{"abstract":"A wrapped media counter is treated as an absolute time and jumps backward.","category":"Media timeline seeking","checks":4,"contract":"For monotonic sample delivery with less than one wrap between observations, map raw counter in [0,modulus) to the smallest timestamp >=last with that residue.","contract_signature":"last, raw, modulus","evaluation_group":"xmed-timestamp-wrap-unroll-nearest-forward","failed_approach":"Adding raw residue to the last timestamp overcounts progress inside a cycle.","family":"xmed-timestamp-wrap-unroll-nearest-forward","id":"FA-11266","implementations":{"attempt":{"sha256":"49500f442179d32cf0ea64000dd5102840d8c51ccd5fc6c3ffb7a21d0662396e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(last, raw, modulus):\n    return last+raw\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(14, 1, 16)),17)\ncheck('fixture 2',solve(*(17, 3, 16)),19)\ncheck('fixture 3',solve(*(3, 3, 16)),3)\ncheck('fixture 4',solve(*(0, 5, 16)),5)\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":"c2f2b31de9aae4977aeb5c9b0df671f4027784e208dd84ef7ca70aac9c01e17a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(last, raw, modulus):\n    return raw\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(14, 1, 16)),17)\ncheck('fixture 2',solve(*(17, 3, 16)),19)\ncheck('fixture 3',solve(*(3, 3, 16)),3)\ncheck('fixture 4',solve(*(0, 5, 16)),5)\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-timestamp-wrap-unroll-nearest-forward","generated_at":"2026-09-29T14:38:46.426760+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":"A wrapped media counter is treated as an absolute time and jumps backward.","sha256":"3e89d205bb7c9b52c5da11408714f6f2f385e2551142fffb3c8925549bb20c6c","title":"Timestamp wrap unroll nearest forward · 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":41.449,"exit_code":1,"observations":[{"actual":15,"check":"fixture 1","expected":17,"passed":false},{"actual":20,"check":"fixture 2","expected":19,"passed":false},{"actual":6,"check":"fixture 3","expected":3,"passed":false},{"actual":5,"check":"fixture 4","expected":5,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 15, \"expected\": 17, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 20, \"expected\": 19, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 6, \"expected\": 3, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 5, \"expected\": 5, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.998,"exit_code":1,"observations":[{"actual":1,"check":"fixture 1","expected":17,"passed":false},{"actual":3,"check":"fixture 2","expected":19,"passed":false},{"actual":3,"check":"fixture 3","expected":3,"passed":true},{"actual":5,"check":"fixture 4","expected":5,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 1, \"expected\": 17, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 3, \"expected\": 19, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 3, \"expected\": 3, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 5, \"expected\": 5, \"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."}}