{"abstract":"Multi-part caption loads keep only the last text fragment.","category":"Subtitle cue timing","checks":8,"contract":"Commands [frame,cmd] at integer fps (time = frame*1000//fps). TEXT:x appends x to the non-displayed memory; ENM erases non-displayed memory; EOC swaps displayed and non-displayed memories; EDM erases displayed memory. Whenever non-empty displayed text is replaced (EOC) or erased (EDM), emit [shown_since_ms, now_ms, text].","contract_signature":"events, fps","evaluation_group":"w2-subtitle-cue-timing-pop-on-caption-buffers","failed_approach":"Writing directly into displayed memory behaves like paint-on captions and breaks pop-on timing.","family":"w2-subtitle-cue-timing-pop-on-caption-buffers-text-load-target","id":"FA-78261","implementations":{"attempt":{"sha256":"71ef86d8d8e813d227b63774305307fb23e136270fa62c90579459664f626315","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, fps):\n    shown=''\n    hidden=''\n    since=None\n    out=[]\n    for frame,cmd in events:\n        t=frame*1000//fps\n        if cmd.startswith('TEXT:'):\n            shown+=cmd[5:]\n        elif cmd=='ENM':\n            hidden=''\n        elif cmd=='EOC':\n            if shown:\n                out.append([since,t,shown])\n            shown,hidden=hidden,shown\n            since=t\n        elif cmd=='EDM':\n            if shown: out.append([since,t,shown])\n            shown=''\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: text load target', [[[3, 'TEXT: there'], [32, 'TEXT: there'], [33, 'TEXT: there'], [48, 'EOC'], [78, 'EOC'], [123, 'TEXT: there']], 25], [[1920, 3120, ' there there there']]), ('regression variant: text load target', [[[30, 'TEXT:Hi'], [75, 'TEXT:Hi'], [120, 'EOC'], [135, 'TEXT:Hi'], [164, 'EDM'], [193, 'TEXT:Hi'], [238, 'EOC'], [267, 'EOC']], 25], [[4800, 6560, 'HiHi'], [9520, 10680, 'HiHi']]), ('partial repair probe: text load target', [[[0, 'EOC'], [7, 'TEXT:Bye'], [52, 'EDM'], [59, 'TEXT:Bye'], [74, 'EOC']], 24], []), ('partial repair variant: text load target', [[[30, 'TEXT: there'], [31, 'EDM']], 24], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[30, 'EOC'], [30, 'TEXT:Hi'], [37, 'ENM']], 24], []), ('normal control', [[[3, 'EDM'], [32, 'EOC']], 29], []), ('normal control', [[[0, 'ENM'], [0, 'EOC'], [30, 'TEXT:Hi']], 24], [])], [('regression: text load target', [[[3, 'TEXT:Hi'], [48, 'EOC'], [49, 'EOC'], [49, 'TEXT:Hi'], [94, 'TEXT:Bye'], [123, 'EOC'], [130, 'EDM']], 25], [[1920, 1960, 'Hi'], [4920, 5200, 'HiHiBye']]), ('regression variant: text load target', [[[30, 'TEXT:Hi'], [31, 'TEXT:Bye'], [61, 'EOC'], [91, 'TEXT:Bye'], [92, 'TEXT: there'], [93, 'ENM'], [93, 'TEXT:Hi'], [122, 'EOC']], 24], [[2541, 5083, 'HiBye']]), ('partial repair probe: text load target', [[[30, 'TEXT:Bye'], [37, 'EOC'], [52, 'EDM'], [52, 'ENM'], [67, 'EDM']], 30], [[1233, 1733, 'Bye']]), ('partial repair variant: text load target', [[[3, 'TEXT: there'], [32, 'TEXT: there'], [33, 'TEXT: there'], [48, 'EOC'], [78, 'EOC'], [123, 'TEXT: there']], 25], [[1920, 3120, ' there there