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My encoding is precise enough to evaluate each device *effective* sample rate: my Nikon sound is spec'd at 44100 Hz but is 44099.688 Hz (all digits are significant) a discrepancy more simply expressed in ppm, here 7 ppm. My Fuji X-E1 shows an error of 33 ppm. Why is this consequential? Because when syncing sound and video from 2 distinct devices at the clip start, the tracks will drift apart slowly and for long enough takes (interviews, live shows) it will be noticeable.

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How long, you ask? Take the maximum acceptable offset between video and sound to be 15 milliseconds (cf link); this small interval would be 33 ppm of the whole recording, hence T = (1e6/33)*15e-3 = 454 seconds! After about 8 minutes the drift is out of spec... The solution? Split the tracks and realign them again each time the offset is bigger than 15 ms. My software suite will have a dedrift program for correcting high drift device takes. ffmpeg based, but how? 🤔

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