FA-78716 / Broadcast timecode arithmetic / Open access

Playout schedule on-air times: inter-clip gap · case 01

The first clip airs late by the black gap.

Verified by executionVariant 1 · 8 checks per implementationDownload source bundle ↓JSON ↗

ROOT CAUSE

Black is inserted before every clip, including the first.

VERIFIED REPAIR

Insert the gap only between consecutive clips.

Unsuccessful approach: Skipping the gap before the last clip instead of the first shifts the final clip early.

Case contract

Clips [SOM, EOM] use non-drop labels at fps with EOM inclusive; a clip may cross midnight on tape. Clips air back to back from start with gap black frames between consecutive clips. Return the on-air label of each clip followed by the exclusive end label of the schedule, wrapping at 24 hours.

Why this case matters

Timecode arithmetic errors misplace edits, commercial breaks and captions against the broadcast clock.

1 / The failure

Exit 1

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

N = 1
observations = []
def solve(start, clips, gap, fps):
    def fr(t):
        h,m,s,f=map(int,t.split(':'))
        return ((h*60+m)*60+s)*fps+f
    def lab(n):
        n%=86400*fps
        return '%02d:%02d:%02d:%02d'%(n//(3600*fps),n//(60*fps)%60,n//fps%60,n%fps)
    t=fr(start)
    out=[]
    for i,(som,eom) in enumerate(clips):
        if True:
            t+=gap
        out.append(lab(t))
        d=(fr(eom)-fr(som))%(86400*fps)
        t+=d+1
    out.append(lab(t))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: inter-clip gap', ['23:59:59:00', [['00:00:00:00', '00:00:01:00'], ['00:00:00:00', '00:00:00:00']], 5, 25], ['23:59:59:00', '00:00:00:06', '00:00:00:07']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['23:59:59:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [], 25, 25], ['00:00:00:00']), ('normal control', ['23:59:50:00', [], 1, 30], ['23:59:50:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:29:24'], ['23:59:59:00', '00:00:01:00']], 0, 25], ['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:10'], ['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '13:59:51:06', '00:00:21:26', '01:00:51:27']), ('regression variant: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair probe: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['00:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:00:00'], ['23:59:59:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00']], 25, 25], ['00:00:00:00', '01:00:31:01', '15:00:32:02', '15:00:35:03', '15:00:36:04']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '10:00:10:00']], 0, 30], ['18:00:00:00', '04:00:29:25', '14:00:39:26']), ('normal control', ['00:00:00:00', [['00:00:00:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:01:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:00:11', '15:00:30:12', '05:00:31:13', '15:01:01:13']), ('normal control', ['18:00:00:00', [], 0, 30], ['18:00:00:00'])], [('regression: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '01:00:30:00']], 5, 30], ['18:00:00:00', '19:00:31:01']), ('regression variant: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00'], ['10:00:00:00', '01:00:30:00']], 25, 25], ['00:00:00:00', '23:00:02:01', '23:00:04:02', '14:00:34:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [], 1, 30], ['18:00:00:00']), ('normal control', ['18:00:00:00', [], 25, 25], ['18:00:00:00']), ('normal control', ['00:00:00:00', [['23:59:59:00', '10:00:29:24']], 0, 30], ['00:00:00:00', '10:00:30:25'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '13:59:50:01']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 5, 25], ['23:59:50:00', '13:59:50:01']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:00:10'], ['10:00:00:00', '10:00:29:24']], 25, 30], ['00:00:00:00', '23:00:01:06', '23:00:31:01']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [['10:00:00:00', '10:00:10:00'], ['10:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:29:24'], ['23:59:59:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:10:01', '14:00:11:02', '00:00:42:02', '10:01:13:02']), ('normal control', ['18:00:00:00', [], 1, 25], ['18:00:00:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:00:00'], ['23:59:59:00', '10:00:10:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['18:00:00:00', '18:00:00:01', '04:00:11:02', '14:00:41:02'])], [('regression: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('regression variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '10:00:29:24'], ['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '01:00:30:00']], 1, 30], ['00:00:00:00', '09:00:29:26', '08:00:30:28', '09:01:01:29']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:00:10'], ['23:59:59:00', '00:00:00:00'], ['00:00:00:00', '10:00:10:00']], 25, 25], ['00:00:00:00', '14:00:01:11', '14:00:03:12', '00:00:13:13']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['00:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:10:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10']], 25, 25], ['23:59:50:00', '23:59:52:01', '10:00:04:02', '19:00:15:03', '19:00:16:14']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '10:00:10:00'], ['01:00:00:00', '01:00:30:00']], 0, 25], ['18:00:00:00', '18:00:01:11', '18:00:11:12', '18:00:41:13']), ('normal control', ['00:00:00:00', [], 0, 25], ['00:00:00:00']), ('normal control', ['18:00:00:00', [], 5, 25], ['18:00:00:00'])]]
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 fixture	Actual	Expected	Outcome
regression: inter-clip gap	`['23:59:59:05', '00:00:00:11', '00:00:00:12']`	`['23:59:59:00', '00:00:00:06', '00:00:00:07']`	Failed
regression variant: inter-clip gap	`['23:59:50:25', '15:00:21:21', '16:00:51:22']`	`['23:59:50:00', '15:00:20:26', '16:00:50:27']`	Failed
partial repair probe: inter-clip gap	`['18:00:01:00', '17:00:03:01', '02:00:14:02', '02:00:16:13', '02:00:16:24']`	`['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']`	Failed
partial repair variant: inter-clip gap	`['23:59:50:25', '23:59:53:01', '15:00:23:27', '15:00:24:28']`	`['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']`	Failed
boundary control	`['18:00:00:00', '18:00:01:00']`	`['18:00:00:00', '18:00:01:00']`	Passed
normal control	`['00:00:00:00']`	`['00:00:00:00']`	Passed
normal control	`['23:59:50:00']`	`['23:59:50:00']`	Passed
normal control	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	Passed

