1 Topic by michaelarrington (edited by michaelarrington 2025-09-06 02:27:34)

  • michaelarrington
  • -
  • Offline

Hello everyone,

I’ve been using Kinovea for a while now, mainly for sports motion analysis and research projects. The software is incredibly useful, but I’ve noticed that when working with high-resolution videos (Full HD or 4K), the performance sometimes drops—playback becomes choppy, and exporting data takes longer than expected.

I wonder if other users have experienced the same issue and how you deal with it. Do you:

Convert your videos to lower resolutions before importing them into Kinovea? that's not my neighbor

Use specific codecs or file formats that are more stable?

Adjust Kinovea settings to improve playback and analysis speed?

Use particular hardware (CPU/GPU/RAM) setups that make a big difference?

I think this is a common challenge for many users, especially as cameras today often record in very high resolutions by default. It would be great to hear about your best practices, tips, or even workarounds to keep Kinovea running smoothly.

Looking forward to your thoughts!

Best,

2 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

Yeah 4K + H.265 is brutal for frame by frame. Pending further investigation the current strategy is to increase the memory buffers in Preferences > Playback > Memory and then reduce the working zone to have it fit in the buffer, then it should be smooth. But that's very limiting at these resolutions, required memory: width*height*3*frames, for 200 frames ~5 GB.

3 Reply by joan (edited by joan 2025-09-08 21:34:04)

  • joan
  • joan
  • Admin
  • Offline

Hi,
I looked into perfs a bit. Specifically I have some 4K @ 60 fps videos which are impossible to browse on the timeline.

Could you tell if you are seeing the same:

1. forward playback is actually decent. It's not buttery smooth but it runs without slowing down too much. I measured between 9 and 25 ms per frame to decode, and on average it can sustain about 45-50 fps so it's usable for the purpose of watching the action in real time.

2. forward frame by frame also works. For example holding the keyboard right arrow down and letting it move forward.

3. It's backward frame by frame and clicking around in the timeline that is horrendous.

Do you get the same behavior?

When you get this it's mainly related to the encoding. This particular video is encoded with key frames every 6 seconds (360 frames).

So whenever we click in the timeline, it will randomly drop in the middle of one of these segments. The way video decoding works we get to the previous key frame and then it has to decode all the frames forward until it gets to the target.

So I'm getting 2 or 3 seconds to get the requested position, just because it has to actually decode hundreds of other frames to get there.

As an experiment I exported it back using the export function (export in Kinovea uses MJPEG exactly for this reason, so every frame is a keyframe), and now I can do frame by frame and timeline browsing without issues, on the same 4K 60 fps video. (But yes the file is 10x bigger).

(edit: my computer is not particularly beefy).

4 Reply by joan

  • joan
  • joan
  • Admin
  • Offline

The way they solve this in video editing software like Shotcut or Premiere Pro, which also need frame by frame navigation, is a workflow known as "Proxy editing".

Essentially they create lower resolution and editing-friendly versions of the files, you create your edits on these proxies, and when you are ready to make the final export they swap in the original footage.

This seems the way to go and the fact that it's an industry standard there is an indication that no amount of buffer optimization or GPU acceleration would truly solve it.

I could add a function to create frame by frame friendly version of the video. I think the simplest would be to create the file next to the original with a suffix, as this would open the way for automatically detecting the kva annotation file when opening the original video. This way we can have a similar workflow: add your annotations on the proxy, then export a video based on the original.

One caveat is for making measurements and tracking as the lower resolution will reduce precision. But I think for the main use case of visually inspecting technique/posture it would be a good solution.

Two ways to go about it, either from the file browser by right clicking the thumbnail and a simple convert menu. Or by first opening the video and having an option under export.

For the resolution it should probably be a preset while keeping the original aspect ratio.