676 Reply by joan

(8 replies, posted in Bug reports)

Hi,
Some issues may arise if the perspective grid is at a very steep angle, as is the case when placing it on the floor seen from a camera that is not very high above ground. Try to stay above 30° or so between the camera axis and the plane. Move the camera higher up and look down if possible.

At a steep angle the coordinates aren't going to be very precise since one pixel in the image will cover a lot of real world area.

Also, the coordinate system origin can be moved independently from the grid, maybe you have moved it inadvertently? If the origin of the coordinate system is outside of view it could yield unexpected results. If it's above the horizon line it is effectively at infinity and things will be completely broken. Once the calibration is active, if you move the grid's corners it's going to move the coordinate system with it.

It's possible to see the actual coordinate system with menu Tools > Coordinate system. If you don't see the origin where you expect it, this should be fixed first. The primary axes are thicker than the other lines and can be dragged around. Move the grid's corners around to make it more rectangular to check where the origin is, and place it where you want relatively to the grid. Then move the grid back to match the real plane.

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677 Reply by joan

(1 replies, posted in General)

Hi,
One immediate thing to check is if the video file produced by the filming camera is marked as 120fps or not. Usually for such speeds the camera will create a file marked as 30fps or 60fps, even if the content is 120fps, when reading the video normally it appears in slow motion.

Assuming Kinovea 0.8.25, go to menu Video > Configure video timing. In the lower panel, check the "Framerate read in the file: XXXfps". If this is not 120, then this is the source of the difference.

In this case, in the same dialog box but in the top panel ("High speed camera"), change the Capture framerate to 120. This should make Kinovea understand the mapping between the time in the file and the real time of the action captured.

Edit: thinking of it, the difference would go the other way compared to what you describe, so it's probably not the culprit.

Another thing is if the SD card on the action camera is not capable of writing fast enough. In this case it will drop frames and the resulting video will be faster than normal.

To check this, record a running stopwatch (tip: you can type "stopwatch" in Google to get one), and review the video in a regular player. If you record 10 seconds of the visible stopwatch but the video doesn't run for that long then the problem is at the recording step in the camera.

Just using class 10 SD card may not be enough depending on the resolution you are using. You can check this page: fastest microsd cards for info about write speed, ratings, etc.

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678 Reply by joan

(3 replies, posted in General)

I added an option to allow multiple instances of Kinovea running at the same time. I'm not 100% sure of the implications of this regarding some file access, but we'll see how it pans out. It will be disabled by default.

The panel containing the capture thumbnails has been rewritten from scratch between 0.8.15 and 0.8.25 so it's possible the issue with dual recording slowing down is fixed already.

What were the other issues that prevented you from using 0.8.25? I remember the ability to record with delay was one and this should be addressed in the next version as well.

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679 Reply by joan

(1 replies, posted in Bug reports)

Hi,
The halving of the maximum delay is by design actually, as it is backed by memory. You may go to Options > Preferences > Capture > Memory, and check the total memory used for capture buffers. When using dual screen, this amount of memory is split between the screens. The maximum memory that you can allocate will be much increased in the next version when using the x64 build.

The image should only freeze if your current delay value places you inside the second half of the delay buffer, where the buffer has to be reconstructed.

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680 Reply by joan

(7 replies, posted in General)

Chas Tennis wrote:

For a Kinovea side-by-side comparison there could be a total of 4 different frame rates for the 2 source videos:

1) video #1 - source frame rate
2) video #1 - recording frame rate
3) video #2 - source frame rate
4) video #2 - recording frame rate

Yes, this scenario gets confusing very quickly. To add to the confusion, there is also the "display" framerate, when you change the "speed slider" value. The final framerate of the composite video takes the speed slider value into account. Note that the speed slider value is given with regards to the recording framerate, not the file framerate.

When you have two videos with differing "recording" framerates, you need to be aware of the value of the following setting: Options > Preferences… > Playback > General > Link speed sliders when comparing videos.

If checked this option will force the speed sliders of both videos to use the same value (ex: 50%), which should make them use the same reference time scale. So if you had filmed the same performance with two different cameras at different recording framerate and the cameras output different file framerates the videos should still be synchronized out of the box ( as long as you set the recording framerate).

I think it's easier to think about all this in terms of frame intervals. The inverse of the recording framerate gives the real world duration between the captured moments.

