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Clarification on TSMP interpretation for precise gyro timing #212

@IRCGraphic

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@IRCGraphic

I've been working with GPMF data from a GoPro HERO11 Black, specifically extracting GYRO and ACCL streams for post-stabilization using Gyroflow (VQF integration). I've encountered a timing inconsistency and would appreciate your insight.

The observation:

First TSMP value in the GPMF stream is 210
Last TSMP value is approximately 129,154
Delta between them is 128,944 samples
The video duration is 637,520 ms
Average sample rate = 128,944 / 637,520 = 202.3 Hz
The question:
What does the first TSMP value (210) represent? Does it indicate:

Samples captured before the record button was pressed (pre-roll buffer)?
A cumulative counter that includes samples from a previous recording session?
A fixed offset that should be subtracted to align the sample timeline with the video start?
Something else entirely?

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