{"abstract":"Duplicating the whole waveform produces channel-major storage.","category":"Audio frame buffers","checks":4,"contract":"Expand each mono sample to a frame of nonnegative channel count; output is frame-major.","contract_signature":"samples, channels","evaluation_group":"xaud-mono-to-multichannel-duplication","failed_approach":"Keeping singleton frames ignores the requested output channel count.","family":"xaud-mono-to-multichannel-duplication","id":"FA-10861","implementations":{"attempt":{"sha256":"907735aa36c9c8fad5f8b6d573b7a17b7dfd6bf6459e4b2090b93352306ba757","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, channels):\n    return [[x] for x in samples]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2], 3)),[[1, 1, 1], [2, 2, 2]])\ncheck('fixture 2',solve(*([], 2)),[])\ncheck('fixture 3',solve(*([5], 1)),[[5]])\ncheck('fixture 4',solve(*([1, 2], 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":"a724fd5cb11080c6b24a429c72f62d39435b175c31a66804cad5167d488b7873","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(samples, channels):\n    return [list(samples) for i in range(channels)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([1, 2], 3)),[[1, 1, 1], [2, 2, 2]])\ncheck('fixture 2',solve(*([], 2)),[])\ncheck('fixture 3',solve(*([5], 1)),[[5]])\ncheck('fixture 4',solve(*([1, 2], 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-mono-to-multichannel-duplication","generated_at":"2026-09-29T14:38:42.912153+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":"Duplicating the whole waveform produces channel-major storage.","sha256":"522d1e9bc6ab42917be4235fa44fb5232636c074ea715b7c6cbb4a3a7d202783","title":"Mono to multichannel duplication · 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":39.472,"exit_code":1,"observations":[{"actual":[[1],[2]],"check":"fixture 1","expected":[[1,1,1],[2,2,2]],"passed":false},{"actual":[],"check":"fixture 2","expected":[],"passed":true},{"actual":[[5]],"check":"fixture 3","expected":[[5]],"passed":true},{"actual":[[1],[2]],"check":"fixture 4","expected":[[],[]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[1], [2]], \"expected\": [[1, 1, 1], [2, 2, 2]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [[5]], \"expected\": [[5]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[1], [2]], \"expected\": [[], []], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":38.782,"exit_code":1,"observations":[{"actual":[[1,2],[1,2],[1,2]],"check":"fixture 1","expected":[[1,1,1],[2,2,2]],"passed":false},{"actual":[[],[]],"check":"fixture 2","expected":[],"passed":false},{"actual":[[5]],"check":"fixture 3","expected":[[5]],"passed":true},{"actual":[],"check":"fixture 4","expected":[[],[]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[1, 2], [1, 2], [1, 2]], \"expected\": [[1, 1, 1], [2, 2, 2]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[], []], \"expected\": [], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [[5]], \"expected\": [[5]], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [], \"expected\": [[], []], \"passed\": false}], \"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."}}