Method

A/V sync drift

A/V sync drift, audio onset vs video luma transition

What we measure and how

Audio onsets (transients in a mono 16 kHz decode) are paired with the nearest visual onset (scene-cut / motion burst) within a window; the median per-pair offset in milliseconds is the measured A/V drift (positive = audio lags video, negative = leads). A least-squares slope of the per-pair offset over programme time additionally flags progressive drift (resample / speed-change) that a constant-offset median would miss. Spec-gated on `assets.audio.sync.max_drift_ms`; progressive drift on `assets.audio.sync.max_drift_ms_per_min`.

Spec fields consulted

These Universal Media Delivery Profile paths resolve this check's thresholds against your spec snapshot at the moment the job was submitted.

• · assets.audio.sync.max_drift_ms
• · assets.audio.sync.max_drift_ms_per_min

The full UMDP schema: /umdp.

Method identifier: av_sync_drift