{"abstract":"A one-bit boundary mask replaces the low-bit refinement mask.","category":"PCM sample encoding","checks":8,"contract":"Restore PCM from arithmetic-shift coarse samples and optional unsigned low-bit refinements; missing refinement bits are zero and out-of-field residual bits are masked.","evaluation_group":"s3-pcm-pcm-progressive-refinement","failed_approach":"Absolute value still permits residual bits above the refinement field.","family":"s3-pcm-pcm-progressive-refinement-residual-mask","id":"FA-49456","implementations":{"attempt":{"sha256":"8a5faca5b8d781544bc869cbdb0d1d59a1e5a24fdeca4e5ea54e7a566c1c441e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(coarse, residuals, missing_bits):\n    scale=1<<missing_bits\n    out=[]\n    for index,base in enumerate(coarse):\n        tail=residuals[index] if index<len(residuals) else 0\n        tail = abs(tail)\n        out.append(base*scale+tail)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, -2, 3], [3, 1, 2], 2)), [7, -7, 14])\ncheck('oracle 2', solve(*([-1, 0], [7, 4], 2)), [-1, 0])\ncheck('oracle 3', solve(*([2, 3, 4], [1], 3)), [17, 24, 32])\ncheck('oracle 4', solve(*([], [], 2)), [])\ncheck('oracle 5', solve(*([1, -1], [0, 0], 0)), [1, -1])\ncheck('oracle 6', solve(*([0, 0], [3, -1], 2)), [3, 3])\ncheck('oracle 7', solve(*([3, -3], [2, 1], 1)), [6, -5])\nif N == 1: check('variant packet 1', solve(*[[1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12])\nif N == 2: check('variant packet 2', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12])\nif N == 3: check('variant packet 3', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 4: check('variant packet 4', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 5: check('variant packet 5', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\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":"774a3348b2febdfa4cfce6b1a25605c4defb11c9bd40de3312176fde9d60fe50","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(coarse, residuals, missing_bits):\n    scale=1<<missing_bits\n    out=[]\n    for index,base in enumerate(coarse):\n        tail=residuals[index] if index<len(residuals) else 0\n        tail &= scale\n        out.append(base*scale+tail)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, -2, 3], [3, 1, 2], 2)), [7, -7, 14])\ncheck('oracle 2', solve(*([-1, 0], [7, 4], 2)), [-1, 0])\ncheck('oracle 3', solve(*([2, 3, 4], [1], 3)), [17, 24, 32])\ncheck('oracle 4', solve(*([], [], 2)), [])\ncheck('oracle 5', solve(*([1, -1], [0, 0], 0)), [1, -1])\ncheck('oracle 6', solve(*([0, 0], [3, -1], 2)), [3, 3])\ncheck('oracle 7', solve(*([3, -3], [2, 1], 1)), [6, -5])\nif N == 1: check('variant packet 1', solve(*[[1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12])\nif N == 2: check('variant packet 2', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12])\nif N == 3: check('variant packet 3', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 4: check('variant packet 4', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 5: check('variant packet 5', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\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":"8bea1a4700c378aff21411c9a049fc5b0a4e68405eb7934ec7cfee54df52d31f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(coarse, residuals, missing_bits):\n    scale=1<<missing_bits\n    out=[]\n    for index,base in enumerate(coarse):\n        tail=residuals[index] if index<len(residuals) else 0\n        tail &= scale-1\n        out.append(base*scale+tail)\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, -2, 3], [3, 1, 2], 2)), [7, -7, 14])\ncheck('oracle 2', solve(*([-1, 0], [7, 4], 2)), [-1, 0])\ncheck('oracle 3', solve(*([2, 3, 4], [1], 3)), [17, 24, 32])\ncheck('oracle 4', solve(*([], [], 2)), [])\ncheck('oracle 5', solve(*([1, -1], [0, 0], 0)), [1, -1])\ncheck('oracle 6', solve(*([0, 0], [3, -1], 2)), [3, 3])\ncheck('oracle 7', solve(*([3, -3], [2, 1], 1)), [6, -5])\nif N == 1: check('variant packet 1', solve(*[[1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12])\nif N == 2: check('variant packet 2', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12])\nif N == 3: check('variant packet 3', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 4: check('variant packet 4', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\nif N == 5: check('variant packet 5', solve(*[[1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3, 