Best way to time a video recording

[BReeves]

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What is the best way to accurately time a video recording. I am trying to use a TTimer ticking off seconds and counting down from some value. When the counter reaches 0, I call a function that closes the logger and saves the file.

It works but the resulting video file isn't as long as One would think it should be.

Setting the count for 30 seconds results in roughly a 22 second recording and setting the count for 60 seconds results in a 43 second video. On another faster computer the 60 second setting results in a 30 second video.

Must be some stuff going on in the capture and Logger threads that are independent of actual time.