there']]), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EOC'], [7, 'EDM'], [14, 'EOC'], [59, 'EOC'], [104, 'EOC'], [133, 'EOC'], [162, 'EOC'], [207, 'EOC']], 25], []), ('normal control', [[[3, 'TEXT:Hi'], [10, 'TEXT:Bye']], 30], []), ('normal control', [[[3, 'EOC'], [18, 'EOC'], [19, 'EOC']], 25], [])], [('regression: text load target', [[[0, 'TEXT:Bye'], [29, 'TEXT: there'], [44, 'TEXT: there'], [44, 'EOC'], [51, 'EOC']], 29], [[1517, 1758, 'Bye there there']]), ('regression variant: text load target', [[[30, 'EOC'], [45, 'TEXT: there'], [75, 'TEXT:Hi'], [105, 'EOC'], [105, 'EOC']], 24], [[4375, 4375, ' thereHi']]), ('partial repair probe: text load target', [[[0, 'EOC'], [30, 'TEXT:Bye'], [31, 'EOC'], [46, 'EOC'], [91, 'TEXT:Hi'], [92, 'TEXT: there'], [99, 'EDM'], [129, 'ENM']], 30], [[1033, 1533, 'Bye']]), ('partial repair variant: text load target', [[[30, 'EOC'], [31, 'TEXT: there'], [31, 'EDM'], [76, 'TEXT:Bye'], [76, 'ENM'], [91, 'EDM']], 30], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EOC'], [7, 'TEXT:Bye'], [14, 'TEXT:Bye']], 25], []), ('normal control', [[[30, 'EOC'], [60, 'TEXT: there']], 29], []), ('normal control', [[[0, 'EOC'], [1, 'EOC'], [30, 'ENM'], [37, 'TEXT:Bye']], 30], [])], [('regression: text load target', [[[30, 'TEXT:Hi'], [30, 'TEXT:Bye'], [60, 'TEXT:Bye'], [105, 'EOC'], [120, 'EOC'], [165, 'EOC'], [180, 'TEXT: there'], [195, 'EDM']], 24], [[4375, 5000, 'HiByeBye'], [6875, 8125, 'HiByeBye']]), ('regression variant: text load target', [[[0, 'EOC'], [0, 'TEXT: there'], [45, 'TEXT:Hi'], [46, 'EOC'], [91, 'EDM'], [120, 'TEXT:Hi'], [127, 'TEXT: there']], 25], [[1840, 3640, ' thereHi']]), ('partial repair probe: text load target', [[[30, 'TEXT:Hi'], [31, 'TEXT: there'], [61, 'EDM'], [106, 'TEXT: there'], [121, 'ENM'], [136, 'TEXT:Hi'], [166, 'EOC']], 24], []), ('partial repair variant: text load target', [[[30, 'TEXT:Bye'], [59, 'EOC'], [66, 'TEXT:Bye'], [111, 'EOC']], 24], [[2458, 4625, 'Bye']]), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EDM'], [15, 'TEXT:Bye']], 29], []), ('normal control', [[[3, 'EOC'], [48, 'ENM']], 30], []), ('normal control', [[[3, 'TEXT:Bye'], [48, 'TEXT:Hi']], 24], [])], [('regression: text load target', [[[3, 'EOC'], [3, 'TEXT: there'], [4, 'TEXT: there'], [34, 'EDM'], [64, 'EOC'], [71, 'EOC'], [78, 'TEXT: there'], [78, 'TEXT: there']], 30], [[2133, 2366, ' there there']]), ('regression variant: text load target', [[[0, 'TEXT: there'], [29, 'TEXT:Bye'], [44, 'EDM'], [73, 'EOC'], [118, 'EOC'], [163, 'TEXT: there'], [192, 'ENM']], 25], [[2920, 4720, ' thereBye']]), ('partial repair probe: text load target', [[[30, 'TEXT: there'], [30, 'EOC'], [59, 'ENM']], 30], []), ('partial repair variant: text load target', [[[0, 'TEXT: there'], [7, 'ENM'], [8, 'EOC'], [9, 'ENM'], [16, 'TEXT:Hi']], 30], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[3, 'EOC'], [4, 'EOC'], [19, 'EOC'], [20, 'EOC'], [21, 'EOC'], [51, 'EDM'], [58, 'EDM'], [58, 'EOC']], 24], []), ('normal control', [[[0, 'TEXT:Bye'], [30, 'ENM'], [59, 'TEXT:Bye'], [104, 'ENM'], [119, 'ENM'], [148, 'TEXT:Bye'], [178, 'ENM']], 