{"abstract":"Invalid PCM samples bypass the hold-last-valid policy.","category":"PCM sample encoding","checks":8,"contract":"Decode PCM with a parallel validity vector, missing flags invalid, holding the most recent valid sample for invalid positions while retaining explicit validity metadata.","contract_signature":"samples, validity, conceal","evaluation_group":"s3-pcm-pcm-sample-validity-sideband","failed_approach":"Always using initial concealment ignores valid history.","family":"s3-pcm-pcm-sample-validity-sideband-invalid-output","id":"FA-50076","implementations":{"attempt":{"sha256":"1e2deb0e6fccf16aabcc9c69f77f7e833ec2e63f2a1b8720ac7d7df1fdff6055","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(samples, validity, conceal):\n    out=[]\n    previous=conceal\n    for index,sample in enumerate(samples):\n        valid=validity[index] if index<len(validity) else False\n        if valid:\n            previous=sample\n        out.append([sample if valid else conceal,bool(valid)])\n    return [out,previous]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, 9, 3, 8], [True, False, True, False], 0)), [[[1, True], [1, False], [3, True], [3, False]], 3])\ncheck('oracle 2', solve(*([9, 2], [False, True], 7)), [[[7, False], [2, True]], 2])\ncheck('oracle 3', solve(*([1, 2, 3], [True], 0)), [[[1, True], [1, False], [1, False]], 1])\ncheck('oracle 4', solve(*([], [], 4)), [[], 4])\ncheck('oracle 5', solve(*([4, 5], [False, False], -1)), [[[-1, False], [-1, False]], -1])\ncheck('oracle 6', solve(*([1, 2, 3], [False, True, False], 5)), [[[5, False], [2, True], [2, False]], 2])\ncheck('oracle 7', solve(*([0], [True], 8)), [[[0, True]], 0])\nif N == 1: check('variant packet 1', solve(*[[1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 2: check('variant packet 2', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 3: check('variant packet 3', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 4: check('variant packet 4', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 5: check('variant packet 5', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\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":"ef824d89c3c662f845ab92f9dd91fcb6c4758d78cb76acbae883a8c28b1a9399","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(samples, validity, conceal):\n    out=[]\n    previous=conceal\n    for index,sample in enumerate(samples):\n        valid=validity[index] if index<len(validity) else False\n        if valid:\n            previous=sample\n        out.append([sample,bool(valid)])\n    return [out,previous]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, 9, 3, 8], [True, False, True, False], 0)), [[[1, True], [1, False], [3, True], [3, False]], 3])\ncheck('oracle 2', solve(*([9, 2], [False, True], 7)), [[[7, False], [2, True]], 2])\ncheck('oracle 3', solve(*([1, 2, 3], [True], 0)), [[[1, True], [1, False], [1, False]], 1])\ncheck('oracle 4', solve(*([], [], 4)), [[], 4])\ncheck('oracle 5', solve(*([4, 5], [False, False], -1)), [[[-1, False], [-1, False]], -1])\ncheck('oracle 6', solve(*([1, 2, 3], [False, True, False], 5)), [[[5, False], [2, True], [2, False]], 2])\ncheck('oracle 7', solve(*([0], [True], 8)), [[[0, True]], 0])\nif N == 1: check('variant packet 1', solve(*[[1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 2: check('variant packet 2', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 3: check('variant packet 3', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 4: check('variant packet 4', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\nif N == 5: check('variant packet 5', solve(*[[1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8, 1, 9, 3, 8], [True, False, True, False], 0]), [[[1, True], [1, False], [3, True], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False], [3, False]], 3])\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":"Stipulated finite model; no claim of hardware timing or full file-format conformance. 