SHA-256 / ed16da8af741cffa8d98e410e844bc700c08720ddd323e196b28796eacb32f60

2 / The unsuccessful fix

Exit 1

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

N = 1
observations = []
def solve(start, clips, gap, fps):
    def fr(t):
        h,m,s,f=map(int,t.split(':'))
        return ((h*60+m)*60+s)*fps+f
    def lab(n):
        n%=86400*fps
        return '%02d:%02d:%02d:%02d'%(n//(3600*fps),n//(60*fps)%60,n//fps%60,n%fps)
    t=fr(start)
    out=[]
    for i,(som,eom) in enumerate(clips):
        if i<len(clips)-1:
            t+=gap
        out.append(lab(t))
        d=(fr(eom)-fr(som))%(86400*fps)
        t+=d+1
    out.append(lab(t))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: inter-clip gap', ['23:59:59:00', [['00:00:00:00', '00:00:01:00'], ['00:00:00:00', '00:00:00:00']], 5, 25], ['23:59:59:00', '00:00:00:06', '00:00:00:07']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['23:59:59:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [], 25, 25], ['00:00:00:00']), ('normal control', ['23:59:50:00', [], 1, 30], ['23:59:50:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:29:24'], ['23:59:59:00', '00:00:01:00']], 0, 25], ['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:10'], ['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '13:59:51:06', '00:00:21:26', '01:00:51:27']), ('regression variant: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair probe: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['00:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:00:00'], ['23:59:59:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00']], 25, 25], ['00:00:00:00', '01:00:31:01', '15:00:32:02', '15:00:35:03', '15:00:36:04']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '10:00:10:00']], 0, 30], ['18:00:00:00', '04:00:29:25', '14:00:39:26']), ('normal control', ['00:00:00:00', [['00:00:00:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:01:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:00:11', '15:00:30:12', '05:00:31:13', '15:01:01:13']), ('normal control', ['18:00:00:00', [], 0, 30], ['18:00:00:00'])], [('regression: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '01:00:30:00']], 5, 30], ['18:00:00:00', '19:00:31:01']), ('regression variant: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00'], ['10:00:00:00', '01:00:30:00']], 25, 25], ['00:00:00:00', '23:00:02:01', '23:00:04:02', '14:00:34:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [], 1, 30], ['18:00:00:00']), ('normal control', ['18:00:00:00', [], 25, 25], ['18:00:00:00']), ('normal control', ['00:00:00:00', [['23:59:59:00', '10:00:29:24']], 0, 30], ['00:00:00:00', '10:00:30:25'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '13:59:50:01']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 5, 25], ['23:59:50:00', '13:59:50:01']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:00:10'], ['10:00:00:00', '10:00:29:24']], 25, 30], ['00:00:00:00', '23:00:01:06', '23:00:31:01']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [['10:00:00:00', '10:00:10:00'], ['10:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:29:24'], ['23:59:59:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:10:01', '14:00:11:02', '00:00:42:02', '10:01:13:02']), ('normal control', ['18:00:00:00', [], 1, 25], ['18:00:00:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:00:00'], ['23:59:59:00', '10:00:10:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['18:00:00:00', '18:00:00:01', '04:00:11:02', '14:00:41:02'])], [('regression: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('regression variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '10:00:29:24'], ['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '01:00:30:00']], 1, 30], ['00:00:00:00', '09:00:29:26', '08:00:30:28', '09:01:01:29']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:00:10'], ['23:59:59:00', '00:00:00:00'], ['00:00:00:00', '10:00:10:00']], 25, 25], ['00:00:00:00', '14:00:01:11', '14:00:03:12', '00:00:13:13']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['00:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:10:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10']], 25, 25], ['23:59:50:00', '23:59:52:01', '10:00:04:02', '19:00:15:03', '19:00:16:14']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '10:00:10:00'], ['01:00:00:00', '01:00:30:00']], 0, 25], ['18:00:00:00', '18:00:01:11', '18:00:11:12', '18:00:41:13']), ('normal control', ['00:00:00:00', [], 0, 25], ['00:00:00:00']), ('normal control', ['18:00:00:00', [], 5, 25], ['18:00:00:00'])]]
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 fixture	Actual	Expected	Outcome
regression: inter-clip gap	`['23:59:59:05', '00:00:00:06', '00:00:00:07']`	`['23:59:59:00', '00:00:00:06', '00:00:00:07']`	Failed
regression variant: inter-clip gap	`['23:59:50:25', '15:00:20:26', '16:00:50:27']`	`['23:59:50:00', '15:00:20:26', '16:00:50:27']`	Failed
partial repair probe: inter-clip gap	`['18:00:01:00', '17:00:03:01', '02:00:14:02', '02:00:15:13', '02:00:15:24']`	`['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']`	Failed
partial repair variant: inter-clip gap	`['23:59:50:25', '23:59:53:01', '15:00:23:02', '15:00:24:03']`	`['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']`	Failed
boundary control	`['18:00:00:00', '18:00:01:00']`	`['18:00:00:00', '18:00:01:00']`	Passed
normal control	`['00:00:00:00']`	`['00:00:00:00']`	Passed
normal control	`['23:59:50:00']`	`['23:59:50:00']`	Passed
normal control	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	Passed

