FA-10956 / Audio playback scheduling / Open access
Playback pause freezes position · case 01
The transport clock advances while playback is paused.
ROOT CAUSE
The transport clock advances while playback is paused.
VERIFIED REPAIR
Apply the explicit PCM/playback contract: Advance a nonnegative playback frame cursor by rendered frames only when not paused.
Unsuccessful approach: Replacing position with block length loses cumulative playback progress.
Case contract
Advance a nonnegative playback frame cursor by rendered frames only when not paused.
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(position, frames, paused):
return position+frames
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(10, 4, True)),10)
check('fixture 2',solve(*(10, 4, False)),14)
check('fixture 3',solve(*(0, 0, False)),0)
check('fixture 4',solve(*(3, 0, True)),3)
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 | 14 | 10 | Failed |
| fixture 2 | 14 | 14 | Passed |
| fixture 3 | 0 | 0 | Passed |
| fixture 4 | 3 | 3 | Passed |
SHA-256 / 37c0c7a77649497760bc04172316aa7b8ff4dc744632ad45aa139fd2c956b013
2 / The unsuccessful fix
Exit 1"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(position, frames, paused):
return position if paused else frames
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(10, 4, True)),10)
check('fixture 2',solve(*(10, 4, False)),14)
check('fixture 3',solve(*(0, 0, False)),0)
check('fixture 4',solve(*(3, 0, True)),3)
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 | 10 | Passed |
| fixture 2 | 4 | 14 | Failed |
| fixture 3 | 0 | 0 | Passed |
| fixture 4 | 3 | 3 | Passed |
SHA-256 / 2cde6fbd8b96fa2fdfffea8c75ac954fc11f489609372325d094a3589966ec0b
3 / The verified repair
Exit 0"""Failure Map reference implementation. Python standard library only."""
import json
import math
N = 1
observations = []
def solve(position, frames, paused):
return position if paused else position+frames
def check(label, actual, expected):
observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
check('fixture 1',solve(*(10, 4, True)),10)
check('fixture 2',solve(*(10, 4, False)),14)
check('fixture 3',solve(*(0, 0, False)),0)
check('fixture 4',solve(*(3, 0, True)),3)
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 | 10 | Passed |
| fixture 2 | 14 | 14 | Passed |
| fixture 3 | 0 | 0 | Passed |
| fixture 4 | 3 | 3 | Passed |
SHA-256 / 6ce7db1d2d9a895d86d6849df5f7178efd72dee81c8b1540d20be166c04892b1
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 2026-09-29T14:38:43.717654+00:00.
Case digest / ac0859bb001f11146afb4b7993bccd31a6880bb473f930c0792e84b121084cce