Chas Tennis wrote:

Would frame rates of the two source videos be found in 'metadata' of the source videos?

Yes the framerate of the video is a metadata. The default display framerate of the video can be found in Kinovea in the top bar above the player screen or in Video > Configure timing in the bottom panel. In Windows by right clicking the file and going into Properties > Details > Video > Frame rate.

Chas Tennis wrote:

Kinovea produces a video file with another frame rate.  How does Kinovea select a default frame rate?  Does the selected Kinovea default frame rate depend on the frame rate of which source video happens to be on the right or the left?

It should not depend on which video is on the left or right.
Each video has its frame interval computed, for the synchronized playback. The common player uses the smallest frame interval to drive the dual video playback. Unless there is a bug, this smallest interval is what should be used in the final composite file.
There is an extra check to limit the interval to 10ms at the smallest, so the final file should never be faster than 100fps. 

Chas Tennis wrote:

How can/should the user select a different frame rate than the Kinovea default frame rate?

You cannot manually specify the output framerate of the composite video at the moment.

Chas Tennis wrote:

If the user selects a Kinovea video frame rate that is accepted by, for example, Youtube or Vimeo, then if frames are still skipped it would probably be a video website issue. ?

You can reopen the composite video in Kinovea and verify frame by frame that everything is there. Maybe it's possible that some combinations of framerates would result in missed frames in one video? Normally since it's driven by the smallest frame interval this shouldn't happen. Instead, the lower frequency video should have duplicated frames.

Chas Tennis wrote:

Are the source video frame rates (metadata) still in a side-by-side Kinovea video file? Could one of those source video frame rates somehow be mistaken for the Kinovea frame rate by a video hosting website?

No the default display framerate of the original videos is no longer present in the final composite video.

If you want to make some experiments you could use the KSV test file format. Here is a KSV file:

<?xml version="1.0" encoding="utf-8"?>
<KinoveaSyntheticVideo>
  <FormatVersion>1.0</FormatVersion>
  <ImageSize>800;800</ImageSize>
  <FramesPerSecond>20</FramesPerSecond>
  <DurationFrames>100</DurationFrames>
  <BackgroundColor>255;128;0;0</BackgroundColor>
  <FrameNumber>true</FrameNumber>
</KinoveaSyntheticVideo>

Copy this in a new text file and save with extension .ksv. Kinovea has special code to interpret this as a video, for testing purposes. You can change the FramesPerSecond field for experimenting. And inside Kinovea you can change the "recording" framerate as if it was a regular video.

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681 Reply by joan

(44 replies, posted in General)

arnopluk wrote:

Next to those issues, I have found a small bug in the implementation of the hotkeys (in all versions I've tested):
When you use the keyboard to increase or decrease the delay, the GUI updates, but the actual delay isn't changed. In the code (below), the value is changed and the control is invalidated, but a 'ValueChanged' event is lacking.

Super thank you for finding and debugging the issue! I have made the correction in the code.

arnopluk wrote:

Unfortunately, I can't get source code compiled in Visual Studio Community 2017 (.NET 4.7), so I can't propose a (tested) fix for this.

Yeah sorry for the state of the build process. At the moment I'd like to keep targetting .NET 3.5 for at least one more version. This has consequences on the build because of the C++/CLI project. Recent versions of Visual Studio don't know how to compile C++/CLI for 3.5. The entire build actually requires VS2008 and VS2010 to be installed on the machine. I'm in the process of writing down a proper guide.

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682 Reply by joan

(7 replies, posted in General)

Chas Tennis wrote:

When does Kinovea save videos as 30 fps and when at 100 fps?    Is there a way to control the playback video frame rate before saving the Kinovea analysis video file on Kinovea 8.25?

Yes, menu Video > Configure video timing > Video. (bottom section).
The value put here will set the framerate value reported by the file in its header, so video players will be "tricked" into playing the video at that framerate. Or, in the case of Vimeo, it should be tricked into not changing the framerate of the video.

This will distort the scale of time when playing back the video. So for example if you were to take a 100fps input video and change this value to 50fps, the live action would be reproduced half as fast as it should. However, step by step operation should correctly visit all the original frames without skips.

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683 Reply by joan

(7 replies, posted in General)

Chas Tennis wrote:

1) sometimes the magnification boxes appeared on Vimeo in different screen locations than in my computer video.  In the wrong place, they blocked video and often obscured the labels, arrows etc that were on the screen.

