Kinovea Playback out of sync

[PicoTTS]

I got 2 ELP cameras recording at 120fps after each shot. The problem is that when I replay the videos, a lot of times they end up out of sync after a few seconds and one is faster than the other.

Anyone know why it might be happening? Is it because the recording are always slightly different lengths( 4.1s vs 4.08s)? Not sure why they always vary in length.

Could it be a system resource thing? I am running a i7 8700 with 32gb ram. I have both the playback and recording memory set to 4gb.

Also as a side question, is there a way to tag a shot? Like labeling a good shot vs bad shot or draw vs hook? Would make sorting through the list much easier.

Thanks

[preludesam]

Are you dropping frames? You should have a dropped frame counter on the recording instance.

[PicoTTS]

oh yeah that seems to be the issue. Is dropped frames due to my computer not being able to handle 2 simultaneous recordings? Or is there another reason that might cause the dropped frames?

[preludesam]

Could be a couple of issues.

1. Not enough RAM is being dedicated to the capture. It's a quick check to just increase the slider and see if you get better results. Remember to make sure you are changing the Recording setting and not Playback.
2. Your processor cannot keep up with the encoding amount required. You can change the setting for raw capture and set the recording to Retroactive.
3. The USB controller is being overloaded. Check to see how many USB devices are connected to your computer. I do not think this would be an issue since the cameras are USB 2.0 and we usually only run into this issue if you are using two high-speed high-resolution color cameras. Nonetheless, disconnect all USB devices except the cameras and see if there is any change.

[PicoTTS]

I believe its my CPU maxing out. Its basically always hitting 100% usage. I've already set it to Retroactive as opposed to Delayed now. I'm don't fully understand the difference between the 2 though.

When you say raw capture, do you mean recording uncompressed? Or are you referring to another setting?

[preludesam]

Yes, uncompressed recording. With uncompressed, the file sizes are going to be large so be careful about running out of hard drive/SSD space. You can also set it to overwrite each new file and manually save the ones you want to keep. Retroactive means it holds the frames in RAM until the capture is done and then completes the file. Did it get any better with those changes?