16 Reply by Reiner

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most of the handy-cameras recorded videos did NOT use a constant framerate. Therefore, it may be favorable
to convert the video to a constant framerate. Furthermore it may help to convert the video to "mjpeg" to store a full frame to every frame. MP4 is the container but does not control the content of the video. Be aware of creating a hugh file using the mjpeg-options.

using FFmpeg the option -c:v mjpeg creates a video that contains a full frame for EVERY frame, not only the difference from one frame to the other. This type of video can be read in Kinovea and it is possible to scroll back and forth from one frame to the other. Furthermore, you could experiment of using a constant framerate for the output-video using the -r option. The quality is controlled by -q:v 2 (highest quality, 23 lowest).

Example
ffmpeg -i input.mov -c:v mjpeg -q:v 3 -r 30 output.mp4

17 Reply by joan (edited by joan 2020-07-22 23:31:01)

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Dr.Dank wrote:

the graphs don't follow the scale set by calibrated lines and all accelerations are shown as zero.

You're right, there is something weird going on. If you go to Preferences > Playback > Units and simply hit save, then open the diagrams dialog again, it should be in the correct units… I'll investigate.

Being the second derivative acceleration is super sensible to even the smallest noise in the positions, and the normal filtering usually don't fix it, and you will get values that go up and down when they really shouldn't. Use this as an approximation. To give an idea, we tested with a simple ball in free fall and it was already hard to get a consistent g, instead we got something varying between 8 and 10 m/s².

The diagrams are somewhat interactive by the way, you can hover the mouse over the Y axis values and scroll, and it will rescale the axis. Inside the graph you can right click and drag to move around.

edit: OK I think I found the issue with the initialization of the speed and acceleration units. This should work in the next version.

18 Reply by Dr.Dank (edited by Dr.Dank 2020-07-29 20:23:29)

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The systems I'm analyzing are simple enough that they can be modeled with only a few parameters, so I've actually been able to somewhat bypass the problem of numerically differentiating noisy data. As an example, when free fall position vs time data are fit by a quadratic the coefficient of the square term is a measurement of g/2. Being a global operation, linear regression is less sensitive to the small-scale noise than local differentiation is so I've gotten values pretty close to the accepted value this way.

To help with my error budget, do you have any estimates for the uncertainty in the position values generated by the path tracker?

19 Reply by bkh8

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I have several instances of Kinovea open. Two to record and two to replay. The cameras will record the swing but then it also records after the swing several clips and those get recorded to the folder as well. And so it will show the swing but then that goes away and it shows me walking around. I have Model: KYT-U100-GS2ML.  I have automation set to audio trigger and under recording set to delayed. I have it set to record for 4 secs with a 2.7 delay.

20 Reply by joan

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Maybe try to tweak the audio threshold so that it only triggers when you want. For example locate the microphone close to the impact area and set it to only trigger when it's really loud. You can test this directly in the preferences dialog.

At the moment there is no "cool down" period where the trigger would be disarmed for a while after recording, hopefully I can integrate this for the next version.

21 Reply by bkh8

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Thanks for responding. I will try and increase the threshold to see if that makes a difference.

I posted some other questions here:

https://golfsimulatorforum.com/forum/bu … ovea/page4

I see you have responded there in the past. Wondering if you had any thoughts about fixes.

I wonder if I got a faulty camera as well. I may see if I can get a refund and a new camera.

B

22 Reply by joan (edited by joan 2020-08-10 22:30:40)

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Reposting my comments here

If you run the executable again the name will be generated based on the order of launch. So the second instance will have name "2", the third will be named "3", etc. This means you will need to launch them in the same order.

There seems to be a bug in this feature that the numbered instances are picking the master preference file and not their respective preferences. So for now please use explicit naming. A simple way to do that is to right click the executable, create a shortcut, and then go in the properties of the shortcut and in the "Target" field add "-name foobar" at the end. Then to launch that instance you use the shortcut.

If you have a single camera in each instance, it will only use the "left" naming scheme.

Edit: I fixed the issue with the instance using the wrong preferences when it's named automatically from its order in the launch sequence. This will be fixed in the next version, in the meantime please use explicit names.

23 Reply by Reiner

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To make it more versatile and adaptable I use the following:

Create a batch file using a text-editor (i.e. Notepad) at a location you can reach easily, i.e.
d:\KinoveaStart.bat

This file contains one line of text:
"FullPath2Kinovea" -name %1

I exclusively use Kinovea from the ZIP-File, storing it in a directory that easily can be found.
So in my case the line contains:
"d:\kinovea093\kinovea.exe" -name %1

If you use the exe-installation of Kinovea, you would have to replace <FullPath2Kinovea> by the path Kinovea is stored.
It is important to use the quotation marks if the path contains a space character.