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":"s3-pcm-pcm-sample-validity-sideband-invalid-output","generated_at":"2026-09-29T14:45:05.919362+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline PCM interchange uses these exact bounded packet and sample representation decisions.","root_cause":"Invalid PCM samples bypass the hold-last-valid policy.","sha256":"06ac056e18d8f185e654ba9455d020b32998b3d10bde58626f4bb43ab5d7e7d6","title":"Pcm sample validity sideband: invalid output · 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":38.919,"exit_code":1,"observations":[{"actual":[[[1,true],[0,false],[3,true],[0,false]],3],"check":"oracle 1","expected":[[[1,true],[1,false],[3,true],[3,false]],3],"passed":false},{"actual":[[[7,false],[2,true]],2],"check":"oracle 2","expected":[[[7,false],[2,true]],2],"passed":true},{"actual":[[[1,true],[0,false],[0,false]],1],"check":"oracle 3","expected":[[[1,true],[1,false],[1,false]],1],"passed":false},{"actual":[[],4],"check":"oracle 4","expected":[[],4],"passed":true},{"actual":[[[-1,false],[-1,false]],-1],"check":"oracle 5","expected":[[[-1,false],[-1,false]],-1],"passed":true},{"actual":[[[5,false],[2,true],[5,false]],2],"check":"oracle 6","expected":[[[5,false],[2,true],[2,false]],2],"passed":false},{"actual":[[[0,true]],0],"check":"oracle 7","expected":[[[0,true]],0],"passed":true},{"actual":[[[1,true],[0,false],[3,true],[0,false],[0,false],[0,false],[0,false],[0,false]],3],"check":"variant packet 1","expected":[[[1,true],[1,false],[3,true],[3,false],[3,false],[3,false],[3,false],[3,false]],3],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[1, true], [0, false], [3, true], [0, false]], 3], \"expected\": [[[1, true], [1, false], [3, true], [3, false]], 3], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[[7, false], [2, true]], 2], \"expected\": [[[7, false], [2, true]], 2], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[[1, true], [0, false], [0, false]], 1], \"expected\": [[[1, true], [1, false], [1, false]], 1], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], 4], \"expected\": [[], 4], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[-1, false], [-1, false]], -1], \"expected\": [[[-1, false], [-1, false]], -1], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[[5, false], [2, true], [5, false]], 2], \"expected\": [[[5, false], [2, true], [2, false]], 2], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[[0, true]], 0], \"expected\": [[[0, true]], 0], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[1, true], [0, false], [3, true], [0, false], [0, false], [0, false], [0, false], [0, false]], 3], \"expected\": [[[1, true], [1, false], [3, true], [3, false], [3, false], [3, false], [3, false], [3, false]], 3], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.478,"exit_code":1,"observations":[{"actual":[[[1,true],[9,false],[3,true],[8,false]],3],"check":"oracle 1","expected":[[[1,true],[1,false],[3,true],[3,false]],3],"passed":false},{"actual":[[[9,false],[2,true]],2],"check":"oracle 2","expected":[[[7,false],[2,true]],2],"passed":false},{"actual":[[[1,true],[2,false],[3,false]],1],"check":"oracle 3","expected":[[[1,true],[1,false],[1,false]],1],"passed":false},{"actual":[[],4],"check":"oracle 4","expected":[[],4],"passed":true},{"actual":[[[4,false],[5,false]],-1],"check":"oracle 5","expected":[[[-1,false],[-1,false]],-1],"passed":false},{"actual":[[[1,false],[2,true],[3,false]],2],"check":"oracle 6","expected":[[[5,false],[2,true],[2,false]],2],"passed":false},{"actual":[[[0,true]],0],"check":"oracle 7","expected":[[[0,true]],0],"passed":true},{"actual":[[[1,true],[9,false],[3,true],[8,false],[1,false],[9,false],[3,false],[8,false]],3],"check":"variant packet 1","expected":[[[1,true],[1,false],[3,true],[3,false],[3,false],[3,false],[3,false],[3,false]],3],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[1, true], [9, false], [3, true], [8, false]], 3], \"expected\": [[[1, true], [1, false], [3, true], [3, false]], 3], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[[9, false], [2, true]], 2], \"expected\": [[[7, false], [2, true]], 2], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[[1, true], [2, false], [3, false]], 1], \"expected\": [[[1, true], [1, false], [1, false]], 1], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], 4], \"expected\": [[], 4], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[4, false], [5, false]], -1], \"expected\": [[[-1, false], [-1, false]], -1], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[[1, false], [2, true], [3, false]], 2], \"expected\": [[[5, false], [2, true], [2, false]], 2], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[[0, true]], 0], \"expected\": [[[0, true]], 0], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[1, true], [9, false], [3, true], [8, false], [1, false], [9, false], [3, false], [8, false]], 3], \"expected\": [[[1, true], [1, false], [3, true], [3, false], [3, false], [3, false], [3, false], [3, false]], 3], \"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."}}