{"abstract":"Byte order swaps the significance of each PCM sample byte.","category":"PCM sample encoding","checks":4,"contract":"Decode a byte-value list of even length as signed 16-bit little-endian PCM samples.","contract_signature":"data","evaluation_group":"xaud-signed-sixteen-little-endian-decode","failed_approach":"Correcting endianness while retaining unsigned interpretation makes negative samples positive.","family":"xaud-signed-sixteen-little-endian-decode","id":"FA-10786","implementations":{"attempt":{"sha256":"ee9c6af23b414cb72ed3ab04494c652a933730d23b8e3d3a20d676667ef4063e","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(data):\n    return [int.from_bytes(bytes(data[i:i+2]),\"little\",signed=False) for i in range(0,len(data),2)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([0, 128, 255, 127],)),[-32768, 32767])\ncheck('fixture 2',solve(*([1, 0, 255, 255],)),[1, -1])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([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":"2c408f56b3210792e500d13ad15f053d221dba75fbe09f268d1fc4fde74e5d69","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(data):\n    return [int.from_bytes(bytes(data[i:i+2]),\"big\",signed=True) for i in range(0,len(data),2)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([0, 128, 255, 127],)),[-32768, 32767])\ncheck('fixture 2',solve(*([1, 0, 255, 255],)),[1, -1])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([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":" 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-signed-sixteen-little-endian-decode","generated_at":"2026-09-29T14:38:42.227296+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":"Byte order swaps the significance of each PCM sample byte.","sha256":"3e80421c1dc293b8389d15a23d5788b6cfe6e12eeb180f58dc30ebc50d131c9a","title":"Signed sixteen little endian decode · 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":45.235,"exit_code":1,"observations":[{"actual":[32768,32767],"check":"fixture 1","expected":[-32768,32767],"passed":false},{"actual":[1,65535],"check":"fixture 2","expected":[1,-1],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0],"check":"fixture 4","expected":[0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [32768, 32767], \"expected\": [-32768, 32767], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1, 65535], \"expected\": [1, -1], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0], \"expected\": [0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":45.454,"exit_code":1,"observations":[{"actual":[128,-129],"check":"fixture 1","expected":[-32768,32767],"passed":false},{"actual":[256,-1],"check":"fixture 2","expected":[1,-1],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0],"check":"fixture 4","expected":[0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [128, -129], \"expected\": [-32768, 32767], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [256, -1], \"expected\": [1, -1], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0], \"expected\": [0], \"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."}}