{"abstract":"Duration ends at the final frame start and omits its displayed duration.","category":"Media timeline seeking","checks":4,"contract":"For a nonempty constant-duration frame sequence, compute full duration from first/last start ticks plus final frame duration, divided by positive timescale.","contract_signature":"first, last, frame_duration, timescale","evaluation_group":"xmed-duration-from-timebase-endpoint","failed_approach":"Using an absolute final endpoint counts the nonzero start offset as duration.","family":"xmed-duration-from-timebase-endpoint","id":"FA-11241","implementations":{"attempt":{"sha256":"bbcb87a854c96d8ce3703d3c4a5cf96451f32bcfefe1fa52abd864306886ba7e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(first, last, frame_duration, timescale):\n    return (last+frame_duration)/timescale\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(100, 140, 20, 100)),0.6)\ncheck('fixture 2',solve(*(0, 0, 25, 100)),0.25)\ncheck('fixture 3',solve(*(50, 50, 0, 100)),0)\ncheck('fixture 4',solve(*(0, 75, 25, 100)),1)\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":"d3296361f865a962fb6870a2a5c37476c1f9a52efd046b00bba4d0cef8ca0c2c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(first, last, frame_duration, timescale):\n    return (last-first)/timescale\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(100, 140, 20, 100)),0.6)\ncheck('fixture 2',solve(*(0, 0, 25, 100)),0.25)\ncheck('fixture 3',solve(*(50, 50, 0, 100)),0)\ncheck('fixture 4',solve(*(0, 75, 25, 100)),1)\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":" 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":"xmed-duration-from-timebase-endpoint","generated_at":"2026-09-29T14:38:46.219057+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A deterministic local media controller stage; metadata and downloaded data are supplied explicitly. No external player, service or codec is required.","root_cause":"Duration ends at the final frame start and omits its displayed duration.","sha256":"19a11db382366680d2a7faac532b78eed78c7027ef15da656ef5662b820cd009","title":"Duration from timebase endpoint · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verified":true,"visibility":"public","verification":{"attempt":{"elapsed_ms":38.713,"exit_code":1,"observations":[{"actual":1.6,"check":"fixture 1","expected":0.6,"passed":false},{"actual":0.25,"check":"fixture 2","expected":0.25,"passed":true},{"actual":0.5,"check":"fixture 3","expected":0,"passed":false},{"actual":1.0,"check":"fixture 4","expected":1,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 1.6, \"expected\": 0.6, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 0.25, \"expected\": 0.25, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 0.5, \"expected\": 0, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 1.0, \"expected\": 1, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.051,"exit_code":1,"observations":[{"actual":0.4,"check":"fixture 1","expected":0.6,"passed":false},{"actual":0.0,"check":"fixture 2","expected":0.25,"passed":false},{"actual":0.0,"check":"fixture 3","expected":0,"passed":true},{"actual":0.75,"check":"fixture 4","expected":1,"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 0.4, \"expected\": 0.6, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 0.0, \"expected\": 0.25, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0.75, \"expected\": 1, \"passed\": false}], \"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."}}