{"abstract":"A mono channel update overwrites every channel in its frame.","category":"Audio frame buffers","checks":4,"contract":"Replace one valid channel in every frame with corresponding per-frame values; values length equals frame count.","evaluation_group":"xaud-replace-one-channel","failed_approach":"Repeating the first replacement sample loses the replacement waveform over time.","family":"xaud-replace-one-channel","id":"FA-10856","implementations":{"attempt":{"sha256":"dff29e4ee8541d791705dd4483806df9c0aa931da8c3679308a06d48d954fa05","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frames, channel, values):\n    return [[values[0] if c==channel else x for c,x in enumerate(frame)] for frame in frames]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 2], [3, 4]], 1, [8, 9])),[[1, 8], [3, 9]])\ncheck('fixture 2',solve(*([[1, 2]], 0, [0])),[[0, 2]])\ncheck('fixture 3',solve(*([], 0, [])),[])\ncheck('fixture 4',solve(*([[1], [2]], 0, [4, 5])),[[4], [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":"60ad1ac977bd0b9f0589dcf35fec4986e36baccbc59db64bb5372f8160c16705","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frames, channel, values):\n    return [[values[i] for x in frame] for i,frame in enumerate(frames)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 2], [3, 4]], 1, [8, 9])),[[1, 8], [3, 9]])\ncheck('fixture 2',solve(*([[1, 2]], 0, [0])),[[0, 2]])\ncheck('fixture 3',solve(*([], 0, [])),[])\ncheck('fixture 4',solve(*([[1], [2]], 0, [4, 5])),[[4], [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"},"fixed":{"sha256":"7ce5a6f9fda5c0b1160414087c1e28c976a485bf519320d997eecfc77463a2e7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\nimport math\nN = 1\nobservations = []\ndef solve(frames, channel, values):\n    return [[values[i] if c==channel else x for c,x in enumerate(frame)] for i,frame in enumerate(frames)]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('fixture 1',solve(*([[1, 2], [3, 4]], 1, [8, 9])),[[1, 8], [3, 9]])\ncheck('fixture 2',solve(*([[1, 2]], 0, [0])),[[0, 2]])\ncheck('fixture 3',solve(*([], 0, [])),[])\ncheck('fixture 4',solve(*([[1], [2]], 0, [4, 5])),[[4], [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-replace-one-channel","generated_at":"2026-09-29T14:38:42.858577+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: Replace one valid channel in every frame with corresponding per-frame values; values length equals frame count.","root_cause":"A mono channel update overwrites every channel in its frame.","sha256":"10b66e80c9c5d87789f5e3db217511cf9c23fa6d0aafe434887f3fd033d6996c","title":"Replace one channel · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":39.489,"exit_code":1,"observations":[{"actual":[[1,8],[3,8]],"check":"fixture 1","expected":[[1,8],[3,9]],"passed":false},{"actual":[[0,2]],"check":"fixture 2","expected":[[0,2]],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[4],[4]],"check":"fixture 4","expected":[[4],[5]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[1, 8], [3, 8]], \"expected\": [[1, 8], [3, 9]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, 2]], \"expected\": [[0, 2]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[4], [4]], \"expected\": [[4], [5]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":39.626,"exit_code":1,"observations":[{"actual":[[8,8],[9,9]],"check":"fixture 1","expected":[[1,8],[3,9]],"passed":false},{"actual":[[0,0]],"check":"fixture 2","expected":[[0,2]],"passed":false},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[4],[5]],"check":"fixture 4","expected":[[4],[5]],"passed":true}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[8, 8], [9, 9]], \"expected\": [[1, 8], [3, 9]], \"passed\": false}, {\"check\": \"fixture 2\", \"actual\": [[0, 0]], \"expected\": [[0, 2]], \"passed\": false}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[4], [5]], \"expected\": [[4], [5]], \"passed\": true}], \"passed\": false}\n"},"fixed":{"elapsed_ms":38.316,"exit_code":0,"observations":[{"actual":[[1,8],[3,9]],"check":"fixture 1","expected":[[1,8],[3,9]],"passed":true},{"actual":[[0,2]],"check":"fixture 2","expected":[[0,2]],"passed":true},{"actual":[],"check":"fixture 3","expected":[],"passed":true},{"actual":[[4],[5]],"check":"fixture 4","expected":[[4],[5]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"fixture 1\", \"actual\": [[1, 8], [3, 9]], \"expected\": [[1, 8], [3, 9]], \"passed\": true}, {\"check\": \"fixture 2\", \"actual\": [[0, 2]], \"expected\": [[0, 2]], \"passed\": true}, {\"check\": \"fixture 3\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"fixture 4\", \"actual\": [[4], [5]], \"expected\": [[4], [5]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}