{"abstract":"Unconsumed channel tails are replaced by consumed prefixes.","category":"PCM sample encoding","checks":8,"contract":"Assemble independently decoded adaptive PCM channel blocks into complete frames, returning per-channel unconsumed tails; require exact channel descriptors.","evaluation_group":"s3-pcm-pcm-adaptive-channel-blocks","failed_approach":"Dropping a remainder sample loses data needed by the next block.","family":"s3-pcm-pcm-adaptive-channel-blocks-tail-position","id":"FA-50331","implementations":{"attempt":{"sha256":"a1724dd13fcf4d568c89149a6be08d3d67885c338cd97762618f7854c18b5018","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(blocks, channels):\n    out=[]\n    for lane_chunks in blocks:\n        if len(lane_chunks)!=channels:\n            out.append(None)\n            continue\n        counts=[len(x) for x in lane_chunks]\n        complete=min(counts) if counts else 0\n        frames=[[(lane_chunks[c][i] if c<len(lane_chunks) and i<len(lane_chunks[c]) else None) for c in range(channels)] for i in range(complete)]\n        tails=[list(x[complete+1:]) for x in lane_chunks]\n        out.append([frames,tails])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[[1, 2, 3], [4, 5]]], 2)), [[[[1, 4], [2, 5]], [[3], []]]])\ncheck('oracle 2', solve(*([[[1], [2], [3]], [[1, 2]]], 2)), [None, None])\ncheck('oracle 3', solve(*([[[1, 2], [3, 4]]], 2)), [[[[1, 3], [2, 4]], [[], []]]])\ncheck('oracle 4', solve(*([], 2)), [])\ncheck('oracle 5', solve(*([[[], []]], 2)), [[[], [[], []]]])\ncheck('oracle 6', solve(*([[[1, 2, 3]]], 1)), [[[[1], [2], [3]], [[]]]])\ncheck('oracle 7', solve(*([[[]]], 1)), [[[], [[]]]])\nif N == 1: check('variant packet 1', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 2: check('variant packet 2', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 3: check('variant packet 3', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 4: check('variant packet 4', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 5: check('variant packet 5', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\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":"0c69299f34efb6512358a1297adbe6190c4391bf6263aa02195152536e3b9f25","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(blocks, channels):\n    out=[]\n    for lane_chunks in blocks:\n        if len(lane_chunks)!=channels:\n            out.append(None)\n            continue\n        counts=[len(x) for x in lane_chunks]\n        complete=min(counts) if counts else 0\n        frames=[[(lane_chunks[c][i] if c<len(lane_chunks) and i<len(lane_chunks[c]) else None) for c in range(channels)] for i in range(complete)]\n        tails=[list(x[:complete]) for x in lane_chunks]\n        out.append([frames,tails])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[[1, 2, 3], [4, 5]]], 2)), [[[[1, 4], [2, 5]], [[3], []]]])\ncheck('oracle 2', solve(*([[[1], [2], [3]], [[1, 2]]], 2)), [None, None])\ncheck('oracle 3', solve(*([[[1, 2], [3, 4]]], 2)), [[[[1, 3], [2, 4]], [[], []]]])\ncheck('oracle 4', solve(*([], 2)), [])\ncheck('oracle 5', solve(*([[[], []]], 2)), [[[], [[], []]]])\ncheck('oracle 6', solve(*([[[1, 2, 3]]], 1)), [[[[1], [2], [3]], [[]]]])\ncheck('oracle 7', solve(*([[[]]], 1)), [[[], [[]]]])\nif N == 1: check('variant packet 1', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 2: check('variant packet 2', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 3: check('variant packet 3', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 4: check('variant packet 4', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 5: check('variant packet 5', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\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":"abc4902b14b6deec7cf5f0a55fd1f38d4dd160266db60861d4525c99e78c934d","source":"\"\"\"Failure Map reference implementation. Python standard library only.