I think that's a bug in the export process in Kinovea that has been corrected for the next version. Same bug that was causing dual view export to not work.

Chas Tennis wrote:

2) often the Vimeo processed video would do single frame so that the faster video (say 240 fps) would advance 2 frames using the Vimeo process for single frame advance.
(...)
I contacted Vimeo about the issue of skipping frames when uploading  Kinovea videos to Vimeo.  Here is their reply.

" The original video you uploaded to Vimeo is 100 fps, which exceeds our 60fps threshold. We reduce the frame rate for all videos exceeding 60fps during our conversion process. Frame drops can occur during our conversion process in this case.

Thanks for the investigation. I can see why they would do that since most people have 60Hz refresh displays and are just playing back the videos at normal speed.
I thought Vimeo had an option for the end viewer to download the original video as a file (original framerate and without the compression), but I'm not sure.

Regarding the capping at 60fps I'm confident it is the same for YouTube.

Chas Tennis wrote:

Vimeo single frame process - Hold down SHIFT KEY & use ARROW KEYS
(...)
Youtube single frame exists - you simply use the "." and ","  keys!!

Wow, that's awesome, I wasn't aware of that!

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684 Reply by joan

(44 replies, posted in General)

Regarding Vimeo and Youtube I think it's an important topic that would be best in its own forum thread so we can collect the knowledge in a single dedicated place there. I'll move the discussion.

Edit: new thread here.

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685 Reply by joan

(44 replies, posted in General)

Hi everyone!
Sorry for the lack of updates lately, I'll try to address all the comments in order.

VF wrote:

Is it possible to change the label color somehow? (...) it was very useful feature in 0.8.15 version and now all the labels just stay black.

Using the text tool? This should work. I can't reproduce the problem, right click on the label > Configuration... I can change the color of the label.

VF wrote:

you've added some new 'trackable' tools. say, i have a video that lasts from point A to point E and i want to track 2 different objects using the spotlight tool (one from point B to point D and another one from point C to point E).

There is some new stuff for the next version in that a tool can start and stop tracking during the lifetime of the video without resetting the tracking data like before, but I'm not sure it'll be very practical with regards to the spotlight tool. This tool is a bit special to handle the fading in/out. Maybe it would be better to be able to take the trajectory tool and have a display mode for the trajectory that would be a spotlight. Or to be able to point the spotlight tool to an existing drawing like a tracked crossmark.

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686 Reply by joan

(44 replies, posted in General)

Right click the marker and select "End path edition", you should get the path. Right click the marker and select "Configuration" to get the display options.

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687 Reply by joan

(44 replies, posted in General)

I can send a private test version if you need this urgently and promise to give feedback about it :-)
I don't know when the next experimental version is going to be finalized. I made good progress on the angular kinematics analysis and export which is the bulk of the release. But I'm abroad for about a month for work and I won't make much progress on Kinovea during that period.

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688 Reply by joan

(44 replies, posted in General)

Please go to Help > Open log folder and collect the log.txt file and sent it over at joan at kinovea dot org. So I can better understand what is happening. Thanks.

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689 Reply by joan

(44 replies, posted in General)

Hi dangthuhuongvn,
It could be linked to the Windows locale used for non-Unicode programs causing an issue when loading the video decoding library. There is an open bug submitted a while ago of a similar thing. Most people don't have the issue but on some systems it causes this problem.

Is your Windows in Vietnamese? Can you see thumbnails for images (.gif, .png, .jpg, etc.) they use a different decoder, it would confirm the origin of the problem.

Please check the following setting in Windows: Control panel > Region > Administrative > Language for non-Unicode programs. What is the value of this?

Try to change this to match the language of your system if it's set to English. This is mostly to test the hypothesis, this may have side-effects on the functionality in other programs so keep that in mind if this fixes the issue but you see bugs arising in other programs.

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690 Reply by joan

(4 replies, posted in Cameras and hardware)

punkduck2064 wrote:

You can see the camera thumbnail, but when you try to capture the video is when you get the error.

What is the error exactly ? Error message saying to try a different format? Black screen? Can you open the camera settings dialog? Can you change the stream format? What is the list of stream formats? Can you paste what the header bar is displaying above the camera screen?

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