1, -2, 3], [3, 1, 2], 2]), [7, -7, 14, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12, 4, -8, 12])\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-progressive-refinement-residual-mask","generated_at":"2026-09-29T14:45:00.190256+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 residual mask.","root_cause":"A one-bit boundary mask replaces the low-bit refinement mask.","sha256":"56ee1766a6f010ff92afa118dfde389fd30fc77a876a879f5613c15fa9c71219","title":"Pcm progressive refinement: residual mask · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":38.17,"exit_code":1,"observations":[{"actual":[7,-7,14],"check":"oracle 1","expected":[7,-7,14],"passed":true},{"actual":[3,4],"check":"oracle 2","expected":[-1,0],"passed":false},{"actual":[17,24,32],"check":"oracle 3","expected":[17,24,32],"passed":true},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[1,-1],"check":"oracle 5","expected":[1,-1],"passed":true},{"actual":[3,1],"check":"oracle 6","expected":[3,3],"passed":false},{"actual":[8,-5],"check":"oracle 7","expected":[6,-5],"passed":false},{"actual":[7,-7,14,4,-8,12],"check":"variant packet 1","expected":[7,-7,14,4,-8,12],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [7, -7, 14], \"expected\": [7, -7, 14], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [3, 4], \"expected\": [-1, 0], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [17, 24, 32], \"expected\": [17, 24, 32], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [1, -1], \"expected\": [1, -1], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [3, 1], \"expected\": [3, 3], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [8, -5], \"expected\": [6, -5], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [7, -7, 14, 4, -8, 12], \"expected\": [7, -7, 14, 4, -8, 12], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":37.692,"exit_code":1,"observations":[{"actual":[4,-8,12],"check":"oracle 1","expected":[7,-7,14],"passed":false},{"actual":[0,4],"check":"oracle 2","expected":[-1,0],"passed":false},{"actual":[16,24,32],"check":"oracle 3","expected":[17,24,32],"passed":false},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[1,-1],"check":"oracle 5","expected":[1,-1],"passed":true},{"actual":[0,4],"check":"oracle 6","expected":[3,3],"passed":false},{"actual":[8,-6],"check":"oracle 7","expected":[6,-5],"passed":false},{"actual":[4,-8,12,4,-8,12],"check":"variant packet 1","expected":[7,-7,14,4,-8,12],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [4, -8, 12], \"expected\": [7, -7, 14], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [0, 4], \"expected\": [-1, 0], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [16, 24, 32], \"expected\": [17, 24, 32], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [1, -1], \"expected\": [1, -1], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [0, 4], \"expected\": [3, 3], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [8, -6], \"expected\": [6, -5], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [4, -8, 12, 4, -8, 12], \"expected\": [7, -7, 14, 4, -8, 12], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.999,"exit_code":0,"observations":[{"actual":[7,-7,14],"check":"oracle 1","expected":[7,-7,14],"passed":true},{"actual":[-1,0],"check":"oracle 2","expected":[-1,0],"passed":true},{"actual":[17,24,32],"check":"oracle 3","expected":[17,24,32],"passed":true},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[1,-1],"check":"oracle 5","expected":[1,-1],"passed":true},{"actual":[3,3],"check":"oracle 6","expected":[3,3],"passed":true},{"actual":[6,-5],"check":"oracle 7","expected":[6,-5],"passed":true},{"actual":[7,-7,14,4,-8,12],"check":"variant packet 1","expected":[7,-7,14,4,-8,12],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [7, -7, 14], \"expected\": [7, -7, 14], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [-1, 0], \"expected\": [-1, 0], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [17, 24, 32], \"expected\": [17, 24, 32], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [1, -1], \"expected\": [1, -1], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [3, 3], \"expected\": [3, 3], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [6, -5], \"expected\": [6, -5], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [7, -7, 14, 4, -8, 12], \"expected\": [7, -7, 14, 4, -8, 12], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}