FA-10976 / Audio playback scheduling / Open access
Latency position subtracts queued · case 01
Submitted position is exposed as audible position before queued audio plays.
ROOT CAUSE
Submitted position is exposed as audible position before queued audio plays.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: Estimate audible frame position as submitted frames minus frames still queued to the device, clamped at zero.
Unsuccessful approach: Adding queued latency moves the estimated audible clock further into the future.
Case contract
Estimate audible frame position as submitted frames minus frames still queued to the device, clamped at zero.
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(submitted, queued):
return submitted
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(100, 20)),80)
check('fixture 2',solve(*(0, 0)),0)
check('fixture 3',solve(*(10, 20)),0)
check('fixture 4',solve(*(10, 0)),10)
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 | 100 | 80 | Failed |
| fixture 2 | 0 | 0 | Passed |
| fixture 3 | 10 | 0 | Failed |
| fixture 4 | 10 | 10 | Passed |
SHA-256 / 6950a40025eac70af1766a75beb9534a05820ecd8a2b5453cc6a2309c9c55d3e
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(submitted, queued):
return submitted+queued
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(100, 20)),80)
check('fixture 2',solve(*(0, 0)),0)
check('fixture 3',solve(*(10, 20)),0)
check('fixture 4',solve(*(10, 0)),10)
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 | 120 | 80 | Failed |
| fixture 2 | 0 | 0 | Passed |
| fixture 3 | 30 | 0 | Failed |
| fixture 4 | 10 | 10 | Passed |
SHA-256 / a03ffd7f6771da90f6d233afd559ddbfe29f13d70d6c11cf925d22c41f9207ab
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(submitted, queued):
return max(0,submitted-queued)
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(100, 20)),80)
check('fixture 2',solve(*(0, 0)),0)
check('fixture 3',solve(*(10, 20)),0)
check('fixture 4',solve(*(10, 0)),10)
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 | 80 | 80 | Passed |
| fixture 2 | 0 | 0 | Passed |
| fixture 3 | 0 | 0 | Passed |
| fixture 4 | 10 | 10 | Passed |
SHA-256 / 37560752baf68caf487221ea415023854f56a0674195ebe3ddf012ef458e897d
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 2026-09-29T14:38:43.840219+00:00.
Case digest / 5ceebc70aad4fcd121fc1d186f0f28d0ada688db458b64d8fa7973c73acb390f