FAILURE MAP
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FA-77846 / Subtitle cue timing / Open access

SRT timestamp parsing: dot separator acceptance · case 01

Timestamps exported with a period before the milliseconds are rejected as invalid.

Verified by executionVariant 1 · 9 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

The separator normalization step is missing, so only the comma form splits into two parts.

VERIFIED REPAIR

Normalize '.' to ',' before splitting the seconds from the fraction.

Unsuccessful approach: Normalizing semicolons instead of periods still rejects the common period-separated export form.

Case contract

Parse an SRT timestamp HH:MM:SS,mmm to integer milliseconds. Hours have 2 or more digits, minutes and seconds are below 60, the fraction has 1 to 3 digits and is right-padded (",5" means 500 ms), "." is accepted as the separator, surrounding whitespace (including a CR from CRLF files) is ignored; invalid text returns None.

Why this case matters

Subtitle timing defects shift, hide or overlap captions that viewers depend on for comprehension and accessibility.

1 / The failure

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

N = 1
observations = []
def solve(s):
    s=s.strip()
    parts=s.split(',')
    if len(parts)!=2: return None
    hms,frac=parts
    fields=hms.split(':')
    if len(fields)!=3: return None
    if not all(p.isdigit() for p in fields) or not frac.isdigit(): return None
    if len(frac)>3: return None
    h,mi,se=int(fields[0]),int(fields[1]),int(fields[2])
    if mi>=60 or se>=60: return None
    ms=int(frac.ljust(3,'0'))
    return h*3600000+mi*60000+se*1000+ms
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: dot separator acceptance', ['01:02:03.004'], 3723004), ('regression variant: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair probe: dot separator acceptance', ['00:30:59;12'], None), ('partial repair variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('boundary control', ['00:00:00,000'], 0), ('boundary control', ['00:60:00,000'], None), ('normal control', ['00:00:01,5'], 1500), ('normal control', ['100:00:00,000'], 360000000), ('normal control', ['00:61:00;5 \r'], None)], [('regression: dot separator acceptance', ['99:00:00.500\r'], 356400500), ('regression variant: dot separator acceptance', ['01:59:00.500\t'], 7140500), ('partial repair probe: dot separator acceptance', ['00:59:00.000'], 3540000), ('partial repair variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('boundary control', ['00:00:01,5'], 1500), ('boundary control', ['100:00:00,000'], 360000000), ('normal control', ['123:60:59,5'], None), ('normal control', ['99:00:59,001 \r'], 356459001), ('normal control', [' 00:61:01;999\r'], None)], [('regression: dot separator acceptance', ['00:59:00.000'], 3540000), ('regression variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('partial repair probe: dot separator acceptance', [' 10:05:00.000'], 36300000), ('partial repair variant: dot separator acceptance', ['02:00:59;999'], None), ('boundary control', ['00:59:59,999\r'], 3599999), ('boundary control', ['00:00:00,000'], 0), ('normal control', [' 00:00:60,12 '], None), ('normal control', [' 10:00:61.001\r'], None), ('normal control', ['00:00:60,1234\r'], None)], [('regression: dot separator acceptance', [' 10:05:00.000'], 36300000), ('regression variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('partial repair probe: dot separator acceptance', [' 00:05:00.5 '], 300500), ('partial repair variant: dot separator acceptance', ['10:00:42;07'], None), ('boundary control', ['00:60:00,000'], None), ('boundary control', ['00:00:01,5'], 1500), ('normal control', ['00:00:60,07'], None), ('normal control', ['99:60:59,12 \r'], None), ('normal control', ['100:60:60,999 '], None)], [('regression: dot separator acceptance', [' 00:05:00.5 '], 300500), ('regression variant: dot separator acceptance', ['123:05:01.12\t'], 443101120), ('partial repair probe: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair variant: dot separator acceptance', ['00:00:42;07\r'], None), ('boundary control', ['100:00:00,000'], 360000000), ('boundary control', ['00:59:59,999\r'], 3599999), ('normal control', [' 10:60:61;999'], None), ('normal control', ['02:00:01,1234 \r'], None), ('normal control', ['02:30:42,5\t'], 9042500)]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: dot separator acceptanceNone3723004Failed
regression variant: dot separator acceptanceNone363582001Failed
partial repair probe: dot separator acceptanceNoneNonePassed
partial repair variant: dot separator acceptanceNone360001500Failed
boundary control00Passed
boundary controlNoneNonePassed
normal control15001500Passed
normal control360000000360000000Passed
normal controlNoneNonePassed

