C.39:5.2 - Preserve a performance’s timing relation

A workshop wants to use a recording for timing feedback. Its constructed acceptance condition permits at most three milliseconds of movement–sound mismatch. If an available qualified recording Method already preserves that relation under these conditions, the workshop uses it and stops.

Suppose instead that the available picture and sound tracks have separate time readings. A supplied synchronization account aligns one event visible and audible in both tracks. The workshop follows that operation on the supplied marker readings:

Subtracting the initial 40 ms leaves mismatches of 0, 2 and 5 ms. Thus aligning the first event does not meet the stipulated limit at the last one.

The workshop first adjusts the constant shift using all three markers. Their offsets are 40, 42 and 45 ms; centering the smallest and largest gives 42.5 ms. Subtracting that shift leaves residuals of -2.5, -0.5 and 2.5 ms, each within the stipulated marker tolerance. A different constant shift therefore supplies a candidate correction without introducing a changing time correspondence.

The search returns that constant-shift candidate and the precise support question: does it preserve the required relation over the interval used for feedback, and can an available qualified editing operation apply it? A suitable calibration result or a narrower qualified interval can close the gap. Fitting the three markers does not establish adequacy between them or an achieved corrected recording. All numbers and professional inputs here are constructed, not device-performance evidence.

For repeated correction work, C.39.RO:5.1 develops this case into an operation on any nonempty finite set of marker offsets. It derives the correction and the smallest achievable worst residual, so a tighter tolerance can return an impossibility result and prompt a different correction method.