Machine Vision

cancel
Showing results for 
Search instead for 
Did you mean: 
Reply

How to set frame rates of DirectShow video devices?

Highlighted
Hi Using USB cameras with WDM DirectShow drivers in MAX does not allow to set frame rates. Only one frame rate is given, e.g. 30 fps. Worse: 60 fps is possible with the specific camera, but can not be set in MAX. Also if it is not possible to set frame rates, it is not possible to run two cameras in parallel on one USB controller, because the bandwidth exceeds. Is there a solution? Stefan
0 Kudos
Message 1 of 16
(3,332 Views)

Our IMAQdx driver is capable in changing settings of USB cameras, which are provided through DirectShow. So if it's not settable in MAX, it's simply not available through DirectShow.

 

Does Winnov provide a tool to change the settings of the camera?

You could also contact support@winnov.de

 

 

Christian

0 Kudos
Message 2 of 16
(3,325 Views)
Hello Christian, Thank you for your reply. I must admit, I do not understand your answer and I also do not understand, what relation a third party company has to my USB cameras. Stefan
0 Kudos
Message 3 of 16
(3,324 Views)

Isn't WDM DirectShow you mentioned in your first post from Winnov?

 

Anyhow, if the attribute is not settable in MAX, it's not available via DirectShow.

 

 

 

Christian

0 Kudos
Message 4 of 16
(3,322 Views)
Christian >Isn't WDM DirectShow you mentioned in your first post from Winnov? No. >Anyhow, if the attribute is not settable in MAX, it's not available via DirectShow. Ok, I have to accept this fact. I suppose, even in future version, this will be not possible, right?
0 Kudos
Message 5 of 16
(3,319 Views)

Well, unlike using Firewire and Gigabit Ethernet cameras which have standards like GeniCam or GigEVision, there is no standard for USB image acquisition right now. That's why we use DirectShow as common interface for USB cameras. There are efforts to create a standard for USB cameras too but there are not very much big vendors right now to promote it. Most of the big and well known vendors choose GigE, and the difference in pricing between USB and GigE is not that much anymore.

 

 

Christian

0 Kudos
Message 6 of 16
(3,317 Views)
Christian, I know that GigE and FireWire are supported much better in LabVIEW. I work for a camera manufacturer and we sell all of these camera types. Unfortunately many of our LabVIEW using customers want to use USB cameras too. Sometime quite more than one camera in one system. This is the reason, why I asked.
0 Kudos
Message 7 of 16
(3,316 Views)

@TIS Stefan wrote:
Hi Using USB cameras with WDM DirectShow drivers in MAX does not allow to set frame rates. Only one frame rate is given, e.g. 30 fps. Worse: 60 fps is possible with the specific camera, but can not be set in MAX. Also if it is not possible to set frame rates, it is not possible to run two cameras in parallel on one USB controller, because the bandwidth exceeds. Is there a solution? Stefan

Hi Stefan,

 

IMAQdx supports changing the framerate if the camera driver implements it in the standard DirectShow mechanism. The way it is defined, the camera provides a list of video modes that each include an image format, an image size, and a range of possible frame rates. IMAQdx enumerates these and expands out the possible combinations as different video modes available. You should see these available as a Video Mode drop-down box on the Acquisition tab in MAX. You can also of course access these programatically via the API in LabVIEW.

directshow_formats.png
Eric

0 Kudos
Message 8 of 16
(3,312 Views)
Hi Eric, I thought the same, when I first saw this image. But: different frame rates mean 1 resolution e.g. 320x240 and *different* frame rates. The list in the image shows for each frame rate only *one* resolution. Stefan
0 Kudos
Message 9 of 16
(3,306 Views)
I would excpect: 640x480 RGB24 60fps 640x480 RGB24 30fps 640x480 RGB24 15fps 640x480 RGB24 7.50fps and so on.
0 Kudos
Message 10 of 16
(3,305 Views)