SHA-256 / 3cdda36c0690b63447252b82cc0b3249e1209ce41813cb15ae5f17ac16c0554b

2 / The unsuccessful fix

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

N = 1
observations = []
def solve(s):
    s=s.strip()
    parts=s.replace(';',',').split(',')
    if len(parts)!=2: return None
    hms,frac=parts
    fields=hms.split(':')
    if len(fields)!=3: return None
    if not all(p.isdigit() for p in fields) or not frac.isdigit(): return None
    if len(frac)>3: return None
    h,mi,se=int(fields[0]),int(fields[1]),int(fields[2])
    if mi>=60 or se>=60: return None
    ms=int(frac.ljust(3,'0'))
    return h*3600000+mi*60000+se*1000+ms
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: dot separator acceptance', ['01:02:03.004'], 3723004), ('regression variant: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair probe: dot separator acceptance', ['00:30:59;12'], None), ('partial repair variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('boundary control', ['00:00:00,000'], 0), ('boundary control', ['00:60:00,000'], None), ('normal control', ['00:00:01,5'], 1500), ('normal control', ['100:00:00,000'], 360000000), ('normal control', ['00:61:00;5 \r'], None)], [('regression: dot separator acceptance', ['99:00:00.500\r'], 356400500), ('regression variant: dot separator acceptance', ['01:59:00.500\t'], 7140500), ('partial repair probe: dot separator acceptance', ['00:59:00.000'], 3540000), ('partial repair variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('boundary control', ['00:00:01,5'], 1500), ('boundary control', ['100:00:00,000'], 360000000), ('normal control', ['123:60:59,5'], None), ('normal control', ['99:00:59,001 \r'], 356459001), ('normal control', [' 00:61:01;999\r'], None)], [('regression: dot separator acceptance', ['00:59:00.000'], 3540000), ('regression variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('partial repair probe: dot separator acceptance', [' 10:05:00.000'], 36300000), ('partial repair variant: dot separator acceptance', ['02:00:59;999'], None), ('boundary control', ['00:59:59,999\r'], 3599999), ('boundary control', ['00:00:00,000'], 0), ('normal control', [' 00:00:60,12 '], None), ('normal control', [' 10:00:61.001\r'], None), ('normal control', ['00:00:60,1234\r'], None)], [('regression: dot separator acceptance', [' 10:05:00.000'], 36300000), ('regression variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('partial repair probe: dot separator acceptance', [' 00:05:00.5 '], 300500), ('partial repair variant: dot separator acceptance', ['10:00:42;07'], None), ('boundary control', ['00:60:00,000'], None), ('boundary control', ['00:00:01,5'], 1500), ('normal control', ['00:00:60,07'], None), ('normal control', ['99:60:59,12 \r'], None), ('normal control', ['100:60:60,999 '], None)], [('regression: dot separator acceptance', [' 00:05:00.5 '], 300500), ('regression variant: dot separator acceptance', ['123:05:01.12\t'], 443101120), ('partial repair probe: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair variant: dot separator acceptance', ['00:00:42;07\r'], None), ('boundary control', ['100:00:00,000'], 360000000), ('boundary control', ['00:59:59,999\r'], 3599999), ('normal control', [' 10:60:61;999'], None), ('normal control', ['02:00:01,1234 \r'], None), ('normal control', ['02:30:42,5\t'], 9042500)]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: dot separator acceptanceNone3723004Failed
regression variant: dot separator acceptanceNone363582001Failed
partial repair probe: dot separator acceptance1859120NoneFailed
partial repair variant: dot separator acceptanceNone360001500Failed
boundary control00Passed
boundary controlNoneNonePassed
normal control15001500Passed
normal control360000000360000000Passed
normal controlNoneNonePassed

SHA-256 / d13f378fae52821a898e1b0fc3b0260c2afa96fd9228aab7ba126111c5940cd2

3 / The verified repair

Exit 0
"""Failure Map reference implementation. Python standard library only."""
import json

