{"abstract":"Feedback treats output code as original-domain amplitude.","category":"PCM sample encoding","checks":8,"contract":"Integer PCM precision reducer with first-order error feedback, even positive step, ties toward positive infinity, explicit reset positions and returned error state.","evaluation_group":"s3-pcm-pcm-error-feedback-quantizer","failed_approach":"Dividing codes by step further changes units.","family":"s3-pcm-pcm-error-feedback-quantizer-restored-amplitude","id":"FA-49601","implementations":{"attempt":{"sha256":"322d3e1ae1003c8bc403bec2d68f0094a44deb61a9e65db541ad72516ccb2896","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(samples, step, error, resets):\n    out=[]\n    for index,sample in enumerate(samples):\n        if index in resets:\n            error=0\n        driven=sample+error\n        code=(driven+step//2)//step\n        restored=code//step\n        error=driven-restored\n        out.append(code)\n    return [out,error]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, 1, 1, 1], 4, 0, [])), [[0, 1, 0, 0], 0])\ncheck('oracle 2', solve(*([3, -3, 2, -2], 4, 1, [])), [[1, -1, 1, -1], 1])\ncheck('oracle 3', solve(*([1, 2, 3, 4], 4, 2, [2])), [[1, 0, 1, 1], -1])\ncheck('oracle 4', solve(*([], 4, 3, [])), [[], 3])\ncheck('oracle 5', solve(*([-1, -1, -1], 2, 0, [])), [[0, -1, 0], -1])\ncheck('oracle 6', solve(*([0, 1, 2], 2, -1, [0])), [[0, 1, 1], -1])\ncheck('oracle 7', solve(*([7, -7, 5], 6, 1, [1])), [[1, -1, 1], -2])\nif N == 1: check('variant packet 1', solve(*[[1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 2: check('variant packet 2', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 3: check('variant packet 3', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 4: check('variant packet 4', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 5: check('variant packet 5', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 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":"3fa0eb8046ec32604f8a179769848271be6f97026e7e380018e992b03273ba87","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(samples, step, error, resets):\n    out=[]\n    for index,sample in enumerate(samples):\n        if index in resets:\n            error=0\n        driven=sample+error\n        code=(driven+step//2)//step\n        restored=code\n        error=driven-restored\n        out.append(code)\n    return [out,error]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, 1, 1, 1], 4, 0, [])), [[0, 1, 0, 0], 0])\ncheck('oracle 2', solve(*([3, -3, 2, -2], 4, 1, [])), [[1, -1, 1, -1], 1])\ncheck('oracle 3', solve(*([1, 2, 3, 4], 4, 2, [2])), [[1, 0, 1, 1], -1])\ncheck('oracle 4', solve(*([], 4, 3, [])), [[], 3])\ncheck('oracle 5', solve(*([-1, -1, -1], 2, 0, [])), [[0, -1, 0], -1])\ncheck('oracle 6', solve(*([0, 1, 2], 2, -1, [0])), [[0, 1, 1], -1])\ncheck('oracle 7', solve(*([7, -7, 5], 6, 1, [1])), [[1, -1, 1], -2])\nif N == 1: check('variant packet 1', solve(*[[1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 2: check('variant packet 2', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 3: check('variant packet 3', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 4: check('variant packet 4', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 5: check('variant packet 5', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 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"},"fixed":{"sha256":"29c1c1c2a97919fa6fcbe73cf6cddb859183d15ccd704f79b4bfde66d32e13b1","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(samples, step, error, resets):\n    out=[]\n    for index,sample in enumerate(samples):\n        if index in resets:\n            error=0\n        driven=sample+error\n        code=(driven+step//2)//step\n        restored=code*step\n        error=driven-restored\n        out.append(code)\n    return [out,error]\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([1, 1, 1, 1], 4, 0, [])), [[0, 1, 0, 0], 0])\ncheck('oracle 2', solve(*([3, -3, 2, -2], 4, 1, [])), [[1, -1, 1, -1], 1])\ncheck('oracle 3', solve(*([1, 2, 3, 4], 4, 2, [2])), [[1, 0, 1, 1], -1])\ncheck('oracle 4', solve(*([], 4, 3, [])), [[], 3])\ncheck('oracle 5', solve(*([-1, -1, -1], 2, 0, [])), [[0, -1, 0], -1])\ncheck('oracle 6', solve(*([0, 1, 2], 2, -1, [0])), [[0, 1, 1], -1])\ncheck('oracle 7', solve(*([7, -7, 5], 6, 1, [1])), [[1, -1, 1], -2])\nif N == 1: check('variant packet 1', solve(*[[1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 2: check('variant packet 2', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 3: check('variant packet 3', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 4: check('variant packet 4', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 0])\nif N == 5: check('variant packet 5', solve(*[[1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1], 4, 0, []]), [[0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0, 0, 1, 0, 0], 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":"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-error-feedback-quantizer-restored-amplitude","generated_at":"2026-09-29T14:45:01.509991+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 