{"abstract":"Transport bits above the octet leak into the high nibble.","category":"PCM sample encoding","checks":8,"contract":"Extract adaptive PCM nibble codes in declared within-octet order; valid count is in nibbles and remaining codes are returned separately as padding.","evaluation_group":"s3-pcm-pcm-nibble-block-order","failed_approach":"Reusing low nibble duplicates the second sample code.","family":"s3-pcm-pcm-nibble-block-order-high-mask","id":"FA-49771","implementations":{"attempt":{"sha256":"3459eaae1962085f920471f7b82bdbf9cebcdec9b72c112f593775b056ae3eea","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(octets, high_first, valid_nibbles):\n    values=[]\n    for byte in octets:\n        high=byte&15\n        low=byte&15\n        values.extend([high,low] if high_first else [low,high])\n    count=min(max(valid_nibbles,0),len(values))\n    return [values[:count],values[count:]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([24, 242], True, 3)), [[1, 8, 15], [2]])\ncheck('oracle 2', solve(*([18, 52], False, 4)), [[2, 1, 4, 3], []])\ncheck('oracle 3', solve(*([427], True, 2)), [[10, 11], []])\ncheck('oracle 4', solve(*([], False, 0)), [[], []])\ncheck('oracle 5', solve(*([128], False, 1)), [[0], [8]])\ncheck('oracle 6', solve(*([255], True, 0)), [[], [15, 15]])\ncheck('oracle 7', solve(*([87, 121], False, 8)), [[7, 5, 9, 7], []])\nif N == 1: check('variant packet 1', solve(*[[24, 242, 24, 242], True, 6]), [[1, 8, 15, 2, 1, 8], [15, 2]])\nif N == 2: check('variant packet 2', solve(*[[24, 242, 24, 242, 24, 242], True, 9]), [[1, 8, 15, 2, 1, 8, 15, 2, 1], [8, 15, 2]])\nif N == 3: check('variant packet 3', solve(*[[24, 242, 24, 242, 24, 242, 24, 242], True, 12]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2], [1, 8, 15, 2]])\nif N == 4: check('variant packet 4', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 15]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15], [2, 1, 8, 15, 2]])\nif N == 5: check('variant packet 5', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 18]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8], [15, 2, 1, 8, 15, 2]])\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":"853bb1c3d573ecf066fec705bb2d6fd81ab8f982136a22ccd2c9eb29c6d737f4","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(octets, high_first, valid_nibbles):\n    values=[]\n    for byte in octets:\n        high=byte>>4\n        low=byte&15\n        values.extend([high,low] if high_first else [low,high])\n    count=min(max(valid_nibbles,0),len(values))\n    return [values[:count],values[count:]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([24, 242], True, 3)), [[1, 8, 15], [2]])\ncheck('oracle 2', solve(*([18, 52], False, 4)), [[2, 1, 4, 3], []])\ncheck('oracle 3', solve(*([427], True, 2)), [[10, 11], []])\ncheck('oracle 4', solve(*([], False, 0)), [[], []])\ncheck('oracle 5', solve(*([128], False, 1)), [[0], [8]])\ncheck('oracle 6', solve(*([255], True, 0)), [[], [15, 15]])\ncheck('oracle 7', solve(*([87, 121], False, 8)), [[7, 5, 9, 7], []])\nif N == 1: check('variant packet 1', solve(*[[24, 242, 24, 242], True, 6]), [[1, 8, 15, 2, 1, 8], [15, 2]])\nif N == 2: check('variant packet 2', solve(*[[24, 242, 24, 242, 24, 242], True, 9]), [[1, 8, 15, 2, 1, 8, 15, 2, 1], [8, 15, 2]])\nif N == 3: check('variant packet 3', solve(*[[24, 242, 24, 242, 24, 242, 24, 242], True, 12]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2], [1, 8, 15, 2]])\nif N == 4: check('variant packet 4', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 15]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15], [2, 1, 8, 15, 2]])\nif N == 5: check('variant packet 5', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 18]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8], [15, 2, 1, 8, 15, 2]])\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":"4f6a87c43584421013fac17a5e9bec4afd624413bad1362e9bea4f2fd23f9dba","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(octets, high_first, valid_nibbles):\n    values=[]\n    for byte in octets:\n        high=(byte>>4)&15\n        low=byte&15\n        values.extend([high,low] if high_first else [low,high])\n    count=min(max(valid_nibbles,0),len(values))\n    return [values[:count],values[count:]]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([24, 242], True, 3)), [[1, 8, 15], [2]])\ncheck('oracle 2', solve(*([18, 52], False, 4)), [[2, 1, 4, 3], []])\ncheck('oracle 3', solve(*([427], True, 2)), [[10, 11], []])\ncheck('oracle 4', solve(*([], False, 0)), [[], []])\ncheck('oracle 5', solve(*([128], False, 1)), [[0], [8]])\ncheck('oracle 6', solve(*([255], True, 0)), [[], [15, 15]])\ncheck('oracle 7', solve(*([87, 121], False, 8)), [[7, 5, 9, 7], []])\nif N == 1: check('variant packet 1', solve(*[[24, 242, 24, 242], True, 6]), [[1, 8, 15, 2, 1, 8], [15, 2]])\nif N == 2: check('variant packet 2', solve(*[[24, 242, 24, 242, 24, 242], True, 9]), [[1, 8, 15, 2, 1, 8, 15, 2, 1], [8, 15, 2]])\nif N == 3: check('variant packet 3', solve(*[[24, 242, 24, 242, 24, 242, 24, 242], True, 12]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2], [1, 8, 15, 2]])\nif N == 4: check('variant packet 4', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 