FAILURE MAP
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FA-49081 / PCM sample encoding / Open access

Pcm byte lane shuffle: all padding clean · case 01

One clean pad lane hides contamination elsewhere.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

One clean pad lane hides contamination elsewhere.

VERIFIED REPAIR

Use the stated conversion contract at all padding clean.

Unsuccessful approach: Requiring pad lanes rejects formats without padding.

Case contract

Repack each fixed-size sample container using an explicit byte-lane map, retain duplicate selections and validate only declared zero-pad lanes.

Why this case matters

Offline PCM interchange uses these exact bounded packet and sample representation decisions.

1 / The failure

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(packets, lanes, ignored):
    out=[]
    for packet in packets:
        selected=[packet[i] for i in lanes]
        ignored_values=[packet[i] for i in ignored]
        good=any(value==0 for value in ignored_values)
        out.append([selected,good,len(selected)])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('oracle 1', solve(*([[1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3])), [[[2, 1], True, 2], [[4, 3], False, 2]])
check('oracle 2', solve(*([[8, 9]], [1, 0, 1], [])), [[[9, 8, 9], True, 3]])
check('oracle 3', solve(*([], [], [])), [])
check('oracle 4', solve(*([[0, 1, 0]], [1], [0, 2])), [[[1], True, 1]])
check('oracle 5', solve(*([[0, 0]], [], [0, 1])), [[[], True, 0]])
check('oracle 6', solve(*([[4, 3, 2, 1]], [3, 1, 0], [2])), [[[1, 3, 4], False, 3]])
check('oracle 7', solve(*([[1]], [0], [])), [[[1], True, 1]])
if N == 1: check('variant packet 1', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 2: check('variant packet 2', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 3: check('variant packet 3', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 4: check('variant packet 4', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 5: check('variant packet 5', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
oracle 1[[[2, 1], True, 2], [[4, 3], True, 2]][[[2, 1], True, 2], [[4, 3], False, 2]]Failed
oracle 2[[[9, 8, 9], False, 3]][[[9, 8, 9], True, 3]]Failed
oracle 3[][]Passed
oracle 4[[[1], True, 1]][[[1], True, 1]]Passed
oracle 5[[[], True, 0]][[[], True, 0]]Passed
oracle 6[[[1, 3, 4], False, 3]][[[1, 3, 4], False, 3]]Passed
oracle 7[[[1], False, 1]][[[1], True, 1]]Failed
variant packet 1[[[2, 1], True, 2], [[4, 3], True, 2], [[2, 1], True, 2], [[4, 3], True, 2]][[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]]Failed

SHA-256 / fcaf5f440c622a65d75d760d3fc15b55f61def5f1218fa47a8fbbe464e4d6ea6

2 / The unsuccessful fix

Exit 1
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(packets, lanes, ignored):
    out=[]
    for packet in packets:
        selected=[packet[i] for i in lanes]
        ignored_values=[packet[i] for i in ignored]
        good=bool(ignored_values) and all(value==0 for value in ignored_values)
        out.append([selected,good,len(selected)])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('oracle 1', solve(*([[1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3])), [[[2, 1], True, 2], [[4, 3], False, 2]])
check('oracle 2', solve(*([[8, 9]], [1, 0, 1], [])), [[[9, 8, 9], True, 3]])
check('oracle 3', solve(*([], [], [])), [])
check('oracle 4', solve(*([[0, 1, 0]], [1], [0, 2])), [[[1], True, 1]])
check('oracle 5', solve(*([[0, 0]], [], [0, 1])), [[[], True, 0]])
check('oracle 6', solve(*([[4, 3, 2, 1]], [3, 1, 0], [2])), [[[1, 3, 4], False, 3]])
check('oracle 7', solve(*([[1]], [0], [])), [[[1], True, 1]])
if N == 1: check('variant packet 1', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 2: check('variant packet 2', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 3: check('variant packet 3', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 4: check('variant packet 4', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 5: check('variant packet 5', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
oracle 1[[[2, 1], True, 2], [[4, 3], False, 2]][[[2, 1], True, 2], [[4, 3], False, 2]]Passed
oracle 2[[[9, 8, 9], False, 3]][[[9, 8, 9], True, 3]]Failed
oracle 3[][]Passed
oracle 4[[[1], True, 1]][[[1], True, 1]]Passed
oracle 5[[[], True, 0]][[[], True, 0]]Passed
oracle 6[[[1, 3, 4], False, 3]][[[1, 3, 4], False, 3]]Passed
oracle 7[[[1], False, 1]][[[1], True, 1]]Failed
variant packet 1[[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]][[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]]Passed

SHA-256 / 89ac53844250c7c60a7fc7a905ed5e709b98d013c42aa96783b5c55edf64105a

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(packets, lanes, ignored):
    out=[]
    for packet in packets:
        selected=[packet[i] for i in lanes]
        ignored_values=[packet[i] for i in ignored]
        good=all(value==0 for value in ignored_values)
        out.append([selected,good,len(selected)])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('oracle 1', solve(*([[1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3])), [[[2, 1], True, 2], [[4, 3], False, 2]])
check('oracle 2', solve(*([[8, 9]], [1, 0, 1], [])), [[[9, 8, 9], True, 3]])
check('oracle 3', solve(*([], [], [])), [])
check('oracle 4', solve(*([[0, 1, 0]], [1], [0, 2])), [[[1], True, 1]])
check('oracle 5', solve(*([[0, 0]], [], [0, 1])), [[[], True, 0]])
check('oracle 6', solve(*([[4, 3, 2, 1]], [3, 1, 0], [2])), [[[1, 3, 4], False, 3]])
check('oracle 7', solve(*([[1]], [0], [])), [[[1], True, 1]])
if N == 1: check('variant packet 1', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 2: check('variant packet 2', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 3: check('variant packet 3', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 4: check('variant packet 4', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
if N == 5: check('variant packet 5', solve(*[[[1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5], [1, 0, 2, 0], [3, 0, 4, 5]], [2, 0], [1, 3]]), [[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]])
print(json.dumps({"observations": observations, "passed": all(x["passed"] for x in observations)}, ensure_ascii=False))
raise SystemExit(0 if all(x["passed"] for x in observations) else 1)
Boundary fixtureActualExpectedOutcome
oracle 1[[[2, 1], True, 2], [[4, 3], False, 2]][[[2, 1], True, 2], [[4, 3], False, 2]]Passed
oracle 2[[[9, 8, 9], True, 3]][[[9, 8, 9], True, 3]]Passed
oracle 3[][]Passed
oracle 4[[[1], True, 1]][[[1], True, 1]]Passed
oracle 5[[[], True, 0]][[[], True, 0]]Passed
oracle 6[[[1, 3, 4], False, 3]][[[1, 3, 4], False, 3]]Passed
oracle 7[[[1], True, 1]][[[1], True, 1]]Passed
variant packet 1[[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]][[[2, 1], True, 2], [[4, 3], False, 2], [[2, 1], True, 2], [[4, 3], False, 2]]Passed

SHA-256 / 9645ffb7d97e201b5c6308039e238f8c182d3af6ec2dc4aa9ee67632414e1743

Verification & scope

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.

Observations recorded using Python 3.12.14 at 2026-09-29T14:44:56.616235+00:00.

Case digest / d359701bc22c53f6bb72437214684fb56b2ef6aefa60508a5e26960636c7249e