{"abstract":"The media timeline advances at normal speed regardless of playback rate.","category":"Media timeline seeking","checks":4,"contract":"Advance media position by nonnegative wall-time delta times nonnegative playback rate; zero rate freezes position.","evaluation_group":"xmed-playback-rate-wall-to-media-delta","failed_approach":"Dividing by rate reverses faster and slower playback behavior.","family":"xmed-playback-rate-wall-to-media-delta","id":"FA-11261","implementations":{"attempt":{"sha256":"986d32d8bfed52bff9d7e23e241cc6d6c15cb1d16a1100dd10620ec90ae2d67a","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(position, wall_delta, rate):\n    return position+wall_delta/rate if rate else position\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(10, 2, 2)),14)\ncheck('fixture 2',solve(*(10, 2, 0.5)),11)\ncheck('fixture 3',solve(*(10, 2, 0)),10)\ncheck('fixture 4',solve(*(0, 0, 1)),0)\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":"ff2496675dfca5eb29706e7496cb2b49b7b475ff83ddb0603735ada9fa2c6c27","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(position, wall_delta, rate):\n    return position+wall_delta\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(10, 2, 2)),14)\ncheck('fixture 2',solve(*(10, 2, 0.5)),11)\ncheck('fixture 3',solve(*(10, 2, 0)),10)\ncheck('fixture 4',solve(*(0, 0, 1)),0)\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":"9f3b4d4a21897c9715a163903ff2f7063894fdae78235373efb4efe6e3721a6c","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(position, wall_delta, rate):\n    return position+wall_delta*rate\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*(10, 2, 2)),14)\ncheck('fixture 2',solve(*(10, 2, 0.5)),11)\ncheck('fixture 3',solve(*(10, 2, 0)),10)\ncheck('fixture 4',solve(*(0, 0, 1)),0)\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-playback-rate-wall-to-media-delta","generated_at":"2026-09-29T14:38:46.303983+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.","repair":"Preserve the media contract: Advance media position by nonnegative wall-time delta times nonnegative playback rate; zero rate freezes position.","root_cause":"The media timeline advances at normal speed regardless of playback rate.","sha256":"54babffdfb212045bfb1ef21d5f56e92978ac9fee30757eeff237d7acbd71811","title":"Playback rate wall to media delta · case 01","variant":1,"variant_policy":"The five numbered cases rerun the same authored boundary fixtures; they are reproducibility runs, not independent input variants.","verification":{"attempt":{"elapsed_ms":42.99,"exit_code":1,"observations":[{"actual":11.0,"check":"fixture 1","expected":14,"passed":false},{"actual":14.0,"check":"fixture 2","expected":11,"passed":false},{"actual":10,"check":"fixture 3","expected":10,"passed":true},{"actual":0.0,"check":"fixture 4","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 11.0, \"expected\": 14, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 14.0, \"expected\": 11, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0.0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.973,"exit_code":1,"observations":[{"actual":12,"check":"fixture 1","expected":14,"passed":false},{"actual":12,"check":"fixture 2","expected":11,"passed":false},{"actual":12,"check":"fixture 3","expected":10,"passed":false},{"actual":0,"check":"fixture 4","expected":0,"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 12, \"expected\": 14, \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": 12, \"expected\": 11, \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": 12, \"expected\": 10, \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.384,"exit_code":0,"observations":[{"actual":14,"check":"fixture 1","expected":14,"passed":true},{"actual":11.0,"check":"fixture 2","expected":11,"passed":true},{"actual":10,"check":"fixture 3","expected":10,"passed":true},{"actual":0,"check":"fixture 4","expected":0,"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": 14, \"expected\": 14, \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": 11.0, \"expected\": 11, \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": 10, \"expected\": 10, \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": 0, \"expected\": 0, \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}