15]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15], [2, 1, 8, 15, 2]])\nif N == 5: check('variant packet 5', solve(*[[24, 242, 24, 242, 24, 242, 24, 242, 24, 242, 24, 242], True, 18]), [[1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8, 15, 2, 1, 8], [15, 2, 1, 8, 15, 2]])\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-nibble-block-order-high-mask","generated_at":"2026-09-29T14:45:03.057234+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.","repair":"Use the stated conversion contract at high mask.","root_cause":"Transport bits above the octet leak into the high nibble.","sha256":"af8073e622ce50593abb4f9b3e72aa08e6681c8c3b6b3602b5926ef8b1739958","title":"Pcm nibble block order: high mask · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":44.307,"exit_code":1,"observations":[{"actual":[[8,8,2],[2]],"check":"oracle 1","expected":[[1,8,15],[2]],"passed":false},{"actual":[[2,2,4,4],[]],"check":"oracle 2","expected":[[2,1,4,3],[]],"passed":false},{"actual":[[11,11],[]],"check":"oracle 3","expected":[[10,11],[]],"passed":false},{"actual":[[],[]],"check":"oracle 4","expected":[[],[]],"passed":true},{"actual":[[0],[0]],"check":"oracle 5","expected":[[0],[8]],"passed":false},{"actual":[[],[15,15]],"check":"oracle 6","expected":[[],[15,15]],"passed":true},{"actual":[[7,7,9,9],[]],"check":"oracle 7","expected":[[7,5,9,7],[]],"passed":false},{"actual":[[8,8,2,2,8,8],[2,2]],"check":"variant packet 1","expected":[[1,8,15,2,1,8],[15,2]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[8, 8, 2], [2]], \"expected\": [[1, 8, 15], [2]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[2, 2, 4, 4], []], \"expected\": [[2, 1, 4, 3], []], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[11, 11], []], \"expected\": [[10, 11], []], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0], [0]], \"expected\": [[0], [8]], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[], [15, 15]], \"expected\": [[], [15, 15]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[7, 7, 9, 9], []], \"expected\": [[7, 5, 9, 7], []], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[8, 8, 2, 2, 8, 8], [2, 2]], \"expected\": [[1, 8, 15, 2, 1, 8], [15, 2]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.743,"exit_code":1,"observations":[{"actual":[[1,8,15],[2]],"check":"oracle 1","expected":[[1,8,15],[2]],"passed":true},{"actual":[[2,1,4,3],[]],"check":"oracle 2","expected":[[2,1,4,3],[]],"passed":true},{"actual":[[26,11],[]],"check":"oracle 3","expected":[[10,11],[]],"passed":false},{"actual":[[],[]],"check":"oracle 4","expected":[[],[]],"passed":true},{"actual":[[0],[8]],"check":"oracle 5","expected":[[0],[8]],"passed":true},{"actual":[[],[15,15]],"check":"oracle 6","expected":[[],[15,15]],"passed":true},{"actual":[[7,5,9,7],[]],"check":"oracle 7","expected":[[7,5,9,7],[]],"passed":true},{"actual":[[1,8,15,2,1,8],[15,2]],"check":"variant packet 1","expected":[[1,8,15,2,1,8],[15,2]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[1, 8, 15], [2]], \"expected\": [[1, 8, 15], [2]], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [[2, 1, 4, 3], []], \"expected\": [[2, 1, 4, 3], []], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[26, 11], []], \"expected\": [[10, 11], []], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0], [8]], \"expected\": [[0], [8]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[], [15, 15]], \"expected\": [[], [15, 15]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[7, 5, 9, 7], []], \"expected\": [[7, 5, 9, 7], []], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[1, 8, 15, 2, 1, 8], [15, 2]], \"expected\": [[1, 8, 15, 2, 1, 8], [15, 2]], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.589,"exit_code":0,"observations":[{"actual":[[1,8,15],[2]],"check":"oracle 1","expected":[[1,8,15],[2]],"passed":true},{"actual":[[2,1,4,3],[]],"check":"oracle 2","expected":[[2,1,4,3],[]],"passed":true},{"actual":[[10,11],[]],"check":"oracle 3","expected":[[10,11],[]],"passed":true},{"actual":[[],[]],"check":"oracle 4","expected":[[],[]],"passed":true},{"actual":[[0],[8]],"check":"oracle 5","expected":[[0],[8]],"passed":true},{"actual":[[],[15,15]],"check":"oracle 6","expected":[[],[15,15]],"passed":true},{"actual":[[7,5,9,7],[]],"check":"oracle 7","expected":[[7,5,9,7],[]],"passed":true},{"actual":[[1,8,15,2,1,8],[15,2]],"check":"variant packet 1","expected":[[1,8,15,2,1,8],[15,2]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[1, 8, 15], [2]], \"expected\": [[1, 8, 15], [2]], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [[2, 1, 4, 3], []], \"expected\": [[2, 1, 4, 3], []], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[10, 11], []], \"expected\": [[10, 11], []], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[], []], \"expected\": [[], []], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0], [8]], \"expected\": [[0], [8]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[], [15, 15]], \"expected\": [[], [15, 15]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[7, 5, 9, 7], []], \"expected\": [[7, 5, 9, 7], []], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[1, 8, 15, 2, 1, 8], [15, 2]], \"expected\": [[1, 8, 15, 2, 1, 8], [15, 2]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}