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The C922 is among the best you can get.

Make sure you are using the most recent Kinovea version even if it's marked experimental, it has many improvements on the capture side.

The framerate and resolution are largely independent but together they define the total bandwidth that the camera has to process and then send over to the computer. The hardware itself is limited by the amount of data it can capture and then the USB link also has a limit to what can be transferred. USB cameras define a set of framerate and resolution combinations that can be selected.

When you go to the camera parameters dialog in Kinovea you will be able to select the stream format, the resolution and framerate. Resolution and framerate option availability depends on the stream format. Set the format to "MJPEG", this way the video will be compressed directly on the camera and the bandwidth to the computer will be much reduced, allowing to choose the top resolution/framerate combo without frame drops.

The PS3Eye has a really low resolution, I wouldn't recommend it in 2018. Some of the Chinese cameras can be interesting but I don't think they have anything above the flagship Logitech if you are looking for top resolution/framerate.

Thanks for testing!

The recording should happen at 120 fps in the sense that all the 120 frames are put into the file per second, however the final video file is marked as 30 fps for replayability purpose. So the final file should look slowed down four times if you play it at 1x speed. This is triggered for any camera feed above 100fps.

There is no setting to change this at the moment. Although you could force it back to 120fps upon reopening by going to Video > Configure video timing > Video framerate.

Hi,

I would say the angle-angle diagram will be the closest thing to cyclical motion analysis, it lets you see the value of a joint angle in relation to the value of another joint angle. It's used for repeating motion like running, swimming or cycling. Each cycle of motion will appear as an oblong ellipsoid shape from which you can infer information. I guess it depends on whether you can define cycle boundaries in terms of a reference joint angle.

There is no stats done on measurements at the moment, for this you will have to export the data to a spreadsheet and run the computation there.

For reference I repost the angle-angle snapshot in case you haven't seen what they look like.

There is no hard limit. I guess it depends on the computer. But it doesn't handle occlusions very well so unless you are tracking things that somehow move on non-crossing path the limiting factor will be the failure of tracking due to something moving in front of the object/joint. If you go frame by frame to verify and adjust when needed it shouldn't be a problem.

It might work but I'm not 100% sure.
One thing is quite certain I think is that you will need to use an externally powered USB hub, one that will provide the standard 500mA *per port*, rather than a non powered one that will pull 500mA from the PC and share it among its downstream ports. These cameras are relatively power hungry.

If you select the MJPEG stream type in the settings the camera will compress the stream on its side and the bandwidth may be manageable. In this case Kinovea won't recompress it before storing so it's the most streamlined scenario. If the limiting factor is the I/O bandwidth at the drive, another trick would be to set the output files to automatically record one camera to the SSD and the other to the internal HDD.

Two C920 recording to an internal SSD via USB 2.0 works in Kinovea but it's already a scenario that requires the right USB setup.

If you have enough RAM on the laptop another trick could be to setup a RAM drive. It's like having a drive backed up by memory, so lower latency and greater bandwidth. I've never tried that myself but in theory it should give the maximum performances. It will compete with the size of the delay buffer if you want to use the live delay feature though, and you have to remember to copy the files over to your main drive before shutting off otherwise they are lost.

Hi,

Not sure if this will suit your needs but here is a little-known trick that may help.

1. Create a text file with the following contents:

<?xml version="1.0" encoding="utf-8"?>
<KinoveaSyntheticVideo>
  <FormatVersion>1.0</FormatVersion>
  <ImageSize>800;600</ImageSize>
  <FramesPerSecond>10</FramesPerSecond>
  <DurationFrames>100</DurationFrames>
  <BackgroundColor>255;255;255;255</BackgroundColor>
  <FrameNumber>false</FrameNumber>
</KinoveaSyntheticVideo>

2. Change the extension of the file to .ksv,
3. Open the file in Kinovea as a video. It will be a blank video of the specified size, framerate and duration,
4. Add drawings to your liking,
5. Copy the current frame by doing a right-click on the frame outside of the drawing and "Copy image to clipboard".

It will copy the entire frame and won't retain transparency so it's not as good as if you could just copy the drawing to paste it on a different background, but maybe it can be acceptable for your scenario. You can change the background color in the KSV file. Color format is ARGB.

Now if you create your drawings in an actual video as a reference, you could do this:
1. Save the reference analysis as a KVA file,
2. Create a KSV file with the same image size, framerate and duration as the original video,
3. Use menu File > Load key images data… and import your KVA into the blank video.

Now the human models tools don't have tracking by default so if you want to store several positions you will either have to create a new drawing at each pose you are interested in, or make them trackable.