\"\"\"\nimport json\n\nN = 1\nobservations = []\ndef solve(blocks, channels):\n    out=[]\n    for lane_chunks in blocks:\n        if len(lane_chunks)!=channels:\n            out.append(None)\n            continue\n        counts=[len(x) for x in lane_chunks]\n        complete=min(counts) if counts else 0\n        frames=[[(lane_chunks[c][i] if c<len(lane_chunks) and i<len(lane_chunks[c]) else None) for c in range(channels)] for i in range(complete)]\n        tails=[list(x[complete:]) for x in lane_chunks]\n        out.append([frames,tails])\n    return out\ndef check(label, actual, expected):\n    observations.append({\"check\": label, \"actual\": actual, \"expected\": expected, \"passed\": actual == expected})\ncheck('oracle 1', solve(*([[[1, 2, 3], [4, 5]]], 2)), [[[[1, 4], [2, 5]], [[3], []]]])\ncheck('oracle 2', solve(*([[[1], [2], [3]], [[1, 2]]], 2)), [None, None])\ncheck('oracle 3', solve(*([[[1, 2], [3, 4]]], 2)), [[[[1, 3], [2, 4]], [[], []]]])\ncheck('oracle 4', solve(*([], 2)), [])\ncheck('oracle 5', solve(*([[[], []]], 2)), [[[], [[], []]]])\ncheck('oracle 6', solve(*([[[1, 2, 3]]], 1)), [[[[1], [2], [3]], [[]]]])\ncheck('oracle 7', solve(*([[[]]], 1)), [[[], [[]]]])\nif N == 1: check('variant packet 1', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 2: check('variant packet 2', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 3: check('variant packet 3', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 4: check('variant packet 4', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\nif N == 5: check('variant packet 5', solve(*[[[[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]], [[1, 2, 3], [4, 5]]], 2]), [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]])\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-adaptive-channel-blocks-tail-position","generated_at":"2026-09-29T14:45:08.126462+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 tail position.","root_cause":"Unconsumed channel tails are replaced by consumed prefixes.","sha256":"8b21cc0772146798f8cbcc12d0f7fb289aa4926bf59e559cfb02191f33212ee2","title":"Pcm adaptive channel blocks: tail position · case 01","variant":1,"variant_policy":"Five numbered records share a model and may reuse boundary fixtures.","verification":{"attempt":{"elapsed_ms":40.844,"exit_code":1,"observations":[{"actual":[[[[1,4],[2,5]],[[],[]]]],"check":"oracle 1","expected":[[[[1,4],[2,5]],[[3],[]]]],"passed":false},{"actual":[null,null],"check":"oracle 2","expected":[null,null],"passed":true},{"actual":[[[[1,3],[2,4]],[[],[]]]],"check":"oracle 3","expected":[[[[1,3],[2,4]],[[],[]]]],"passed":true},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[[[],[[],[]]]],"check":"oracle 5","expected":[[[],[[],[]]]],"passed":true},{"actual":[[[[1],[2],[3]],[[]]]],"check":"oracle 6","expected":[[[[1],[2],[3]],[[]]]],"passed":true},{"actual":[[[],[[]]]],"check":"oracle 7","expected":[[[],[[]]]],"passed":true},{"actual":[[[[1,4],[2,5]],[[],[]]],[[[1,4],[2,5]],[[],[]]]],"check":"variant packet 1","expected":[[[[1,4],[2,5]],[[3],[]]],[[[1,4],[2,5]],[[3],[]]]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[[1, 4], [2, 5]], [[], []]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[[[1, 3], [2, 4]], [[], []]]], \"expected\": [[[[1, 3], [2, 4]], [[], []]]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[], [[], []]]], \"expected\": [[[], [[], []]]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[[[1], [2], [3]], [[]]]], \"expected\": [[[[1], [2], [3]], [[]]]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[[], [[]]]], \"expected\": [[[], [[]]]], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[[1, 4], [2, 5]], [[], []]], [[[1, 4], [2, 