Weird GetTimeStamp() results

[pourfard]

Hi,

I get timestamp of the grab results using GetTimeStamp(). When the camera's FPS is 10, the difference between two consecutive frames is always 0.125 seconds. But i expect it should be 0.1 seconds. How can i get the actual timestamp of the frames in seconds or milliseconds. When I set FPS to 20, difference between frames is 0.075 seconds.

print(grabResult.GetTimeStamp() / 1e8)

here is the output of the above code for some frames while i'm getting 10 frames per seconds:

921920.39391752
921920.51891786
921920.6439182
921920.76891854

Is your camera operational in Basler pylon viewer on your platform

Yes

Hardware setup & camera model(s) used

PC:

• CPU: ARM64
• OS: Ubuntu
• RAM: 4GB

Runtime information:

python: 3.10.6 (main, Nov 14 2022, 16:10:14) [GCC 11.3.0]
platform: linux/aarch64/5.10.110-rockchip-rk3588
pypylon: 4.0.0 / 8.0.0.10

[thiesmoeller]

What is gives you the resulting frame period feature ? What is your exposure time ?

There can be other factors reducing the framerate below your set frame rate Exposure time Transport layer configurations like throttled bandwidth

[pourfard]

What is gives you the resulting frame period feature ? What is your exposure time ?

There can be other factors reducing the framerate below your set frame rate Exposure time Transport layer configurations like throttled bandwidth

In fact, i am getting 10 frames per second and there is no problem in fps, but grab result steps are larger.

Is it possible I get two similar frames with different ID? Each frame has unique ID.

Exposure is about 400.

How can I get period feature?

[thiesmoeller]

As you didn't mention your camera model I assume, that you use a gige camera in standard ( not ieee1588 ) mode

In this case the tick frequency of the timestamp is 125mhz not 1ghz

[pourfard]

As you didn't mention your camera model I assume, that you use a gige camera in standard ( not ieee1588 ) mode

In this case the tick frequency of the timestamp is 125mhz not 1ghz

Yes, I have a gige camera. Can I convert it by multiplying to 8?

I need timestamp in milliseconds, I am calculating speed of vehicles in Km/h and I need time diff between two frames.

[thiesmoeller]

You divide the timestamp you get from the çamera by 125e3 to get milli seconds

You can check the docs for your camera https://docs.baslerweb.com/timestamp

[HighImp]

Hi, please use the value of "GevTimestampTickFrequency" for your calculations, as @thiesmoeller mentioned, the tick-frequency is not static when changing the settings of PTP

[pourfard]

Thanks for your help.