Now you can create a Link on the desktop to start Kinovea with a specific -name convention
To start Kinovea i.e. with -name "Front", in the link-dialog fill out the field "target" with the following
D:\KinoveaStart.bat Front

To start a second, independent Kinovea with -name "DL", create a second link with
D:\KinoveaStart.bat DL

Do NO

24 Reply by hhsospam

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The same thing can also be achieved by adding the -name XXX directly in the target box (First create a shortcut of Kinovea.exe, then right click on the Kinovea shortcut -> Properties) of the shortcut without the batch file. You can create different shortcut with different -name. E.g., c:\temp\Kinovea\Kinovea.exe -name Front, c:\temp\Kinovea\Kinovea.exe -name DL


Reiner wrote:

To make it more versatile and adaptable I use the following:

Create a batch file using a text-editor (i.e. Notepad) at a location you can reach easily, i.e.
d:\KinoveaStart.bat

This file contains one line of text:
"FullPath2Kinovea" -name %1

I exclusively use Kinovea from the ZIP-File, storing it in a directory that easily can be found.
So in my case the line contains:
"d:\kinovea093\kinovea.exe" -name %1

If you use the exe-installation of Kinovea, you would have to replace <FullPath2Kinovea> by the path Kinovea is stored.
It is important to use the quotation marks if the path contains a space character.

Now you can create a Link on the desktop to start Kinovea with a specific -name convention
To start Kinovea i.e. with -name "Front", in the link-dialog fill out the field "target" with the following
D:\KinoveaStart.bat Front

To start a second, independent Kinovea with -name "DL", create a second link with
D:\KinoveaStart.bat DL

Do NO

25 Reply by hhsospam

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If you follow others' advice to launch different instances of Kinovea with the -name parameter (c:\Kinovea\kinovea.exe -name Record1, c:\Kinovea\kinovea.exe -name Record2, c:\Kinovea\kinovea.exe -name Playback1, c:\Kinovea\kinovea.exe -name Playback2,   and still have the problem. Check the following.

Since you have multiple instances running, be sure to check the delay recording and the audio trigger settings are set in the correct instance(s). I have mistakenly configured the wrong instances and experienced something similar to what you described.


bkh8 wrote:

I have several instances of Kinovea open. Two to record and two to replay. The cameras will record the swing but then it also records after the swing several clips and those get recorded to the folder as well. And so it will show the swing but then that goes away and it shows me walking around. I have Model: KYT-U100-GS2ML.  I have automation set to audio trigger and under recording set to delayed. I have it set to record for 4 secs with a 2.7 delay.

26 Reply by bkh8

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Looking at the recorded file closer, the file actually does include my swing but it includes closer to 8 seconds of data condensed into 4 seconds. The file is then speed up and replayed as a 4 second file. Is that a USB issue?

I will try and set up the shortcuts as you recommend. thanks for the tips around that.

27 Reply by Reiner

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It rather sounds like a bottleneck in your system.

I would go step by step to evaluate it.

- Use only 1 camera with your recording parameters. 1,5 seconds delay and 2,5 seconds recording time fits perfectly to grab a golf swing.
- Set the recording mode to „retroactive“. Kinovea then grabs the video into memory and writes it to disk AFTER recording. So you can eliminate slow disk speed.
- During recording, look on the amount of dropped frames DURING recording. Simply click on the red button to get your video.
- If dropping occurs , try to use uncompressed formats like MKV or AVI, reduce the video size or reduce the framerate, if your camera supports it. I don’t know the options you have with your camera. Lowering size and fps will reduce load and dropping. Your camera still is monochrome, so the amount of data to be transferred is still low than using a color camera.
- Check your CPU-load to see, if your system (processor and chipset) is capable of transferring the data to the system. To my knowledge, direct measuring the USB-load is somehow difficult. At this stage, try to avoid any elongation cable to connect the camera. Plug it in directly.?Basler has a tool to measure the maximal bandwidth, but you have to connect a Basler camera. By the way, they have a new camera line released this year at about 290 Euro that is very interesting.
- Once you get a stable run with 1 Camera, you could add the second camera. The best option is to have a second USB-Port on your system. However, a lot of systems have more than one USB-connectors, but NOT a real second independent port. It depends on your Chipset of your motherboard. if you have 1 USB2 and 1 USB3, connect each camera to one of these ports. Be sure not to have other demanding devices connected parallel on this ports.
- If you have connected the second camera (related to a separate Instance of Kinovea), check your CPU-Load again. On a motherboard having one of the newest Chipset Z390 with 2 independent USB-Ports (1 USB2, 1USB3.1), using an Intel i5/9600K one instance uses about 35% of CPU-Load during delayed recording. Upgrading to an i9/9900 it decreases to about 15-20% of CPU-load.

Hope that helps.

28 Reply by joan

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Also double check the framerate received by Kinovea is the one you expect. You can see this in the infobar above the capture screen. The "Signal" value should be near the framerate you expect. If it's around half what you expect you will get a sped up video as you describe. If you are in low light conditions for example the camera can decide to increase exposure time and lower the framerate automatically, disregarding the configuration.

29 Reply by bkh8

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Both post were very helpful.

I am noticing that I have the camera set to 120fps but the signal is 20 fps.

So I need to increase lighting? Could it be an issue with the camera?

30 Reply by bkh8

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I bought two same cameras. I have only ever had an issue with one of the cameras. The other camera signal is 120 fps. I have moved this camera to different ports and had it be by itself as well. Still signal is at 20. I will try and unistall and reinstall driver maybe?