{"abstract":"Labels with a seconds field of 60 appear.","category":"Broadcast timecode arithmetic","checks":8,"contract":"Given a valid drop-frame label at rate \"29.97\" (nominal 30, drop 2) or \"59.94\" (nominal 60, drop 4), return the next label: frames carry into seconds at the nominal rate, seconds into minutes, minutes into hours (wrapping at 24); on entering a new minute not divisible by 10 the first drop labels are skipped.","contract_signature":"tc, rate","evaluation_group":"w2-broadcast-timecode-arithmetic-df-label-increment","failed_approach":"Carrying at 59 drops the last second of every minute.","family":"w2-broadcast-timecode-arithmetic-df-label-increment-second-carry","id":"FA-78446","implementations":{"attempt":{"sha256":"f4daf0cc8979ae2130c14de197b5740334b1daccfd074e613980faf6b0b1c2a8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re\nN = 1\nobservations = []\ndef solve(tc, rate):\n    n=30 if rate=='29.97' else 60\n    drop=2 if n==30 else 4\n    h,m,s,f=map(int,re.split('[:;]',tc))\n    f+=1\n    if f==n:\n        f=0\n        s+=1\n        if s==59:\n            s=0\n            m+=1\n            if m==60:\n                m=0\n                h=(h+1)%24\n            if m%10!=0:\n                f=drop\n    return '%02d:%02d:%02d;%02d'%(h,m,s,f)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: second carry', ['00:00:59;29', '29.97'], '00:01:00;02'), ('regression variant: second carry', ['09:10:59;29', '29.97'], '09:11:00;02'), ('partial repair probe: second carry', ['00:00:59;59', '59.94'], '00:01:00;04'), ('partial repair variant: second carry', ['01:10:58;29', '29.97'], '01:10:59;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['01:01:01;02', '29.97'], '01:01:01;03'), ('normal control', ['09:19:58;05', '59.94'], '09:19:58;06'), ('normal control', ['09:19:59;58', '59.94'], '09:19:59;59')], [('regression: second carry', ['00:09:59;29', '29.97'], '00:10:00;00'), ('regression variant: second carry', ['09:00:59;29', '29.97'], '09:01:00;02'), ('partial repair probe: second carry', ['23:59:59;29', '29.97'], '00:00:00;00'), ('partial repair variant: second carry', ['23:09:59;29', '29.97'], '23:10:00;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['01:00:59;02', '29.97'], '01:00:59;03'), ('normal control', ['09:01:01;00', '29.97'], '09:01:01;01'), ('normal control', ['01:29:58;58', '59.94'], '01:29:58;59')], [('regression: second carry', ['00:00:59;59', '59.94'], '00:01:00;04'), ('regression variant: second carry', ['23:59:59;59', '59.94'], '00:00:00;00'), ('partial repair probe: second carry', ['09:01:59;29', '29.97'], '09:02:00;02'), ('partial repair variant: second carry', ['00:59:59;59', '59.94'], '01:00:00;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['23:00:00;00', '59.94'], '23:00:00;01'), ('normal control', ['23:59:59;03', '59.94'], '23:59:59;04'), ('normal control', ['23:01:58;03', '29.97'], '23:01:58;04')], [('regression: second carry', ['23:59:59;29', '29.97'], '00:00:00;00'), ('regression variant: second carry', ['23:09:59;59', '59.94'], '23:10:00;00'), ('partial repair probe: second carry', ['09:10:59;29', '29.97'], '09:11:00;02'), ('partial repair variant: second carry', ['01:00:59;29', '29.97'], '01:01:00;02'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['00:09:01;00', '59.94'], '00:09:01;01'), ('normal control', ['23:19:59;05', '59.94'], '23:19:59;06'), ('normal control', ['09:59:59;30', '59.94'], '09:59:59;31')], [('regression: second carry', ['09:01:59;29', '29.97'], '09:02:00;02'), ('regression variant: second carry', ['23:09:59;29', '29.97'], '23:10:00;00'), ('partial repair probe: second carry', ['09:00:59;29', '29.97'], '09:01:00;02'), ('partial repair variant: second carry', ['01:01:59;59', '59.94'], '01:02:00;04'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['00:10:01;59', '59.94'], '00:10:02;00'), ('normal