30], []), ('normal control', [[[3, 'EOC'], [48, 'EOC'], [55, 'TEXT: there']], 24], [])]]\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":"2e9256284ab8c623e50cbc455e4ebd86fb9a52a9ab04bf530548000ac51fcbc8","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(events, fps):\n    shown=''\n    hidden=''\n    since=None\n    out=[]\n    for frame,cmd in events:\n        t=frame*1000//fps\n        if cmd.startswith('TEXT:'):\n            hidden=cmd[5:]\n        elif cmd=='ENM':\n            hidden=''\n        elif cmd=='EOC':\n            if shown:\n                out.append([since,t,shown])\n            shown,hidden=hidden,shown\n            since=t\n        elif cmd=='EDM':\n            if shown: out.append([since,t,shown])\n            shown=''\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\nfixtures = [[('regression: text load target', [[[3, 'TEXT: there'], [32, 'TEXT: there'], [33, 'TEXT: there'], [48, 'EOC'], [78, 'EOC'], [123, 'TEXT: there']], 25], [[1920, 3120, ' there there there']]), ('regression variant: text load target', [[[30, 'TEXT:Hi'], [75, 'TEXT:Hi'], [120, 'EOC'], [135, 'TEXT:Hi'], [164, 'EDM'], [193, 'TEXT:Hi'], [238, 'EOC'], [267, 'EOC']], 25], [[4800, 6560, 'HiHi'], [9520, 10680, 'HiHi']]), ('partial repair probe: text load target', [[[0, 'EOC'], [7, 'TEXT:Bye'], [52, 'EDM'], [59, 'TEXT:Bye'], [74, 'EOC']], 24], []), ('partial repair variant: text load target', [[[30, 'TEXT: there'], [31, 'EDM']], 24], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[30, 'EOC'], [30, 'TEXT:Hi'], [37, 'ENM']], 24], []), ('normal control', [[[3, 'EDM'], [32, 'EOC']], 29], []), ('normal control', [[[0, 'ENM'], [0, 'EOC'], [30, 'TEXT:Hi']], 24], [])], [('regression: text load target', [[[3, 'TEXT:Hi'], [48, 'EOC'], [49, 'EOC'], [49, 'TEXT:Hi'], [94, 'TEXT:Bye'], [123, 'EOC'], [130, 'EDM']], 25], [[1920, 1960, 'Hi'], [4920, 5200, 'HiHiBye']]), ('regression variant: text load target', [[[30, 'TEXT:Hi'], [31, 'TEXT:Bye'], [61, 'EOC'], [91, 'TEXT:Bye'], [92, 'TEXT: there'], [93, 'ENM'], [93, 'TEXT:Hi'], [122, 'EOC']], 24], [[2541, 5083, 'HiBye']]), ('partial repair probe: text load target', [[[30, 'TEXT:Bye'], [37, 'EOC'], [52, 'EDM'], [52, 'ENM'], [67, 'EDM']], 30], [[1233, 1733, 'Bye']]), ('partial repair variant: text load target', [[[3, 'TEXT: there'], [32, 'TEXT: there'], [33, 'TEXT: there'], [48, 'EOC'], [78, 'EOC'], [123, 'TEXT: there']], 25], [[1920, 3120, ' there there there']]), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EOC'], [7, 'EDM'], [14, 'EOC'], [59, 'EOC'], [104, 'EOC'], [133, 'EOC'], [162, 'EOC'], [207, 'EOC']], 25], []), ('normal control', [[[3, 'TEXT:Hi'], [10, 'TEXT:Bye']], 30], []), ('normal control', [[[3, 'EOC'], [18, 'EOC'], [19, 'EOC']], 25], [])], [('regression: text load target', [[[0, 'TEXT:Bye'], [29, 'TEXT: there'], [44, 'TEXT: there'], [44, 'EOC'], [51, 'EOC']], 29], [[1517, 1758, 'Bye there there']]), ('regression variant: text load target', [[[30, 'EOC'], [45, 'TEXT: there'], [75, 'TEXT:Hi'], [105, 'EOC'], [105, 'EOC']], 24], [[4375, 4375, ' thereHi']]), ('partial repair