{"abstract":"All output channels read the first accumulator.","category":"PCM sample encoding","checks":8,"contract":"Decode channel-banked residual PCM, resetting predictors only at specified frame boundaries and exporting final per-channel amplitudes.","evaluation_group":"s3-pcm-pcm-channel-reconstruction","failed_approach":"Returning residual codes skips reconstruction.","family":"s3-pcm-pcm-channel-reconstruction-returned-channel","id":"FA-49371","implementations":{"attempt":{"sha256":"446dbb70e6d8fed632966fd68a93db868716ccae12c528fbf656f64cd13fa3b7","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames, seeds, resets):\n    state=list(seeds)\n    out=[]\n    for index,frame in enumerate(frames):\n        if index in resets:\n            state=list(seeds)\n        reconstructed=[]\n        for channel,residual in enumerate(frame):\n            state[channel]+=residual\n            reconstructed.append(residual)\n        out.append(reconstructed)\n    return [out,state]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[3, 2], [2, -1]], [2, 8], [])), [[[5, 10], [7, 9]], [7, 9]])\ncheck('oracle 2', solve(*([[1, 2], [2, 3], [4, 1]], [1, 2], [1])), [[[2, 4], [3, 5], [7, 6]], [7, 6]])\ncheck('oracle 3', solve(*([], [3, 4], [])), [[], [3, 4]])\ncheck('oracle 4', solve(*([[1], [2], [-1]], [0], [2])), [[[1], [3], [-1]], [-1]])\ncheck('oracle 5', solve(*([[-1, -1], [2, -2]], [-1, 4], [])), [[[-2, 3], [0, 1]], [0, 1]])\ncheck('oracle 6', solve(*([[1, 2, 3]], [3, 2, 1], [0])), [[[4, 4, 4]], [4, 4, 4]])\ncheck('oracle 7', solve(*([[0, 0], [0, 0]], [1, -1], [])), [[[1, -1], [1, -1]], [1, -1]])\nif N == 1: check('variant packet 1', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]])\nif N == 2: check('variant packet 2', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11]], [17, 11]])\nif N == 3: check('variant packet 3', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12]], [22, 12]])\nif N == 4: check('variant packet 4', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13]], [27, 13]])\nif N == 5: check('variant packet 5', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13], [30, 15], [32, 14]], [32, 14]])\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":"fe182b47c541ed424145508b9041961787502b212c813eab470a0356dea17717","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames, seeds, resets):\n    state=list(seeds)\n    out=[]\n    for index,frame in enumerate(frames):\n        if index in resets:\n            state=list(seeds)\n        reconstructed=[]\n        for channel,residual in enumerate(frame):\n            state[channel]+=residual\n            reconstructed.append(state[0])\n        out.append(reconstructed)\n    return [out,state]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[3, 2], [2, -1]], [2, 8], [])), [[[5, 10], [7, 9]], [7, 9]])\ncheck('oracle 2', solve(*([[1, 2], [2, 3], [4, 1]], [1, 2], [1])), [[[2, 4], [3, 5], [7, 6]], [7, 6]])\ncheck('oracle 3', solve(*([], [3, 4], [])), [[], [3, 4]])\ncheck('oracle 4', solve(*([[1], [2], [-1]], [0], [2])), [[[1], [3], [-1]], [-1]])\ncheck('oracle 5', solve(*([[-1, -1], [2, -2]], [-1, 4], [])), [[[-2, 3], [0, 1]], [0, 1]])\ncheck('oracle 6', solve(*([[1, 2, 3]], [3, 2, 1], [0])), [[[4, 4, 4]], [4, 4, 4]])\ncheck('oracle 7', solve(*([[0, 0], [0, 0]], [1, -1], [])), [[[1, -1], [1, -1]], [1, -1]])\nif N == 1: check('variant packet 1', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]])\nif N == 2: check('variant packet 2', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11]], [17, 11]])\nif N == 3: check('variant packet 3', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12]], [22, 12]])\nif N == 4: check('variant packet 4', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13]], [27, 13]])\nif N == 5: check('variant packet 5', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13], [30, 15], [32, 14]], [32, 14]])\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":"bd77d255bc46a03c0e54aefecfad0107d3ab5dcd73e9f1f57c9a170163b565bf","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(frames, seeds, resets):\n    