FA-10851 / Audio frame buffers / Open access
Channel remap framewise · case 01
A configured channel-routing map is ignored.
ROOT CAUSE
A configured channel-routing map is ignored.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: For each equal-width frame, select source channel indices in exact mapping order, allowing repetition and an empty mapping.
Unsuccessful approach: Sorting routing indices changes channel destination order.
Case contract
For each equal-width frame, select source channel indices in exact mapping order, allowing repetition and an empty mapping.
Why this case matters
A pure Python local audio pipeline stage with explicit sample formats and frame conventions; no real-time device or signal-spectrum claims.
1 / The failure
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(frames, mapping):
return [list(frame) for frame in frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[1, 2, 3], [4, 5, 6]], [2, 0])),[[3, 1], [6, 4]])
check('fixture 2',solve(*([[1, 2]], [1, 1])),[[2, 2]])
check('fixture 3',solve(*([], [0])),[])
check('fixture 4',solve(*([[1, 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[1, 2, 3], [4, 5, 6]] | [[3, 1], [6, 4]] | Failed |
| fixture 2 | [[1, 2]] | [[2, 2]] | Failed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[1, 2]] | [[]] | Failed |
SHA-256 / c24aa581a2a5a823f6d3aa99566eeff1eb4b4a50d0f3214b79a8392358c75274
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(frames, mapping):
return [[frame[i] for i in sorted(mapping)] for frame in frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[1, 2, 3], [4, 5, 6]], [2, 0])),[[3, 1], [6, 4]])
check('fixture 2',solve(*([[1, 2]], [1, 1])),[[2, 2]])
check('fixture 3',solve(*([], [0])),[])
check('fixture 4',solve(*([[1, 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[1, 3], [4, 6]] | [[3, 1], [6, 4]] | Failed |
| fixture 2 | [[2, 2]] | [[2, 2]] | Passed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[]] | [[]] | Passed |
SHA-256 / adfeb31b6d95b0ba6f41bf92ac749d07a33da8c258c8adcdaf2444f3a86b9c01
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(frames, mapping):
return [[frame[i] for i in mapping] for frame in frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[1, 2, 3], [4, 5, 6]], [2, 0])),[[3, 1], [6, 4]])
check('fixture 2',solve(*([[1, 2]], [1, 1])),[[2, 2]])
check('fixture 3',solve(*([], [0])),[])
check('fixture 4',solve(*([[1, 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 fixture | Actual | Expected | Outcome |
|---|---|---|---|
| fixture 1 | [[3, 1], [6, 4]] | [[3, 1], [6, 4]] | Passed |
| fixture 2 | [[2, 2]] | [[2, 2]] | Passed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[]] | [[]] | Passed |
SHA-256 / a0a0f9f58cc519c424b3a9e6a556a0fe27d30957621bfd14a1ae126e3d6d800e
Verification & scope
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 2026-09-29T14:38:42.817208+00:00.
Case digest / 4bf7990e1f5b59e1f322768ef549dc2126261b752003d8273bec4720068ab049