{"abstract":"Summed audio exceeds normalized output range.","category":"Audio channel mixing","checks":4,"contract":"Mix equal-length sources of finite intermediate amplitudes and clamp each final mixed sample into [-1,1].","contract_signature":"sources","evaluation_group":"xaud-mix-saturate-after-sum","failed_approach":"Clipping each source before summation changes cancellation and still permits summed overflow.","family":"xaud-mix-saturate-after-sum","id":"FA-10896","implementations":{"attempt":{"sha256":"0e56b3477f608fa8b2dd60236e5a14a6eb88ae76013265dd8556215bc35d89d6","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(sources):\n    return [sum(max(-1,min(1,x)) for x in frame) for frame in zip(*sources)] if sources else []\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[0.75, 0.5], [0.75, -0.5]],)),[1, 0])\ncheck('fixture 2',solve(*([[2], [-1]],)),[1])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([[0.25], [0.25]],)),[0.5])\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":"a146b4d0be5f794ad1b22539c4d694cad87d914dc635bf95b890f82d5e245ff3","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(sources):\n    return [sum(frame) for frame in zip(*sources)] if sources else []\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[0.75, 0.5], [0.75, -0.5]],)),[1, 0])\ncheck('fixture 2',solve(*([[2], [-1]],)),[1])\ncheck('fixture 3',solve(*([],)),[])\ncheck('fixture 4',solve(*([[0.25], [0.25]],)),[0.5])\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-mix-saturate-after-sum","generated_at":"2026-09-29T14:38:43.150650+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":"Summed audio exceeds normalized output range.","sha256":"b2b157480c134e253c1cbc32c9c71c2776a5ba63902f7152959fc3df2e90b6e6","title":"Mix saturate after sum · 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":39.802,"exit_code":1,"observations":[{"actual":[1.5,0.0],"check":"fixture 1","expected":[1,0],"passed":false},{"actual":[0],"check":"fixture 2","expected":[1],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0.5],"check":"fixture 4","expected":[0.5],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1.5, 0.0], \"expected\": [1, 0], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [0], \"expected\": [1], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0.5], \"expected\": [0.5], \"passed\": true}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.105,"exit_code":1,"observations":[{"actual":[1.5,0.0],"check":"fixture 1","expected":[1,0],"passed":false},{"actual":[1],"check":"fixture 2","expected":[1],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[0.5],"check":"fixture 4","expected":[0.5],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [1.5, 0.0], \"expected\": [1, 0], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [1], \"expected\": [1], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [0.5], \"expected\": [0.5], \"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."}}