state=list(seeds)\n    out=[]\n    for index,frame in enumerate(frames):\n        if index in resets:\n            state=list(seeds)\n        reconstructed=[]\n        for channel,residual in enumerate(frame):\n            state[channel]+=residual\n            reconstructed.append(state[channel])\n        out.append(reconstructed)\n    return [out,state]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[3, 2], [2, -1]], [2, 8], [])), [[[5, 10], [7, 9]], [7, 9]])\ncheck('oracle 2', solve(*([[1, 2], [2, 3], [4, 1]], [1, 2], [1])), [[[2, 4], [3, 5], [7, 6]], [7, 6]])\ncheck('oracle 3', solve(*([], [3, 4], [])), [[], [3, 4]])\ncheck('oracle 4', solve(*([[1], [2], [-1]], [0], [2])), [[[1], [3], [-1]], [-1]])\ncheck('oracle 5', solve(*([[-1, -1], [2, -2]], [-1, 4], [])), [[[-2, 3], [0, 1]], [0, 1]])\ncheck('oracle 6', solve(*([[1, 2, 3]], [3, 2, 1], [0])), [[[4, 4, 4]], [4, 4, 4]])\ncheck('oracle 7', solve(*([[0, 0], [0, 0]], [1, -1], [])), [[[1, -1], [1, -1]], [1, -1]])\nif N == 1: check('variant packet 1', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]])\nif N == 2: check('variant packet 2', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11]], [17, 11]])\nif N == 3: check('variant packet 3', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12]], [22, 12]])\nif N == 4: check('variant packet 4', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13]], [27, 13]])\nif N == 5: check('variant packet 5', solve(*[[[3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1], [3, 2], [2, -1]], [2, 8], []]), [[[5, 10], [7, 9], [10, 11], [12, 10], [15, 12], [17, 11], [20, 13], [22, 12], [25, 14], [27, 13], [30, 15], [32, 14]], [32, 14]])\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":"Stipulated finite model; no claim of hardware timing or full file-format conformance. 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":"s3-pcm-pcm-channel-reconstruction-returned-channel","generated_at":"2026-09-29T14:44:59.301347+00:00","license":"CC0-1.0","python":"3.12.14","seed":1,"split":"open-access"},"relevance":"Offline PCM interchange uses these exact bounded packet and sample representation decisions.","repair":"Use the stated conversion contract at returned channel.","root_cause":"All output channels read the first accumulator.","sha256":"85c1853350efb22b3317733171e3e12739e504f55b64566b95a46a1d7eda0a35","title":"Pcm channel reconstruction: returned channel · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":41.767,"exit_code":1,"observations":[{"actual":[[[3,2],[2,-1]],[7,9]],"check":"oracle 1","expected":[[[5,10],[7,9]],[7,9]],"passed":false},{"actual":[[[1,2],[2,3],[4,1]],[7,6]],"check":"oracle 2","expected":[[[2,4],[3,5],[7,6]],[7,6]],"passed":false},{"actual":[[],[3,4]],"check":"oracle 3","expected":[[],[3,4]],"passed":true},{"actual":[[[1],[2],[-1]],[-1]],"check":"oracle 4","expected":[[[1],[3],[-1]],[-1]],"passed":false},{"actual":[[[-1,-1],[2,-2]],[0,1]],"check":"oracle 5","expected":[[[-2,3],[0,1]],[0,1]],"passed":false},{"actual":[[[1,2,3]],[4,4,4]],"check":"oracle 6","expected":[[[4,4,4]],[4,4,4]],"passed":false},{"actual":[[[0,0],[0,0]],[1,-1]],"check":"oracle 7","expected":[[[1,-1],[1,-1]],[1,-1]],"passed":false},{"actual":[[[3,2],[2,-1],[3,2],[2,-1]],[12,10]],"check":"variant packet 1","expected":[[[5,10],[7,9],[10,11],[12,10]],[12,10]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[3, 2], [2, -1]], [7, 9]], \"expected\": [[[5, 10], [7, 9]], [7, 9]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[[1, 2], [2, 3], [4, 1]], [7, 6]], \"expected\": [[[2, 4], [3, 5], [7, 6]], [7, 6]], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[], [3, 4]], \"expected\": [[], [3, 4]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[[1], [2], [-1]], [-1]], \"expected\": [[[1], [3], [-1]], [-1]], \"passed\": false}, {\"check\": \"oracle 5\", \"actual\": [[[-1, -1], [2, -2]], [0, 1]], \"expected\": [[[-2, 3], [0, 1]], [0, 1]], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[[1, 2, 3]], [4, 4, 