FA-10946 / Audio playback scheduling / Open access
Callback event half open window · case 01
A boundary event is scheduled in two adjacent callbacks.
ROOT CAUSE
A boundary event is scheduled in two adjacent callbacks.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: Select timestamped events in the callback frame interval [start,start+frames), returning callback-relative frame offsets.
Unsuccessful approach: Filtering correctly but retaining absolute timestamps places events beyond the current block.
Case contract
Select timestamped events in the callback frame interval [start,start+frames), returning callback-relative frame offsets.
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(events, start, frames):
return [[time-start,value] for time,value in events if start<=time<=start+frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[10, 'a'], [13, 'b'], [14, 'c']], 10, 4)),[[0, 'a'], [3, 'b']])
check('fixture 2',solve(*([[4, 'a']], 4, 0)),[])
check('fixture 3',solve(*([[3, 'a']], 4, 2)),[])
check('fixture 4',solve(*([[0, 'a']], 0, 1)),[[0, 'a']])
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 | [[0, 'a'], [3, 'b'], [4, 'c']] | [[0, 'a'], [3, 'b']] | Failed |
| fixture 2 | [[0, 'a']] | [] | Failed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[0, 'a']] | [[0, 'a']] | Passed |
SHA-256 / 4aaed42710b5d01845485dd09f9cf9f9655b4b50f982eae540219b72baf94053
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(events, start, frames):
return [[time,value] for time,value in events if start<=time<start+frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[10, 'a'], [13, 'b'], [14, 'c']], 10, 4)),[[0, 'a'], [3, 'b']])
check('fixture 2',solve(*([[4, 'a']], 4, 0)),[])
check('fixture 3',solve(*([[3, 'a']], 4, 2)),[])
check('fixture 4',solve(*([[0, 'a']], 0, 1)),[[0, 'a']])
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 | [[10, 'a'], [13, 'b']] | [[0, 'a'], [3, 'b']] | Failed |
| fixture 2 | [] | [] | Passed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[0, 'a']] | [[0, 'a']] | Passed |
SHA-256 / 1dbe34befbfdb888c0a1fc27e3d8d0ef41e055a28aa424e2620424ecb4a3fa84
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(events, start, frames):
return [[time-start,value] for time,value in events if start<=time<start+frames]
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*([[10, 'a'], [13, 'b'], [14, 'c']], 10, 4)),[[0, 'a'], [3, 'b']])
check('fixture 2',solve(*([[4, 'a']], 4, 0)),[])
check('fixture 3',solve(*([[3, 'a']], 4, 2)),[])
check('fixture 4',solve(*([[0, 'a']], 0, 1)),[[0, 'a']])
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 | [[0, 'a'], [3, 'b']] | [[0, 'a'], [3, 'b']] | Passed |
| fixture 2 | [] | [] | Passed |
| fixture 3 | [] | [] | Passed |
| fixture 4 | [[0, 'a']] | [[0, 'a']] | Passed |
SHA-256 / b89d4702a84adc73ac993692fa629c6fc71d0663de991559bfbef390b22d8f27
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 2026-09-29T14:38:43.674649+00:00.
Case digest / cbb6d81386e5564ec57d216b9d220ca3bef65f5e7afd46d52f8a39b4f58d4dec