restored amplitude.","root_cause":"Feedback treats output code as original-domain amplitude.","sha256":"4cfd065e7f9f771bf23b45fde6d9c51a7821600b70256c73ba504b42ea56f6e6","title":"Pcm error feedback quantizer: restored amplitude · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.646,"exit_code":1,"observations":[{"actual":[[0,1,1,1],4],"check":"oracle 1","expected":[[0,1,0,0],0],"passed":false},{"actual":[[1,0,1,0],1],"check":"oracle 2","expected":[[1,-1,1,-1],1],"passed":false},{"actual":[[1,1,1,2],7],"check":"oracle 3","expected":[[1,0,1,1],-1],"passed":false},{"actual":[[],3],"check":"oracle 4","expected":[[],3],"passed":true},{"actual":[[0,-1,-1],-1],"check":"oracle 5","expected":[[0,-1,0],-1],"passed":false},{"actual":[[0,1,2],2],"check":"oracle 6","expected":[[0,1,1],-1],"passed":false},{"actual":[[1,-1,0],-1],"check":"oracle 7","expected":[[1,-1,1],-2],"passed":false},{"actual":[[0,1,1,1,1,2,2,2],8],"check":"variant packet 1","expected":[[0,1,0,0,0,1,0,0],0],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[0, 1, 1, 1], 4], \"expected\": [[0, 1, 0, 0], 0], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[1, 0, 1, 0], 1], \"expected\": [[1, -1, 1, -1], 1], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[1, 1, 1, 2], 7], \"expected\": [[1, 0, 1, 1], -1], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], 3], \"expected\": [[], 3], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0, -1, -1], -1], \"expected\": [[0, -1, 0], -1], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[0, 1, 2], 2], \"expected\": [[0, 1, 1], -1], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[1, -1, 0], -1], \"expected\": [[1, -1, 1], -2], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[0, 1, 1, 1, 1, 2, 2, 2], 8], \"expected\": [[0, 1, 0, 0, 0, 1, 0, 0], 0], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":40.534,"exit_code":1,"observations":[{"actual":[[0,1,1,1],1],"check":"oracle 1","expected":[[0,1,0,0],0],"passed":false},{"actual":[[1,0,1,0],-1],"check":"oracle 2","expected":[[1,-1,1,-1],1],"passed":false},{"actual":[[1,1,1,2],4],"check":"oracle 3","expected":[[1,0,1,1],-1],"passed":false},{"actual":[[],3],"check":"oracle 4","expected":[[],3],"passed":true},{"actual":[[0,-1,-1],-1],"check":"oracle 5","expected":[[0,-1,0],-1],"passed":false},{"actual":[[0,1,1],1],"check":"oracle 6","expected":[[0,1,1],-1],"passed":false},{"actual":[[1,-1,0],-1],"check":"oracle 7","expected":[[1,-1,1],-2],"passed":false},{"actual":[[0,1,1,1,1,1,1,1],1],"check":"variant packet 1","expected":[[0,1,0,0,0,1,0,0],0],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[0, 1, 1, 1], 1], \"expected\": [[0, 1, 0, 0], 0], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [[1, 0, 1, 0], -1], \"expected\": [[1, -1, 1, -1], 1], \"passed\": false}, {\"check\": \"oracle 3\", \"actual\": [[1, 1, 1, 2], 4], \"expected\": [[1, 0, 1, 1], -1], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [[], 3], \"expected\": [[], 3], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0, -1, -1], -1], \"expected\": [[0, -1, 0], -1], \"passed\": false}, {\"check\": \"oracle 6\", \"actual\": [[0, 1, 1], 1], \"expected\": [[0, 1, 1], -1], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[1, -1, 0], -1], \"expected\": [[1, -1, 1], -2], \"passed\": false}, {\"check\": \"variant packet 1\", \"actual\": [[0, 1, 1, 1, 1, 1, 1, 1], 1], \"expected\": [[0, 1, 0, 0, 0, 1, 0, 0], 0], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":41.279,"exit_code":0,"observations":[{"actual":[[0,1,0,0],0],"check":"oracle 1","expected":[[0,1,0,0],0],"passed":true},{"actual":[[1,-1,1,-1],1],"check":"oracle 2","expected":[[1,-1,1,-1],1],"passed":true},{"actual":[[1,0,1,1],-1],"check":"oracle 3","expected":[[1,0,1,1],-1],"passed":true},{"actual":[[],3],"check":"oracle 4","expected":[[],3],"passed":true},{"actual":[[0,-1,0],-1],"check":"oracle 5","expected":[[0,-1,0],-1],"passed":true},{"actual":[[0,1,1],-1],"check":"oracle 6","expected":[[0,1,1],-1],"passed":true},{"actual":[[1,-1,1],-2],"check":"oracle 7","expected":[[1,-1,1],-2],"passed":true},{"actual":[[0,1,0,0,0,1,0,0],0],"check":"variant packet 1","expected":[[0,1,0,0,0,1,0,0],0],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[0, 1, 0, 0], 0], \"expected\": [[0, 1, 0, 0], 0], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [[1, -1, 1, -1], 1], \"expected\": [[1, -1, 1, -1], 1], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[1, 0, 1, 1], -1], \"expected\": [[1, 0, 1, 1], -1], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [[], 3], \"expected\": [[], 3], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[0, -1, 0], -1], \"expected\": [[0, -1, 0], -1], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[0, 1, 1], -1], \"expected\": [[0, 1, 1], -1], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[1, -1, 1], -2], \"expected\": [[1, -1, 1], -2], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[0, 1, 0, 0, 0, 1, 0, 0], 0], \"expected\": [[0, 1, 0, 0, 0, 1, 0, 0], 0], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}