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Shuji
March 27, 2014, 10:09:52
Hello,

I am using DMK 72AUC02 camera.
I have two problems of Live video, either with my work environment (C Wrapper dll v3.2.0.4) and QT ) or with IC Capture 2.2.

1. there are some horizontal lines appears with live video, I usie IC_SetFrameReadyCallback and only show the image in buffer directement without any compression. We try to block the memory in the callbak function but the problem persist. Some problem with the IC Capture 2.2 application.
I use Y800 1600x1200 with 13.36 fps, or Y800 2592x1944 with 5.99 fps, the problem appears with both settings.


2. The video stop at a moment (about several times per days) just like the live mode is off without any changes of setting, it looks like the camera is "sleeping" and no new frame available, the callback function is not called in this case. I have to make a "stop live - start live" to restart the video. This problem has appeared with IC Capture 2.2 too.
I use Y800 1600x1200 with 13.36 fps.
If I set Y800 1600x1200 with 10.0 fps, it stops almost all the time. It looks like there's something with the frame rate setting.

Thanks in advance for any advice.

Shuji

Stefan Geissler
March 27, 2014, 10:26:08
1. there are some horizontal lines appears with live video, I usie IC_SetFrameReadyCallback and only show the image in buffer directement without any compression. We try to block the memory in the callbak function but the problem persist. Some problem with the IC Capture 2.2 application.
I use Y800 1600x1200 with 13.36 fps, or Y800 2592x1944 with 5.99 fps, the problem appears with both settings.

They are caused by the idle states of the CPU. As far as we know, following happens: The communications controller receives a list of commands from the CPU. It starts to execute this list. Now the CPU is idle again and changes in the C3 state for power saving. When the communications controller has finished the command list, it asks the CPU for new commands. While it waits for the CPU coming from C3 into C0, the video capture device keeps sending data, which are not picked up by the communications controller. This causes a buffer overrun and leads to lost data blocks.
The USB camera driver can detect these incomplete images and will drop them or if they are not detected, you have these lines.

In case you use an Intel CPU, you may try Processor Idle State Manager. It tries to prevent the CPU going into C3 state. The program can be downloaded from http://www.theimagingsource.com/en_US/support/downloads/


2. The video stop at a moment (about several times per days) just like the live mode is off without any changes of setting, it looks like the camera is "sleeping" and no new frame available, the callback function is not called in this case. I have to make a "stop live - start live" to restart the video. This problem has appeared with IC Capture 2.2 too.
I use Y800 1600x1200 with 13.36 fps.
If I set Y800 1600x1200 with 10.0 fps, it stops almost all the time. It looks like there's something with the frame rate setting.

The camera can not stop on its own, it can only create images and send them out. The USB controller must pick up the data blocks. If the controller fails, then you can get the problem you see. However, the Processor Idle State Manager may solves this issue.

Shuji
March 27, 2014, 11:32:57
Hello Stefan,

I use a dell pc (Latitude E6420) with Intel CPU.
I have disabled the C state of the BIOS, installed the Processor Idle State Manager and let it runing.
But the horizontal lines problem still appears.
For the video stop problem, it still stops when I set Y800 1600x1200 with both 10.0 fps(always) and 13.36 fps (rarely)

Is there any more setting I need to change?

Thank again for you support.
Shuji

Stefan Geissler
March 27, 2014, 11:51:15
Please have a look in the device manager. Maybe there are devices on the same USB controller, that also interrupt the image data transfer, e.g. Modems, Bluetooth etc. Disable them and see, what happens.

For the video stop problem, it still stops when I set Y800 1600x1200 with both 10.0 fps(always) and 13.36 fps (rarely)
No idea yet. They both work fine on my computer. However, the lines in the image point to a data transfer issue.