4]], \"expected\": [[[4, 4, 4]], [4, 4, 4]], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[[0, 0], [0, 0]], [1, -1]], \"expected\": [[[1, -1], [1, -1]], [1, -1]], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[[3, 2], [2, -1], [3, 2], [2, -1]], [12, 10]], \"expected\": [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":42.396,"exit_code":1,"observations":[{"actual":[[[5,5],[7,7]],[7,9]],"check":"oracle 1","expected":[[[5,10],[7,9]],[7,9]],"passed":false},{"actual":[[[2,2],[3,3],[7,7]],[7,6]],"check":"oracle 2","expected":[[[2,4],[3,5],[7,6]],[7,6]],"passed":false},{"actual":[[],[3,4]],"check":"oracle 3","expected":[[],[3,4]],"passed":true},{"actual":[[[1],[3],[-1]],[-1]],"check":"oracle 4","expected":[[[1],[3],[-1]],[-1]],"passed":true},{"actual":[[[-2,-2],[0,0]],[0,1]],"check":"oracle 5","expected":[[[-2,3],[0,1]],[0,1]],"passed":false},{"actual":[[[4,4,4]],[4,4,4]],"check":"oracle 6","expected":[[[4,4,4]],[4,4,4]],"passed":true},{"actual":[[[1,1],[1,1]],[1,-1]],"check":"oracle 7","expected":[[[1,-1],[1,-1]],[1,-1]],"passed":false},{"actual":[[[5,5],[7,7],[10,10],[12,12]],[12,10]],"check":"variant packet 1","expected":[[[5,10],[7,9],[10,11],[12,10]],[12,10]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[5, 5], [7, 7]], [7, 9]], \"expected\": [[[5, 10], [7, 9]], [7, 9]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[[2, 2], [3, 3], [7, 7]], [7, 6]], \"expected\": [[[2, 4], [3, 5], [7, 6]], [7, 6]], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[], [3, 4]], \"expected\": [[], [3, 4]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[[1], [3], [-1]], [-1]], \"expected\": [[[1], [3], [-1]], [-1]], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[-2, -2], [0, 0]], [0, 1]], \"expected\": [[[-2, 3], [0, 1]], [0, 1]], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[[4, 4, 4]], [4, 4, 4]], \"expected\": [[[4, 4, 4]], [4, 4, 4]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[[1, 1], [1, 1]], [1, -1]], \"expected\": [[[1, -1], [1, -1]], [1, -1]], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[[5, 5], [7, 7], [10, 10], [12, 12]], [12, 10]], \"expected\": [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.354,"exit_code":0,"observations":[{"actual":[[[5,10],[7,9]],[7,9]],"check":"oracle 1","expected":[[[5,10],[7,9]],[7,9]],"passed":true},{"actual":[[[2,4],[3,5],[7,6]],[7,6]],"check":"oracle 2","expected":[[[2,4],[3,5],[7,6]],[7,6]],"passed":true},{"actual":[[],[3,4]],"check":"oracle 3","expected":[[],[3,4]],"passed":true},{"actual":[[[1],[3],[-1]],[-1]],"check":"oracle 4","expected":[[[1],[3],[-1]],[-1]],"passed":true},{"actual":[[[-2,3],[0,1]],[0,1]],"check":"oracle 5","expected":[[[-2,3],[0,1]],[0,1]],"passed":true},{"actual":[[[4,4,4]],[4,4,4]],"check":"oracle 6","expected":[[[4,4,4]],[4,4,4]],"passed":true},{"actual":[[[1,-1],[1,-1]],[1,-1]],"check":"oracle 7","expected":[[[1,-1],[1,-1]],[1,-1]],"passed":true},{"actual":[[[5,10],[7,9],[10,11],[12,10]],[12,10]],"check":"variant packet 1","expected":[[[5,10],[7,9],[10,11],[12,10]],[12,10]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[5, 10], [7, 9]], [7, 9]], \"expected\": [[[5, 10], [7, 9]], [7, 9]], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [[[2, 4], [3, 5], [7, 6]], [7, 6]], \"expected\": [[[2, 4], [3, 5], [7, 6]], [7, 6]], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[], [3, 4]], \"expected\": [[], [3, 4]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[[1], [3], [-1]], [-1]], \"expected\": [[[1], [3], [-1]], [-1]], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[-2, 3], [0, 1]], [0, 1]], \"expected\": [[[-2, 3], [0, 1]], [0, 1]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[[4, 4, 4]], [4, 4, 4]], \"expected\": [[[4, 4, 4]], [4, 4, 4]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[[1, -1], [1, -1]], [1, -1]], \"expected\": [[[1, -1], [1, -1]], [1, -1]], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]], \"expected\": [[[5, 10], [7, 9], [10, 11], [12, 10]], [12, 10]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}