FAILURE MAP
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FA-49556 / PCM sample encoding / Open access

Au pcm payload limit: whole frame prefix · case 01

Incomplete sample-frame bytes are returned as playable data.

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

ROOT CAUSE

Incomplete sample-frame bytes are returned as playable data.

THE FAILURE

Incomplete sample-frame bytes are returned as playable data.

Unsuccessful approach: A frame count is mistakenly used as byte slice length.

Case contract

Locate a bounded AU-like PCM byte body at an absolute data offset; -1 alone means unknown size, and incomplete frame bytes are returned separately.

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(buffers, offset, declared, frame_bytes):
    out=[]
    for blob in buffers:
        body=blob[min(offset,len(blob)):]
        body=body if declared==-1 else body[:max(0,declared)]
        complete=len(body)
        out.append([body[:complete],body[complete:]])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('oracle 1', solve(*([[9, 9, 1, 2, 3, 4, 5]], 2, -1, 2)), [[[1, 2, 3, 4], [5]]])
check('oracle 2', solve(*([[0, 1, 2, 3, 4]], 1, 3, 2)), [[[1, 2], [3]]])
check('oracle 3', solve(*([[0, 1, 2]], 1, 0, 1)), [[[], []]])
check('oracle 4', solve(*([[]], 4, -1, 2)), [[[], []]])
check('oracle 5', solve(*([], 2, 4, 2)), [])
check('oracle 6', solve(*([[9, 1, 2, 3, 4]], 1, 8, 3)), [[[1, 2, 3], [4]]])
check('oracle 7', solve(*([[9, 1, 2, 3]], 1, 2, 2)), [[[1, 2], []]])
if N == 1: check('variant packet 1', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 2: check('variant packet 2', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 3: check('variant packet 3', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 4: check('variant packet 4', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[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]]])
if N == 5: check('variant packet 5', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[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]]])
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[[[1, 2, 3, 4, 5], []]][[[1, 2, 3, 4], [5]]]Failed
oracle 2[[[1, 2, 3], []]][[[1, 2], [3]]]Failed
oracle 3[[[], []]][[[], []]]Passed
oracle 4[[[], []]][[[], []]]Passed
oracle 5[][]Passed
oracle 6[[[1, 2, 3, 4], []]][[[1, 2, 3], [4]]]Failed
oracle 7[[[1, 2], []]][[[1, 2], []]]Passed
variant packet 1[[[1, 2, 3, 4, 5], []], [[1, 2, 3, 4, 5], []]][[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]]Failed

SHA-256 / 326232ff2694ca1a58c79941b2eecf2eff5b4ac4ef5e76cf35adf719743fcc58

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(buffers, offset, declared, frame_bytes):
    out=[]
    for blob in buffers:
        body=blob[min(offset,len(blob)):]
        body=body if declared==-1 else body[:max(0,declared)]
        complete=len(body)//frame_bytes
        out.append([body[:complete],body[complete:]])
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('oracle 1', solve(*([[9, 9, 1, 2, 3, 4, 5]], 2, -1, 2)), [[[1, 2, 3, 4], [5]]])
check('oracle 2', solve(*([[0, 1, 2, 3, 4]], 1, 3, 2)), [[[1, 2], [3]]])
check('oracle 3', solve(*([[0, 1, 2]], 1, 0, 1)), [[[], []]])
check('oracle 4', solve(*([[]], 4, -1, 2)), [[[], []]])
check('oracle 5', solve(*([], 2, 4, 2)), [])
check('oracle 6', solve(*([[9, 1, 2, 3, 4]], 1, 8, 3)), [[[1, 2, 3], [4]]])
check('oracle 7', solve(*([[9, 1, 2, 3]], 1, 2, 2)), [[[1, 2], []]])
if N == 1: check('variant packet 1', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 2: check('variant packet 2', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 3: check('variant packet 3', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]])
if N == 4: check('variant packet 4', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[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]]])
if N == 5: check('variant packet 5', solve(*[[[9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5], [9, 9, 1, 2, 3, 4, 5]], 2, -1, 2]), [[[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]]])
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[[[1, 2], [3, 4, 5]]][[[1, 2, 3, 4], [5]]]Failed
oracle 2[[[1], [2, 3]]][[[1, 2], [3]]]Failed
oracle 3[[[], []]][[[], []]]Passed
oracle 4[[[], []]][[[], []]]Passed
oracle 5[][]Passed
oracle 6[[[1], [2, 3, 4]]][[[1, 2, 3], [4]]]Failed
oracle 7[[[1], [2]]][[[1, 2], []]]Failed
variant packet 1[[[1, 2], [3, 4, 5]], [[1, 2], [3, 4, 5]]][[[1, 2, 3, 4], [5]], [[1, 2, 3, 4], [5]]]Failed

SHA-256 / 427f7e15e2f3e9b36f02c947dd7590e91d43db8e302bc12c418faf656728727f

HELD IN THE MEMBER ARCHIVE

The verified repair and its recorded checks are member-only.

This mechanism has 8 recorded checks per implementation. The open-access tier publishes the failure and the unsuccessful fix; the repaired source that passes every check, and the observations that prove it, are available to members.

Every case sharing this mechanism uses the same contract and the same repair, so this one record is held back for all of them.

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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 2026-09-29T14:45:01.157790+00:00.

Case digest / 55102da8b831d68af5b03399b030a5f8cbeeb9aa165851109a6ad364b3dfd53c