5]], [[], []]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]], \"passed\": false}], \"passed\": false}\n"},"broken":{"elapsed_ms":43.012,"exit_code":1,"observations":[{"actual":[[[[1,4],[2,5]],[[1,2],[4,5]]]],"check":"oracle 1","expected":[[[[1,4],[2,5]],[[3],[]]]],"passed":false},{"actual":[null,null],"check":"oracle 2","expected":[null,null],"passed":true},{"actual":[[[[1,3],[2,4]],[[1,2],[3,4]]]],"check":"oracle 3","expected":[[[[1,3],[2,4]],[[],[]]]],"passed":false},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[[[],[[],[]]]],"check":"oracle 5","expected":[[[],[[],[]]]],"passed":true},{"actual":[[[[1],[2],[3]],[[1,2,3]]]],"check":"oracle 6","expected":[[[[1],[2],[3]],[[]]]],"passed":false},{"actual":[[[],[[]]]],"check":"oracle 7","expected":[[[],[[]]]],"passed":true},{"actual":[[[[1,4],[2,5]],[[1,2],[4,5]]],[[[1,4],[2,5]],[[1,2],[4,5]]]],"check":"variant packet 1","expected":[[[[1,4],[2,5]],[[3],[]]],[[[1,4],[2,5]],[[3],[]]]],"passed":false}],"passed":false,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[[1, 4], [2, 5]], [[1, 2], [4, 5]]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]]], \"passed\": false}, {\"check\": \"oracle 2\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[[[1, 3], [2, 4]], [[1, 2], [3, 4]]]], \"expected\": [[[[1, 3], [2, 4]], [[], []]]], \"passed\": false}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[], [[], []]]], \"expected\": [[[], [[], []]]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[[[1], [2], [3]], [[1, 2, 3]]]], \"expected\": [[[[1], [2], [3]], [[]]]], \"passed\": false}, {\"check\": \"oracle 7\", \"actual\": [[[], [[]]]], \"expected\": [[[], [[]]]], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[[1, 4], [2, 5]], [[1, 2], [4, 5]]], [[[1, 4], [2, 5]], [[1, 2], [4, 5]]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]], \"passed\": false}], \"passed\": false}\n"},"fixed":{"elapsed_ms":37.482,"exit_code":0,"observations":[{"actual":[[[[1,4],[2,5]],[[3],[]]]],"check":"oracle 1","expected":[[[[1,4],[2,5]],[[3],[]]]],"passed":true},{"actual":[null,null],"check":"oracle 2","expected":[null,null],"passed":true},{"actual":[[[[1,3],[2,4]],[[],[]]]],"check":"oracle 3","expected":[[[[1,3],[2,4]],[[],[]]]],"passed":true},{"actual":[],"check":"oracle 4","expected":[],"passed":true},{"actual":[[[],[[],[]]]],"check":"oracle 5","expected":[[[],[[],[]]]],"passed":true},{"actual":[[[[1],[2],[3]],[[]]]],"check":"oracle 6","expected":[[[[1],[2],[3]],[[]]]],"passed":true},{"actual":[[[],[[]]]],"check":"oracle 7","expected":[[[],[[]]]],"passed":true},{"actual":[[[[1,4],[2,5]],[[3],[]]],[[[1,4],[2,5]],[[3],[]]]],"check":"variant packet 1","expected":[[[[1,4],[2,5]],[[3],[]]],[[[1,4],[2,5]],[[3],[]]]],"passed":true}],"passed":true,"stderr":"","stdout":"{\"observations\": [{\"check\": \"oracle 1\", \"actual\": [[[[1, 4], [2, 5]], [[3], []]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]]], \"passed\": true}, {\"check\": \"oracle 2\", \"actual\": [null, null], \"expected\": [null, null], \"passed\": true}, {\"check\": \"oracle 3\", \"actual\": [[[[1, 3], [2, 4]], [[], []]]], \"expected\": [[[[1, 3], [2, 4]], [[], []]]], \"passed\": true}, {\"check\": \"oracle 4\", \"actual\": [], \"expected\": [], \"passed\": true}, {\"check\": \"oracle 5\", \"actual\": [[[], [[], []]]], \"expected\": [[[], [[], []]]], \"passed\": true}, {\"check\": \"oracle 6\", \"actual\": [[[[1], [2], [3]], [[]]]], \"expected\": [[[[1], [2], [3]], [[]]]], \"passed\": true}, {\"check\": \"oracle 7\", \"actual\": [[[], [[]]]], \"expected\": [[[], [[]]]], \"passed\": true}, {\"check\": \"variant packet 1\", \"actual\": [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]], \"expected\": [[[[1, 4], [2, 5]], [[3], []]], [[[1, 4], [2, 5]], [[3], []]]], \"passed\": true}], \"passed\": true}\n"}},"verified":true,"visibility":"public"}