N = 1
observations = []
def solve(s):
    s=s.strip()
    parts=s.replace('.',',').split(',')
    if len(parts)!=2: return None
    hms,frac=parts
    fields=hms.split(':')
    if len(fields)!=3: return None
    if not all(p.isdigit() for p in fields) or not frac.isdigit(): return None
    if len(frac)>3: return None
    h,mi,se=int(fields[0]),int(fields[1]),int(fields[2])
    if mi>=60 or se>=60: return None
    ms=int(frac.ljust(3,'0'))
    return h*3600000+mi*60000+se*1000+ms
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: dot separator acceptance', ['01:02:03.004'], 3723004), ('regression variant: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair probe: dot separator acceptance', ['00:30:59;12'], None), ('partial repair variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('boundary control', ['00:00:00,000'], 0), ('boundary control', ['00:60:00,000'], None), ('normal control', ['00:00:01,5'], 1500), ('normal control', ['100:00:00,000'], 360000000), ('normal control', ['00:61:00;5 \r'], None)], [('regression: dot separator acceptance', ['99:00:00.500\r'], 356400500), ('regression variant: dot separator acceptance', ['01:59:00.500\t'], 7140500), ('partial repair probe: dot separator acceptance', ['00:59:00.000'], 3540000), ('partial repair variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('boundary control', ['00:00:01,5'], 1500), ('boundary control', ['100:00:00,000'], 360000000), ('normal control', ['123:60:59,5'], None), ('normal control', ['99:00:59,001 \r'], 356459001), ('normal control', [' 00:61:01;999\r'], None)], [('regression: dot separator acceptance', ['00:59:00.000'], 3540000), ('regression variant: dot separator acceptance', [' 100:00:01.50\r'], 360001500), ('partial repair probe: dot separator acceptance', [' 10:05:00.000'], 36300000), ('partial repair variant: dot separator acceptance', ['02:00:59;999'], None), ('boundary control', ['00:59:59,999\r'], 3599999), ('boundary control', ['00:00:00,000'], 0), ('normal control', [' 00:00:60,12 '], None), ('normal control', [' 10:00:61.001\r'], None), ('normal control', ['00:00:60,1234\r'], None)], [('regression: dot separator acceptance', [' 10:05:00.000'], 36300000), ('regression variant: dot separator acceptance', ['123:59:59.000 \r'], 446399000), ('partial repair probe: dot separator acceptance', [' 00:05:00.5 '], 300500), ('partial repair variant: dot separator acceptance', ['10:00:42;07'], None), ('boundary control', ['00:60:00,000'], None), ('boundary control', ['00:00:01,5'], 1500), ('normal control', ['00:00:60,07'], None), ('normal control', ['99:60:59,12 \r'], None), ('normal control', ['100:60:60,999 '], None)], [('regression: dot separator acceptance', [' 00:05:00.5 '], 300500), ('regression variant: dot separator acceptance', ['123:05:01.12\t'], 443101120), ('partial repair probe: dot separator acceptance', ['100:59:42.001\r'], 363582001), ('partial repair variant: dot separator acceptance', ['00:00:42;07\r'], None), ('boundary control', ['100:00:00,000'], 360000000), ('boundary control', ['00:59:59,999\r'], 3599999), ('normal control', [' 10:60:61;999'], None), ('normal control', ['02:00:01,1234 \r'], None), ('normal control', ['02:30:42,5\t'], 9042500)]]
for label, args, expected in fixtures[N-1]:
    check(label, solve(*args), expected)
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
regression: dot separator acceptance37230043723004Passed
regression variant: dot separator acceptance363582001363582001Passed
partial repair probe: dot separator acceptanceNoneNonePassed
partial repair variant: dot separator acceptance360001500360001500Passed
boundary control00Passed
boundary controlNoneNonePassed
normal control15001500Passed
normal control360000000360000000Passed
normal controlNoneNonePassed

SHA-256 / 5db26b4702a6c344980c4e8fd336efb41fbf1a7a0f802b18b714894eedc9d12c

Verification & scope

A deterministic bounded teaching model with a stipulated toy contract; it does not claim conformance to any subtitle standard. 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 2026-09-29T14:49:29.741984+00:00.

Case digest / 298603c9dc6f57dafeba2a63685ce30d5c5c754c97c72851e38694e6bdddb1d2