{"abstract":"Dropping muted samples advances the playback timeline instead of silencing it.","category":"Audio channel mixing","checks":4,"contract":"Mute replaces mono samples with signed-PCM silence while retaining buffer length; unmuted buffers pass through.","contract_signature":"samples, muted","evaluation_group":"xaud-mute-preserves-duration","failed_approach":"Unconditional zeroing silences channels when mute is disabled.","family":"xaud-mute-preserves-duration","id":"FA-10921","implementations":{"attempt":{"sha256":"e9358fa89a3f8671a409e7f46ccd48f5c0a44c75081aad1150de2b275f000cf3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, muted):\n    return [0]*len(samples)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2, 3], True)),[0, 0, 0])\ncheck('fixture 2',solve(*([1, 2], False)),[1, 2])\ncheck('fixture 3',solve(*([], True)),[])\ncheck('fixture 4',solve(*([-1], False)),[-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":"e063d4b6b6fc16c82aa259e81e82d6c51090df34067c05ad3f4a9481e16ce455","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, muted):\n    return [] if muted else list(samples)\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2, 3], True)),[0, 0, 0])\ncheck('fixture 2',solve(*([1, 2], False)),[1, 2])\ncheck('fixture 3',solve(*([], True)),[])\ncheck('fixture 4',solve(*([-1], False)),[-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":"xaud-mute-preserves-duration","generated_at":"2026-09-29T14:38:43.429530+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.","root_cause":"Dropping muted samples advances the playback timeline instead of silencing it.","sha256":"5375a01a638eaaad60be23e61da7076c69e77069ad0c0ab10cc9f50127acb4dc","title":"Mute preserves duration · 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":39.007,"exit_code":1,"observations":[{"actual":[0,0,0],"check":"fixture 1","expected":[0,0,0],"passed":true},{"actual":[0,0],"check":"fixture 2","expected":[1,2],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0],"check":"fixture 4","expected":[-1],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0, 0, 0], \"expected\": [0, 0, 0], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [0, 0], \"expected\": [1, 2], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0], \"expected\": [-1], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.58,"exit_code":1,"observations":[{"actual":[],"check":"fixture 1","expected":[0,0,0],"passed":false},{"actual":[1,2],"check":"fixture 2","expected":[1,2],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[-1],"check":"fixture 4","expected":[-1],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [], \"expected\": [0, 0, 0], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1, 2], \"expected\": [1, 2], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [-1], \"expected\": [-1], \"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."}}