probe: text load target', [[[0, 'EOC'], [30, 'TEXT:Bye'], [31, 'EOC'], [46, 'EOC'], [91, 'TEXT:Hi'], [92, 'TEXT: there'], [99, 'EDM'], [129, 'ENM']], 30], [[1033, 1533, 'Bye']]), ('partial repair variant: text load target', [[[30, 'EOC'], [31, 'TEXT: there'], [31, 'EDM'], [76, 'TEXT:Bye'], [76, 'ENM'], [91, 'EDM']], 30], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EOC'], [7, 'TEXT:Bye'], [14, 'TEXT:Bye']], 25], []), ('normal control', [[[30, 'EOC'], [60, 'TEXT: there']], 29], []), ('normal control', [[[0, 'EOC'], [1, 'EOC'], [30, 'ENM'], [37, 'TEXT:Bye']], 30], [])], [('regression: text load target', [[[30, 'TEXT:Hi'], [30, 'TEXT:Bye'], [60, 'TEXT:Bye'], [105, 'EOC'], [120, 'EOC'], [165, 'EOC'], [180, 'TEXT: there'], [195, 'EDM']], 24], [[4375, 5000, 'HiByeBye'], [6875, 8125, 'HiByeBye']]), ('regression variant: text load target', [[[0, 'EOC'], [0, 'TEXT: there'], [45, 'TEXT:Hi'], [46, 'EOC'], [91, 'EDM'], [120, 'TEXT:Hi'], [127, 'TEXT: there']], 25], [[1840, 3640, ' thereHi']]), ('partial repair probe: text load target', [[[30, 'TEXT:Hi'], [31, 'TEXT: there'], [61, 'EDM'], [106, 'TEXT: there'], [121, 'ENM'], [136, 'TEXT:Hi'], [166, 'EOC']], 24], []), ('partial repair variant: text load target', [[[30, 'TEXT:Bye'], [59, 'EOC'], [66, 'TEXT:Bye'], [111, 'EOC']], 24], [[2458, 4625, 'Bye']]), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[0, 'EDM'], [15, 'TEXT:Bye']], 29], []), ('normal control', [[[3, 'EOC'], [48, 'ENM']], 30], []), ('normal control', [[[3, 'TEXT:Bye'], [48, 'TEXT:Hi']], 24], [])], [('regression: text load target', [[[3, 'EOC'], [3, 'TEXT: there'], [4, 'TEXT: there'], [34, 'EDM'], [64, 'EOC'], [71, 'EOC'], [78, 'TEXT: there'], [78, 'TEXT: there']], 30], [[2133, 2366, ' there there']]), ('regression variant: text load target', [[[0, 'TEXT: there'], [29, 'TEXT:Bye'], [44, 'EDM'], [73, 'EOC'], [118, 'EOC'], [163, 'TEXT: there'], [192, 'ENM']], 25], [[2920, 4720, ' thereBye']]), ('partial repair probe: text load target', [[[30, 'TEXT: there'], [30, 'EOC'], [59, 'ENM']], 30], []), ('partial repair variant: text load target', [[[0, 'TEXT: there'], [7, 'ENM'], [8, 'EOC'], [9, 'ENM'], [16, 'TEXT:Hi']], 30], []), ('boundary control', [[[0, 'EOC'], [5, 'EDM']], 30], []), ('normal control', [[[3, 'EOC'], [4, 'EOC'], [19, 'EOC'], [20, 'EOC'], [21, 'EOC'], [51, 'EDM'], [58, 'EDM'], [58, 'EOC']], 24], []), ('normal control', [[[0, 'TEXT:Bye'], [30, 'ENM'], [59, 'TEXT:Bye'], [104, 'ENM'], [119, 'ENM'], [148, 'TEXT:Bye'], [178, 'ENM']], 30], []), ('normal control', [[[3, 'EOC'], [48, 'EOC'], [55, 'TEXT: there']], 24], [])]]\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 any subtitle 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-subtitle-cue-timing-pop-on-caption-buffers-text-load-target","generated_at":"2026-09-29T14:49:33.471885+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Subtitle timing defects shift, hide or overlap captions that viewers depend on for comprehension and accessibility.","root_cause":"Each TEXT command replaces non-displayed memory instead of