{"abstract":"Sample bytes are emitted in network order for a little-endian PCM sink.","category":"PCM sample encoding","checks":4,"contract":"Encode integer samples in signed 16-bit range into a flat little-endian byte-value list.","evaluation_group":"xaud-signed-sixteen-encode-little-endian","failed_approach":"Encoding magnitudes removes the waveform negative half-cycle.","family":"xaud-signed-sixteen-encode-little-endian","id":"FA-10796","implementations":{"attempt":{"sha256":"08619c25c97d9f4c807f8d881701a4225db92bc072bbc68b553f0356b6b6ff46","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples):\n    return [b for x in samples for b in abs(x).to_bytes(2,\"little\",signed=False)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, -1],)),[1, 0, 255, 255])\ncheck('fixture 2',solve(*([-32768, 32767],)),[0, 128, 255, 127])\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":"efc3cfc63c7ec021d206bb35a1dc7a276b4e46ec3f27def60f46e50470df5c93","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples):\n    return [b for x in samples for b in x.to_bytes(2,\"big\",signed=True)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, -1],)),[1, 0, 255, 255])\ncheck('fixture 2',solve(*([-32768, 32767],)),[0, 128, 255, 127])\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"},"fixed":{"sha256":"4695b0ed0a87c50f70168e86e35473a1a0947085c17f1bc3047d41f1b5b5457f","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples):\n    return [b for x in samples for b in x.to_bytes(2,\"little\",signed=True)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, -1],)),[1, 0, 255, 255])\ncheck('fixture 2',solve(*([-32768, 32767],)),[0, 128, 255, 127])\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-encode-little-endian","generated_at":"2026-09-29T14:38:42.330837+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.","repair":"Apply the explicit PCM/playback contract: Encode integer samples in signed 16-bit range into a flat little-endian byte-value list.","root_cause":"Sample bytes are emitted in network order for a little-endian PCM sink.","sha256":"af447cc6720f2b3300cd2ed9d2009d66898c20976b6bbc8d79a8ad9c42da7397","title":"Signed sixteen encode little endian · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":42.989,"exit_code":1,"observations":[{"actual":[1,0,1,0],"check":"fixture 1","expected":[1,0,255,255],"passed":false},{"actual":[0,128,255,127],"check":"fixture 2","expected":[0,128,255,127],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1, 0, 1, 0], \"expected\": [1, 0, 255, 255], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [0, 128, 255, 127], \"expected\": [0, 128, 255, 127], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":41.898,"exit_code":1,"observations":[{"actual":[0,1,255,255],"check":"fixture 1","expected":[1,0,255,255],"passed":false},{"actual":[128,0,127,255],"check":"fixture 2","expected":[0,128,255,127],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [0, 1, 255, 255], \"expected\": [1, 0, 255, 255], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [128, 0, 127, 255], \"expected\": [0, 128, 255, 127], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":43.876,"exit_code":0,"observations":[{"actual":[1,0,255,255],"check":"fixture 1","expected":[1,0,255,255],"passed":true},{"actual":[0,128,255,127],"check":"fixture 2","expected":[0,128,255,127],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0,0],"check":"fixture 4","expected":[0,0],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1, 0, 255, 255], \"expected\": [1, 0, 255, 255], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [0, 128, 255, 127], \"expected\": [0, 128, 255, 127], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0, 0], \"expected\": [0, 0], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}