SHA-256 / 4c9379eac56382d7b6a30ec1ee0ce34148a9db9079eb7003b5854a982e4bf945

3 / The verified repair

Exit 0

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

N = 1
observations = []
def solve(start, clips, gap, fps):
    def fr(t):
        h,m,s,f=map(int,t.split(':'))
        return ((h*60+m)*60+s)*fps+f
    def lab(n):
        n%=86400*fps
        return '%02d:%02d:%02d:%02d'%(n//(3600*fps),n//(60*fps)%60,n//fps%60,n%fps)
    t=fr(start)
    out=[]
    for i,(som,eom) in enumerate(clips):
        if i:
            t+=gap
        out.append(lab(t))
        d=(fr(eom)-fr(som))%(86400*fps)
        t+=d+1
    out.append(lab(t))
    return out
def check(label, actual, expected):
    observations.append({"check": label, "actual": actual, "expected": expected, "passed": actual == expected})
fixtures = [[('regression: inter-clip gap', ['23:59:59:00', [['00:00:00:00', '00:00:01:00'], ['00:00:00:00', '00:00:00:00']], 5, 25], ['23:59:59:00', '00:00:00:06', '00:00:00:07']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['23:59:59:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [], 25, 25], ['00:00:00:00']), ('normal control', ['23:59:50:00', [], 1, 30], ['23:59:50:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:29:24'], ['23:59:59:00', '00:00:01:00']], 0, 25], ['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:10'], ['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '13:59:51:06', '00:00:21:26', '01:00:51:27']), ('regression variant: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair probe: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '01:00:30:00'], ['00:00:00:00', '01:00:30:00']], 25, 30], ['23:59:50:00', '15:00:20:26', '16:00:50:27']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['00:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:00:00'], ['23:59:59:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00']], 25, 25], ['00:00:00:00', '01:00:31:01', '15:00:32:02', '15:00:35:03', '15:00:36:04']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '10:00:29:24'], ['00:00:00:00', '10:00:10:00']], 0, 30], ['18:00:00:00', '04:00:29:25', '14:00:39:26']), ('normal control', ['00:00:00:00', [['00:00:00:00', '00:00:00:10'], ['10:00:00:00', '01:00:30:00'], ['10:00:00:00', '00:00:01:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:00:11', '15:00:30:12', '05:00:31:13', '15:01:01:13']), ('normal control', ['18:00:00:00', [], 0, 30], ['18:00:00:00'])], [('regression: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '01:00:30:00']], 5, 30], ['18:00:00:00', '19:00:31:01']), ('regression variant: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair probe: inter-clip gap', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['23:59:59:00', '00:00:01:00']], 5, 25], ['18:00:00:00', '18:00:01:16', '18:00:03:17']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '00:00:00:00'], ['10:00:00:00', '01:00:30:00']], 25, 25], ['00:00:00:00', '23:00:02:01', '23:00:04:02', '14:00:34:03']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [], 1, 30], ['18:00:00:00']), ('normal control', ['18:00:00:00', [], 25, 25], ['18:00:00:00']), ('normal control', ['00:00:00:00', [['23:59:59:00', '10:00:29:24']], 0, 30], ['00:00:00:00', '10:00:30:25'])], [('regression: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 25, 30], ['23:59:50:00', '13:59:50:01']), ('regression variant: inter-clip gap', ['23:59:50:00', [['10:00:00:00', '00:00:00:00']], 5, 25], ['23:59:50:00', '13:59:50:01']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:01:00'], ['10:00:00:00', '00:00:00:10']], 1, 30], ['00:00:00:00', '14:00:01:02', '04:00:01:13']), ('partial