{"abstract":"Zero bytes pad unsigned audio with maximum negative amplitude.","category":"PCM sample encoding","checks":4,"contract":"Pad unsigned8 PCM to at least nonnegative size with midpoint silence, preserving existing samples even when already longer.","contract_signature":"samples, size","evaluation_group":"xaud-unsigned-eight-bit-silence-padding","failed_approach":"Trimming existing samples turns padding into destructive resize.","family":"xaud-unsigned-eight-bit-silence-padding","id":"FA-10816","implementations":{"attempt":{"sha256":"a82463c33830b4e931cdea064d3a5aa586fdd6921cd1f5df17d8487950530312","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, size):\n    return list(samples[:size])+[128]*max(0,size-len(samples))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([130], 3)),[130, 128, 128])\ncheck('fixture 2',solve(*([], 2)),[128, 128])\ncheck('fixture 3',solve(*([1, 2, 3], 2)),[1, 2, 3])\ncheck('fixture 4',solve(*([128], 1)),[128])\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":"a6ea73f4903b8ab9ba8d812c7a709d49052bac6d16bb9c5866cf4010e53020d0","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, size):\n    return list(samples)+[0]*max(0,size-len(samples))\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([130], 3)),[130, 128, 128])\ncheck('fixture 2',solve(*([], 2)),[128, 128])\ncheck('fixture 3',solve(*([1, 2, 3], 2)),[1, 2, 3])\ncheck('fixture 4',solve(*([128], 1)),[128])\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-unsigned-eight-bit-silence-padding","generated_at":"2026-09-29T14:38:42.491916+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":"Zero bytes pad unsigned audio with maximum negative amplitude.","sha256":"870f0825bce0ea911a27e10c094a9deea8cd81d9309cb6c945de98a42e2969d4","title":"Unsigned eight bit silence padding · 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":42.565,"exit_code":1,"observations":[{"actual":[130,128,128],"check":"fixture 1","expected":[130,128,128],"passed":true},{"actual":[128,128],"check":"fixture 2","expected":[128,128],"passed":true},{"actual":[1,2],"check":"fixture 3","expected":[1,2,3],"passed":false},{"actual":[128],"check":"fixture 4","expected":[128],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [130, 128, 128], \"expected\": [130, 128, 128], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [128, 128], \"expected\": [128, 128], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [1, 2], \"expected\": [1, 2, 3], \"passed\": false}, {\"check\": \"fixture 4\", \"actual\": [128], \"expected\": [128], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.839,"exit_code":1,"observations":[{"actual":[130,0,0],"check":"fixture 1","expected":[130,128,128],"passed":false},{"actual":[0,0],"check":"fixture 2","expected":[128,128],"passed":false},{"actual":[1,2,3],"check":"fixture 3","expected":[1,2,3],"passed":true},{"actual":[128],"check":"fixture 4","expected":[128],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [130, 0, 0], \"expected\": [130, 128, 128], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [0, 0], \"expected\": [128, 128], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [1, 2, 3], \"expected\": [1, 2, 3], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [128], \"expected\": [128], \"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."}}