Does trimming sync windows by their distance from the fitted clock line, with no tuned threshold, beat the peak-sharpness gate on real audio?
research/capture-residgate
Does a clip-free residual-from-the-clock-line trim beat the PSR gate? At 0 dB a little (1.4% to 0.9% of cuts over a frame); at -10 dB no (46% vs 38% for PSR).
What it found
Follow-up to capture-syncgate. Drops GCC windows more than 2–20 ms off a Theil-Sen clock line (up to 3 rounds), a threshold in time rather than in peak sharpness, over 10 real LibreOffice gallery clips (4 cameras, 12 windows, ±40 ppm, 12 seeds). At 0 dB SNR with gamma 0.25 the share of cuts jumping over a frame falls from 1.4% to 0.9% for any tolerance in the range, mostly from one clip (untie). At −10 dB it helps little (46.1% vs 47.6% ungated) where the PSR gate gets 37.8%; combined 37.4%. It does not fix the held-out gamma-choice failure from capture-syncgate (9.9%). Why trimming drops so many windows: for space2 66% of windows are period aliases (a 12.1 ms near-tone; errors at multiples of the period, 0% under a control period), wallewal 12% aliases and 14% gross, untie and soft 25–34% gross early-start failures of unknown cause. Limits: ten clips from one gallery, synthetic delay and white noise, assumed clock rates, small grids, assumed one-frame criterion.
Paper, code and results
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- Does a robust fit or a Kalman filter hold a camera's clock better between audio re-syncs than a least-squares line, once the clock drift comes from a real crystal curve?Does a robust fit or a Kalman filter hold a camera clock better between audio re-syncs? On a clock rate computed from a sourced AT-cut crystal curve the plain offset hold is already fine up to 1800 s and every fit ties; only a Kalman filter tuned to an assumed 30 ppm wobble wins. Synthetic audio.
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Produced with AI assistance (Claude). Results are from the code in this repository and are simulated or stylised unless the abstract says otherwise; nothing here implies affiliation with or endorsement by any lab, researcher or company cited. MIT licensed.