block size', [1688437], '15:38:57;17'), ('boundary control', [1799], '00:00:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [683315], '06:19:59;29'), ('normal control', [666705], '06:10:45;21')], [('regression: ten-minute block size', [5138128], '23:37:22;12'), ('regression variant: ten-minute block size', [2535623], '23:30:05;11'), ('partial repair probe: ten-minute block size', [1073449], '09:56:57;13'), ('partial repair variant: ten-minute block size', [1264068], '11:42:57;22'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [3599], '00:02:00;03'), ('normal control', [431569], '04:00:00;01'), ('normal control', [737264], '06:50:00;02')], [('regression: ten-minute block size', [703099], '06:31:00;03'), ('regression variant: ten-minute block size', [757044], '07:01:00;02'), ('partial repair probe: ten-minute block size', [4738204], '19:54:58;06'), ('partial repair variant: ten-minute block size', [489111], '04:31:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [1799], '00:00:59;29'), ('normal control', [3598], '00:02:00;02'), ('normal control', [1092788], '10:07:42;22'), ('normal control', [-464827], None)], [('regression: ten-minute block size', [916013], '08:29:24;11'), ('regression variant: ten-minute block size', [1508377], '13:58:49;17'), ('partial repair probe: ten-minute block size', [451349], '04:10:59;29'), ('partial repair variant: ten-minute block size', [235565], '02:10:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [143856], '01:20:00;00'), ('normal control', [449552], '04:10:00;02'), ('normal control', [557441], '05:09:59;29')]]\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":"e3197423a98dc41c2d67cc15f466e91e82eb32eb28ab9cb9a1d1c5e9ab3b6205","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,18000)\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: ten-minute block size', [17982], '00:10:00;00'), ('regression variant: ten-minute block size', [1183387], '10:58:05;23'), ('partial repair probe: ten-minute block size', [985344], '09:07:57;20'), ('partial repair variant: ten-minute block size', [793007], '07:20:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [1799], '00:00:59;29'), ('normal control', [-1], None), ('normal control', [107891], '00:59:59;29')], [('regression: ten-minute block size', [2589407], '23:59:59;29'), ('regression variant: ten-minute block size', [2576030], '23:52:33;18'), ('partial repair probe: ten-minute block size', [1190345], '11:01:57;25'), ('partial repair variant: ten-minute block size', [1688437], '15:38:57;17'), ('boundary control', [1799], '00:00:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [683315], '06:19:59;29'), ('normal control', [666705], '06:10:45;21')], [('regression: ten-minute block size', [5138128], '23:37:22;12'), ('regression variant: ten-minute block size', [2535623], '23:30:05;11'), ('partial repair probe: ten-minute block size', [1073449], '09:56:57;13'), ('partial repair variant: ten-minute block size', [1264068], '11:42:57;22'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [3599], '00:02:00;03'), ('normal control', [431569], '04:00:00;01'), ('normal control', [737264], '06:50:00;02')], [('regression: ten-minute block size', [703099], '06:31:00;03'), ('regression variant: ten-minute block size', [757044], '07:01:00;02'), ('partial repair probe: ten-minute block size', [4738204], '19:54:58;06'), ('partial repair variant: ten-minute block size', [489111], '04:31:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [1799], '00:00:59;29'), ('normal control', [3598], '00:02:00;02'), ('normal control', [1092788], '10:07:42;22'), ('normal control', [-464827], None)], [('regression: ten-minute block size', [916013], '08:29:24;11'), ('regression variant: ten-minute block size', [1508377], '13:58:49;17'), ('partial repair probe: ten-minute block size', [451349], '04:10:59;29'), ('partial repair variant: ten-minute block size', [235565], '02:10:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [143856], '01:20:00;00'), ('normal control', [449552], '04:10:00;02'), ('normal control', [557441], '05:09:59;29')]]\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":"93d8ef6c51b268434453149d2294c4ff644ec4d95a38c5ffb5a5c390fa12773e","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: ten-minute block size', [17982], '00:10:00;00'), ('regression variant: ten-minute block size', [1183387], '10:58:05;23'), ('partial repair probe: ten-minute block size', [985344], '09:07:57;20'), ('partial repair variant: ten-minute block size', [793007], '07:20:59;29'), ('boundary control', [1800], '00:01:00;02'), ('boundary control', [0], '00:00:00;00'), ('normal control', [1799], '00:00:59;29'), ('normal control', [-1], None), ('normal control', [107891], '00:59:59;29')], [('regression: ten-minute block size', [2589407], '23:59:59;29'), ('regression variant: ten-minute block size', [2576030], '23:52:33;18'), ('partial repair probe: ten-minute block size', [1190345], '11:01:57;25'), ('partial repair variant: ten-minute block size', [1688437], '15:38:57;17'), ('boundary control', [1799], '00:00:59;29'), ('boundary control', [-1], None), ('normal control', [-2], None), ('normal control', [683315], '06:19:59;29'), ('normal control', [666705], '06:10:45;21')], [('regression: ten-minute block size', [5138128], '23:37:22;12'), ('regression variant: ten-minute block size', [2535623], '23:30:05;11'), ('partial repair probe: ten-minute block size', [1073449], '09:56:57;13'), ('partial repair variant: ten-minute block size', [1264068], '11:42:57;22'), ('boundary control', [107892], '01:00:00;00'), ('boundary control', [1800], '00:01:00;02'), ('normal control', [3599], '00:02:00;03'), ('normal control', [431569], '04:00:00;01'), ('normal control', [737264], '06:50:00;02')], [('regression: ten-minute block size', [703099], '06:31:00;03'), ('regression variant: ten-minute block size', [757044], '07:01:00;02'), ('partial repair probe: ten-minute