appending.","sha256":"d60382b48bf2736a9f02e6cfad9009d406b331beb3e74947754f9b17271bb69e","title":"Pop-on caption buffer timing: text load target · 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":42.456,"exit_code":1,"observations":[{"actual":[[null,1920," there there there"]],"check":"regression: text load target","expected":[[1920,3120," there there there"]],"passed":false},{"actual":[[null,4800,"HiHi"],[4800,6560,"Hi"],[4800,9520,"Hi"],[9520,10680,"HiHi"]],"check":"regression variant: text load target","expected":[[4800,6560,"HiHi"],[9520,10680,"HiHi"]],"passed":false},{"actual":[[0,2166,"Bye"],[0,3083,"Bye"]],"check":"partial repair probe: text load target","expected":[],"passed":false},{"actual":[[null,1291," there"]],"check":"partial repair variant: text load target","expected":[],"passed":false},{"actual":[],"check":"boundary control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: text load target\", \"actual\": [[null, 1920, \" there there there\"]], \"expected\": [[1920, 3120, \" there there there\"]], \"passed\": false}, {\"check\": \"regression variant: text load target\", \"actual\": [[null, 4800, \"HiHi\"], [4800, 6560, \"Hi\"], [4800, 9520, \"Hi\"], [9520, 10680, \"HiHi\"]], \"expected\": [[4800, 6560, \"HiHi\"], [9520, 10680, \"HiHi\"]], \"passed\": false}, {\"check\": \"partial repair probe: text load target\", \"actual\": [[0, 2166, \"Bye\"], [0, 3083, \"Bye\"]], \"expected\": [], \"passed\": false}, {\"check\": \"partial repair variant: text load target\", \"actual\": [[null, 1291, \" there\"]], \"expected\": [], \"passed\": false}, {\"check\": \"boundary control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.179,"exit_code":1,"observations":[{"actual":[[1920,3120," there"]],"check":"regression: text load target","expected":[[1920,3120," there there there"]],"passed":false},{"actual":[[4800,6560,"Hi"],[9520,10680,"Hi"]],"check":"regression variant: text load target","expected":[[4800,6560,"HiHi"],[9520,10680,"HiHi"]],"passed":false},{"actual":[],"check":"partial repair probe: text load target","expected":[],"passed":true},{"actual":[],"check":"partial repair variant: text load target","expected":[],"passed":true},{"actual":[],"check":"boundary control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true},{"actual":[],"check":"normal control","expected":[],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"regression: text load target\", \"actual\": [[1920, 3120, \" there\"]], \"expected\": [[1920, 3120, \" there there there\"]], \"passed\": false}, {\"check\": \"regression variant: text load target\", \"actual\": [[4800, 6560, \"Hi\"], [9520, 10680, \"Hi\"]], \"expected\": [[4800, 6560, \"HiHi\"], [9520, 10680, \"HiHi\"]], \"passed\": false}, {\"check\": \"partial repair probe: text load target\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"partial repair variant: text load target\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"boundary control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"normal control\", \"actual\": [], \"expected\": [], \"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."}}