control', ['23:00:59;58', '59.94'], '23:00:59;59'), ('normal control', ['00:29:58;00', '29.97'], '00:29:58;01')]]\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":"ad5bb594e3641512f33e2b2404500edf5a216f6723465ab6d9217ba5b55e8559","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport re\nN = 1\nobservations = []\ndef solve(tc, rate):\n    n=30 if rate=='29.97' else 60\n    drop=2 if n==30 else 4\n    h,m,s,f=map(int,re.split('[:;]',tc))\n    f+=1\n    if f==n:\n        f=0\n        s+=1\n        if s>60:\n            s=0\n            m+=1\n            if m==60:\n                m=0\n                h=(h+1)%24\n            if m%10!=0:\n                f=drop\n    return '%02d:%02d:%02d;%02d'%(h,m,s,f)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: second carry', ['00:00:59;29', '29.97'], '00:01:00;02'), ('regression variant: second carry', ['09:10:59;29', '29.97'], '09:11:00;02'), ('partial repair probe: second carry', ['00:00:59;59', '59.94'], '00:01:00;04'), ('partial repair variant: second carry', ['01:10:58;29', '29.97'], '01:10:59;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['01:01:01;02', '29.97'], '01:01:01;03'), ('normal control', ['09:19:58;05', '59.94'], '09:19:58;06'), ('normal control', ['09:19:59;58', '59.94'], '09:19:59;59')], [('regression: second carry', ['00:09:59;29', '29.97'], '00:10:00;00'), ('regression variant: second carry', ['09:00:59;29', '29.97'], '09:01:00;02'), ('partial repair probe: second carry', ['23:59:59;29', '29.97'], '00:00:00;00'), ('partial repair variant: second carry', ['23:09:59;29', '29.97'], '23:10:00;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['01:00:59;02', '29.97'], '01:00:59;03'), ('normal control', ['09:01:01;00', '29.97'], '09:01:01;01'), ('normal control', ['01:29:58;58', '59.94'], '01:29:58;59')], [('regression: second carry', ['00:00:59;59', '59.94'], '00:01:00;04'), ('regression variant: second carry', ['23:59:59;59', '59.94'], '00:00:00;00'), ('partial repair probe: second carry', ['09:01:59;29', '29.97'], '09:02:00;02'), ('partial repair variant: second carry', ['00:59:59;59', '59.94'], '01:00:00;00'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['23:00:00;00', '59.94'], '23:00:00;01'), ('normal control', ['23:59:59;03', '59.94'], '23:59:59;04'), ('normal control', ['23:01:58;03', '29.97'], '23:01:58;04')], [('regression: second carry', ['23:59:59;29', '29.97'], '00:00:00;00'), ('regression variant: second carry', ['23:09:59;59', '59.94'], '23:10:00;00'), ('partial repair probe: second carry', ['09:10:59;29', '29.97'], '09:11:00;02'), ('partial repair variant: second carry', ['01:00:59;29', '29.97'], '01:01:00;02'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['00:09:01;00', '59.94'], '00:09:01;01'), ('normal control', ['23:19:59;05', '59.94'], '23:19:59;06'), ('normal control', ['09:59:59;30', '59.94'], '09:59:59;31')], [('regression: second carry', ['09:01:59;29', '29.97'], '09:02:00;02'), ('regression variant: second carry', ['23:09:59;29', '29.97'], '23:10:00;00'), ('partial repair probe: second carry', ['09:00:59;29', '29.97'], '09:01:00;02'), ('partial repair variant: second carry', ['01:01:59;59', '59.94'], '01:02:00;04'), ('boundary control', ['00:01:00;02', '29.97'], '00:01:00;03'), ('normal control', ['00:10:01;59', '59.94'], '00:10:02;00'), ('normal control', ['23:00:59;58', '59.94'], '23:00:59;59'), ('normal control', ['00:29:58;00', '29.97'], '00:29:58;01')]]\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-df-label-increment-second-carry","generated_at":"2026-09-29T14:49:35.323493+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.","root_cause":"Seconds carry only after exceeding 60.","sha256":"323805aecf47fca59421fee2045ae526188d1af16c4576759c48d19c87e7ae79","title":"Drop-frame label increment: second carry · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":40.493,"exit_code":1,"observations":[{"actual":"00:00:60;00","check":"regression: second carry","expected":"00:01:00;02","passed":false},{"actual":"09:10:60;00","check":"regression variant: second carry","expected":"09:11:00;02","passed":false},{"actual":"00:00:60;00","check":"partial repair probe: second carry","expected":"00:01:00;04","passed":false},{"actual":"01:11:00;02","check":"partial repair variant: second carry","expected":"01:10:59;00","passed":false},{"actual":"00:01:00;03","check":"boundary control","expected":"00:01:00;03","passed":true},{"actual":"01:01:01;03","check":"normal control","expected":"01:01:01;03","passed":true},{"actual":"09:19:58;06","check":"normal control","expected":"09:19:58;06","passed":true},{"actual":"09:19:59;59","check":"normal control","expected":"09:19:59;59","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: second carry\", \"actual\": \"00:00:60;00\", \"expected\": \"00:01:00;02\", \"passed\": false}, {\"check\": \"regression variant: second carry\", \"actual\": \"09:10:60;00\", \"expected\": \"09:11:00;02\", \"passed\": false}, {\"check\": \"partial repair probe: second carry\", \"actual\": \"00:00:60;00\", \"expected\": \"00:01:00;04\", \"passed\": false}, {\"check\": \"partial repair variant: second carry\", \"actual\": \"01:11:00;02\", \"expected\": \"01:10:59;00\", \"passed\": false}, {\"check\": \"boundary control\", \"actual\": \"00:01:00;03\", \"expected\": \"00:01:00;03\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"01:01:01;03\", \"expected\": \"01:01:01;03\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"09:19:58;06\", \"expected\": \"09:19:58;06\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"09:19:59;59\", \"expected\": \"09:19:59;59\", \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":47.25,"exit_code":1,"observations":[{"actual":"00:00:60;00","check":"regression: second carry","expected":"00:01:00;02","passed":false},{"actual":"09:10:60;00","check":"regression variant: second carry","expected":"09:11:00;02","passed":false},{"actual":"00:00:60;00","check":"partial repair probe: second carry","expected":"00:01:00;04","passed":false},{"actual":"01:10:59;00","check":"partial repair variant: second carry","expected":"01:10:59;00","passed":true},{"actual":"00:01:00;03","check":"boundary control","expected":"00:01:00;03","passed":true},{"actual":"01:01:01;03","check":"normal control","expected":"01:01:01;03","passed":true},{"actual":"09:19:58;06","check":"normal control","expected":"09:19:58;06","passed":true},{"actual":"09:19:59;59","check":"normal control","expected":"09:19:59;59","passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: second carry\", \"actual\": \"00:00:60;00\", \"expected\": \"00:01:00;02\", \"passed\": false}, {\"check\": \"regression variant: second carry\", \"actual\": \"09:10:60;00\", \"expected\": \"09:11:00;02\", \"passed\": false}, {\"check\": \"partial repair probe: second carry\", \"actual\": \"00:00:60;00\", \"expected\": \"00:01:00;04\", \"passed\": false}, {\"check\": \"partial repair variant: second carry\", \"actual\": \"01:10:59;00\", \"expected\": \"01:10:59;00\", \"passed\": true}, {\"check\": \"boundary control\", \"actual\": \"00:01:00;03\", \"expected\": \"00:01:00;03\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"01:01:01;03\", \"expected\": \"01:01:01;03\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"09:19:58;06\", \"expected\": \"09:19:58;06\", \"passed\": true}, {\"check\": \"normal control\", \"actual\": \"09:19:59;59\", \"expected\": \"09:19:59;59\", \"passed\": true}], \"passed\": false}\n"}},"member_only":{"stages":["fixed"],"fields":["implementations.fixed","verification.fixed","harness","repair"],"note":"The verified repair, its recorded checks, the repair description, and the scoring harness are available to members."}}