block size', [4738204], '19:54:58;06'), ('partial repair variant: ten-minute block size', [489111], '04:31:59;29'), ('boundary control', [0], '00:00:00;00'), ('boundary control', [1799], '00:00:59;29'), ('normal control', [3598], '00:02:00;02'), ('normal control', [1092788], '10:07:42;22'), ('normal control', [-464827], None)], [('regression: ten-minute block size', [916013], '08:29:24;11'), ('regression variant: ten-minute block size', [1508377], '13:58:49;17'), ('partial repair probe: ten-minute block size', [451349], '04:10:59;29'), ('partial repair variant: ten-minute block size', [235565], '02:10:59;29'), ('boundary control', [-1], None), ('boundary control', [107892], '01:00:00;00'), ('normal control', [143856], '01:20:00;00'), ('normal control', [449552], '04:10:00;02'), ('normal control', [557441], '05:09:59;29')]]\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-ten-minute-block-size","generated_at":"2026-09-29T14:49:35.274194+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":"Divide the count into 17982-frame blocks.","root_cause":"The ten-minute block uses the nominal 18000 frames instead of the 17982 real frames.","sha256":"9e58d99b3a9e952a8445ea35ebeb918b20e09abd556a0486bfa5f1ba7c5b7b4b","title":"Frame count to drop-frame 29.97 label: ten-minute block size · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":43.02,"exit_code":1,"observations":[{"actual":"00:10:00;00","check":"regression: ten-minute block size","expected":"00:10:00;00","passed":true},{"actual":"10:58:05;23","check":"regression variant: ten-minute block size","expected":"10:58:05;23","passed":true},{"actual":"09:07:57;22","check":"partial repair probe: ten-minute block size","expected":"09:07:57;20","passed":false},{"actual":"07:21:00;01","check":"partial repair variant: ten-minute block size","expected":"07:20:59;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":"00:00:59;29","check":"normal control","expected":"00:00:59;29","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:59:59;29","check":"normal control","expected":"00:59:59;29","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: ten-minute block size\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"regression variant: ten-minute block size\", \"actual\": \"10:58:05;23\", \"expected\": \"10:58:05;23\", \"passed\": true}, {\"check\": \"partial repair probe: ten-minute block size\", \"actual\": \"09:07:57;22\", \"expected\": \"09:07:57;20\", \"passed\": false}, {\"check\": \"partial repair variant: ten-minute block size\", \"actual\": \"07:21:00;01\", \"expected\": \"07:20:59;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\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:59:59;29\", \"expected\": \"00:59:59;29\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.52,"exit_code":1,"observations":[{"actual":"00:10:00;02","check":"regression: ten-minute block size","expected":"00:10:00;00","passed":false},{"actual":"10:58:05;21","check":"regression variant: ten-minute block size","expected":"10:58:05;23","passed":false},{"actual":"09:07:57;20","check":"partial repair probe: ten-minute block size","expected":"09:07:57;20","passed":true},{"actual":"07:20:59;29","check":"partial repair variant: ten-minute block size","expected":"07:20:59;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":"00:00:59;29","check":"normal control","expected":"00:00:59;29","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:59:59;29","check":"normal control","expected":"00:59:59;29","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: ten-minute block size\", \"actual\": \"00:10:00;02\", \"expected\": \"00:10:00;00\", \"passed\": false}, {\"check\": \"regression variant: ten-minute block size\", \"actual\": \"10:58:05;21\", \"expected\": \"10:58:05;23\", \"passed\": false}, {\"check\": \"partial repair probe: ten-minute block size\", \"actual\": \"09:07:57;20\", \"expected\": \"09:07:57;20\", \"passed\": true}, {\"check\": \"partial repair variant: ten-minute block size\", \"actual\": \"07:20:59;29\", \"expected\": \"07:20:59;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\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:59:59;29\", \"expected\": \"00:59:59;29\", \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":47.49,"exit_code":0,"observations":[{"actual":"00:10:00;00","check":"regression: ten-minute block size","expected":"00:10:00;00","passed":true},{"actual":"10:58:05;23","check":"regression variant: ten-minute block size","expected":"10:58:05;23","passed":true},{"actual":"09:07:57;20","check":"partial repair probe: ten-minute block size","expected":"09:07:57;20","passed":true},{"actual":"07:20:59;29","check":"partial repair variant: ten-minute block size","expected":"07:20:59;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":"00:00:59;29","check":"normal control","expected":"00:00:59;29","passed":true},{"actual":null,"check":"normal control","expected":null,"passed":true},{"actual":"00:59:59;29","check":"normal control","expected":"00:59:59;29","passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: ten-minute block size\", \"actual\": \"00:10:00;00\", \"expected\": \"00:10:00;00\", \"passed\": true}, {\"check\": \"regression variant: ten-minute block size\", \"actual\": \"10:58:05;23\", \"expected\": \"10:58:05;23\", \"passed\": true}, {\"check\": \"partial repair probe: ten-minute block size\", \"actual\": \"09:07:57;20\", \"expected\": \"09:07:57;20\", \"passed\": true}, {\"check\": \"partial repair variant: ten-minute block size\", \"actual\": \"07:20:59;29\", \"expected\": \"07:20:59;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\": \"00:00:59;29\", \"expected\": \"00:00:59;29\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": null, \"expected\": null, \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"00:59:59;29\", \"expected\": \"00:59:59;29\", \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}