{"abstract":"Samples within each PCM bitplane are read in reverse order.","category":"PCM sample encoding","checks":8,"contract":"Restore signed PCM sample integers from least-significant-bit-first bitplanes; sample index selects a bit inside each plane, and extra planes are ignored.","contract_signature":"planes, samples, width","evaluation_group":"s3-pcm-pcm-bitplane-restore","failed_approach":"Reusing the first sample bit repeats the first waveform value.","family":"s3-pcm-pcm-bitplane-restore-sample-bit-offset","id":"FA-49096","implementations":{"attempt":{"sha256":"544f837a1871ed284eb0fd06ab87b18820fcc076cb1045ff93450155afe42566","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(planes, samples, width):\n    out=[0]*samples\n    for bit,plane in enumerate(planes[:width]):\n        for i in range(samples):\n            value=plane&1\n            out[i]|=value<<bit\n    sign=1<<(width-1)\n    return [x-(1<<width) if x&sign else x for x in out]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([5, 6, 3], 3, 3)), [-3, -2, 3])\ncheck('oracle 2', solve(*([1, 2, 4, 7], 3, 3)), [1, 2, -4])\ncheck('oracle 3', solve(*([0, 0, 7], 3, 3)), [-4, -4, -4])\ncheck('oracle 4', solve(*([3, 0], 2, 2)), [1, 1])\ncheck('oracle 5', solve(*([], 0, 4)), [])\ncheck('oracle 6', solve(*([1], 1, 1)), [-1])\ncheck('oracle 7', solve(*([0, 1, 0, 0], 1, 3)), [2])\nif N == 1: check('variant packet 1', solve(*[[5, 6, 3], 4, 3]), [-3, -2, 3, 0])\nif N == 2: check('variant packet 2', solve(*[[5, 6, 3], 5, 3]), [-3, -2, 3, 0, 0])\nif N == 3: check('variant packet 3', solve(*[[5, 6, 3], 6, 3]), [-3, -2, 3, 0, 0, 0])\nif N == 4: check('variant packet 4', solve(*[[5, 6, 3], 7, 3]), [-3, -2, 3, 0, 0, 0, 0])\nif N == 5: check('variant packet 5', solve(*[[5, 6, 3], 8, 3]), [-3, -2, 3, 0, 0, 0, 0, 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":"bec33d8c859b9ff1b0e23d10d7248ac4e965a2c25fc94005be78d19b757a3606","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(planes, samples, width):\n    out=[0]*samples\n    for bit,plane in enumerate(planes[:width]):\n        for i in range(samples):\n            value=(plane>>(samples-1-i))&1\n            out[i]|=value<<bit\n    sign=1<<(width-1)\n    return [x-(1<<width) if x&sign else x for x in out]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([5, 6, 3], 3, 3)), [-3, -2, 3])\ncheck('oracle 2', solve(*([1, 2, 4, 7], 3, 3)), [1, 2, -4])\ncheck('oracle 3', solve(*([0, 0, 7], 3, 3)), [-4, -4, -4])\ncheck('oracle 4', solve(*([3, 0], 2, 2)), [1, 1])\ncheck('oracle 5', solve(*([], 0, 4)), [])\ncheck('oracle 6', solve(*([1], 1, 1)), [-1])\ncheck('oracle 7', solve(*([0, 1, 0, 0], 1, 3)), [2])\nif N == 1: check('variant packet 1', solve(*[[5, 6, 3], 4, 3]), [-3, -2, 3, 0])\nif N == 2: check('variant packet 2', solve(*[[5, 6, 3], 5, 3]), [-3, -2, 3, 0, 0])\nif N == 3: check('variant packet 3', solve(*[[5, 6, 3], 6, 3]), [-3, -2, 3, 0, 0, 0])\nif N == 4: check('variant packet 4', solve(*[[5, 6, 3], 7, 3]), [-3, -2, 3, 0, 0, 0, 0])\nif N == 5: check('variant packet 5', solve(*[[5, 6, 3], 8, 3]), [-3, -2, 3, 0, 0, 0, 0, 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":"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-bitplane-restore-sample-bit-offset","generated_at":"2026-09-29T14:44:56.938680+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":"Samples within each PCM bitplane are read in reverse order.","sha256":"06c075d4e41c2846012a53ca9fae4cd95e91bd50f3b86bae0588eac883b189da","title":"Pcm bitplane restore: sample bit offset · 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":45.726,"exit_code":1,"observations":[{"actual":[-3,-3,-3],"check":"oracle 1","expected":[-3,-2,3],"passed":false},{"actual":[1,1,1],"check":"oracle 2","expected":[1,2,-4],"passed":false},{"actual":[-4,-4,-4],"check":"oracle 3","expected":[-4,-4,-4],"passed":true},{"actual":[1,1],"check":"oracle 4","expected":[1,1],"passed":true},{"actual":[],"check":"oracle 5","expected":[],"passed":true},{"actual":[-1],"check":"oracle 6","expected":[-1],"passed":true},{"actual":[2],"check":"oracle 7","expected":[2],"passed":true},{"actual":[-3,-3,-3,-3],"check":"variant packet 1","expected":[-3,-2,3,0],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [-3, -3, -3], \"expected\": [-3, -2, 3], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [1, 1, 1], \"expected\": [1, 2, -4], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [-4, -4, -4], \"expected\": [-4, -4, -4], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [1, 1], \"expected\": [1, 1], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [-1], \"expected\": [-1], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [-3, -3, -3, -3], \"expected\": [-3, -2, 3, 0], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.736,"exit_code":1,"observations":[{"actual":[3,-2,-3],"check":"oracle 1","expected":[-3,-2,3],"passed":false},{"actual":[-4,2,1],"check":"oracle 2","expected":[1,2,-4],"passed":false},{"actual":[-4,-4,-4],"check":"oracle 3","expected":[-4,-4,-4],"passed":true},{"actual":[1,1],"check":"oracle 4","expected":[1,1],"passed":true},{"actual":[],"check":"oracle 5","expected":[],"passed":true},{"actual":[-1],"check":"oracle 6","expected":[-1],"passed":true},{"actual":[2],"check":"oracle 7","expected":[2],"passed":true},{"actual":[0,3,-2,-3],"check":"variant packet 1","expected":[-3,-2,3,0],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [3, -2, -3], \"expected\": [-3, -2, 3], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [-4, 2, 1], \"expected\": [1, 2, -4], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [-4, -4, -4], \"expected\": [-4, -4, -4], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [1, 1], \"expected\": [1, 1], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [-1], \"expected\": [-1], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [2], \"expected\": [2], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [0, 3, -2, -3], \"expected\": [-3, -2, 3, 0], \"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."}}