repair variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '00:00:00:10'], ['10:00:00:00', '10:00:29:24']], 25, 30], ['00:00:00:00', '23:00:01:06', '23:00:31:01']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['00:00:00:00', [['10:00:00:00', '10:00:10:00'], ['10:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:29:24'], ['23:59:59:00', '10:00:29:24']], 0, 25], ['00:00:00:00', '00:00:10:01', '14:00:11:02', '00:00:42:02', '10:01:13:02']), ('normal control', ['18:00:00:00', [], 1, 25], ['18:00:00:00']), ('normal control', ['18:00:00:00', [['00:00:00:00', '00:00:00:00'], ['23:59:59:00', '10:00:10:00'], ['00:00:00:00', '10:00:29:24']], 0, 25], ['18:00:00:00', '18:00:00:01', '04:00:11:02', '14:00:41:02'])], [('regression: inter-clip gap', ['18:00:00:00', [['01:00:00:00', '00:00:01:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10'], ['00:00:00:00', '00:00:00:10']], 25, 25], ['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']), ('regression variant: inter-clip gap', ['00:00:00:00', [['01:00:00:00', '10:00:29:24'], ['01:00:00:00', '00:00:01:00'], ['23:59:59:00', '01:00:30:00']], 1, 30], ['00:00:00:00', '09:00:29:26', '08:00:30:28', '09:01:01:29']), ('partial repair probe: inter-clip gap', ['00:00:00:00', [['10:00:00:00', '00:00:00:10'], ['23:59:59:00', '00:00:00:00'], ['00:00:00:00', '10:00:10:00']], 25, 25], ['00:00:00:00', '14:00:01:11', '14:00:03:12', '00:00:13:13']), ('partial repair variant: inter-clip gap', ['23:59:50:00', [['00:00:00:00', '00:00:01:00'], ['23:59:59:00', '10:00:10:00'], ['01:00:00:00', '10:00:10:00'], ['23:59:59:00', '00:00:00:10']], 25, 25], ['23:59:50:00', '23:59:52:01', '10:00:04:02', '19:00:15:03', '19:00:16:14']), ('boundary control', ['18:00:00:00', [['10:00:00:00', '10:00:00:24']], 0, 25], ['18:00:00:00', '18:00:01:00']), ('normal control', ['18:00:00:00', [['23:59:59:00', '00:00:00:10'], ['10:00:00:00', '10:00:10:00'], ['01:00:00:00', '01:00:30:00']], 0, 25], ['18:00:00:00', '18:00:01:11', '18:00:11:12', '18:00:41:13']), ('normal control', ['00:00:00:00', [], 0, 25], ['00:00:00:00']), ('normal control', ['18:00:00:00', [], 5, 25], ['18:00:00:00'])]]
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 fixture	Actual	Expected	Outcome
regression: inter-clip gap	`['23:59:59:00', '00:00:00:06', '00:00:00:07']`	`['23:59:59:00', '00:00:00:06', '00:00:00:07']`	Passed
regression variant: inter-clip gap	`['23:59:50:00', '15:00:20:26', '16:00:50:27']`	`['23:59:50:00', '15:00:20:26', '16:00:50:27']`	Passed
partial repair probe: inter-clip gap	`['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']`	`['18:00:00:00', '17:00:02:01', '02:00:13:02', '02:00:15:13', '02:00:15:24']`	Passed
partial repair variant: inter-clip gap	`['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']`	`['23:59:50:00', '23:59:52:06', '15:00:23:02', '15:00:24:03']`	Passed
boundary control	`['18:00:00:00', '18:00:01:00']`	`['18:00:00:00', '18:00:01:00']`	Passed
normal control	`['00:00:00:00']`	`['00:00:00:00']`	Passed
normal control	`['23:59:50:00']`	`['23:59:50:00']`	Passed
normal control	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	`['18:00:00:00', '18:00:01:01', '03:00:31:01', '03:00:33:02']`	Passed

SHA-256 / 8c3244b3bf1154cb8c860c3d638c109b5fdfa63f381e9130dd7f4884f27feef1

Verification & scope

A deterministic bounded teaching model with a stipulated toy contract; it does not claim conformance to SMPTE or any broadcast 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 2026-09-29T14:49:37.964693+00:00.

Case digest / b54c81c066309cdd3132f783db31bfa400d828d82e2d279b899d140545b55041