 Re: How to avoid frame drops (audio/video out of sync) when using screen capture soft
The basic explanation is that if your cpu is >100% stressed and can't keep up, it will start to drop frames (either audio or video or both). It has to playback the original file, while simultaneously recording the output. If there are not enough resources, it will drop frames in the output file (priority is given to the original playback so it looks smooth and in sync, but the recorded file might be choppy and out of sync - essentially "something has to give" and that's the output file).
Certain processes require more CPU resources, e.g playing a bigger frame sized video will take more than a smaller one etc... Hence the recommendation to capture a smaller framesize if the CPU usage was indeed the culprit for frame drops.
Depending on how you are recording, the software often tells you the # of frame drops. If you open taskmanager and look at cpu usage while you are doing this, you can see how stressed out your cpu cores are, this might give you a clue if you are dropping frames
If you are doing this online, each drop or desync will cause usually a approx -200ms delay, so it gets progressively worse at each drop point. You would have to identify the segements, add the appropriate +/- delay to each segment. I've done this before , it take hours/days to process even a tiny 1/2 hour video (very tedious!)
To rule out 100% the possiblilty of bandwith bottleneck being the culprit, the recommendation is to do it offline (i.e. from the file saved on the PC)
I should also warn you that doing this might violate the Terms of Service (TOS) ....do so at your own risk
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04-02-2009, 08:59 PM
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