1 (edited by CEPOMAN 2011-11-08 12:47:26)

Hi all Kinovea users

I'm new to Kinovea but what i've tried already is fantastic. But I have a problem using Logitech C910 Pro in capture mode. IT DOESN'T run smoothly at all. it says it runs 10 fps at 22?? x 15?? (can't remember big_smile) It wont record either? How do i downsize the resolution to 640x480 so it will run with 30 fps or higher...?

I'm using it for gait analysis in my sports shop. Currently i use an old microsoft Lifecam vx-500 which is fine but a bit rough in slowmotion at times... big_smile

Can somebody please help?


Hi Cepoman,
Did you find a solution to improve your frame rate with an usb webcam? I'm interested in this use of kinovea.

3 (edited by milandjupovac 2014-10-12 22:52:51)

Hello Cepoman,

Check this post http://www.kinovea.org/en/forum/viewtopic.php?id=736 similar camera Logitech C920, same issue, still we did not solve it, we done tons of videos but have get hi-quality videos, only thing that we can do is to test dual capture mode with powerful computer (tons of ram memory and processor hertz and cores wink ) Please let us know if you manage it somehow


Also you can check following files, done with Logitech c920 camera and same options in dual capture
https://commons.wikimedia.org/wiki/File … ajder.webm
https://commons.wikimedia.org/wiki/File … Rebur.webm
https://commons.wikimedia.org/wiki/File … glava.webm


The issue with the capture side of things is that there is many different hardware and I can't test most of them.

I am starting to redesign the capture pipeline to integrate benchmarking capabilities and find where the bottlenecks are. At the moment I am just at the "measurability" stage. Trying to take every detail in account.

I want to answer things like:
- What is the the actual grabbing framerate ?
- Is it stable or does it varies widely ? What is its standard deviation ? Median ? 95th percentile ?
- What is the sustainable recording framerate ?
- What is the sustainable display framerate ?
- Does it matter if delayed-display is active ? How large should the buffers be ?
- Should we degrade the display framerate while recording, by how much ?
- What is the best tradeoff between compressing the images (takes CPU time) and not compressing (takes I/O bandwidth) for the current capture configuration ?
- What is the fastest method to write sequential data to the disk ?
- Are the bottlenecks the same between an HDD and an SSD ?
- etc.

I am considering the option of storing captured images to a dedicated format, optimized for fast writing, rather than going through a classic video format as is done currently.
I have a monochrome Basler camera capable of 2048x1084 @ 50fps. Uncompressed, this is about 106 MB/s. The goal is to fully support that kind of bandwidth, and then up from there.



Please let us know progress of redesign of capture pipeline, we have two Logitech 920 HD pro usb 2.0 cameras, if you need any test please let us know, cameras as capable for full hd 1080@30fps


Yes I'll definitely come back to you for testing help, thanks.